Are you confused about the different types of humans that got it on with each other?
If you are, then in this blog entry, I provide a summary factsheet style of the pairs of hominids that interbred with each other, with evidence for and against it, and the current conclusion. All dates are expressed as years before present, and be aware that in the field of ancient DNA, human contamination is always an issue that can potentially confound the results.
Hominid Action Pair #1: Neanderthals + Humans: Non-Africans
Home-turf: Europe/Asia Global
Lived from: 400,000 – 30,000 200,000- present
When and where: 47,000-65,000 Middle East
Evidence for getting it on: If the different colours represent different genetic make-up, then the answer to the question “Where did the modern humans get their genes from?” can only be “from mating with Neanderthals”.
Current status: The literature arguing against interbreeding has been focused on the pitfalls of the method used. Nevertheless, new methods are now confirming that Neanderthals and humans were up in a tree K.I.S.S.I.N.G. Now, we are starting to identify what genes we got from them.
Hominid Action Pair #2: Denisovans + Humans: Asians/ Oceanians
Home-turf: Siberia (Tropics?) Oceania
Lived from: ? – ~50,000 200,000- present
When and where: S.E Asia and prior to 44,000
Evidence for getting it on: It’s the same case as the evidence for mating between Neanderthals and humans, except here the genes that went into the ancestral populations of the Aboriginal Australians, Near Oceanians, Polynesians, Fijians, East Indonesians, and Philippine Mamanwas and Manobos can only have come from the Denisovans.
Evidence against getting it on: While models are presented in the literature for discussion, they have been argued against. The consequence of which is that the results are described as a best fit to the data.
Current Status: We know that the action took place BUT we don’t know enough about the Denisovans. We only have a tooth and small finger bone from a Siberian cave. Watch this space!
Hominid Action Pair #3: Denisovans + Homo erectus?
Home-turf: Siberia (Tropics?) Africa, China, Indonesia
Lived from: ? – ~50,000 1.9 million years- 150,000
When and where: ? and Asia?
Evidence for getting it on: The Denisovan tooth has some features that you can find in some of the older Homo species, and the DNA appears to also look quite archaic. Homo erectus was widespread across Asia, so it does seem likely that the two hominids crossed paths.
Evidence against getting it on: At the minute, there isn’t any. This model was proposed as the most likely scenario to a result that arose from another study.
Current Status: As already said before, we don’t know that much about the Denisovans. There are still a lot of gaps making this a hypothesis.
Hominid Action Pair #4: Neanderthals + Denisovans
Home-turf: Europe/Asia Siberia (Tropics?)
Lived from: 400,000 – 30,000 ? – ~50,000
When and where: ? and Europe/Asia?
Evidence for getting it on: Evidence against getting it on: Not presented.
Current Status: This has just recently been published, and the amount of DNA material from the Neanderthals into the Denisovans is calculated to have been very small. More analyses will have to be done.
Here is a final tree summarising the relationships between the hominids, and the arrows indicate where interbreeding took place. Adapted from Prufer et al 2014.
While I used a lot of literature to create the above summary, if you are looking for more information then I recommend Veeramah and Hammer 2014, Nature Reviews Genetics 15, 149-162 as it provides an up to date informative review while also including relevant references.