Caprines of the Distant Past

Reconstruction of Myotragus balearicus
(Note the odd position of the eyes)

Having said something about all the living species of goat-like animal, it's time to wrap up with a review of where they all came from. Although fossil goats have not received the attention of sabre-tooth cats, let alone dinosaurs, we do have a number of remains, especially from the most recent epoch before today, the Pleistocene. Goats, after all, are reasonably sized animals, and both sexes have prominent horns, which can help to make them distinctive.

Indeed, goats and their kin seem to have done rather well during the Ice Ages of the Pleistocene. Because they are well-adapted to harsh and cold environments, vast ice sheets covering the north were less of a problem for them than for many other animals. They could not, of course, live on the ice sheets themselves, but then very little could. But with most of the rest of Europe, and large swathes of Asia and North America, covered in chilly tundra, that was as good a place for goats as mountainous plateaus are today.

It perhaps particularly suited muskoxen, which, unlike true goats, prefer lowlands rather than precipitous mountains. Even today they are found on the chilly tundra plains of Siberia and Canada and the coasts of Alaska and Greenland. During the Ice Ages, such terrain stretched further south, and (the world being a globe, and continental masses being where they are) that meant there was more of it. That muskoxen are exceptionally large by the standards of "goats" means that they also left some pretty big and impressive skeletons.

Caprines: The World's Largest Goats

Takin (Sichuan subspecies)

All of the various kinds of caprine that I have described so far in this series have looked, more or less, either goat-like or sheep-like. There are just two species left, and those form something of an exception. While most caprines are fairly medium-sized as hoofed animals go, these are much larger, more muscular, animals.

It used to be thought, on this basis, that they were closely related to one another, representing an early branch in the evolution of goat-like animals that split away from their relatives well before the appearance of actual goats or sheep. From modern genetic evidence, that no longer looks the case. They are, as we suspected, caprines, (although, despite the title of this post, not literally goats) but within that group, they are not particular closely related to one another. Instead, their apparent similarities are a coincidence, a case of parallel evolution where two animals, both fairly goat-like to start with, faced selective pressures to become larger.

The first of these animals is the takin (Budorcas taxicolor). Takins are very distinctive animals, quite hard to mistake for anything else, once you get a good look at them. The most obvious point, as I've already implied, is the size. A fully grown male takin stands over four feet high at the shoulder, and weighs upwards of 300 kg (660 lbs). The females are noticeably smaller, but still larger than even the males of any other caprine species (with, of course, one exception that I'll get to in a moment).

Following the Herd

A number of mammal species live in large groups, including dolphins, monkeys, and wolves, among others. Among the most familiar, though, are the various hoofed herd animals. In order to maintain a herd - or any similarly sized group - it is important that the animals all move together, and that there has to be some kind of communal decision-making process that everyone agrees on. It's no good one animal wandering off on its own, if nobody will follow it, but, equally, if all animals have an equal right to decide where the herd should go, its just going to mill about, not going anywhere.

Undoubtedly, different species will have different methods for making such decisions, depending on their biology, the nature of the environment, and so on. If the group is really big (as might be the case with, say, bison or wildebeest), options are fairly limited, and there is unlikely to be one single leader - if only because not all the members of the herd will be easily able to see him. Among animals that live in smaller groups, leadership by single individuals, or by a small group of individuals, becomes more of a realistic possibility, although alternatives do exist. But which individuals do the leading?