Savannah Defined

20 Oct 1995 15:33:41 GMT

'savannah' is the common term used for the temperate and tropical woodland
biomes. These have scattered trees and fire is important in maintaining
them. Temperate and tropical grasslands are a somewhat different biome,
since they are a successional stage maintained by extensive burning.

The 'savannah ape' theory of hominid evolution suggests that the
patchiness of the woodlands that replaced the temperate and tropical
forests in the Miocene led to quadrupedal and bipedal adaptions to moving
on the ground. Bipedal adaptions were possibly more important in smaller,
more gracial animals since that seems to be the pattern in modern gibbons
and squirrel monkeys, while quadrupedal adaptions were more important for
the heavier apes, but all the hominids and anthropoid apes in the system
probably used the full set of behaviors. This led to a mixed system with
many species with subtle niche differences, probably exploiting different
components of the savannah ecosystem.

H. erectus, by using fire, then shifted the entire ecology to a tropical
grassland biome, with distinctly higher productivity, but no room for many
of the savannah-adapted hominids.

Harry Erwin
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PhD student in comp neurosci: "Glitches happen" & "Meaning is emotional"