Humans may have evolved just by chance: Study
Mere chance may have caused humans to evolve into smarter, more advanced beings than our ancestors, according to a study which refutes the theory that our race originated in response to climate change.
Many scientists have argued that an influx, described as a “pulse,” of new animal species appear in the African fossil record between 2.8 and 2.5 million years ago, including our own genus Homo.
Experts believe it takes a broad-scale event like global climate change to spark the origination of so many diverse new species.
However, W Andrew Barr from George Washington University in the US said that it is possible the pulse of new species could have occurred by chance and might not be directly related to climate change.
It is generally accepted that when major environmental changes occur, some species will go extinct and others will originate, which can create a cluster or pulse of new species in the fossil record.
However, there is no set definition of what is considered a pulse, so experts have disagreed about which clusters constitute meaningful events and which can be explained as random fluctuations.
Barr used computer simulation to model what the fossil record might look like over time in the absence of any climate change and found clusters of species originations that were of similar magnitude to the clusters observed in the fossil record.
This means random patterns are likely under-credited for their role in speciation fluctuation, he said.
Barr’s findings mean scientists may need to rethink widely-accepted ideas about why human ancestors became smarter and more sophisticated.
“The idea that our genus originated more than 2.5 million years ago as part of a turnover pulse in direct response to climate change has a deep history in palaeoanthropology,” Barr said. -PTI