After just under a year in space…

After just under a year in space, astronaut Scott Kelly’s gene expression changed significantly and it’s different to his identical twin brother’s DNA. A new NASA statement suggests the physical and mental stresses of Scott Kelly’s year in orbit may have activated hundreds of “space genes” that altered the astronaut’s immune system, bone formation, eyesight and other bodily processes. While most of these genetic changes reverted to normal following Scott Kelly’s return to Earth, about 7 percent of the astronaut’s gene expression remained altered — and it may stay that way permanently.

Of all the humans tested so far…

Of all the humans tested so far, everyone has contained the same DNA from 1 of at least 2 ancestors. Mitochondrial DNA being traced back matrilineally to a specific “mT-Eve,” and a Y-chromosome being traced back patrilineally to a specific “Y-chromosomal Adam.” We are not descended from a singular couple, but rather we are all seemingly descended from singular ancestors that may have lived hundreds of thousands of years apart.