The Cave Bear Story

"I picked this book because it’s similar to my own academic research trajectory. This book was written in the 1970s and cave bears are the most common Pleistocene fossil that we find. There are thousands of them in caves across Europe and by looking at these fossils it’s possible to reconstruct the evolutionary story of these animals all the way through to their extinction. Which is what he does here. It’s kind of what I do, but, rather than just looking at fossils, we extract DNA from these fossils and try to follow the story through time – looking at their evolutionary history by how their DNA sequence has changed. This is the first time anybody looked specifically at one species and tried to see: how did they grow? How did they interact with their environment? What happened when other species turned up in their environment? What was the immediate effect of humans on this species that disappeared? He’s also a very good writer, so it’s a really interesting story to read. It’s a little outdated in parts. There are some bits of it that are wrong. But despite that it’s such a compelling history of a species and how that species changed in response to first environmental change – the Ice Age – and people competing with them in the landscape and then competition with brown bears: who eventually won, brown bears are still alive and cave bears are not. I’ve just started working with a collaborator on Germany – Michi Hofreiter – on a big cave bear genomics project. So I have a special fondness for this book because it’s setting up hypotheses that we’re intending to test with DNA in the next couple of years. This is another brilliant thing about this book. Most people around this time when they were talking about why a species went extinct would say either it was A or B. Either it was humans who killed them, or climate change that killed them. He doesn’t do that. He says that it was a combination of all these things: it was competition with brown bears; it was people who were killing both brown bears and cave bears; and it was change in habitat, change in resource availability that gave brown bears an advantage over cave bears so they eventually won out. But it took all of those things together to make them go extinct and any of those things separately wouldn’t be sufficient. It’s a similar story to what’s going on with things that go extinct in North America within the last ten or fifteen thousand years. For a long time the competing hypotheses were: the ice age killed them or people turned up and hunted them to death. We now know pretty clearly that it must have been a combination of these things. The DNA sequences that we’ve extracted from these remains show us populations of things like bison and horses – which went extinct in north america about fourteen thousand years ago (they were reintroduced by Europeans a couple of hundred years ago). Bison almost went extinct, mammoths did go extinct. The initial decline of all of these populations began something like thirty-five thousand or forty thousand years ago and this is important because the peak of the last Ice Age was about twenty or twenty-five thousand years ago. The decline was well before the peak of the last Ice Age, and there’s no evidence for large numbers of humans in North America till around fourteen thousand years ago. The initial stages of the declines of these species is not caused by humans hunting them. It can’t be. We weren’t there. It must be a combination of all these things. I’m not willing to let us off the hook ultimately for the extinction of these species. But clearly there was something going on that was bad for them prior to people turning up. The jury is out. Nobody really know what Neanderthals worshipped. There’s cave art from modern humans in which bears and lions and other things feature. They were pretty awesome creatures. We might want to worship them if they were alive today. Spectacularly large – just beautiful animals."