Throughout history, the human being has evolved thanks to small variations genetics that have been transmitted generation after generation until we are what we are today.
But as it collects Science Alert, a new study suggests that evolution is no longer strictly tied to genes. Instead, human culture it may be driving evolution faster than genetic mutations can work.
In this conception, evolution no longer requires genetic mutations that confer a survival advantage that are transmitted and generalized. Instead, learned behaviors transmitted through culture it is the ‘mutations’ that provide survival advantages.
This so-called cultural evolution may now shape the destiny of humanity more strongly than natural selection, the researchers argue. “When a virus attacks a species, it normally becomes immune to that virus through genetic evolution,” said the study co-author, Zach Wood, a postdoctoral researcher in the College of Biology and Ecology at the University of Maine.
Such evolution works slowly, as those who are most susceptible die and only those who survive pass on their genes. But today, most humans do not need to genetically adapt to such threats. Instead, we adapt by developing vaccines and other medical interventions, which are not the result of the work of one person, but of many people who are based on the accumulated ‘mutations’ of cultural knowledge.
By developing vaccines, human culture improves its “immune system” collective, said study co-author Tim Waring, an associate professor of socio-ecological systems modeling at the University of Maine.
The example of lactose tolerance
And sometimes, cultural evolution can lead to genetic evolution. “The classic example is lactose tolerance,” Waring said. “Drinking cow’s milk it started out as a cultural trait that then drove the genetic evolution of a group of humans. ”In that case, the cultural change preceded the genetic change, not the other way around.
The concept of cultural evolution began with the father of evolution himself, Waring said. Charles Darwin understood that behaviors could evolve and be passed on to offspring just like physical traits, but scientists of his day believed that changes in behaviors were inherited. For example, if a mother had a trait that inclined her to teach her daughter to forage for food, would pass on this inherited trait to his daughter. In turn, your daughter might be more likely to survive and, as a result, that trait would become more common in the population.
Waring and Wood argue in their new study, published June 2 in the journal Proceedings of the Royal Society B, that at some point in human history, culture began to snatch the evolutionary control of our DNA. And now, they say, culture change is allowing us to evolve in ways that biological change alone could not.
Here’s why: Culture is group-oriented, and people in those groups speak, learn, and imitate each other. These group behaviors allow people to pass on the adaptations they learned through culture faster than genes can pass on similar survival benefits.
An individual can learn skills and information from an almost unlimited number of people in a small amount of time and, in turn, spread that information to many others. And the more people available to learn, the better. Large groups they solve problems faster than smaller groups, and competition between groups stimulates adaptations that could help those groups survive. As ideas spread, cultures develop new traits.
In contrast, a person only inherits genetic information from two parents and accumulates relatively little random mutations in your eggs or sperm, which takes about 20 years to pass to your small handful of children. That’s just a much slower rate of change.
“This theory has been a long time coming”said Paul Smaldino, an associate professor of cognitive and information sciences at the University of California, Merced, who was not affiliated with this study. “People have been working for a long time to describe how evolutionary biology interacts with culture.”
The researchers suggest that the emergence of human culture may represent a key evolutionary milestone. “His great argument is that the culture it’s the next evolutionary transition state, “said Smaldino.
Throughout the history of life, key transition states have had enormous effects on the pace and direction of evolution. The evolution of cells with DNA was a great transitional state, and then when larger cells with organelles and complex internal structures arrived, it changed the game again.. Cell fusion in plants and animals It was another great sea change, just like the evolution of sex, the transition to life on earth, and so on.
Each of these events changed the way evolution acted, and now humans could be in the middle of another evolutionary transformation. We may still evolve genetically, but that may no longer control human survival very much.
“In the very long term, we suggest that humans are evolving from individual genetic organisms to cultural groups that function as superorganisms, similar to ant colonies and hives“concludes Waring.