Human Origins

22 Sep 2017

An article in New Scientist (26th August 2017) by Colin Barras, p 22-33. said, 'the story of human origins is being re-written. The past 15 years have called into question every assumption about who we are and where we come from' - a sweeping statement. Until recently the consensus was that our great march Out of Africa began 60,000 years ago and that by 30,000 years ago every other contender for humanity had disappeared. Only modern humans remained - a species with a linear evolutionary history stretching back 6 million years. The Natural History Museum in New York currently has a display on human origins - and no doubt the same applies to the Natural History Museum in London (and elsewhere). These origins are considered to be, most likely, in the African Bush (the tropical forest zone). Early hominids are said to have come down from the trees - where chimpanzees still live. Then, to spoil the well rehearsed song sheet, three discoveries added new layers and confusion to the story line. These include Orrorin tugenensis, Ardipithecus ramidus, and Sahelanthropus tchadensis, which pushed a long held assumption about our evolution to the breaking point. Genetic backtracking has led our scientists to think humans split from chimpanzees between 6.5 and 5.5 million years ago. These new discoveries looked more human than chimp which on the face of it indicates human lineage is much older than assumed. Later, in 2012, revised estimations of how fast genetic differences accumulate forced another re-assessment - and now the human to chimp split is said to have occurred 7 to 13 million years ago (almost doubling the evolutionary transition period). Or is guesswork once again at play?

The confusion then increased as Homo naledi remains from South Africa were dated to just 230,000 to 335,000 years ago - an apparently early member of Homo sapiens. The implication from all this is that the evolutionary tree was too hastily constructed in the first place - with too little fossil evidence to support it. Whilst a revision of the evolutionary tree appears to be in order, and measures tend to keep strictly to the consensus view, do we really know how far back our ancestors go - or not go. There are too many missing chapters. What all this means is that palaeo-anthropologists are in disagreement and each new discovery causes further disagreement - which in fact is healthy science at play. The see sawing of the debate in the New Scientist article is covered fairly well at ... but as a Creationist web site it means they find all the confusion evidence that evolutionary theory is all mixed up - but is it. Adjustments to the consensus scheme merely highlight anthropologists have built their linear line of descent on shaky ground - out of a few old bones found mainly in the African Rift Valley. The reality is more interesting - and that may involve dating anomalies associated with the uniformitarian model.