Scientists and engineers are working on technologies that will make it possible for humans to travel to planet Mars. Visionaries including SpaceX CEO Elon Musk even look forward to a human colony on the Red Planet.
New Human Species On Mars
Scientists, however, said that humans traveling to and living in Mars could possibly lead to the creation of new human species.
At the "Evolution Beyond Earth" program that was held at New York University on Thursday, June 8, panel scientists said that thousands of genes change their structure once humans get into space.
Astronauts experience bone loss, eye problems, muscle atrophy and kidney stone after staying for extended periods in space. Although returning to Earth forces them to readjust to the conditions of the home planet, studies have found that astronauts never completely returned to their original state before they went to space.
Humans who will travel and live in Mars permanently will likely go through significant changes, scientists said. Molecular biologist Ting Wu of Harvard Medical School said that by the second or third generation, Mars colonists will start to see changes in genes.
"Within a few generations you would probably have a more extensive version of what humans would go through in the space station," Wu said. "There is evidence now that an individual organism will be able to pick up on a response or a trait developed by its parent that will be inheritable for generations until the stimulus from which it was created disappears."
The idea that organisms can pass down the characteristics they have acquired in their lifetime to their offspring, known as Lamarckism, leads to speculations that colonists on the Red Planet may evolve into a new kind of human species after years of living on Mars.
Changes In Human Body
The gravity and sunlight in this arid world are far weaker compared with those on Earth and mutation-causing radiation is more intense, which can lead to the bodies of those who will colonize Mars to change.
Scientists, though, noted that speciation — the formation of new and distinct species in the course of evolution — is a long-term process that requires reproductive isolation over long periods of time albeit the changes may occur more rapidly on Mars.
"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. In just a few hundred generations — perhaps as little as 6,000 years — a new type of human might emerge," evolutionary biologist Scott Solomon, of Rice University, said.
Solomon said that whether or not colonists will evolve into a new species, they will likely have anatomical, immunological and physiological features that are different from those who live on Earth. Colonists, for instance, may evolve to have thicker bones as a result of the low gravity environment on Mars that can give them a more robust appearance. The lower level of sunlight may also lead to colonists developing bigger eyes.