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December 9, 2014

45,000 Year Old Human Genome Sequenced



(p. A14) Scientists have reconstructed the genome of a man who lived 45,000 years ago, by far the oldest genetic record ever obtained from modern humans. The research, published on Wednesday [October 22, 2014] in the journal Nature, provided new clues to the expansion of modern humans from Africa about 60,000 years ago, when they moved into Europe and Asia.

And the genome, extracted from a fossil thighbone found in Siberia, added strong support to a provocative hypothesis: Early humans interbred with Neanderthals.

"It's irreplaceable evidence of what once existed that we can't reconstruct from what people are now," said John Hawks, a paleoanthropologist at the University of Wisconsin who was not involved in the study. "It speaks to us with information about a time that's lost to us."


. . .


By comparing the Ust'-Ishim man's long stretches of Neanderthal DNA with shorter stretches in living humans, Dr. Paabo and his colleagues estimated the rate at which they had fragmented. They used that information to determine how long ago Neanderthals and humans interbred.

Previous studies, based only on living humans, had yielded an estimate of 37,000 to 86,000 years. Dr. Paabo and his colleagues have now narrowed down that estimate drastically: Humans and Neanderthals interbred 50,000 to 60,000 years ago, according to the new data.



For the full story, see:

Carl Zimmer. "Man's Genome From 45,000 Years Ago Is Reconstructed." The New York Times (Thurs., OCT. 23, 2014): A14.

(Note: ellipsis, and bracketed date, added.)

(Note: the online version of the story has the date OCT. 22, 2014.)






November 3, 2014

Evidence Some Flies Can Adapt to Climate Change



(p. D7) In the early 2000s, Ary A. Hoffmann, a biologist then at La Trobe University in Melbourne, Australia, wondered how the many species in tropical rain forests would cope when their humid environment dried out.


. . .


. . . at the end of the experiment, the flies were no more resistant to dry air than their forebears. The flies seemed to lack the genetic potential to evolve. Those results suggested that if the rain forest home of Drosophilia birchii loses its high humidity, the flies will die off.


. . .


Recently, two of Dr. Hoffmann's collaborators -- Belinda van Heerwaarden and Carla M. Sgrò of Monash University -- decided to rerun the experiment, but with a crucial twist.

Rather than expose the flies to 10 percent relative humidity, Dr. van Heerwaarden and Dr. Sgrò tried 35 percent. That's still far drier than the moist air of rain forests, but it's not the aridity one might encounter on a summer day in Death Valley.

"It's a humidity that's more relevant to the predictions for how dry the environment would become in the next 30 to 50 years," Dr. Sgrò said.


. . .


Unlike the flies in the earlier studies, it didn't take long for these to start evolving. After just five generations, one species was able to survive 23 percent longer in 35 humidity.



For the full story, see:

Carl Zimmer. "MATTER; Study Gives Hope of Adaptation to Climate Change." The New York Times (Tues., JULY 29, 2014): D7.

(Note: ellipses added.)

(Note: the online version of the story has the date JULY 24, 2014.)


The recent paper discussed above, is:

van Heerwaarden, Belinda, and Carla M. Sgrò. "Is Adaptation to Climate Change Really Constrained in Niche Specialists?" Proceedings of the Royal Society B: Biological Sciences 281, no. 1790 (2014): 1-1.






October 11, 2014

Variable Gene Expression Gives Us "Surprising Resilience"



(p. 11) As a physician who researches and treats rare genetic disorders, Sharon Moalem, the author of "Inheritance," sees firsthand how sharply DNA can constrain our lives. Yet "our genes aren't as fixed and rigid as most of us have been led to believe," he says, for while genetic defects often create havoc, variable gene expression (our genes' capacity to respond to the environment with a flexibility only now being fully recognized) can give our bodies and minds surprising resilience. In his new book, Moalem describes riveting dramas emerging from both defective genes and reparative epigenetics.


. . .


Moalem's earthy, patient-focused account reminds us that whatever its promise, genetics yet stands at a humble place.



For the full review, see:

DAVID DOBBS. "The Fault in Our DNA." The New York Times Book Review (Sun., July 13, 2014): 11.

(Note: ellipsis added.)

(Note: the online version of the review has the date July 10, 2014.)


Book under review:

Moalem, Sharon. Inheritance: How Our Genes Change Our Lives--and Our Lives Change Our Genes. New York: Grand Central Publishing, 2014.






September 27, 2014

Theory Said Giant Bird Could Not Fly, But It Flew Anyway



(p. A3) Scientists have identified the largest flying bird ever found--an ungainly glider with a wingspan of 21 feet or more that likely soared above ancient seas 25 million years ago.

Until now, though, it was a bird that few experts believed could get off the ground. By the conventional formulas of flight, the extinct sea bird--twice the size of an albatross, the largest flying bird today--was just too heavy to fly on its long, fragile wings.

But a new computer analysis reported Monday [July 7, 2014] in the Proceedings of the National Academy of Sciences shows that the bird apparently could ride efficiently on rising air currents, staying aloft for a week or more at a stretch.


. . .


"You have to conclude that this animal was capable of flapping its wings and taking off, even though it is much heavier than the theoretical maximum weight of a flapping flying bird," said Luis Chiappe, an expert on flight evolution at the Los Angeles County Natural History Museum, who wasn't involved in the project. "Our modern perspective on the diversity of flight is rather narrow," he said. "These were very unique birds."


. . .


"This was a pretty impressive creature," said avian paleontologist Daniel T. Ksepka at the Bruce Museum in Greenwich, Conn., who conducted the analysis of the bird's biomechanics. "Science had made a rule about flight, and life found a way around it."



For the full story, see:

ROBERT LEE HOTZ. "U.S. NEWS; Giant Bird Was Able to Fly, Scientists Find; Computer Analysis Shows Ancient Glider Could Get Off the Ground, Defying Conventional Theories of Flight." The Wall Street Journal (Tues., July 8, 2014): A3.

(Note: ellipses, and bracketed date, added.)

(Note: the online version of the article has the date July 7, 2014.)






July 15, 2014

Reigning Intellectual Orthodoxy on Race Is Wrong



ATroublesomeInheritanceBK2014-06-05.jpg















Source of book image: http://ecx.images-amazon.com/images/I/41BYpEQumNL._.jpg





(p. C5) The reigning intellectual orthodoxy is that race is a "social construct," a cultural artifact without biological merit.

The orthodoxy's equivalent of the Nicene Creed has two scientific tenets. The first, promulgated by geneticist Richard Lewontin in "The Apportionment of Human Diversity" (1972), is that the races are so close to genetically identical that "racial classification is now seen to be of virtually no genetic or taxonomic significance." The second, popularized by the late paleontologist Stephen Jay Gould, is that human evolution in everything but cosmetic differences stopped before humans left Africa, meaning that "human equality is a contingent fact of history," as he put it in an essay of that title in 1984.

Since the sequencing of the human genome in 2003, what is known by geneticists has increasingly diverged from this orthodoxy, even as social scientists and the mainstream press have steadfastly ignored the new research. Nicholas Wade, for more than 20 years a highly regarded science writer at the New York Times, has written a book that pulls back the curtain.

It is hard to convey how rich this book is. It could be the textbook for a semester's college course on human evolution, systematically surveying as it does the basics of genetics, evolutionary psychology, Homo sapiens's diaspora and the recent discoveries about the evolutionary adaptations that have occurred since then. The book is a delight to read--conversational and lucid. And it will trigger an intellectual explosion the likes of which we haven't seen for a few decades.

The title gives fair warning: "A Troublesome Inheritance: Genes, Race and Human History." At the heart of the book, stated quietly but with command of the technical literature, is a bombshell. It is now known with a high level of scientific confidence that both tenets of the orthodoxy are wrong.



For the full review, see:

CHARLES MURRAY. "The Diversity of Life; A scientific revolution is under way--upending one of our reigning orthodoxies." The Wall Street Journal (Sat., May 3, 2014): C5 & C7.

(Note: ellipses added.)

(Note: the online version of the review has the date May 2, 2014, and has the title "Book Review: 'A Troublesome Inheritance' by Nicholas Wade; A scientific revolution is under way--upending one of our reigning orthodoxies.")


The book under review is:

Wade, Nicholas. A Troublesome Inheritance: Genes, Race and Human History. New York: The Penguin Press, 2014.






