I wonder if all species are somewhat maladapted to the current environment since the earth has warmed substantially in the last 10k years.
Good question.
With some species such as the panda having the worst of it though lucky enough to find an ecological niche to survive. Perhaps their diet included more meat when it was colder(?)
I wondered about that too, but when I searched for info on their past diet, the books and science articles I found said that giant pandas have always been eating mostly bamboo and that even their predecessor species was eating lots of bamboo before them! However, scientists have gotten the diets of some species very wrong (such as the chimpanzee, which eats significantly more meat and insects than the early vegetarian bias of scientists led them to guess), so I wouldn't be surprised if giant pandas actually eat a bit more non-bamboo foods in the wild than currently believed when the right foods are available. However, the reported reason that giant pandas don't eat much meat is that their ancestor lost a certain gene(s) that resulted in them losing the taste for meat. Interestingly, however, female pandas apparently seek out insects and other forms of meat/fat when they want to get pregnant (which is very rarely mentioned anywhere--perhaps because pandas are thought of as cuddly, friendly "vegetarian" animals and zoos don't want to lose funding by admitting that they sometimes eat yucky insects and evil meats
).
[Soapbox side note I can't resist venting about
: My guess is that it's the fat more than the protein of the insects and small animals that the female GPs are after when they want to get pregnant. I cringe every time I hear a naturalist say "It's a good source of protein" when referring to insects and other small animals and fish in the wild. All carnivorous and omnivorous mammals, including hunter-gatherers, seem to preferentially seek out sources of animal FAT more than protein. So the dingbat naturalists and scientists should be saying "It's a good source of FAT," which would of course shock the TV viewers, and thus it isn't likely to become commonplace anytime soon.]
Other species such as humans clearly took a wrong turn once the megafauna died out and became addicted to grain.
Yes, whatever caused the extinction of most of the megafauna, it was perhaps the biggest catastrophe in human history so far (perhaps second only to the development of large-scale crop agriculture?).
I wonder if the great cats would be better fed and would not have the teeth issues if the larger game with more fat reserves were around.
Good question. I don't know.
Isn't it true that the animals like the mammoth (and elephant) are a higher percentage of fat than the other African deer-type species?
That would be my guess.
Also, I would assume the colder weather would likely necessitate a larger amount of body fat for all animals, especially in the winter.
Perhaps, but the camel also seems to have quite a generous hump of fat and the hippo doesn't seem to be terribly lacking in fat (though Cordain says it's not as fatty as it looks). IIRC, according to one science article I read, generous fat depots seem to be more correlated with the need to store energy than with cold weather. Regardless, there were certainly many much larger animals in the past and my guess is that Stone Agers preferentially selected the fatty parts of mammoths and other large megafauna (along with certain organs) and thus had easy access to much more fat than most humans do today.
The same thing kind of thinking can be applied to all species since the earth has (I believe) been cooler than it is now for a much higher percentage of the time. Perhaps frugivorous primates did not have the selection of fruit they do now and suffer some mild consequences with some cavities that they would not have been exposed to in the past.
Interesting hypothesis--thanks for sharing it. I'll keep my eyes open for evidence of that. Maybe the earth was more like a Shangri-la in the past than we realize. For example, it is said that colobus monkeys are the favorite food of chimps. There were more monkeys in the past, so maybe chimps ate more of them in the past.
