It’s been a long time since I made my living as a biologist, but I do try to stay current, and this is one of those stories that makes biology interesting. There are four basic types of speciation: Allopatric, sympatric, parapatric and quantum. Now, on the Galapagos, biologists studying the iconic finches there have found an instance of hybrid speciation. Excerpt from the story:
It’s not every day that scientists observe a new species emerging in real time. Charles Darwin believed that speciation probably took place over hundreds if not thousands of generations, advancing far too gradually to be detected directly. The biologists who followed him have generally defaulted to a similar understanding and have relied on indirect clues, gleaned from genomes and fossils, to infer complex organisms’ evolutionary histories.
Some of those clues suggest that interbreeding plays a larger role in the formation of new species than previously thought. But the issue remains contentious: Hybridization has been definitively shown to cause widespread speciation only in plants. When it comes to animals, it has remained a hypothesis (albeit one that’s gaining increasing support) about events that typically occurred in the distant, unseen past.
Until now. In a paper published last month in Science, researchers reported that a new animal species had evolved by hybridization — and that it had occurred before their eyes in the span of merely two generations. The breakneck pace of that speciation event turned heads both in the scientific community and in the media. The mechanism by which it occurred is just as noteworthy, however, because of what it suggests about the undervalued role of hybrids in evolution.
Know why this is interesting? Look in the mirror. If you, like yr obdt., is of mostly northern European or west Asian descent, you have some Neandertal genes, maybe as much as 3-4%. What precisely happened to the Neandertal is still the subject of some debate, but the Neandertal genome has been sequenced, and we now know a little of them lives on in us.
That wasn’t a speciation event, though. It was an absorption at best. As far as I’m aware this hybrid event with the finches is new, and that’s interesting in and of itself.