June 23, 2014

Some Birds "with Higher Radiation Exposure May Show Greater Adaptation"



MousseauTimothyStudiesBatsAtChernobyl2014-05-31.jpg With an unfinished cooling tower at the Chernobyl plant in the background, Timothy Mousseau, right, and an assistant set out microphones to study bats in the contaminated area." Source of caption and photo: online version of the NYT article quoted and cited below.


(p. D1) In dozens of papers over the years Dr. Mousseau, his longtime collaborator, Anders Pape Moller of the National Center for Scientific Research in France, and colleagues have reported evidence of radiation's toll: . . .

(p. D2) But their most recent findings, published last month, showed something new. Some bird species, they reported in the journal Functional Ecology, appear to have adapted to the radioactive environment by producing higher levels of protective antioxidants, with correspondingly less genetic damage. For these birds, Dr. Mousseau said, chronic exposure to radiation appears to be a kind of "unnatural selection" driving evolutionary change.


. . .


The findings . . . suggest that in some cases radiation levels might have an inverse effect -- birds in areas with higher radiation exposure may show greater adaptation, and thus less genetic damage, than those in areas with lower radiation levels.

Like almost all of the studies by Dr. Mousseau and his colleagues, the latest one takes advantage of the unique circumstances of the Chernobyl exclusion zone as a real-world laboratory. "Nature is a much more stressful environment than the lab," Dr. Mousseau said.



For the full story, see:

HENRY FOUNTAIN. "Adapting to Chernoby." The New York Times (Tues., MAY 6, 2014): D1 & D2.

(Note: ellipses added.)

(Note: the online version of the story has the date MAY 5, 2014, and has the title "At Chernobyl, Hints of Nature's Adaptation.")


The research discussed above is more fully elaborated in:

Galván, Ismael, Andrea Bonisoli-Alquati, Shanna Jenkinson, Ghanem Ghanem, Kazumasa Wakamatsu, Timothy A. Mousseau, and Anders P. Møller. "Chronic Exposure to Low-Dose Radiation at Chernobyl Favours Adaptation to Oxidative Stress in Birds." Functional Ecology (Early View published online on May 17, 2014).






April 29, 2014

More Evidence that Humans May Not Have Killed Off the Woolly Mammoth After All




On April 20, 2014 I posted an entry citing research that humans may not have been the main cause of the extinction of the mammoths. The article quoted below provides further evidence:


(p. D2) Many woolly mammoths from the North Sea had a superfluous rib attached to their seventh vertebra, a sign that they suffered from inbreeding and harsh conditions during pregnancy, researchers report.

This may have contributed to their eventual extinction, say the scientists who looked at fossil samples that date to the late Pleistocene age, which ended about 12,000 years ago.


. . .


Woolly mammoths died out 12,000 to 10,000 years ago, when flowery plant covers disappeared from the tundra. Human hunting may also have contributed to their demise.

But the cervical ribs are a clear indication that "they were already struggling before that," Dr. Galis said.



For the full story, see:

SINDYA N. BHANOO. "Observatory; In Extra Rib, a Harbinger of Mammoth's Doom." The New York Times (Tues., April 1, 2014): D2.

(Note: ellipsis added.)

(Note: the online version of the commentary has the date MARCH 31, 2014.)


The mammoth research summarized above was published in:

Reumer, Jelle W.F., Clara M.A. ten Broek, and Frietson Galis. "Extraordinary Incidence of Cervical Ribs Indicates Vulnerable Condition in Late Pleistocene Mammoths." PeerJ (2014).






April 20, 2014

Humans May Not Have Killed Off the Woolly Mammoth After All



MammothTusk2014-04-10.jpg "A mammoth tusk." Source of caption and photo: online version of the NYT article quoted and cited below.


(p. D2) A 50,000 year analysis of Arctic vegetation history reveals that a change in diet may have led to the demise of the woolly mammoth, the woolly rhinoceros and other large animals, according to a study in the journal Nature. About 10,000 years ago in the Arctic steppe, grasslands began to replace forbs, a flowery plant cover. Animals may have relied on forbs as a source of protein.


For the original story, see:

"'Observatory; Tiny Plants' Loss May Have Doomed Mammoths." The New York Times (Tues., FEB. 11, 2014): D2.

(Note: Sindya N. Bhanoo is listed as the author of the second "Observatory" short entry, but it is not at all clear if that is intended to imply that she also is author of the first "Observatiory" short entry on the "Tiny Plants Loss . . . " Her name does not appear anywhere in the online version.)

(Note: the online version of the interview has the date FEB. 10, 2014, and has the title "'SCIENCE; Tiny Plants' Loss May Have Doomed Mammoths." )


The study in Nature mentioned above, is:

Willerslev, Eske, John Davison, Mari Moora, Martin Zobel, Eric Coissac, Mary E. Edwards, Eline D. Lorenzen, Mette Vestergård, Galina Gussarova, James Haile, Joseph Craine, Ludovic Gielly, Sanne Boessenkool, Laura S. Epp, Peter B. Pearman, Rachid Cheddadi, David Murray, Kari Anne Bråthen, Nigel Yoccoz, and Heather Binney. "Fifty Thousand Years of Arctic Vegetation and Megafaunal Diet." Nature 506, no. 7486 (Feb. 6, 2014): 47-51.






March 10, 2014

Dinosaurs Show that Size Does Not Assure Success, or Even Survival



(p. 504) If the Museum of Natural History was going to be, as Carnegie intended, a world-class institution, it needed more than mummies, ana-(p. 505)tomical models, and Appalachian minerals. It had to have a dinosaur or two. The dinosaur was more than simply a crowd-pleaser. For Carnegie and other devotees of evolutionary science, it was an apt symbol of the unpredictability of a universe in which species and races fell into extinction when they failed to adapt to new environments. For men of slight stature, such as Carnegie, there must have been something quite enthralling about this most vivid demonstration that size and power did not guarantee survival.


Source:

Nasaw, David. Andrew Carnegie. New York: Penguin Press, 2006.

(Note: the pagination of the hardback and paperback editions of Nasaw's book are the same.)






February 13, 2014

Some Dogs, Like Humans, Thrive If They Have a Project



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Source of book image: http://www.stephthebookworm.com/wp-content/uploads/2013/12/What-the-Dog-Knows.jpg



(p. 40) Warren, a science journalism professor at North Carolina State University, never dreamed of becoming a cadaver dog handler, searching woods and rubble for dead bodies. She just wanted a new German shepherd puppy after the death of her saintly dog Zev. What she got was Solo: "a maniacal clown," loving and intensely smart, but "an unpredictable sociopath with other dogs." . . .

. . . Fortunately, Warren understood behavior issues are rarely the dog's fault. They often just mean humans haven't found the right way to channel their pet's energy.

. . . it's . . . a moving story of how one woman transformed her troubled dog into a loving companion and an asset to society, all while stumbling on the beauty of life in their searches for death.



For the full review, see:

REBECCA SKLOOT. "Release the Hounds." The New York Times Book Review (Sun., December 8, 2013): 40.

(Note: ellipses added.)

(Note: the online version of the review has the date December 6, 2013.)


Book under review:

Warren, Cat. What the Dog Knows: The Science and Wonder of Working Dogs. New York: Touchstone, 2013.






February 9, 2014

M.R.I. Evidence that Emotions Are Similar in Dogs and Humans



HowDogsLoveUsBK2014-01-18.jpg




















Source of book image: http://2.bp.blogspot.com/-VIlNHG9gZ4M/Uo6zpfJTahI/AAAAAAAAU9U/9ASa-7VHHKc/s1600/a0c2a640e1085a57e07c368bfe5151f0_XL.jpg



(p. 40) Gregory Berns wasn't sure if his pug Newton really loved him. Newton wagged his tail and gave kisses, but that wasn't enough. Berns, a neuroscientist, wanted hard data. He also hoped to uncover "what makes for a strong dog-human bond" and how that might improve canine welfare. So he built a special M.R.I. machine, and trained dogs to lie still inside it, allowing him to study their brains. Though the results may seem obvious to dog lovers (that humans and dogs experience emotions similarly), they're not a given for science. Berns's book is a beautiful story about dogs, love and neurology that shows how nonhuman relationships are inspiring researchers to look at animals in new ways, for their benefit and ours.


