Explore evolution in a way Charles Darwin couldn’t imagine–by delving into the DNA evidence of each species’ unique evolutionary journey.
Geneticist and author Sean B. Carroll will explain how DNA holds a living record of the evolutionary adaptations that allow species to evolve and thrive in diverse environments all over the Earth.
By Brian Handwerk,
Special contributor to NatGeo News Watch
The story of evolution is written in our genes. But that story isn’t merely the “survival of the fittest,” it’s also a story about how the fittest are made.
“It’s a look at evolution at its most fundamental level, the genetic changes that make individuals and species different. Species change because of changes in their DNA,” said University of Wisconsin geneticist Sean B. Carroll.
Sean B. Carroll is the author of The Making of the Fittest (2006, W.W. Norton) and of Endless Forms Most Beautiful: The New Science of Evo Devo (2005, W.W. Norton).
His book, The Making of the Fittest, describes how scientists have learned to pinpoint the specific genetic changes that cause evolutionary adaptations. DNA evidence records the many gene shifts that gave rise to incredible species like fish able to live in sub-freezing waters, or birds that see in ultraviolet light, as well as others no less incredible but more familiar–including ourselves.
Carroll will take listeners inside the gene, and celebrate the 150th anniversary of Darwin’s On the Origin of Species, in a lecture, “The Making of the Fittest,” delivered Wednesday, November 4 (8 p.m. ET) at the University of Wisconsin and live to the Web audience around the world.
Drinking out of the firehose
The past decade has seen the discovery of a massive new record of evolution, locked in the DNA of species both living and extinct. Geneticists working with this material are learning to pinpoint the specific DNA changes that have enabled species to adapt to wherever they may live on the planet
In fact, in recent years DNA studies have begun to produce so much evidence that Carroll calls the analysis “drinking out of the firehose.” The amount of information contained in the genes of a particular creature is simply enormous.
“All the sets of changes that have occurred that make it different from its existing relatives or previous species [are in evidence],” he explained. “Which ones account for changes in form, physiology, behavior–it’s just a massive amount of information.”
Evolution itself only moves forward, but evidence of the process may be traced in either direction.
“Information in DNA can tell us how current species are different from their ancestors, not just in new information that’s gained but also in old information that’s lost or decayed–fossil genes,” Carroll said. “Those broken pieces of genetic information give a hint as to how these species’ ancestors lived.”
The record not only shows when successful adaptations occurred. It also evidences what kinds of genes, slowly decaying through the generations, are no longer important to species but were once vital to their ancestors.
“For example a lot of our human genes for detecting odors are in the process of decay, whereas they are intact in animals like mice that are still living by their noses. A shift in our lifestyle made us probably more dependent on vision and has relaxed pressure on our olfactory system. The evidence of that is right here in the DNA.”
Darwin’s Mystery Solved
Carroll adds that the evolutionary study of DNA is replete with surprises, like finding the same type of adaptations happening again and again, in different species, in different parts of the world, at different times. In that case the DNA record shows that different animals came up with the same genetic solution to the same survival problems.
“There is nothing like repetition to drill home the message, and that’s what biology has conveniently [provided],” he said.
Charles Darwin himself, of course, couldn’t pursue his theories into the study of DNA. The science simply didn’t exist. But the father of evolution understood that the mechanism of heredity was essential, though he didn’t know exactly how traits were inherited at the most basic level.
“He knew in time that if we understood heredity we’d understand variation,” Carroll said.
Darwin Live on the Web
“The Making of the Fittest” is the third of a free Webcast lecture series in which some of the world’s top scientific minds tackle evolutionary topics.
Later speakers will include E.O. Wilson on the future frontiers of evolutionary biology (November 24).
The first lecture, Everett Mendelsohn on The World Before Darwin, is archived here.
The second lecture, Jonathan Weiner’ On Variation, can be heard here.
The series was organized by a group of volunteer Darwin devotees who also hope to rally 1,000,000 users to a Facebook group (http://www.facebook.com/group.php?gid=53320310123) celebrating this year’s 150th anniversary of On the Origin of Species.
Darwin Facebook campaign:
Hundreds of thousands of people from all walks of life joined a Facebook group devoted to the celebration of this year’s 200th anniversary of the birth of the “Father of Evolution,” Charles Darwin. Now the organizers of the Facebook group are hoping hundreds of thousands more will sign up to celebrate the 150th anniversary of the publishing of Darwin’s famous book, On the Origin of Species.
Travel back in time to visit “The World Before Darwin,” courtesy of a free webcast lecture with Everett Mendelsohn, emeritus professor at Harvard University. (See the lecture here.) Mendelsohn explored the milieu in which Darwin published “On the Origin of Species” 150 years ago, reveal its other evolutionary thinkers, and shed light on skeptics from the worlds of religion and science.
Pulitzer Prize-winning author and Columbia University professor Jonathan Weiner delved into Darwin’s evolutionary theories in the webcast lecture “On Variation.” (Hear the podcast here.) Weiner tracked Darwin’s footsteps to reveal how the Father of Evolution deduced that many species are descended from common ancestors, and that the variation among them evidences their evolutionary journeys of natural selection.
Darwin’s First Clues (National Geographic Magazine)
Was Darwin Wrong? (National Geographic Magazine)
PHOTOS: 7 Major “Missing Links” Since Darwin (National Geographic News)
“Instant” Evolution Seen in Darwin’s Finches, Study Says (National Geographic News)
Darwin’s Secret Notebooks (National Geographic Channel)
PHOTOS: How Do Species Evolve? (National Geographic News)