Geneticists Discover Hidden ‘Whole Genome Duplication’ That May Explain Why Some Species Survived Mass Extinctions
The big-picture finding suggests that there may be many more overlooked, shared WGDs in other species before periods of extreme environmental upheaval throughout Earth's tumultuous history. The research, led by Professor Aoife McLysaght and Dr Anthony Redmond, has just been published.
Professor Aoife McLysaght said: “Whole genome duplication is exactly as it sounds -- it’s a fascinating evolutionary event where an entire genome is copied and pasted so that a species suddenly has twice the genetic material as it did before. Whereas most species, like us, are ‘diploid’ -- having pairs of chromosomes, one from each parent -- after whole genome duplication everything is in four copies. This effectively provides a lot of raw material for mutations -- and evolution -- to occur. Eventually, a species genome will revert to the typical pairs through a process called rediploidisation.”
“We’ve know about whole genome duplication and rediploidisation for a long time but what is new, and exciting, is that we have shown that the time it takes for the second part of the process to complete is very important. In this case, it took a long, long time -- so long that some gene duplications appear to be species-specific, occurring after the two species went their separate ways on the tree of life. As a result, the ancient original whole genome duplication that happened before the species had separated had been missed until now. We believe the same thing might have happened in many other species lineages and that is important given the possibility that it generated genomic conditions that helped the species survive mass extinctions.”