For the full review, see:

REBECCA SKLOOT. "Release the Hounds." The New York Times Book Review (Sun., December 8, 2013): 40.

(Note: the online version of the review has the date December 6, 2013.)


Book under review:

Berns, Gregory. How Dogs Love Us: A Neuroscientist and His Adopted Dog Decode the Canine Brain. New York: Houghton Mifflin Harcourt Publishing, 2013.



CallieDogMRI2014-01-18.jpg "After training and hot dog treats, Callie is ready for an MRI." Source of caption and photo: online version of the NYT review quoted and cited above.







February 5, 2014

Evidence Babies Are Born with a Sense of Fairness



JustBabiesBK2014-01-18.jpg














Source of book image: http://news.yale.edu/sites/default/files/imce/main-bloom.jpg




(p. 15) Is morality innate? In his new book, "Just Babies," the psychologist Paul Bloom draws from his research at the Yale Infant Cognition Center to argue that "certain moral foundations are not acquired through learning. . . . They are instead the products of biological evolution." Infants may be notoriously difficult to study (rats and pigeons "can at least run mazes or peck at levers"), but according to Bloom, they are, in fact, "moral creatures."

He describes a study in which 1-year-olds watched a puppet show where a ball is passed to a "nice" puppet (who passes it back) or to a "naughty" puppet (who steals it). Invited to reward or punish the puppets, children took treats away from the "naughty" one. These 1-year-olds seem to be making moral judgments, but is this an inborn ability? They have certainly had opportunities in the last 12 months to learn good from bad. However, Bloom has found that infants as young as 3 months old reach for and prefer looking at a "helper" rather than a "hinderer," which he interprets as evidence of moral sense, that babies are "drawn to the nice guy and repelled by the mean guy." He may be right, but he hasn't proved innateness.

Proving innateness requires much harder evidence -- that the behavior has existed from Day 1, say, or that it has a clear genetic basis. Bloom presents no such evidence. His approach to establishing innateness is to argue from universalism: If a behavior occurs across cultures, then surely it can't be the result of culture.



For the full review, see:

SIMON BARON-COHEN. "Little Angels." The New York Times Book Review (Sun., December 29, 2013): 15.

(Note: ellipsis in original.)

(Note: the online version of the review has the date December 27, 2013.)


Book under review:

Bloom, Paul. Just Babies: The Origins of Good and Evil. New York: Crown Publishers, 2013.






August 29, 2013

Philosopher Herbert Spencer Defended Capitalism in America



BanquetAtDelmonicosBK2013-08-12.jpg












Source of book image: online version of the WSJ review quoted and cited below.






Spencer was sometimes a much better philosopher than the modern caricature portrays, a caricature exemplified by the review quoted below and, perhaps, by the book reviewed. I would like to look at this book sometime, because there may be some interesting history in it---though I am not optimistic about the book's economic assumptions, or its account of Spencer's philosophy.


(p. A11) Herbert Spencer, the 19th-century British philosopher, is remembered today as the forbidding -- almost forbidden -- father of "Social Darwinism," a school of thought declaring that the fittest prosper in a free marketplace and the human race is gradually improved because only the strong survive. In Barry Werth's satisfying "Banquet at Delmonico's," Spencer is also a querulous 62-year-old celibate whose 1882 American tour culminates in a feast to which are invited the "mostly Republican men of science, religion, business, and government" who shared and spread the Spencerian creed.

Applying Darwinian insights about evolution to political, economic and social life -- though he did not himself use the term "Social Darwinism" -- Spencer concluded that vigorous competition and unfettered capitalism conduced to the betterment of society. He predicted that the American, raised in liberty, would evolve into "a finer type of man than has hitherto existed," dazzling the world with "the highest form of government" and "a civilization grander than any the world has known."


. . .


The public clamor over the visit of a dyspeptic foreign philosopher to these shores was partly due to the indefatigable promotion of Edward Livingston Youmans, Spencer's chief American proselytizer, who called his beau ideal the most original thinker in the history of mankind. Youmans is among the several critics and apostles of Spencer and Darwin whose profiles Mr. Werth skillfully interweaves in this Gilded Age tapestry.



For the full review, see:

BILL KAUFFMAN. "BOOKSHELF; Darwin in the New World; When the father of Social Darwinism came to America, the place where the fittest were supposed to thrive." The Wall Street Journal (Fri., January 9, 2009): A11.

(Note: ellipsis added; italics in original.)


The book under review is:

Werth, Barry. Banquet at Delmonico's: Great Minds, the Gilded Age, and the Triumph of Evolution in America. New York: Random House, 2009.


For a more balanced account of Spencer, see the first review below for the mostly good in Spencer, and the second review below for the mostly bad in Spencer:

Diamond, Arthur M., Jr. "Spencer's Tragedy: Review of Herbert Spencer's The Principles of Ethics." Modern Age 24, no. 4 (Fall 1980): 419-421.

Diamond, Arthur M., Jr. "The State of Spencer: Review of Herbert Spencer's The Man Versus the State." Modern Age 28, nos. 2-3 (Spring/Summer 1984): 286-288.






August 24, 2013

A Path to Bringing Back the Extinct Woolly Mammoth



(p. D3) For the first time in 43,000 years, a woolly mammoth has breathed again on earth.

Well, not the mammoth itself but its hemoglobin, the stuff in red blood cells that takes on oxygen in the lungs and offloads it in the tissues. By reconstructing the mammoth's hemoglobin, a team led by Kevin L. Campbell of the University of Manitoba in Canada has discovered how the once-tropical species adapted to living in arctic temperatures.

Dr. Campbell's work raises a somewhat astonishing possibility: that much of the physiology of extinct animals may one day be recoverable from the DNA extracted from their remains.


. . .


Two years ago, scientists at Penn State University sequenced a large part of the mammoth's genome from a clump of hair. They published the sequence along with the arresting suggestion that for just $10 million it might be possible to complete the sequence and use it to generate a living mammoth.

The suggestion was not as wild as it might seem, given that the idea came from George Church, a leading genome technologist at the Harvard Medical School. The mammoth's genome differs at about 400,000 sites from that of the African elephant. Dr. Church has been developing a method for altering 50,000 sites at a time, though he is not at present applying it to mammoths. In converting four sites on the elephant genome to the mammoth version, Dr. Campbell has resurrected at least one tiny part of the mammoth.



For the full story, see:

NICHOLAS WADE. "Mammoth Hemoglobin Offers More Clues to Its Arctic Evolution." The New York Times (Tues., May 4, 2010): D3.

(Note: ellipsis added.)

(Note: the online version of the article has the date May 3, 2010.)






April 17, 2013

Chagnon Enraged Cultural Anthropologists By Showing Tribal Violence



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Source of book image: http://media.npr.org/assets/bakertaylor/covers/n/noble-savages/9780684855103_custom-4deac679a847f1d6e7d64424b01d0be54b54e3a7-s6-c10.jpg



(p. C) In the 1960s, cultural anthropologists led by Marvin Harris argued that conflict among prestate people was mostly over access to scarce protein. Dr. Chagnon disputed this, arguing that Yanomamo Indians' chief motive for raiding and fighting--which they did a great deal--seemed to be to abduct, recover or avenge the abduction of women. He even claimed that Indian men who had killed people ("unokais") had more wives and more children than men who had not killed, thus gaining a Darwinian advantage.

Such claims could not have been more calculated to enrage the presiding high priests of cultural anthropology, slaughtering as it did at least three sacred cows of the discipline: that uncontacted tribal people were peaceful, that Darwinism had nothing to say about human behavior and culture, and that material resources were the cause of conflict.


. . .


Meanwhile the science has been going Dr. Chagnon's way. Recent studies have confirmed that mortality from violence is very common in small-scale societies today and in the past. Almost one-third of such people die in raids and fights, and the death rate is twice as high among men as among women. This is a far higher death rate than experienced even in countries worst hit by World War II. Thomas Hobbes's "war of each against all" looks more accurate for humanity in a state of nature than Jean-Jacques Rousseau's "noble savage," though anthropologists today prefer to see a continuum between these extremes.



For the full commentary, see:

MATT RIDLEY. "MIND & MATTER; Farewell to the Myth of the Noble Savage." The Wall Street Journal (Sat., January 26, 2013): C4.

(Note: the online version of the review has the date January 25, 2013.)

