wild and wilder horses

28 May 2016

At http://phys.org/print383382056.html ... science has been having a look at wild horses and how they survived the last Ice Age into the Holocene and the modern world. In the open landscape of the Late Pleistocene the wild horse was common. In the post glacial wooded environment horses were confined to a few refugia, it is thought. Mostly they were confined to the steppe zone and central Asia which is where they were eventually domesticated. Did wild horses survive into the 19th and 20th centuries. It is thought most of these were feral - domesticated horses gone wild.

At http://phys.org/print383377285.html ... body size may have led to the extinction of Pleistocene mega fauna we are told. You know, all those big versions of bison and elephant etc. However, rather than succombing to human hunters, as a preferred reason for extinction according to one group of theorists, in spite of small human numbers during the Palaeolithic, the new study says yes, hunting was a factor but more importantly, it was the reduction in available food resources that led to animals becoming smaller. Not sure if this works because a classic Ice Age scenario means an extension southwards of the polar zone and subsequently a contraction of the temperate zone. Was there really lots of food for large herbivores to eat - greater in comparison to the vegetation available in the early to mid Holocene?

The researchers argue that even the big cats would have required much more food (or prey species) if only to provide the energy to keep warm in the Ice Age. There appears something of a paradox here but I like the way they steer away from the human hunting killed off all the large mammals syndrome. However, there must be more to it than just climate change. Okay, the climate in NW Europe, for example, was very different in the Pleistocene to what it became in the Holocene but this ignores the problem of what caused that climate change. Something must have happened to generate climate change and the fact that large mammals became extinct in association with that climate change should be explored - and this is what this new study is doing (in a non-catastrophist way).