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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

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