But do we know we can’t? I mean, as has been mentioned, other species have done it. Take, for example, wheat, canola, the mule, or the lyger. Hell, they had a HOUSECAT carry a tiger to term, didn’t they? AFAIK, no one has tried to form a zygote from human and non-human gametes. I’m definitely not up to date on this, though, but damn if it would’t have made it to the news! There are way to many ethical questions involved, and although I’m sure there are people out there just waiting for the chance to actually do it, I think no one reputatable would touch this experiment with a 10 foot pole! The world doesn’t even want cloning right now. Imagine trying to introduce a human-other species hybrid? It would never go.
Personally, I wouldn’t be surprised if it were possible.
Quoth Keeve: “Achernar, I think that AHunter3 was too subtle for you.”
Ah ha ha ha ha ha! Yeah, I get it now. I’m an idiot. For some reason I read “another species” as an animal and “that species” as human. Pret-ty clever. But I guess that still doesn’t answer the OP. Oh well.
There are no recorded cases of successful human/non-human matings. This leads me to belive that there have never been any.
There are several barriers to inter-species reproduction. First is obviously mate choice. Second, the sperm needs to recognize and bind to the ovum, and the protiens involved in this process mutate relatively quickly, so different species usually have different protiens. Third, different genes and different arrangement of genes in different species would completely mess up the developing embryo, and it would almost certainly get aborted. Fourth, the process of imprinting (which governs whether certain genes are used only from the maternal genome, paternal genome, or both) varies widely even between closely related species, and incorrect imprinting results in horribly messed up embryos, which may be aborted or may kill the mother. There are probably a few barriers I’m missing.
It is possible for SOME related species to reproduce, if the genes responsible have not mutated. Most related species cannot (yes, it’s been tried with a number of species). The only real way to test if a particular pair of closely related species can reproduce is to try it. Now, given the propensity of horny humans to stick it in anything warm and concave, I would guess that there have been a significant number of human/non-human-primate matings (think pets, zoos, and captured animals in areas where they are endemic). I have NEVER seen a report of a live birth that was a human hybrid, and I do think it would make news, especially with us geneticists.
A couple of caveats:
I’m talking about modern humans and non-human primates here. Obviously if you go back in evolution, there was probably a time when proto-humans and proto-chimps still sufficiently similar that they could interbreed.
In my list of barriers above, numbers 1 and 2 would prevent conception, and thus pregnancy. Numbers 3 and 4 would result in early spontaneous abortion, but that could be considered a pregancy by the OP. It is possible that human/nonhuman matings can proceed to conception, and this could be tested by mixing human sperm and non-human ova in a dish, and looking for fertilization. I don’t know if anyone has ever done this.
This definition of species seems to be falling out of favor. According to this article (warning: subscriber only article, link may not work) from Science News, the definition is moving towards something like:
The simple answer is NO. Humans cannot impregnant another species, but it does not mean impossible.
Reason that it maybe possible is that freaks of nature happens.
I hope you’re kidding - wheat and canola? Lyger? But as to the mule - the defenition we usually give is that two different species cannot mate to give fertile offspring. A horse and a donkey can mate, but because they are different species, the offspring (mule) is not fertile.
It has to do with number of chromosomes, but also with meiosis - gametes don’t get made right when the chromosome complements don’t match.
Of course it is possible…
no less an authority thatn the Weekly World News frequently has articles on the insemination of human women by Sasquatches (Bigfeet… Bigfoots?), and occasionally female Sasquatches by human males.
If that ain’t the truth, I don’t know what is.
Infertile hybridisation between plant species may be more common than amongst animals, though I would doubt it. I highly doubt fertile hybridisation between species is more common. I’ve seen papers suggesting that the classical species concept of infertile breeding under natural conditions is applied far more rigorously to plants than animals (and criticising the practice).
Both animal and plant species can hybridise across species (and occasionally across Genera) and produce fertile offspring. Both animals and plants do so in the wild.
In many areas where humans and the great apes share territory there is an extremely strong taboo on having sex with them, more so than other forms of bestiality. Also, most of the animals that humans tend to have sex with are either easy to overpower or so domesticated that they won’t fight back when a human tries it. I find it hard to imagine that a human male would be able to rape an adult chimpanzee or gorilla.
Surprised that no one has mentioned that, about 30-40k years ago, H. sapiens may have interbred with another species quite frequently…H. neanderthalis. Not proven, of course, but a definite possibility. I suspect other past homonid species were possibilities too.
