First Life

The face of Australopithecus

The first life appeared around 1000 Million years after the formation of the Earth. Early life began in the sea, and consisted mainly of algae, plankton and bacteria. It was only 530 million years ago, during the Cambrian Period that life began to diversify in the sea, with mollusks, corals, vertebrates, amphibians and insects appearing around this time. Some of these creatures developed the ability to live on land at this time, and new forms of life evolved there. reptiles start to appear 200 million years later, with dinosaurs among them. These giants roamed the earth for 120 million years - a remarkable achievement for any animal - but disappeared 65 million years ago. The earth was inherited by the meek thereafter, with birds and mammals replacing their lacertian predecessors. These started off quite small, but gradually grew in size, and split into many of the species we would recognise today. A very familiar species started to appear not long after: 60 Million years ago, the first primates appeared, and slowly, they morphed into monkeys, apes and humans. The human story is the one of most interest from this point.

It was between 8 - 5 million years ago that the first primates distinct from apes appeared. The evidence found suggests that this development took place in Africa; 4 million year old footprints in Tanzania show a decidedly upright gait in whatever primate forms they were that roamed those regions then. But whatever these first hominids were, they walked upright as they adapted from forest to Savannah, as the Ice age climate changed (one theory suggests that because the ice held so much water, it was not moved, rainfall dwindled, and as the forest receded for wan of water, it left Savannah in its shadow). Whatever caused it to happen, these were the conditions which evolution waited for before throwing man onto the chronology of the world.

The first known hominids were the Australopiths - "man apes" - who were very much smaller than modern humans. The most famous of these was "Lucy", Australopithecus afarensis, the name given to a 3.5 million year old skeleton found in Ethiopia. The adults cannot have been imposing, at 3 - 4 feet in height, and not more than 30kg in weight., their brains too small for speech. But it was a start. Australopihticene man grew over time and their brains with them.

About 2.5 million years ago the first properly called "man" appeared: homo habilis, he was called. No longer an ape. His remains have been found in eastern and southern Africa. Homo habilis was roughly 5 foot in height, and weight 110 lb, with a brain of 800 cc to match (only 400 cc smaller than modern man). Importantly he had the first signs of speech.

What then is human? The traditional definition is based on the fact that humans fashion tools. It was around 2.5 million years ago that man began to use the first rudimentary tools, mainly wooded, or from reeds, barks and hides than stones. But it is from now that we speak of the Early Stone age first. His tools were sufficient to defend himself against carnivores, and for hunting, something made easier by his upright stance