Not likely, since we obviously did interbreed successfully.
You misunderstand. We do not know that there was both neanderthal male/sapiens female and sapines male/neanderthal feamle sucessful breedings. The lack of maternal mithocondrial lines sugges the possiblity that a hybrid fetus were unable to survive in a neanderthal uterine environment, whereas a sapiens one may have been occasioanlly survivable.
Unless this is something that has been seen in other closely related mammalian interspecies matings, then I don’t see any reason we need to postulate it since there are other more parsimonious explanations.
Are they interfertile? I once did a search on chimp-bonobo hybrids, the behavioral differences was fascinating. But I found no confirmed cases. Is there some I missed?
Lions and Tiger offspring are heavily influenced by the uterine environment. The offspring are so different that they’ve been given different names depending on the sex of the mother and father. Simple size differences means certain breeds of dog could not breed successfully in the wild unless the father was of the smaller breed. I expect other cases exist.
It is quite possible for species to evolve features that make backbreeding even with recent relatives difficult. Anyway, evolution is more of a fits-and-starts thing than a smooth progress.
Yes, this happened in the early 20the century in captivity before scientist realized they were different species and would keep them together.
No, they are influenced by the peculiarities of feline genetics. This is caused by genomic imprinting not conditions in the uterus during pregnancy.
All hybrid animals are named thusly (except those like mules which have been around before the scientific understanding of hybridization). Link.
This is not unique to Ligers or Tigons. Hence, you have Coydogs, Wholphins, and Zorses.
Dog are domestic animals, so talking about their behavior in the wild doesn’t make much sense. However, there is no such size difference between Moderns and Neanderthals.
Sometimes yes, and sometimes no. At any rate, my key point stands. There are no known mammal populations that are as closely related as Moderns and Neanderthals that are not completely inter-fertile. Period. End of story.
Neanderthal women’s hips may not have been large enough for birthing the oversized homo-sapien head. Also the gestation period may be a bit longer for us than them, if a human baby is in a neanderthal mother’s womb 9 months when it’s supposed to only be there for 6 it could just be too big and kill the mother and baby, or vice versa miscarry the child at a very young age. Plenty of ways things can go wrong one way but not the other.
Neanderthals had larger brains than sapiens. But they were similar in size at birth, possibly larger in the Neanderthal if face size matters: “While the face of the Neanderthal is already larger than in a modern human at the time of birth, their brain shapes and volumes are very similar”: Cite
They wouldn’t be larger at an earlier gestation period.
It’s certainly possible that differences in head shape/size and pelvic size would skew the distribution of hybrids one way or the other, but not so much as to eliminate one type altogether. We’re not that different.
Today, of course, we would just resort to Caesarian as needed.
Maybe human men found Neaderthal women too unattractive to get with them.
Certainly possible, as well as vice versa.
Or, they have been especially prized for whatever reason (good luck, mystical powers, whatever). We really have no way of knowing at this point.
Or Neanderthal women were simply the spoils of tribal conquest
“Maybe human men found Neaderthal women too unattractive to get with them.”
Highly doubtful. Get either side hungry enough for some nookums and everybody’s beautiful. Maybe even manatees.
Example: I just finished reading an account of Magellan’s voyage around the world. These sailors get to what is now Brazil, hang out for a couple weeks and apparently hook up with the local women 24/7.
So here’s a guy who hasn’t bathed in months, if ever. Filthy clothes. Wipes his backside with a tar-covered rope. Lives on worm-ridden hardtack. Doesn’t brush his scurvious teeth. Skin parasites…etc.
I don’t know what kind of shape the local ladies were in either, but given that they were a fairly primitive tribe, maybe not much more presentable.
Pigafetta, the chronicler, more or less says the two sides went at it enthusiastically the whole time, and both sides were very sad at the parting.
CP: I agree that it is unlikely. We can speculate all we want, but we simply have no way of knowing. If, however, I had to bet… my money would be on few, if any, physical attraction barriers to mating.