To reply to a digest, insert the relevant message header; don't reply to the digest header ------------------------------------------------------------- This third program deals with Home ergaster (and his successor out of Africa, Home erectus) and so covers a period of about one million years from 1.5 mya - 0.5 mya. It so happened that I came home from work and cooked my usual dinner of a couple of lightly grilled osso bucco, so I was eating bone marrow as I was watching - not contrived, it just eventuated. The thing that this series has helped me to understand better than all my previous reading is just how close these ancestors were to us in terms of physiology, but how distant they were intellectually, culturally and socially. Robert Winston narrates that 'we can see in ergaster the seeds of humanity and also recognize how much of ape man is alive in us today' With ergaster we get the ability to sweat. This relieves us of having to pant to keep cool and enables us, unique among mammals, to stride out relatively comfortably in the sun. Not having to pant also frees the throat for speaking. The program opens as a two-day trek following a wildebeest nears its end, the wildebeest exhausted by the ergasters' relentless pursuit. The hunting party comprises both men and women. The scene is used to bring out four things: 1. the intellectual developments which make ergaster the first of our ancestors to achieve revolutionary levels of insight into the surroundings: recognizing footprints for what they were, predicting weather from clouds or bird behaviour. Such understanding gave massive increases in control over the environment. The result is that adaptability is no longer necessarily physical; it becomes increasingly mental and cultural 2. the hunt as a cooperative endeavour in which participants accumulated skills and knowledge over time. The group cohered not for protection or under a dominant male, but because of the many benefits of friendship and monogamy. Ergaster, Winston suggests, was the first to have whites to their eyes, a development which enabled them to read more clearly the mood and meaning of others 3. the use of meat as a currency and the sharing of meat to help bind the group. The return to the group of hunters with meat was shown as an occasion of jubilation. In the program, the group members were very demonstrative: hooting (they had no language as such) in rudimentary unison and they trudged home with their kill, dancing to celebrate the success for the group and animated showing off by the successful hunters 4. the creation of the first stone tools, another skill passed on as culture was transmitted across generations. The stone tools also reveal a puzzle for contemporary archaeologists: why is it that the transition into a tool-making culture was not followed for over a million years by any further development or sophistication in tool types? The program finishes with speculation that 0.5 mya, our ancestors began to control fire and that this was the trigger for the next great change: the developments associated with Homo heidelbergensis and their successors. As Winston narrates: 'perhaps when we today look into a fire we see the shadow of our prehistoric thought'. The program was predominantly about cultural development, but the following points came out: a. a battle between two young men over a woman showed the survivor was the one who triumphed in this 'sudden and shocking eruption of violence'. The suddenness was brought home by depicting the couple courting placidly, then the male spotting the intruder and within seconds transforming into a violent killer. Cortisol on the job! b. ergaster's brain consumed one-sixth of their calories c. meat was an underlying thread through tonight's broadcast. Carrying parts of a carcass over miles would be physically demanding activity. My own observation is that slippery organ meat would not likely be taken far from the carcass; boned limbs would make an easier load. From the accompanying book there is: d. the advantages given by sweating were probably used and so ergaster was far more active than its ancestors e. the Nariokotome skeleton suggests they were stronger than us today f. the physiological drivers for monogamy were: big brain + narrower hips > need for earlier birth > longer period of infant dependency > society more oriented to child raising g. a female ergaster skeleton shows clear evidence of hypervitaminosis, an excess of vitamin A which would have led to a slow, disabling and painful death. I guess that the lesson for us is that just because a certain food was eaten regularly in the Pleistocene, does not mean it was wholly beneficial for them, for their entire lives, let alone for us. h. Ergaster's slim build indicates a smaller stomach made feasible by a diet of nutritionally dense meat rather than plants. Next week: life in a cold climate. Keith ----------------------------------------------------------------- The FAQ for Evolutionary Fitness is at http://www.evfit.com/faq.htm To unsubscribe from the list send an e-mail to [log in to unmask] with the words SIGNOFF EVOLUTIONARY-FITNESS in the _body_ of the e-mail.