Back to GLS 102: Plat du Jour

The story of life on earth started about 3 billion years ago; the affairs of humans comprise a tiny fraction of that story. Here is a history of the world in seven minutes.

Biological evolution--descent with modification and speciation, a branching process--results in the tremendous diversity of life forms that are related one to the other as an evolutionary tree.  Human beings represent a single leaf of this enormous tree.

Our ancestors (hominids) separated* from the ape lineage approximately 8 million years ago (mya).  The evolution of hominids was also a branching process that went in fits and starts and was accompanied by many extinctions.  Homo sapiens, our species, appeared approximately 100,000 years ago.

Domesticated animals tend to be mammals or birds; mammals provide milk, meat, wool, skins, fuel, fertiliser, transport and  draught power.  Mammals originated about 200 mya, but came to ascendance much later--about 65 mya, shortly after which the grass-eating ungulates evolved; the antelope, goat and sheep diversified about 8 mya. 

Dogs were domesticated about 14-10,000 years ago, while the herding animals, sheep and goats, were domesticated about 8,000 years ago.

Domesticated plants tend to be flowering plants that provide food, shelter, medicine.  They may have originated 180-140 mya~.  Grasses, producing abundant, edible seeds, evolved about 56 mya--and set the stage for the evolution of herding animals, the ungulates. 

Wheat, a grass, was domesticated about 8,000 years ago--the beginning of agriculture.

Over the last 14,000 years, domestication has occurred of 40 animal species and several hundred plant species in different parts of the world.

Globalization is a human-mediated process that is thought to have started around 2,500 - or 500 years ago.  It is a process that connects people across the globe.  A significant process that affects human lives and the earth in multiple ways, it is the focus of much discussion and controversy.