(Note: ellipsis added.)


The Chagnon book that Ridley is discussing:

Chagnon, Napoleon. Noble Savages: My Life among Two Dangerous Tribes -- the Yanomamo and the Anthropologists. New York: Simon & Schuster, 2013.






April 8, 2013

Darwin's Worry About Gradual Evolution of Eye



Darwin and others have worried about whether an eye could have evolved gradually. The issue is whether the earlier gradations leading up to the eye would have given any survival advantage. Matt Ridley's column, quoted below, argues that Darwin need not have worried.


(p. C4) Davide Pisani and colleagues from the National University of Ireland have traced the ancestry of the three kinds of "opsin" protein that animals use, in combination with a pigment, to detect light.


. . .


. . . , the anatomy of eyes shows every gradation between simple light-sensitive spots and full cameras. The detailed genetic evidence of descent with modification from a single common ancestor further vindicates Darwin and has largely silenced the Intelligent Design movement's use of the eye as a favored redoubt.

After the duplications that led to working opsin molecules, there seems to have been a long pause before complex eyes appeared.

The first lensed eyes that fossilized belonged to the trilobites which dominated the Cambrian oceans after 525 million years ago.



For the full commentary, see:

MATT RIDLEY. "MIND & MATTER; A Relief to Darwin: The Eyes Have It." The New York Times (Tues., November 3, 2012): C4.

(Note: ellipses added.)

(Note: the online version of the commentary has the November 2, 2012.)






February 22, 2013

Darwin Shared His Thought Processes Without Condescension



DarwinCharlesIn1881.jpg














"SAGE OF AGES; Portrait of Charles Darwin in 1881, by Julia Margaret Cameron." Source of caption and photo: online version of the WSJ article quoted and cited below.






(p. C14) . . . Mr. Johnson observes:

No scientific innovator has ever taken more trouble to smooth the way for lay readers without descending into vulgarity. What is almost miraculous about the book is Darwin's generosity in sharing his thought processes, his lack of condescension. There is no talking down, but no hauteur, either. It is a gentlemanly book.

In both style and substance, this passage is classic Paul Johnson.


. . .


What makes Darwin good, in the biographer's estimation, is the scientist's democratic dissemination of knowledge. Darwin triumphed with "The Origin of Species," Mr. Johnson contends, not only because of his ability to portray the theory of evolution as the inescapable outcome of his decades of study and the work of fellow scientists, whom he was careful to praise, but because he was acutely aware that he had to present his notions of natural selection and survival of the fittest so as not to stir up public controversy. To an extraordinary degree, Darwin deflected attacks by couching his discoveries in terms of the plants he liked to examine and cultivate. He had relatively little to say about human evolution.



For the full review, see:

CARL ROLLYSON. "Studies of the Moral Animal." The Wall Street Journal (Sat., December 15, 2012): C14.

(Note: ellipses added.)

(Note: the online version of the review essay has the date December 14, 2012.)



The book under review is:

Johnson, Paul M. Darwin: Portrait of a Genius. New York: Viking Adult, 2012.







January 13, 2013

Harvard University Press Dropped Watson's "The Double Helix" as Too Controversial



WatsonAndCrick2013-01-11.jpg



"Partners; James D. Watson, left, with Francis Crick and their model of part of a DNA molecule in 1953. Crick did not like Dr. Watson's book at first." Source of caption: print version of the NYT article quoted and cited below. Source of photo: online version of the NYT article quoted and cited below.





(p. D2) Anyone seeking to understand modern biology and genomics could do much worse than start with the discovery of the structure of DNA, on which almost everything else is based. The classic account of the discovery, "The Double Helix," by James D. Watson, was first published in 1968 and has now been reissued in an annotated and illustrated edition.


. . .


An appendix makes it clear how close "The Double Helix" came to being suppressed. Dr. Watson sent the manuscript to many of the central players, inviting their comments on its accuracy. Harvard University Press had accepted it for publication, but the Harvard authorities came to feel it was too hot a potato and dropped it.

Atheneum Publishers, which picked it up, requested a blander title -- previous versions had included "Honest Jim" and "Base Pairs." The latter -- referring to the paired sets of chemical bases that form the steps in the double helix, and by extension to the two discoverers -- gave particular offense to Crick, who failed to see why he should be considered base. Atheneum's lawyers then tried to make the text inoffensive to the many possible litigants.

But Dr. Watson was able to resist many changes. He had cannily persuaded Bragg to write a foreword, and this endorsement from an establishment figure provided sufficient protection for the book to be published. It proceeded to sell more than a million copies.



For the full review, see:

NICHOLAS WADE. "BOOKS ON SCIENCE; Twists in the Tale of the Great DNA Discovery." The New York Times (Tues., November 13, 2012): D2.

(Note: ellipsis added.)

(Note: the online version of the review has the date November 12, 2012.)



The annotated version of the Watson book is:

Watson, James D. The Annotated and Illustrated Double Helix. New York: Simon & Schuster, 2012.






March 29, 2012

Small Is Beautiful as Life Adapts to Global Warming



SifrhippusFirstHorse2012-03-10.jpg "Artist's reconstruction of Sifrhippus sandrae (right) touching noses with a modern Morgan horse (left) that stands about 5 feet high at the shoulders and weighs approximately 1000 lbs." Source of caption and photo: online version of the NYT article quoted and cited below.




(p. D3) The horse (siff-RIP-us, if you have to say the name out loud) lived in what is still horse country, in the Bighorn Basin of Wyoming, where wild mustangs roam.


. . .


Its preserved fossils, abundant in the Bighorn Basin, provide an excellent record of its size change over a 175,000-year warm period in the Earth's history known as the Paleocene-Eocene thermal maximum, when temperatures are estimated to have risen by 9 to 18 degrees Fahrenheit at the start, and dropped again at the end.

Scientists have known that many mammals appear to have shrunk during the warming period, and the phenomenon fits well with what is known as Bergmann's rule, which says, roughly, that mammals of a given genus or species are smaller in hotter climates.

Although the rule refers to differences in location, it seemed also to apply to changes over time. But fine enough detail was lacking until now.

In Science, Ross Secord, of the University of Nebraska-Lincoln; Jonathan Bloch, of the Florida Museum of Natural History at the University of Florida in Gainesville; and a team of other researchers report on the collection and analysis of Sifrhippus fossils from the Bighorn Basin.

They report that the little horse got 30 percent smaller over the first 130,000 years, and then -- as always seems to happen with weight loss -- shot back up and got 75 percent bigger over the next 45,000 years.


. . .


"It seems to be natural selection," said Dr. Secord. He said animals evolved to be smaller during warming because smaller animals did better in that environment, perhaps because the smaller an animal is, the easier it is to shed excess heat.




For the full story, see:

JAMES GORMAN. "As the Planet Heated Up, First Horse Got Tinier ." The New York Times (Tues., February 28, 2012): D3.

(Note: ellipses added.)

(Note: the online version of the story is dated February 23 [sic], 2012 and has the title "A Tiny Horse That Got Even Tinier as the Planet Heated Up.")





December 7, 2011

Some Traits (Including Some Diseases) Depend on Many Genes Rather than a Single Gene



(p. D3) A new exploration of how evolution works at the genomic level may have a significant impact on drug development and other areas of medicine.

The report, published in Nature last week, offers new evidence in a longstanding debate about how organisms evolve. One well-known path to change is a heavily favorable mutation in a single gene. But it may be well known only because it is easy to study. Another path is exploitation of mildly favorable differences that already exist in many genes.


. . .


Three biologists at the University of California, Irvine, Molly K. Burke, Michael R. Rose and Anthony D. Long, followed populations of fruit flies through 600 generations and studied the whole genome of some 250 flies in order to see what kinds of genetic change they had undergone.


. . .


The conventional view is that evolutionary change is generally mediated by a favorable mutation in a gene that then washes through the whole population, a process called a hard sweep because all other versions of the gene are brushed away. The alternative, called a soft sweep, is that many genes influence a trait, in this case the rate of maturation, and that the growth-accelerating versions of each of these genes become just a little more common. Each fly has a greater chance of inheriting these growth-promoting versions and so will mature faster.

In sequencing their subjects' genomes, the researchers found that a soft sweep was indeed responsible for the earlier hatching. No single gene had swept through the population to effect the change; rather, the alternative versions of a large number of genes had become slightly more common.


