More in Common Than Meets the Eye

If we've learned anything since the elucidation of DNA's structure in the 1950s, it's that there is so much more to our genes than just genes. After all, if they boil down to combinations and repatternings of the same four letters, how do we get a planet so full of diverse--and yet closely related--life forms? And of particular interest to us as humans, what make us so special next to the rest of the animal kingdom?

Potential answers to this question continue to pour out of genetics and genomics labs worldwide. Recently, a team working between Beijing, Harvard, and Taiwan published a report proposing a new mechanistic explanation for the origin of humankind in relation to other primates. The study centered around the question of how we, so similar to and yet so different from other primates, might have accumulated the molecular traits that make us unique. If we possess such complex genes that no other primates have, did our hominin ancestors build them from scratch or did they have something pre-existing to build on?

The team led by Jia-Yu Chen looked into the properties of genetic material called lncRNAs (long non-coding RNA's), proposing that unique de novo human genes might owe their origins to non-coding RNA ancestral to primates. If a small change takes a long piece of genetic material from coding for nothing at all to producing a protein, certainly the ramifications could be huge. The scientists found that various tissue types in chimpanzees and rhesus macaques were capable of transcribing human-specific genes from DNA into RNA, with these transcripts becoming lncRNAs incapable of translation. The capability to process distinctly human genes into lncRNA could suggest that chimps and rhesus monkey possess "silent" lncRNA versions of the very genes that make us human. This in turn may imply the non-coding stretches of RNA have existed for a long time as primitive, ancient traits that remained largely unchanged in most primates. For who knows how long, the genetic secret to being human sat quietly in the cells of prehistoric primates, and in a lucky few, change after change took these lncRNAs from totally quiet to big and loud---the genes that make humanity.

Click here to read the full paper from Chen et al.

Chen, Jia-Yu et al. “Emergence, Retention and Selection: A Trilogy of Origination for Functional De Novo Proteins from Ancestral LncRNAs in Primates.” Ed. Jianzhi Zhang. PLoS Genetics 11.7 (2015): e1005391. PMC. Web. 16 Sept. 2015.