Sunday 28 April 2024

Call of the Elephants

Arguably the single most significant feature that has enabled our own species to dominate the Earth is our possession of language. This enables us to communicate and cooperate to achieve things we could not do individually, to an extent unparalleled outside of social insects, which lack our ability for complex thought in other ways. Without language, it's hard to see how we would have built cities, or maintained the incremental advance in knowledge that has marked many thousands of years of our history.

Yet language, of course, did not arise from nowhere. There is an understandable interest among scientists in determining how it might have evolved, and what from. Since we can't go back in time to perform linguistic analysis on the likes of Homo erectus, one of our major sources of information is determining how other species of mammals communicate using sound, rather than the scent marks that are so important to many of them. Much of the focus here is on primates, since these are the most likely to hold clues to our own origins, but this can be extended to other species, too. To what extent do other animals have something that could be considered ancestral to language?

Sunday 21 April 2024

Antelopine Antelopes: The Gazelles of Asia

Arabian gazelles
I suspect that, on the whole, westerners associate gazelles with Africa. We think of the ones we see in wildlife documentaries, being pursued by cheetahs or leopards across the plains of the Serengeti or similar places. However, the most current theory suggests that they may have originated in Asia and various species survive on both continents today, having split apart around 2 or 3 million years ago at or shortly before, the start of the Ice Ages.

How many species that might be is still a matter of debate, and much of it centres on what's probably the first part of Asia you'd think of to look for desert-dwelling animals: the Middle East. For much of the 20th century, there were generally regarded as being two species living here, not counting one or two then thought to be extinct. And then, well, all that fell apart for reasons I wrote about on this blog back in 2013.

Sunday 14 April 2024

Oligocene (Pt 8): The First Tapir and the Last Hoofless Horse

A close look at the evolutionary history of horses reveals that it's more complicated than sometimes presented, with numerous side branches forming a bushy tree of different species, many of which ultimately died out without descendants. This applies both to the origins of the group in its early days and its period of great diversification through the Miocene and Pliocene epochs. In the Oligocene, however, the picture, at least so far as we can tell, was rather simpler.

We know of two genera of horse that made it into the Oligocene from the preceding epoch. Mesohippus had been around for a while, Miohippus was a relative newcomer, appearing towards the very end of the Eocene. The two are rather similar, to the point that it has been argued they should be treated as different species of the same genus (which would be Miohippus, as that was named first) and they are both found in fossil beds across the United States and southern Canada, with Miohippus being known from Washington state to Florida and Mesohippus primarily in the west. The similarity also led to proposals early on that the one directly evolved into the other, but it's now clear that they lived alongside one another for millions of years, which scuppers that idea.

Sunday 7 April 2024

Wild Mammals of London

Arguably the single biggest threat to the continued survival of animal and plant species is loss of habitat. Even if an animal isn't actively hunted, the ever-growing human population means that there are simply fewer suitable places for them to live. Logging and the expansion of agriculture are probably the biggest factors here, at least in terms of the area affected, but it's hard to argue that the recent growth of urban sprawl isn't another.

The urban environment is obviously a difficult or impossible one for most wild mammals to exploit. House mice and rats are an obvious exception, and there are also domesticated pets, but for truly wild creatures it's a different matter. While it may no longer have (say) bison or wolves, upstate New York is still home to seven species of shrew, three moles, four hares or rabbits, 22 different kinds of rodent, ten bats, nine mustelids, two foxes, and three deer, plus coyotes, bobcats, raccoons, striped skunks, and black bears. Manhattan... not so much.