So if this hypothesis is proven to be true what would it mean for how we think about mankind?
Is this likely to be proven?
It’s not really all that earth-shattering since we already know we derive from the same species. This is just about the details. Nature doesn’t respect our concept of “species”, and there is cross-breeding between what we call species all the time.
The 4M year gap is a bit surprising, and maybe that won’t hold up over time, but we know that chimps and bonobos can interbreed and they diverged from each other about 2M years ago. They don’t interbreed in the wild because their populations are separated by a very wide river.
Let me add that your thread title gets it wrong. The interbreeding is between human and chimp ancestors. The human ancestor doing the interbreeding would not be a member of the genus Homo, and hence would not be considered “human”. If that species were alive today, you’d see it in a zoo, not living next door.
Well, obviously you haven’t seen my neighbors!
Courtesy of the “Low Hanging Fruit and Fish In A Barrel” department.
Actually, I think this is a pretty good explanation for soccer hooligans …
One implication of this theory (not mentioned in the linked article) is that it casts doubt on certain fossils like Sahelanthropus tchadensis, whose disoverors claim it to be a 7M year old upright human ancestor. It’s hard to imagine a knuckle-walking ape and an upright walking ape viewing each other as mating partners. Frankly, I thought the claims for that species being upright were a bit shaky, to say the least. In fact, there is some contention that it represents a gorilla ancestor and not a human ancestor.
(BTW, the OP did get his title from the linked article, so he really can’t be blamed for the error I noted above.)
One question this brought up for me was I thought that the human line split from the ape line before the chimp and gorilla lines split. So would humans be breding with a common anestor to both the chimp and gorilla? Or am I getting things totally wrong?
That’s a good point, and I was thinking along the same lines, too. But I think what they’re saying is that line split 10M years ago, then merged again briefly about 5.5M years ago. The gorilla is thought to have split off 7M years ago, so that would be before the interbreeding took place.
Of course, this assumes that there was no interbreeding in that 4M year gap, which seems very suspicious. Also, someone needs to do this analysis between human and gorilla and chimp and gorilla to get the whole story. Man, there might’ve been some wild sex going on back then!!! 
Sure I was horney, but I was really only dating her for her brains[sup]*[/sup].
[sup]*[/sup]they were delicious.
There are a few couples I remember from high school, let’s just say …
Well, we’re pretty sure that Laura is human!
might as well get that one out of the way.
You must live in a more upscale neighborhood than mine. 
You’re getting things wrong. We’ve known for a while that chimps and humans are more closely related to each other than either of us are to gorillas.
Well, considering how some people feel about sheep 
The bit I read in the Times this morning seemed to indicate that Sahelanthropus tchadensis represented the pre-divergence state, and evidence for convergence came from DNA. If Sahelanthropus tchadensis were not a direct ancestor, I don’t think I’d get why the time of the only divergence couldn’t be taken from the DNA evidence. Given a convergence, doesn’t the DNA indicate the time of the last interbreeding? It could have been going on at any point before that.
Wild monkey sex, even.
Wow, I completely misread his post the first time. You’re right-- the conventional wisdom is that gorillas split off 1M years before the human and chimp/bonobo lines split.
But like I said earlie, this new data means we need to go back and look at the gorilla and chimp and the gorilla and human DNA comparison using the same technique. We may find intermingling of the ancestors of all 4 lving African apes (putting humans in the category of “African ape” for easy of labeling).
I was discussing this on another board and a poster said:
And I am not sure how to respond. I think part of the problem is his defintion of species is wrong and too rigid. But I haven’t studied biology since college. How would you respond?
Is there any other kind of monkey sex to have?
Would it be completely inappropriate to make a smirking comment about King Kong and Ann Darrow here? Uhm, yeah, now that I see it in print … it would be.
If my next door neighbors are silver-backed apes, are they “Gorillas In Our Midst”? (I gotta’ get myself a drummer for the rim shots!)
Two populations are considered different species if they cannot interbreed or if they don’t interbreed in the wild to a signficant extent. But cross fertility between species is extremely common, in the lab if not in the wild. For instance, all sepcies in the genus *Canis * can interbreed. Wolves and coyotes even interbreed in the wild, but not often enough to be considered the same species.
Let me pick this apart even further because this person does not know what he or she is talking about.
Different “genera” would be at a higher level of classification than the species level. He means “race” or “subspecies”, not “genera”. Further, he uses the term “family” incorrectly, as that is a level above “genus”. The hierarchy is:
Family
Genus
Species
As I said above, the list of species that can interbreed is quite long. Many can even produce fertile offspring. There are even species in different genera that can interbreed. But as long as they don’t form a a continuous interbreeding population in the wild, they are considered different species.