. . .


Haldane favored the single mutation mechanism, but Fisher and Wright backed multiple gene change.


. . .


The demise of the Haldane view "is very bad news for the pharmaceutical industry in general," Dr. Rose said. If disease and other traits are controlled by many genes, it will be hard to find effective drugs; a single target would have been much simpler.



For the full story, see:

NICHOLAS WADE. "Natural Selection Cuts Broad Swath Through Fruit Fly Genome." The New York Times (Tues., September 21, 2010): D3.

(Note: ellipses added.)

(Note: the online version of the article is dated September 20, 2010.)






November 26, 2011

Crows Use Tools Too



NewCaledonianCrowStickTool2011-11-09.jpg










"A captive New Caledonian crow forages for food using a stick tool." Source of caption and photo: online version of the NYT article quoted and cited below.




(p. D3) New Caledonian crows, found in the South Pacific, are among nature's most robust nonhuman tool users. They are well known for using twigs to dislodge beetle larvae from tree trunks.

And there's a good reason. By foraging for just a few larvae, a crow can satisfy its daily nutritional needs, which explains the evolutionary advantage of learning how to use tools, researchers report in the journal Science.



For the full story, see:

SINDYA N. BHANOO. "OBSERVATORY; Crows Put Tools to Use to Access a Nutritious Diet." The New York Times (Tues., September 21, 2010): D3.

(Note: the online version of the article is dated September 20, 2010.)






December 8, 2010

After Being "Nasty and Unruly for Decades" Henry Becomes a Father at Age 111



TuataraLivingFossil2010-12-06.jpg












"TUATARA. The tuatara, scientists have learned, is in some ways a so-called living fossil." Source of caption and photo: online version of the NYT article quoted and cited below.




(p. D1) . . . the animal that may well be New Zealand's most bizarrely instructive species at first glance looks surprisingly humdrum: the tuatara. A reptile about 16 inches long with bumpy, khaki-colored skin and a lizardly profile, the tuatara could easily be mistaken for an iguana. Appearances in this case are wildly deceptive. The tuatara -- whose name comes from the Maori language and means "peaks on the back" -- is not an iguana, is not a lizard, is not like any other reptile alive today.

In fact, as a series of recent studies suggest, it is not like any other vertebrate alive today. The tuatara, scientists have learned, is in some ways a so-called living fossil, its basic skeletal layout and skull shape almost identical to that of tuatara fossils dating back hundreds of millions of years, to before the rise of the dinosaurs. Cer-(p. D2)tain tuatara organs and traits also display the hallmarks of being, if not quite primitive, at least closer to evolutionary baseline than comparable structures in other animals.


. . .


Tuataras are living fossils in more than one sense of the term. Through long-term capture, tag and recapture studies that were begun right after World War II, researchers have found that tuataras match and possibly exceed in attainable life span that other Methuselah of the animal kingdom, the giant tortoise. "Tuataras routinely live to 100, and I couldn't tell you they don't live to 150, 200 years or even more," said Dr. Daugherty.

They live, and live it up. "We know there are females that are still reproducing in their 80s," said Dr. Daugherty. At the Southland Museum and Art Gallery in Invercargill, New Zealand, a captive male tuatara named Henry, a local celebrity that had been nasty and unruly for decades until a malignancy was removed from his genitals, mated with an 80-year-old female named Mildred, and last year became a first-time father -- at the age of 111.



For the full story, see:

NATALIE ANGIER. "Basics; Reptile's Pet-Store Looks Belie Its Triassic Appeal." The New York Times (Tues., November 23, 2010): D1 & D2.

(Note: ellipses added.)

(Note: the online version of the article is dated November 22, 2010.)





December 4, 2010

"A Really Nice Story about Adaptability of Our Life Form"



WolfeSimonFelisaArsenicBacterium2010-12-03.jpg"Felisa Wolfe-Simon takes samples from a sediment core she pulled up from the remote shores of 10 Mile Beach at Mono Lake in California." Source of caption and photo: online version of the NYT article quoted and cited below.


(p. A1) Scientists said Thursday that they had trained a bacterium to eat and grow on a diet of arsenic, in place of phosphorus -- one of six elements considered essential for life -- opening up the possibility that organisms could exist elsewhere in the universe or even here on Earth using biochemical powers we have not yet dared to dream about.

The bacterium, scraped from the bottom of Mono Lake in California and grown for months in a lab mixture containing arsenic, gradually swapped out atoms of phosphorus in its little body for atoms of arsenic.

Scientists said the results, if confirmed, would expand the notion of what life could be and where it could be. "There is basic mystery, when you look at life," said Dimitar Sasselov, an astronomer at the Harvard-Smithsonian Center for Astrophysics and director of an institute on the origins of life there, who was not involved in the work. "Nature only uses a restrictive set of molecules and chemical reactions out of many thousands available. This is our first glimmer that maybe there are other options."

Felisa Wolfe-Simon, a NASA astrobiology fellow at the United States Geological Survey in Menlo Park, Calif., who led the experiment, said, "This is a microbe that has solved the problem of how to live in a different way."

This story is not about Mono Lake or arsenic, she said, but about "cracking open the door and finding that what we think are fixed constants of life are not."


. . .


(p. A4) Caleb Scharf, an astrobiologist at Columbia University who was not part of the research, said he was amazed. "It's like if you or I morphed into fully functioning cyborgs after being thrown into a room of electronic scrap with nothing to eat," he said.

Gerald Joyce, a chemist and molecular biologist at the Scripps Research Institute in La Jolla, Calif., said the work "shows in principle that you could have a different form of life," but noted that even these bacteria are affixed to the same tree of life as the rest of us, like the extremophiles that exist in ocean vents.

"It's a really nice story about adaptability of our life form," he said. "It gives food for thought about what might be possible in another world."



For the full story, see:

DENNIS OVERBYE. "Microbe Finds Arsenic Tasty; Redefines Life." The New York Times (Fri., December 3, 2010): A1 & A4.

(Note: ellipsis added.)

(Note: the online version of the article is dated December 2, 2010.)





November 24, 2010

"It Can Be Hard to Tell a Crank from an Unfamiliar Gear"



VanValenLeigh2010-11-13.jpg














"Leigh Van Valen." Source of caption and photo: online version of the NYT article quoted and cited below.



(p. 33) His beard, it was said, was longer than God's but not as long as Charles Darwin's. Thousands of books teetered perilously in his office, and a motion-sensitive door startled visitors with cricket chirps. He took notes on his own thoughts while conversing with others.

The evolutionary biologist Leigh Van Valen's eccentricities were legend far beyond the University of Chicago, where brilliant and idiosyncratic professors rule. He named 20 fossil mammals he had discovered after characters in J. R. R. Tolkien's fiction, and his most famous hypothesis -- among the most cited in the literature of evolution -- was named for the Red Queen in Lewis Carroll's "Through the Looking Glass."

That hypothesis helped explain why organisms, competing for survival, developed two sexes. It did not explain why Professor Van Valen gave better grades to students who disagreed with him -- provoking an instant evolutionary adaptation in the tone of student essays -- much less why he wrote songs about the sex lives of dinosaurs and paramecia.


. . .


After his Red Queen paper was initially, and repeatedly, rejected, Dr. Van Valen started his own journal, Evolutionary Theory, to publish it. As its longtime editor, he treated all submissions seriously. "It can be hard to tell a crank from an unfamiliar gear," he wrote.



For the full obituary, see:

DOUGLAS MARTIN. "Leigh Van Valen, a Revolutionary in the Study of Evolution, Dies at 76." The New York Times, First Section (Sun., October 31, 2010): 33.

(Note: ellipsIs added.)

(Note: the online version of the article is dated October 30, 2010 and has the title "Leigh Van Valen, Evolution Revolutionary, Dies at 76.")





June 12, 2010

Finding the Neanderthal in Us



VindijaCaveCroatiaNeanderthalBones2010-05-19.jpg"The Vindija cave in Croatia where three small Neanderthal bones were found." Source of caption and photo: online version of the NYT article cited below.


(p. A3) The burly Ice Age hunters known as Neanderthals, a long-extinct species, survive today in the genes of almost everyone outside Africa, according to an international research team who offer the first molecular evidence that early humans mated and produced children in liaisons with Neanderthals.

