Today is International Darwin Day—the day Charles Darwin was born (Feb. 12) in 1809.
As the fine folks behind International Darwin Day assert, Charles Darwin single-handedly rewrote our origin story with bold thinking.
And science.
“The truth will out, as they say, and as Copernicus struggled to free the truth behind a heliocentric system, so too did Charles Darwin muster an immense intellectual bravery, a perpetual curiosity, and a ravenous hunger for truth in an attempt to understand the origins of modern life.”
Yes, Darwin deserves a day to himself as much as anyone else!
A ravenous hunger for the truth—for sure.
As the International Darwin Day website continues, Darwin’s discovery of natural section as the mechanism for evolution “unclasped scientific progress from theological limitations and paved the way for a fuller understanding of our place in the universe. Without the discovery of natural selection, the greatest achievements in health, philosophy, and human well-being over the past two hundred years would have been impossible.”
Of course we know that humans continue to evolve. The process continues. Natural selection continues. Change is happening.
Scientists have proved it. They have discovered three important changes in the human body as signs of our ongoing adaptation.
This excellent article posted on Inverse (written by Sarah Sloat) makes it clear.
Evolution waits for no man.
“What we eat, how we use our bodies, and who we choose to have kids with are just some of the many factors that can cause the human body to change. Genetic mutations lead to new traits—and with the world population now above 7 billion and rising, the chances of genetic mutations that natural selection can potentially act on is only increasing.”
There have been recent changes, though by “recent,” we mean from an evolutionary perspective. We are not talking about since last Tuesday. (We highly recommend the entire article.)
A summary:
First, we are cooling down. The perfect/normal human body temperature is 98.6 degrees, right? Wrong. A recent study found it’s more likely 97.9 degrees, based no medical records from the past 200 years. The study found there has been a gradual decrease in body temperature of 0.05 degrees Fahrenheit every decade. Why? Perhaps because many infectious diseases have been eradicated. That means less inflammation. And perhaps living comfortably indoors has helped. We don’t have to work as hard to stay comfortable, which would lower metabolism and allow us to operate at cooler temps.
Second, our genes are changing. Genes are adapting to vegetarian diets, allowing those on a vegetarian diet to efficiently process omega-3 and omega-6 fatty acids from non-meat sources. Also, genes that control lactose tolerance are also increasing.
“As of several thousand years ago, the enzyme that helps people drink milk without getting sick turned off when people reached adulthood. But later gene mutations that sprung up around the world during a time period of between 2,000 to 20,000 years ago have helped people tolerate dairy well into their dotage. Researchers estimate that, in East Africa, that genetic change happened as recently as 3,000 years ago, as raising cattle became a larger part of human life,” writes Sloat.
Third, our bones are becoming lighter. In a 2014, scientists determined that our skeletons have become much lighter since the rise of agriculture. The trend is likely to continue—people are moving less now than ever, the researchers predicted. “It’s only in the last say 50 to 100 years that we’ve been so sedentary—dangerously so,” explained co-author Colin Shaw, a researcher at the University of Cambridge. “Sitting in a car or in front of a desk is not what we have evolved to do.”
We aren’t challenging our bones. We aren’t using our bodies the way they were intended to be used over the “recent” few hundred thousand years. The bodies we’ve got today evolved from hard work, the vast majority of it devoted to one basic need.
Survival.
So, on International Darwin Day, take a look around. You might not be able to see it, but how we go about our lives today is shaping the way we’ll look in the future.
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