Human evolution

Animals shaped early human environment, not drought?

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From University of Utah at EurekAlert:

The shores of Lake Turkana, in Kenya, are dry and inhospitable, with grasses as the dominant plant type. It hasn’t always been that way. Over the last four million years, the Omo-Turkana basin has seen a range of climates and ecosystems, and has also seen significant steps in human evolution. Scientists previously thought that long-term drying of the climate contributed to the growth of grasslands in the area and the rise of large herbivores, which in turn may have shaped how humans developed. It’s tough to prove that hypothesis, however, because of the difficulty of reconstructing four million years of climate data.

Researchers from the University of Utah have found a better way. By analyzing isotopes of oxygen preserved in herbivore teeth and tusks, they can quantify the aridity of the region and compare it to indicators of plant type and herbivore diet. The results show that, unexpectedly, no long-term drying trend was associated with the expansion of grasses and grazing herbivores. Instead, variability in climate events, such as rainfall timing, and interactions between plants and animals may have had more influence on our ancestors’ environment. This shows that the expansion of grasslands isn’t solely due to drought, but more complex climate factors are at work, both for modern Africans now and ancient Africans in the Pleistocene. More.

Tough? Maybe impossible?  See also: The search for our earliest ancestors: signals in the noise

One Reply to “Animals shaped early human environment, not drought?

  1. 1
    vmahuna says:

    Well, the East African weather is all very interesting, but if Europeans were already living in the river valleys in what is now the Mediterranean Sea 800,000 years ago, who cares?

    Humans, “homo erectus”, appeared POOF! a million years ago without any obvious ancestors. We then QUICKLY moved north into Europe and Asia, spinning off the NFL breeding experiment that resulting in Neanderthals, who DOMINATED Eurasia for 250,000 years. Other than homo sapiens sapiens, our Neander cousins are the MOST ADVANCED humans who have ever existed.

    We all CAME from Africa, but getting OUT of Africa was what caused the explosion of ADVANCED human culture around the world. Subsaharan culture apparently stagnated until Mideastern and Mediterranean cultures SLOWLY re-established contact with the Mother Country.

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