[Editor’s note: On Charles Darwin’s 200 year birthday and nearly 150 years after “On the Origin of Species” was published, scientists are beginning to unravel our own evolution thru the study of genetic markers spread across different geographies. This graphic explores topics include Malaria, Mysterious Hair, Light Skin Outside Africa, Food and Climate, and Milk Mutations.]
Republished from The Washington Post.
Originally published 12 February 2009.
Graphic by Patterson Clark and Mary Kate Cannistra. (Updated 11 March 2009)
About 10 percent of human genes have continued to evolve since modern human beings emerged in Africa 200,000 years ago. Traits for disease resistance and environmental adaptation are undergoing natural selection.
Washington Post Staff Writer
Thursday, February 12, 2009; Page A01
In biology’s most famous book, “On the Origin of Species,” Charles Darwin steered clear of applying his revolutionary theory of evolution to the species of greatest interest to his readers — their own.
He couldn’t avoid it forever, of course. He eventually wrote another tome nearly as famous, “The Descent of Man.” But he knew in 1859, when “Species” was published, that to jump right into a description of how human beings had tussled with the environment and one another over eons, changing their appearance, capabilities and behavior in the process, would be hard for people to accept. Better to stick with birds and barnacles.
Darwin was born 200 years ago today. “On the Origin of Species” will be 150 years old in a few months. There’s no such reluctance now.
The search for signs of natural selection in human beings has just begun. It will ultimately be as revelatory as Newton’s description of the mathematics of motion 322 years ago, or the unlocking of the atom’s secrets that began in the late 1800s.
The inundation of data since the completion of the Human Genome Project in 2003, and the capacity to analyze it at the finest level of detail — the individual DNA nucleotides that make up the molecule of heredity — are giving us a look at humanity’s autobiography in a way that was once unimaginable.
In small, discrete changes in our genes that have accumulated over time, we are seeing evolution’s tracery, as durable as it is delicate. It is slowly revealing how climate, geography, disease, culture and chance sculpted Homo sapiens into the unique and diverse species it is today.
Biologists are discovering that the size of our limbs and brains, the enzymes in our spit and stomachs, the color of our skin, the contour of our hair, and the armament of our immune systems are each to some degree the products of evolutionary adaptation. They are the hard-earned, but unintended, bequests of our ancestors’ struggle to survive.
This, of course, is no surprise. Darwin knew it was so — and he’d never heard of a gene.