In a significant advance, the researchers mapped most of the Neanderthal genome--the first time that the heredity of such an ancient human species has been reliably reconstructed. The researchers, able for the first time to compare the relatively complete genetic coding of modern and prehistoric human species, found the Neanderthal legacy accounts for up to 4% of the human genome among people in much of the world today.

By comparing the Neanderthal genetic information to the modern human genome, the scientists were able to home in on hints of subtle differences between the ancient and modern DNA affecting skin, stature, fertility and brain power that may have given Homo sapiens an edge over their predecessors.

"It is tantalizing to think that the Neanderthal is not totally extinct," said geneticist Svante Pääbo at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, who pioneered the $3.8 million research project. "A bit of them lives on in us today."


. . .


For their analysis, Dr. Pääbo and his colleagues extracted DNA mostly from the fossil remains of three Neanderthal women who lived and died in Croatia between 38,000 and 45,000 years ago. From thimblefuls of powdered bone, the researchers pieced together about three billion base pairs of DNA, covering about two-thirds of the Neanderthal genome. The researchers checked those samples against fragments of genetic code extracted from three other Neanderthal specimens.

"It is a tour de force to get a genome's worth," said genetic database expert Ewan Birney at the European Bioinformatics Institute in Cambridge, England.

In research published Thursday in Science, the researchers compared the Neanderthal DNA to the genomes drawn from five people from around the world: a San tribesman from South Africa; a Yoruba from West Africa; a Han Chinese; a West European; and a Pacific islander from Papua, New Guinea. They also checked it against the recently published genome of bio-entrepreneur Craig Venter. Traces of Neanderthal heredity turned up in all but the two African representatives.



For the full story, see:

ROBERT LEE HOTZ. "Most People Carry Neanderthal Genes; Team Finds up to 4% of Human Genome Comes From Extinct Species, the First Evidence It Mated With Homo Sapiens." The Wall Street Journal (Fri., MAY 7, 2010): A3.

(Note: ellipsis added.)

(Note: the online version of the review is dated MAY 6, 2010.)



A related article, the online version of which is the source for the caption and photo above, is:

NICHOLAS WADE. "Analysis of Neanderthal Genome Points to Interbreeding with Modern Humans." The New York Times (Fri., May 7, 2010): A9.

(Note: the online version of the review is dated May 6, 2010 and has the title "Signs of Neanderthals Mating With Humans.")


VindijaCaveBone2010-05-19.jpg"A close-up of the bone Vindija 33.16 from Vindija cave, Croatia." Source of caption and photo: online version of the WSJ article quoted and cited above.





June 8, 2010

"Climate Change Was One of the Forces that Led to the Triumph of Homo Sapiens"



Handprint30000YearsOld2010-05-19.jpg








"The David H. Koch Hall of Human Origins in Washington includes this 30,000-year-old handprint from France." Source of caption and photo: online version of the NYT article quoted and cited below.



(p. C32) The exhibition's theme is "What Does It Mean to Be Human?" And the new image of the human it creates is different from the one from a century ago. It isn't that nature has suddenly become a pastoral paradise. Some of the most unusual objects here are fossilized human bones bearing scars of animal attacks: a 3-year-old's skull from about 2.3 million years ago is marked by eagle talons in the eye sockets; an early human's foot shows the bite marks of a crocodile. In one of the exhibition's interactive video stations, in which you are cleverly shown how excavated remains are interpreted, you learn that the teeth of a leopard's lower jaw found in a cave at the Swartkrans site in South Africa match the puncture marks in a nearby early-human skull: evidence of a 1.8 million-year-old killing.


. . .


During the brief 200,000-year life of Homo sapiens, at least three other human species also existed. And while this might seem to diminish any remnants of pride left to the human animal in the wake of Darwin's theory, the exhibition actually does the opposite. It puts the human at the center, tracing how through these varied species, central characteristics developed, and we became the sole survivors. The show humanizes evolution. It is, in part, a story of human triumph.


. . .


. . . at recent excavations in China, at Majuangou, stone tools were found in four layers of rock dating from 1.66 million to 1.32 million years ago; fossil pollen proved that each of these four time periods was also associated with a different habitat. "The toolmaker, Homo erectus," we read, "was able to survive in all of these habitats."

That ability was crucial. The hall emphasizes that enormous changes in the planet's climate accompanied hominin development, suggesting that the ability to adapt to such differing circumstances was the human's strength. Climate change was one of the forces that led to the triumph of Homo sapiens.



For the full review, see:

EDWARD ROTHSTEIN. "Exhibition Review; Hall of Human Origins; Searching the Bones of Our Shared Past." The New York Times (Fri., March 19, 2010): C25 & C32.

(Note: italics in original; ellipses added.)

(Note: the online version of the review is dated March 18, 2010.)





May 21, 2010

"The Evolutionary Concomitant of Incessant Climate Change Was Human Resilience"



CreativeObjectsEarlyMan2010-05-14.jpg"Early Homo sapiens created these symbolic objects between 60,000 and 30,000 years ago. Using natural materials and creativity, they combined animal and human features into fantastical creatures and fashioned instruments for making music. "Source of caption and photo: online version of the WSJ article quoted and cited below.


The sort of artifacts displayed above have been used to argue that homo sapiens had essentially reached their modern capabilities at least by 40,000 years ago.

The handaxes below are fascinating, in that they clearly display progress, and they clearly display how slow that progress was.


(p. D13) The mysterious Ice Age extinction of the Neanderthals, losers in the competition against modern humans, still fires the popular imagination. So it's startling to learn that as recently as 70,000 years ago, at least four human species coexisted, including tenacious, long-lived Homo erectus and diminutive, hobbit-like Homo floresiensis, found in Indonesia in 2003.

The sensational 1974 discovery in Ethiopia of "Lucy," resembling an ape but walking upright, located human origins 3.2 million years in the past. Those same fossil deposits have recently yielded even more-ancient ancestors, who stood on their own two feet as far back as six million years ago.

Paleoanthropology is thriving, and human fossil finds--more than 6,000 and counting--regularly force revisions of old timelines and theories. Our species, Homo sapiens, turns out to have had an abundance of long-lost cousins, though scientists are still arguing about the closeness of those relationships. The new David H. Koch Hall of Human Origins at the Smithsonian National Museum of Natural History, whose opening marked the museum's centennial, provides a formidable overview of this still-developing story.


. . .


It's long been accepted that different human species were adapted to thrive in specific climatic niches. Neanderthals had short, compact bodies to conserve heat and large nasal passages to warm frigid air, while some of our African forebears had long, skinny frames suited to hotter climes. But this exhibition contends that the evolutionary concomitant of incessant climate change was human resilience--the flexibility to make it almost anywhere, thanks to large, sophisticated brains and social networks.

Versatility apparently characterized even our oldest relatives. The ability to walk upright through the drier, more open grasslands did not immediately divest them of their penchant for climbing trees in the shrinking woodlands. A diorama of Lucy (Australopithecus afarensis) depicts her with one foot on the ground and another on a tree limb, symbolizing her straddling of two environments.



For the full review, see:

JULIA M. KLEIN. "Natural History; Our Species Rediscovers Its Cousins." The Wall Street Journal (Tues., May 11, 2010): D13.

(Note: ellipsis added.)


HandaxesSlowlyEvolved2010-05-13.jpg"Handaxes -- multipurpose tools used to chop wood, butcher animals, and make other tools -- dominated early human technology for more than a million years. Left to right: Africa (1.6 million years old), Asia (1.1 million years old), and Europe (250,000 years old)." Source of caption and photo: online version of the WSJ article quoted and cited above.





October 27, 2009

Fossil Found of Much Earlier Human Ancestor



HominidGraphic2009-10-04.jpgSource of graphic: online version of the NYT article quoted and cited below.


(p. A1) Ardi, short for Ardipithecus ramidus, is the newest fossil skeleton out of Africa to take its place in the gallery of human origins. At an age of 4.4 million years, it lived well before and was much more primitive than the famous 3.2-million-year-old Lucy, of the species Australopithecus afarensis.

Since finding fragments of the older hominid in 1992, an international team of scientists has been searching for more specimens and on Thursday presented a fairly complete skeleton and their first full analysis. By replacing Lucy as the earliest known skeleton from the human branch of the primate family tree, the scientists said, Ardi opened a window to "the early evolutionary steps that our ancestors took after we diverged from our common ancestor with chimpanzees."


