It's easy to think humans have stopped evolving, but nothing could be further from the truth. Though modern medicine and civilization's graces make the struggle to survive more subtle, evolution's engine keeps churning. In the last few thousand years, in fact, a time when human evolution was once thought to have slowed, it may actually have sped up.
Charles Darwin, born on this day in 1809, might have been pleasantly surprised.
At least at first, the father of evolution -- pictured at right in the later stages of Wired's Darwin photoshop tennis contest -- didn't talk much about the human implications of his theory. "Light will be thrown on the origin of man and his history," wrote Darwin in 1859's On the Origin of Species, leaving it to scientists like Thomas Huxley to make the full and then-controversial case for humanity's origins in a common ancestor with apes.
Only with The Descent of Man, published in 1871 for audiences that had finally wrapped their heads around evolution itself, did Darwin tackle its existence in humans. Though much of the book focused on the importance of mate preferences to shaping traits, he speculated in one section that humankind's altruistic tendencies may have changed our evolutionary trajectory, giving people who would once have died a chance to reproduce.
This type of reasoning would lead a widely-held view that human evolution had slowed or even stopped, but research over the last several decades, and in particular the last few years, have led to a very different view. Human evolution is still going strong.
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Humanity 2.0: Now More Evolvable
Humanity hasn't yet spawned X-Men-style superheroes, at least not outside the cosplay community, but there's a kernel of truth to the comic-book trope of unknown powers latent in humanity's masses. Over the last 10,000 years or so, human populations have grown from a few million to more than 7 billion. Every successful fusion of sperm and egg carries a few brand-new mutations; this population explosion means that humanity is awash with new mutations, the raw material of evolution.
The image above is a graphical representation of these genetic patterns. It depicts a population-wide tabulation genetic variations collectively present in each part of the human genome, dated to before (left) and after (right) the population boom. Some mutations will have no effect. Others will be harmful. Others may, in the right genetic or environmental circumstances, contain the seeds of extraordinary traits.
Images: 1) X-Men cosplayers. (Pat Loika/Flickr) 2) Charles Darwin Photoshop tennis iteration. (emmanuelrio76/Flickr) 3) Fu et al./Nature