Astronaut Scott Kelly is no longer half of a pair of identical twins. He set the record for most consecutive days in orbit, and when he returned his genetic composition had been altered from that of his twin brother. Researchers analyzing the astronauts condition and genetic makeup after his year-long stay aboard the International Space Station as part of NASA’s “Twins Study” found that 7% of Kelly's DNA had gone through an unanticipated change.
Acquired vs. Inherited Traits
Now, as I recall from basic High School biology acquired traits are not supposed to be transferred to your genetic makeup, basically they can't be handed down intergenerationally - so how I wondered is this DNA alteration even possible ?
An acquired trait is a characteristic or trait that is the result of environmental influence. Acquired traits are not coded into DNA and scientists have always believed that they can't be passed down to the next generation. In order for a characteristic or trait to be inherited it has to be part of the individual's genotype, which they were born with acquired traits, such as the case of Scott Kelly are not.
Darwin initially adopted the concept of acquired traits being inherited in his first publication of his Theory of Evolution through Natural Selection. He later took this out as mounting evidence demonstrated that acquired traits were not passed down from generation to generation. Does the Kelly DNA scenario prove the first draft of Darwins theory of evolution correct ?
Space Genes
As per NASA, Kelly’s year [340 days] in orbit probably activated what scientists describe as “space genes.” Space genes are thought to be induced by the stress the body is subjected to durring space travel.
Comments From NASA
“This [Space Genes] is thought to be from the stresses of space travel, which can cause changes in a cell’s biological pathways and ejection of DNA and RNA,”
“Scott’s telomeres (endcaps of chromosomes that shorten as one ages) actually became significantly longer in space,” NASA researchers wrote in a statement. The space agency added that Kelly had hundreds of “space genes” activated by the year-long flight which reportedly altered the astronaut’s “immune system, DNA repair, bone formation networks, hypoxia, and hypercapnia.”
“By studying how space travel can influence chemical changes in RNA and DNA, new ‘space genes’ were reported, indicating significant cell stress and correlations with changes noted by other Twins Study investigators,” explained NASA. “Whole-genome sequencing showed each twin has hundreds of unique mutations in their genome, more than expected, and some were found only after spaceflight.”
From The BBC ...What happens to our genes in space? Professor Chris Mason is a space geneticist and author of The Next 500 Years Engineering Life to Reach New Worlds, published by The MIT Press, in which he argues that we don't need to terraform a hostile planet like Mars in order to be able to build a permanent human settlement: we could instead manipulate human genes to make the Martian atmosphere more palatable.
