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Margaret
18 January 2013 @ 02:56 pm
The second episode of Prehistoric Autopsy was all about Homo erectus, and they were building a model of Nariokotome Boy. This is a 1.5 million year old near complete Homo erectus skeleton & the most complete one ever found. They started off with context, again - Homo erectus only died out relatively recently, but was around for 2 million years, which is the longest of any human species. It's also one of the first hominids that can be thought of as human, and we and all the other ones that were around in the recent (geologically speaking) past are descended from them. They also lived outside Africa, and were the first hominids to do so.

Homo erectus co-existed with several different hominid species over time - they talked in detail about one, Paranthropus boisei. The skull they showed had a massive jaw, a skull ridge and very flared cheekbones to fit the chewing muscles behind. A diet of particularly solid things seems plausible, like nuts and seeds. As well as that sort of food there's evidence of wear from grasses on their teeth.

They showed us research into the climate over the time period - I loved this bit, there's just something so neat about being able to find out what the world was like so long ago with such a simple concept. They do it using samples taken of the sediment on the ocean floor. It's laid down layer upon layer over time, and you can look at things like the sort of mud it is and the sorts of plant seeds/pollen you find in it to build up an idea of what the weather and landscape was like on nearby continents. We got shown a particular example of a core where you could see a colour change in the mud from top (~5000 years ago) to bottom (~10,000 years ago), and told us that the changes correspond to a change in the nearby climate (East Africa, if I remember right) from wetter to more dry. Over the 2 million years that Homo erectus existed the climate seems to've undergone lots of swings between hotter & colder or wetter & dryer conditions and they speculate that why Homo erectus survived and the other hominids didn't is that Homo erectus was more adaptable.

And that they were more adaptable because of their bigger brains and because of the different way they interacted with the environment around them. There's evidence that Homo erectus used fire, and they cooked their food (at least at the end of the time period, I wasn't clear if there was no evidence from earlier on or if they hadn't done the analysis (yet)). Their tools are more sophisticated than earlier hominid tools - instead of just breaking rocks for a sharp edge their tools are carefully shaped and show evidence of being planned and involving skill to make. So Homo erectus seems to've had the cognitive ability to shape the environment to suit themselves, rather than put up with the environment they find themselves in. There's also evidence that they took care of older members of their groups - a skull has been found where the individual lost their teeth a few years before death, and quite clearly wouldn't've survived without help.

Because of the model building the programme also spent some time discussing the probable physique of Nariokotome Boy. Homo erectus show many adaptions for running, and were probably lean and hairless (to the extent that modern humans are hairless, I mean). Because of the lack of hair they'd've had dark skins to protect themselves from the UV of the African sun - and this limited their spread north, they don't seem to've got the low melanin mutation that permitted us to live in more northern climates. Also in this section they showed us evidence that Homo erectus may've suffered from tuberculosis, which is astonishing - it is a disease that we get from cattle originally, and was assumed to've become a human disease only more recently when modern humans started living in close proximity to cattle because they'd become herders. The marks and signs on the Homo erectus skull they were looking at (not Nariokotome Boy, another one) were very similar to the ones on a modern human who'd died of TB, so seemed convincing evidence. Which raises all sorts of interesting questions.




We also watched the last episode of Wartime Farm, which unsurprisingly covered 1945 and the immediate aftermath of the war, as well as wrapping up with a "what we've learnt" segment. So they were mostly concentrating on the fact that once the war was won, that didn't mean life returned to how it had been pre-war - not only did people still need fed, but in some ways the situation was even more precarious because Britain was close to bankrupt and couldn't afford to import food yet the fields were becoming less fertile due to a lack of manure and from being over-farmed. They also talked about the celebrations that people had (and the thing they dramatised was a firework elephant, which was awesome :D ). And they harvested the wheat crop they'd spent the year growing, using a brand new combine harvester (well, 70 year old one ...).

This was a good series, although I've struggled to write more than a paragraph per episode. I'm not quite sure why, but I guess partly because there was a lot of "look at how we did things" which isn't easy to transform into text. I did feel that they spread it all too thin, perhaps they couldn't do it half the number of episodes, but I do think they could've cut it down a bit. The format of half-dramatising, half-telling still feels like it shouldn't've worked, but they pulled it off very well.