GUNS, GERMS AND STEEL - Cloverport Independent Schools

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GUNS, GERMS, AND STEEL
Aboriginal Australians and New Guineans have also diverged genetically,
physically, and linguistically from each other. For instance, among
the major (genetically determined) human blood groups, groups B of the
so-called ABO system and S of the MNS system occur in New Guinea as
well as in most of the rest of the world, but both are virtually absent in
Australia. The tightly coiled hair of most New Guineans contrasts with
the straight or wavy hair of most Australians. Australian languages and
New Guinea's Papuan languages are unrelated not only to Asian languages
but also to each other, except for some spread of vocabulary in both directions
across Torres Strait.
All that divergence of Australians and New Guineans from each other
reflects lengthy isolation in very different environments. Since the rise of
the Arafura Sea finally separated Australia and New Guinea from each
other around 10,000 years ago, gene exchange has been limited to tenuous
contact via the chain of Torres Strait islands. That has allowed the populations
of the two hemi-continents to adapt to their own environments.
While the savannas and mangroves of coastal southern New Guinea are
fairly similar to those of northern Australia, other habitats of the hemicontinents
differ in almost all major respects.
Here are some of the differences. New Guinea lies nearly on the equator,
while Australia extends far into the temperate zones, reaching almost
40 degrees south of the equator. New Guinea is mountainous and
extremely rugged, rising to 16,500 feet and with glaciers capping the highest
peaks, while Australia is mostly low and flat—94 percent of its area
lies below 2,000 feet of elevation. New Guinea is one of the wettest areas
on Earth, Australia one of the driest. Most of New Guinea receives over
100 inches of rain annually, and much of the highlands receives over 200
inches, while most of Australia receives less than 20 inches. New Guinea's
equatorial climate varies only modestly from season to season and year to
year, but Australia's climate is highly seasonal and varies from year to year
far more than that of any other continent. As a result, New Guinea is laced
with permanent large rivers, while Australia's permanently flowing rivers
are confined in most years to eastern Australia, and even Australia's largest
river system (the Murray-Darling) has ceased flowing for months during
droughts. Most of New Guinea's land area is clothed in dense rain forest,
while most of Australia's supports only desert and open dry woodland.
New Guinea is covered with young fertile soil, as a consequence of volcanic
activity, glaciers repeatedly advancing and retreating and scouring