Are human hands really more primitive than chimp hands?

Human hands have changed very little over the past 6 million years, says a new study, while chimps and orangutan hand structures have evolved notably.

When humans think about primate evolution, we tend to picture ourselves at the pinnacle. But could we be overplaying our hands?

New research suggests that human hands may actually be more primitive than the hands of other dexterous primates, like chimpanzees. The study was led by Sergio Almécija, a paleoanthropologist at Stony Brook University, and published Tuesday in Nature Communications.

Paleoanthropological studies tend to lean on the notion that human ancestors were originally monkey-like, slowly losing those traits through evolutionary time. But in some ways, that may not be entirely true.

"Contrarily to most studies in the field of human evolution, we did not assume that the last common ancestor of humans and chimpanzees was like a chimpanzee," Dr. Almécija says in a phone interview. "Instead, we tested that assumption by incorporating actual morphological and phylogenetic information in a large sample of primate species."

Almécija and his colleagues found that the hands of our distant ancestors were actually very similar to our own. By contrast, chimpanzee hands have changed significantly "since their last common ancestor, around 6 million years ago," Almécija says. Most strikingly, their fingers have become much longer. They share hand structure with orangutans, who probably evolved them independently.

"Digital lengthening in chimpanzees and orangutans probably relates to specialized, below-branch locomotion in large bodied apes," says Almécija.

"Humans have just subtly changed our hand proportions – a little bit of thumb lengthening, a little bit of digital reduction – to improve our 'precision grips.' ”

Almécija says that this new finding could shift how paleoanthropologists approach human evolution.

"The bigger implication of our study is that any evolutionary model of human hand evolution assuming a chimpanzee-like ancestor will likely be flawed from the beginning," Almécija says.

"Our results indicate that our overall hand proportions haven’t changed that much – they have been inherited from a last common ancestor that was, in this respect, more similar to a human than to a chimpanzee," Almécija adds. "Thus, when the humans first started to produce stone tools systematically, their hands were pretty much like ours today."

You've read  of  free articles. Subscribe to continue.

Dear Reader,

About a year ago, I happened upon this statement about the Monitor in the Harvard Business Review – under the charming heading of “do things that don’t interest you”:

“Many things that end up” being meaningful, writes social scientist Joseph Grenny, “have come from conference workshops, articles, or online videos that began as a chore and ended with an insight. My work in Kenya, for example, was heavily influenced by a Christian Science Monitor article I had forced myself to read 10 years earlier. Sometimes, we call things ‘boring’ simply because they lie outside the box we are currently in.”

If you were to come up with a punchline to a joke about the Monitor, that would probably be it. We’re seen as being global, fair, insightful, and perhaps a bit too earnest. We’re the bran muffin of journalism.

But you know what? We change lives. And I’m going to argue that we change lives precisely because we force open that too-small box that most human beings think they live in.

The Monitor is a peculiar little publication that’s hard for the world to figure out. We’re run by a church, but we’re not only for church members and we’re not about converting people. We’re known as being fair even as the world becomes as polarized as at any time since the newspaper’s founding in 1908.

We have a mission beyond circulation, we want to bridge divides. We’re about kicking down the door of thought everywhere and saying, “You are bigger and more capable than you realize. And we can prove it.”

If you’re looking for bran muffin journalism, you can subscribe to the Monitor for $15. You’ll get the Monitor Weekly magazine, the Monitor Daily email, and unlimited access to