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Evolution Webcast: Darwin on Variation

Delve into Darwin’s evolutionary theories with a free webcast lecture “On Variation,” by Pulitzer Prize-winning author and Columbia University professor Jonathan Weiner.

Weiner will follow in 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.

By Brian Handwerk

Special contributor to NatGeo News Watch

Variety is the spice of life, an old saying goes, but Charles Darwin took the idea a step further. The legendary scientist was the first to explain how variation actually produced life as we know it, by playing a key role in evolution.

“Variation is a good place to start talking about the evolution of species because that’s where Darwin himself starts,” said Jonathan Weiner, a professor at Columbia University and Pulitzer Prize-winning author.

Weiner will celebrate the 150th anniversary of Darwin’s On the Origin of Species in a lecture, “On Variation,” delivered Wednesday, October 7 (8 p.m. ET) at Columbia University and live to web audiences around the world.


“Look around the family dinner table and see how much variation there is from face to face,” Weiner explained in an interview. “There’s that much variation, or more, in every species of plant and animal on the planet. That variability became the cornerstone for Darwin’s great theory.”

Weiner saw Darwinian variation firsthand while writing The Beak of the Finch: A Story of Evolution in Our Time, winner of the 1995 Pulitzer Prize for General Non-Fiction. He worked with acclaimed scientists Peter Grant and Rosemary Grant, who have observed evolution in some 20 generations of Galapagos Islands finches once studied by the Father of Evolution.

“There you see how a fraction of a millimeter really can make the difference between life and death for these finches,” he explained. “If your beak is just a bit longer or a little wider it might allow you to crack that last tough seed that nobody else on the island is able to crack in a drought. You might survive and pass on those genes, and no one else in your generation might make it.”

Pigeon Power

Scientists of the Victorian era believed that all species were individually created by God and not variable. To illustrate the variation that underpinned his theories of natural selection, Darwin first turned to a more familiar phenomenon–artificial selection.

He studied and wrote on the many varieties of domestic animals, specializing in the pigeon and its astonishing array of diverse breeds. The birds sported beaks of various shapes and sizes, feet that were or were not webbed, tails that fanned out and those that didn’t, and even different calls, flight patterns, and growth rates.

Yet this entire flock of pigeon species descended from the wild rock pigeon Columba livia, which Darwin illustrated by creating the first evolutionary “tree” for a species.

If pigeon breeders could select for desirable trades in physiology or behavior, and produce birds that enjoyed these traits, why couldn’t the same happen naturally, over much greater lengths of time, Darwin wondered.


NGS illustration of pigeons by Hashime Murayama 

“[Scientists] admit that many of our domestic races have descended from the same parents–may they not learn a lesson of caution, when they deride the idea of species in a state of nature being lineal descendants of other species?” he wrote in On the Origin of Species.

What Darwin Could Not Know

Darwinian natural selection occurs when individuals have variations in physical characteristics or behaviors that somehow impact survival and the ability to reproduce. These variations may play an evolutionary role if they are passed along to offspring.

Darwin’s studies on variation were eloquently introduced in On the Origin of Species, and discussed in detail in a later volume The Variation of Animals and Plants Under Domestication (1868).

But the Father of Evolution’s observations on variation and evolution were all the more amazing for what he wasn’t able to know–the science of genetics at the core of modern evolutionary science was completely unknown to him.

“He could hypothesize about the mechanisms of heredity but he couldn’t go very far in that direction,” Weiner said. “The sources of variation are, most importantly, in our genes–and he couldn’t go there.”

“The variation that we see is where Darwin was a brilliant observer and theorist. The invisible variation that underlies it all at the level of DNA, that’s some of the most exciting science on the planet right now.”

“The variation that we see is where Darwin was a brilliant observer and theorist. The invisible variation that underlies it all at the level of DNA, that’s some of the most exciting science on the planet right now.”

Darwin Live on the Web

Darwin on Variation is the second of a free webcast lecture series in which some of the world’s top scientific minds will tackle evolutionary topics.

Later speakers will include Sean Carroll (November 4) on “On the Origin of Species” itself, and 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 series was organized by a group of volunteer Darwin devotees who also hope to rally 1,000,000 users to a Facebook group celebrating this year’s 150th anniversary of On the Origin of Species.

Darwin Facebook campaign:

Darwin Devotees Make “Father of Evolution” Facebook Superstar

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.

The World Before Darwin

Travel back in time to visit “The World Before Darwin,” courtesy of a free webcast lecture with Everett Mendelsohn, emeritus professor at Harvard University. 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.

Darwin resources:

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)

The Complete Work of Charles Darwin Online

Darwin Correspondence Project

Darwin Digital Library of Evolution

The Charles Darwin Trust