If humans were to inhabit Mars, it is likely that we would quickly evolve into a new species to survive our new environment.
The conditions on Mars are similar to that of Earth comparatively with other planets, but it has sub-Antarctic temperature, an atmosphere of roughly 95 per cent carbon dioxide and with minor traces of water, nitrogen oxide and neon – an environment that could trigger rapid evolution.
Scott Solomon, an evolutionary biologist and author of ‘Future Humans: Inside the Science of Our Continuing Evolution’, wrote that humans on Mars would be subjected to the ‘founder effect’.
The founder effect is a phenomenon where species adapt very quickly due to the population being very small in a new environment, creating a genetic bottleneck which accelerates mutations.
— Scott Solomon (@ScottESolomon) March 8, 2017
In his paper on Nautilus, Scott wrote:
This happens routinely to animals and plants isolated on islands—think of Darwin’s famous finches. But while speciation on islands can take thousands of years, the accelerated mutation rate on Mars and the stark contrasts between conditions on Mars and Earth, would likely speed up the process.
Rapid, in evolutionary terms, is just a few hundred generations, potentially as few as 6,000 years of human life for a new species to evolve.
Scott gave the example of Mars’s weak gravity as a environmental feature that could cause a rapid loss in bone density which would in turn lead to a greater rate of broken bones in humans.
In response to this pressure, Solomon explains that ‘after many generations, Martian people could end up with naturally thicker bones than their forebears, lending them a more robust appearance’.
In response to the high levels of radiation on Mars, Scott said colonists’ bodies increased the production of melanin, which protects against radiation but also darkens skin, leading to Martians with ‘darker skin than anyone on Earth’.
Scott actually predicts that humans will turn orange due to the body producing copious amounts of carotenoid (the material that makes carrots orange) to protect skin from radiation.
Future humans are turning out to look pretty weird – orange, bulky-boned and with huge heads.