Hundreds of thousands of years ago, a previously unknown species of ape roamed the forests of Central Africa. We know this not because archeologists have unearthed physical evidence but because there are clues in bonobo DNA, New Scientist reports.
Bonobos would have co-existed with this mystery ape and even mated to produce fertile offspring. Hence, the species lives on, if only in its descendants' genes.
Martin Kuhlwilm from the Institute of Evolutionary Biology in Barcelona, Spain, presented the research at the AsiaEvo conference in China. He "discovered" this mystery (or "ghost) ape after comparing the genes of bonobos and common chimps, searching for any odd traces or bizarre fragments of DNA that could not be explained either by mutations or mating between the two species.
And he found some in the genes of the bonobos. In fact, roughly 1 percent of the bonobos' genes was inherited from this ghost ancestor. He calculated that the two chimp species likely interbred 400,000 or so years ago.
This would not be the first case of two separate species mating to produce so-called viable offspring. For example, there is the beefalo – a cross between a cow and a buffalo, not a chunk of meat. Then there are studies suggesting that red and eastern wolves are not so much their own species but coyote-grey wolf hybrids.
Evolutionarily speaking, hybrids can in fact help strengthen a species by introducing useful DNA. Big cats have a long history of interbreeding, even before humans sought to get a fast buck from ligers and tigons, and hybrids may be responsible for improving jaguars' vision.
As for humans, new research confirms our ancestors got busy with some of our hominid relatives. Around 1 to 3 percent of DNA in people outside of sub-Saharan Africa is Neanderthal, and Denisovan DNA is what allows people in Tibet to survive in high altitudes.
Which brings us to so-called "ghost species", species that are only known through fragments of DNA passed down to their descendants. A 2017 study discovered a lost hominin via modern human spit. It was this study that inspired Kuhlwilm to search for odd bits of DNA in bonobos and chimps, and it makes you wonder, how many more "ghost" species are lurking in genomes across the animal kingdom?
[H/T: New Scientist]