. . .


(p. A6) Scientists not involved in the new research hailed its importance, placing the Ardi skeleton on a pedestal alongside notable figures of hominid evolution like Lucy and the 1.6-million-year-old Turkana Boy from Kenya, an almost complete specimen of Homo erectus with anatomy remarkably similar to modern Homo sapiens.

David Pilbeam, a professor of human evolution at Harvard University who had no role in the discovery, said in an e-mail message that the Ardi skeleton represented "a genus plausibly ancestral to Australopithecus" and began "to fill in the temporal and structural 'space' between the apelike common ancestor and Australopithecus."

Andrew Hill, a paleoanthropologist at Yale University who was also not involved in the research, noted that Dr. White had kept "this skeleton in his closet for the last 15 years or so, but I think it has been worth the wait." In some ways the specimen's features are surprising, Dr. Hill added, "but it makes a very satisfactory animal for understanding the changes that have taken place along the human lineage."

The first comprehensive reports describing the skeleton and related findings, the result of 17 years of study, are being published Friday in the journal Science. Eleven papers by 47 authors from 10 countries describe the analysis of more than 110 Ardipithecus specimens from a minimum of 36 different individuals, including Ardi.

The paleoanthropologists wrote in one of the articles that Ardipithecus was "so rife with anatomical surprises that no one could have imagined it without direct fossil evidence."

A bounty of animal and plant material -- "every seed, every piece of fossil wood, every scrap of bone," Dr. White said -- was gathered to set the scene of the cooler, more humid woodland habitat in which these hominids had lived.

This was one of the first surprises, said Giday WoldeGabriel, a geologist at Los Alamos National Laboratory, because it upset the hypothesis that upright walking had evolved as an adaptation to life on grassy savanna.



For the full story, see:

JOHN NOBLE WILFORD. "Fossil Skeleton From Africa Predates Lucy." The New York Times (Fri., October 1, 2009): A1 & A6.

(Note: ellipsis added.)


ArdiFossil2009-10-04.jpg



















"A fairly complete skeleton of Ardipithecus ramidus, which replaced Lucy as the earliest known skeleton from the human branch of the primate family tree." Source of caption and photo: online version of the NYT article quoted and cited above.






September 23, 2009

Scientists Believe Life Emerged from a Process of "Creative Destruction" and Global Warming



CosmicCrashSite2009-09-07.jpgSource of graphic: online version of the WSJ article quoted and cited below.


(p. A9) In a paradox of creation, new evidence suggests that devastating avalanches of cosmic debris may have fostered life on Earth, not annihilated it. If so, life on our planet may be older than scientists previously thought -- and more persistent.

Astronomers world-wide have been transfixed by a roiling gash the size of Earth in the atmosphere of Jupiter, caused by an errant comet or asteroid that smashed into the gas giant last month. The lingering turbulence is an echo of a cataclysmic bombardment that shaped the origin of life here 3.9 billion years ago, when millions of asteroids, comets and meteors pummeled our planet.


. . .


But in their super-heated plunge through the atmosphere, these asteroids and meteors may have helped create conditions ideal for emerging life. "Everyone focuses on the meteor that hits the ground," says geochemist Richard Court at London's Imperial College. "No one thinks about the products of its journey that get pumped into the atmosphere."

As they vented, they collectively could have imported billions of tons of life-sustaining water into the air every year, Dr. Court and his colleague Mark Sephton recently determined. They calculated that these showers of volatile rocks delivered 10 times the daily outflow of the Mississippi River every year for 20 million years. By analyzing the fumes emitted under such extreme heat, they discovered these rocks also could have injected billions of tons of carbon dioxide into the air every year.

Combined with so much water vapor, the carbon dioxide could have induced a global greenhouse effect. That could have kept any life emerging on Earth safely in a planetary incubator at a time when the planet might easily have frozen because the Sun radiated 25% less energy than today. "The amount of CO2 that was produced is about the same we produce today through fossil fuel use and we know that is a climate-changing volume," says Dr. Court.


. . .


"It is literally a revolution in our ideas about how our solar system evolved," says asteroid expert William Bottke at the Southwest Research Institute. "It could be that our form of life today -- every living thing that we see today -- is due to this bombardment that happened 3.9 billion years ago."



For the full commentary, see:

ROBERT LEE HOTZ. "SCIENCE JOURNAL; Some Creative Destruction on a Cosmic Scale; Scientists Say Asteroid Blasts, Once Thought Apocalyptic, Fostered Life on Earth by Carrying Water and Protective Greenhouse Gas." The Wall Street Journal (Fri., AUGUST 14, 2009): A9.

(Note: ellipses added.)





February 12, 2009

"A Splendid Birthday Present" for Charles Darwin


WhyEvolutionIsTrueBK.jpg












Source of the book image: http://images.barnesandnoble.com/images/34510000/34519930.jpg


(p. A13) . . ., on Feb. 12, biologists the world over will celebrate Charles Darwin's 200th birthday. Throughout the year, at festivals galore marking his bicentennial, "On the Origin of Species," a mere 150 years old, will be hailed as one of the greatest works in the history of the sciences.

. . .

Mr. Coyne begins with a succinct account of what is at stake. "Life on earth evolved gradually beginning with one primitive species -- perhaps a self-replicating molecule -- that lived more than 3.5 billion years ago; it then branched out over time, throwing off many and diverse species; and the mechanism for most (but not all) of evolutionary change is natural selection."

Darwinism is thus a claim with several basic components, and the book is structured by carefully exhibiting the evidence for each. Making that structure explicit allows readers to recognize just where they are in the argument. As they follow Mr. Coyne's parade of evidence -- his discussions of the fossil record, of vestigial traits, of the ways in which living things constantly make novel use of the bits and pieces they have inherited, of the distribution of plants and animals -- the components of Darwin's thesis are sequentially supported. We have a list of things to be shown, they are shown and the truth of evolution is established.

. . .

Yet will any defense of Darwin, however painstaking and lucid, succeed in substantially modifying the public-opinion survey results? Mr. Coyne has seen the opposition first-hand, recounting his experience of talking to a group of businessmen about evolution and eliciting the reaction: "Very convincing -- but I don't believe it." This sort of skepticism is often rooted in a sense that Darwinism somehow discredits morality -- a perception that Mr. Coyne argues against, cogently, in a brief final chapter. But he does not seem to appreciate the depth of popular hostility toward Darwin.

. . .

Whether or not he succeeds in bringing Americans en masse to learn to love evolution, he has offered Darwin a splendid birthday present.



For the full review, see:

PHILIP KITCHER. "Bookshelf; Following the Evidence." Wall Street Journal (Thurs., JANUARY 29, 2009): A13.

(Note: ellipses added.)

The reviewed book is:

Coyne, Jerry A. Why Evolution Is True. New York: Viking, 2009.


A classic paper on whether the speed of a scientist's acceptance of evolution was related to the scientist's age, is:

David L. Hull, Peter D. Tessner and Arthur M. Diamond. "Planck's Principle: Do Younger Scientists Accept New Scientific Ideas with Greater Alacrity than Older Scientists?" Science 202 (November 17, 1978): 717-723.




February 15, 2008

Private Money Supports Quest for Dinosaur DNA

 

   Source of graphic: the online version of the WSJ article quoted and cited below.

 

(p. A1)  JORDAN, Mont. -- Prospecting in Montana's badlands, rock ax in hand, paleontologist Jack Horner picks up a piece of the jawbone of a dinosaur. He examines the splinter, then puts it back and moves on. It isn't the kind of bone he is looking for.

Prof. Horner is searching for something that many scientists believe no longer exists: dinosaur bones that harbor blood cells, protein and, perhaps, even DNA.

"Most people looking for dinosaurs are looking for beautiful skeletons," he says. "We are looking for information."

. . .  

Prof. Horner, a curator at the Museum of the Rockies in Bozeman, is among the world's most influential and offbeat paleontologists. He pioneered studies of dinosaur parent-(p. A12)ing behavior, species variation and bone cells. He is dyslexic, a former Special Forces operative of the Vietnam War era, a MacArthur Foundation "genius" fellow, and a chaired professor of Montana State University who never finished a formal college degree.

