Close to 25 million years ago a parasite entered into a gene important for tail development. The gene Tbxt was altered by the inversion and scientists believe this is the cause of monkeys having tails but not apes. Scientists believe the insertion of this parasite is the reason why humans and apes do not have tails. The parasite called an Alu element is a transposons, which inserts itself into the host's DNA. Over 140 genes involved in tail development in vertebrates were examined and it was discovered that a “chunk” of the gene Tbxt was missing. The scientists called this their eureka moment when discovering it and believe this missing chunk is responsible for the lack of tail in apes and in humans.
https://www.sciencenews.org/article/genetic-parasite-humans-apes-tail-loss-evolution
https://www.newscientist.com/article/2291130-how-our-ape-ancestors-suddenly-lost-their-tails-25-million-years-ago/#:~:text=What%20Xia%20found%20is%20that,a%20loop%20in%20the%20mRNA.
I've never actually thought about how odd it is that apes don't have tails despite how closely related they are to monkeys. Also interesting how in the article it says the missing chunk was found in an intron which we just learned in class does not actually code for any expressed genes. I've always kind of thought mutated introns did not have much affect but clearly they do!
ReplyDeleteI found the article really interesting. It made me realize that the lack of tails may have given certain advantages to the ancestors of apes and humans, possibly linked to their movement, balance, or other aspects of their lives. Discovering the genetic change responsible for this trait gives us insight into the pressures that influenced the evolution of these species.
ReplyDeleteIt is interesting on how a parasite insertion that happened years ago is now taken place into the evolution of the tails in these species. This is now concluding into the discovery of genes changes and the evolutionary traits. It is just impressing on how small genetic changes can have a big impacted into the development on these species.
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