"The lenses that people normally use to look at stuff are broken in Jack," says Mary Schweitzer, an assistant professor of paleontology at North Carolina State University, who has worked with him for years. "That's what makes Jack such a good scientist. Every now and then, every field should get a renegade weirdo in it who challenges assumptions."

. . .  

"The chances of finding any [dinosaur] DNA are pretty low," Prof. Horner acknowledges. "I am still hopeful."

In a field mostly outside the mainstream of federal research funding, Prof. Horner has a knack for attracting private grants. Star Wars producer George Lucas, Qualcomm co-founder Klein Gilhousen and Wade Dokken, a developer of Montana real estate, have contributed toward his research, the university says. Nathan Myhrvold, formerly chief technology officer at Microsoft Corp. and co-founder of Intellectual Ventures LLC, is helping to underwrite this season's fieldwork.

This summer, in Montana's Hell Creek Formation, Prof. Horner is searching the last landscape inhabited by dinosaurs. More than 65 million years ago, this plain was a wetland where herds of horned Triceratops watered. Today, it is an arid outwash of boulders, cactus and sage. The red and gray soil is littered with white shards of petrified wood that ring like bone china when tapped together and countless crumbs of dinosaur bone.

. . .

"As long as you are not bound by preconceived ideas of what you can find," Prof. Horner says, "there are an awful lot of things you can discover."

 

For the full story, see:

ROBERT LEE HOTZ. "Dinosaur Hunter Seeks More Than Just Bare Bones; Prof. Horner Searches For Traces of Blood, DNA; Lucky Break From T. Rex."  The Wall Street Journal  (Fri., August 24, 2007):  A1 & A12.

(Note:  ellipses added.)

  

     At top, Prof. Horner; at bottom: "Sarah Keenan, 21, an undergraduate at the University of St. Andrews in Scotland who is working this summer for Prof. Horner, covers the fossilized triceratops frill in a protective jacket of plaster."  Source of caption and photos: the online version of the WSJ article quoted and cited above.

 




May 10, 2006

Google Evolves

Gary Hamel has recently penned some thoughtful observations about what practices of Google have led to its success.  An excerpt from that analysis appears below.  (Hamel earlier wrote a popular book in which he makes extensive use of Schumpeter's process of creative destruction.)

Only time will tell whether Google has succeeded in building an evolutionary advantage.  But consider:  Since it's founding, it has repeatedly morphed its business model.  Google 1.0 was a search engine that crawled the Web but generated little revenue; which led to Google 2.0, a company that sold its search capacity to AOL/Netscape, Yahoo and other major portals; which gave way to Google 3.0, an Internet contrarian that rejected banner ads and instead sold simple text ads linked to search results; which spawned Google 4.0, an increasingly global entity that found a way to insert relevant ads into any and all Web content, dramatically enlarging the online ad business; which mutated into Google 5.0, an innovation factory that produces a torrent of new Web-based services, including Gmail, Google Desktop, and Google Base.  More than likely, 6.0 is around the corner.

Of course Google may ultimately fall victim to hubris and imperial overstretch as it takes on Microsoft, Yahoo, eBay, the occasional telecom giant and pretty much everyone else in cyberspace.  Or like Microsoft, it may simply become like every other big company as it grows.  But that's not the way I'd bet.  Google seems to have grasped the new century's most important business lesson:  The capacity to evolve is the most important advantage of all.

 

For the full commentary, see:

Hamel, Gary.  "Management à la Google."  The Wall Street Journal  (Weds., April 26, 2006):  A16.

 

 

 

And here is the information on Hamel's most recent book:

 

Hamel, Gary. Leading the Revolution: How to Thrive in Turbulent Times by Making Innovation a Way of Life. Revised & Updated ed.  Harvard Business School Press, 2002.

 

 Source of image: http://www.amazon.com/gp/product/B000EPFVBE/sr=8-1/qid=1146333251/ref=pd_bbs_1/104-5668094-9083929?%5Fencoding=UTF8




May 6, 2006

Missing Link Found Between Sea and Land Animals: More Evidence for Evolution

 

Model recreation of missing link animal.  Source of image:  Online version of NYT article cited below.

 

Scientists have discovered fossils of a 375-million-year-old fish, a large scaly creature not seen before, that they say is a long-sought missing link in the evolution of some fishes from water to a life walking on four limbs on land. 

In two reports today in the journal Nature, a team of scientists led by Neil H. Shubin of the University of Chicago say they have uncovered several well-preserved skeletons of the fossil fish in sediments of former streambeds in the Canadian Arctic, 600 miles from the North Pole.

The skeletons have the fins, scales and other attributes of a giant fish, four to nine feet long.  But on closer examination, the scientists found telling anatomical traits of a transitional creature, a fish that is still a fish but has changes that anticipate the emergence of land animals -- and is thus a predecessor of amphibians, reptiles and dinosaurs, mammals and eventually humans.

In the fishes' forward fins, the scientists found evidence of limbs in the making.  There are the beginnings of digits, proto-wrists, elbows and shoulders.  The fish also had a flat skull resembling a crocodile's, a neck, ribs and other parts that were similar to four-legged land animals known as tetrapods.

Other scientists said that in addition to confirming elements of a major transition in evolution, the fossils were a powerful rebuttal to religious creationists, who have long argued that the absence of such transitional creatures are a serious weakness in Darwin's theory.  

The discovery team called the fossils the most compelling examples yet of an animal that was at the cusp of the fish-tetrapod transition.  The fish has been named Tiktaalik roseae, at the suggestion of elders of Canada's Nunavut Territory.  Tiktaalik (pronounced tic-TAH-lick) means ''large shallow water fish.''

''The origin of limbs,'' Dr. Shubin's team wrote, ''probably involved the elaboration and proliferation of features already present in the fins of fish such as Tiktaalik.''  

In an interview, Dr. Shubin, an evolutionary biologist, let himself go.  ''It's a really amazing, remarkable intermediate fossil,'' he said.  ''It's like, holy cow.''  

Two other paleontologists, commenting on the find in a separate article in the journal, said that a few other transitional fish had been previously discovered from approximately the same Late Devonian time period, 385 million to 359 million years ago.  But Tiktaalik is so clearly an intermediate ''link between fishes and land vertebrates,'' they said, that it ''might in time become as much an evolutionary icon as the proto-bird Archaeopteryx,'' which bridged the gap between reptiles (probably dinosaurs) and today's birds.  

The writers, Erik Ahlberg of Uppsala University in Sweden and Jennifer A. Clack of the University of Cambridge in England, are often viewed as rivals to Dr. Shubin's team in the search for intermediate species in the evolution from fish to the first animals to colonize land.

H. Richard Lane, director of paleobiology at the National Science Foundation, said in a statement, ''These exciting discoveries are providing fossil 'Rosetta Stones' for a deeper understanding of this evolutionary milestone -- fish to land-roaming tetrapods.''

 

For the full story, see:

JOHN NOBLE WILFORD.  "Fossil Called Missing Link From Sea to Land Animals."  The New York Times  (Thursday, April 6, 2006):  A1.

 

  Source of graphic: http://www.news.harvard.edu/gazette/2006/04.06/09-missinglink.html

 




April 22, 2006

Evidence for Darwin's Claim that Small Changes Can Accumulate Into Bigger Changes

By reconstructing ancient genes from long-extinct animals, scientists have for the first time demonstrated the step-by-step progression of how evolution created a new piece of molecular machinery by reusing and modifying existing parts.

The researchers say the findings, published today in the journal Science, offer a counterargument to doubters of evolution who question how a progression of small changes could produce the intricate mechanisms found in living cells.

. . .

The researchers found the modern equivalent of the stress hormone receptor in lampreys and hagfish, two surviving jawless primitive species. The team also found two modern equivalents of the receptor in skate, a fish related to sharks.

After looking at the genes that produced them, and comparing the genes' similarities and differences among the genes, the scientists concluded that all descended from a single common gene 450 million years ago, before animals emerged from oceans onto land, before the evolution of bones.

The team recreated the ancestral receptor in the laboratory and found that it could bind to the kidney regulating hormone, aldosterone and the stress hormone, cortisol.

Thus, it turned out that the receptor for aldosterone existed before aldosterone. Aldosterone is found just in land animals, which appeared tens of millions of years later.


For the full story, see:

KENNETH CHANG. "Study, in a First, Explains Evolution's Molecular Advance." The New York Times (Fri., April 7, 2006): A19.




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