The British Humanist Association (BHA) last night held its 8th annual Darwin Day lecture, marking the anniversary of the birth of Charles Darwin, 201 years ago. Professor Chris Stringer, Research Leader in Human Origins at the Natural History Museum, explored the history of human beings; how, where and why we evolved into the modern human being from our ancient ancestors. The lecture was introduced by BHA Vice President Professor Richard Dawkins, returning as chair.
Dr Stringer took the audience through a fascinating history of the first recordings of Neanderthals and other early human fossils, where fossils had only been discovered in Europe, and Europeans were keen to claim the origins of human beings to their lands. Many respected scientists even believed that the now infamous fake fossil “Piltdown man” was genuine, very much in the hope that England was really the birthplace of the human race. However, once fossils began to be discovered in Africa, the story of human evolution really began to unfold, with thousands and thousands of well-preserved skeletons and even footprints for scientists to record, date and work on. It quickly became generally accepted that all modern human beings have their origins in Africa.
Dr Stringer then looked to different theories which attempt to explain how we evolved from apes to humans. For example, he discussed competing theories of “bipedalism” – how and when our ancestors began to walk upright and on two feet – explaining that some scientists believe that the process is central to the story of evolution, whereas others believe it is an off-shoot, and not necessarily central to natural selection processes. He also discussed a rather controversial theory, the “Expensive Tissue Hypothesis” which posits that it was not until our early ancestors began to eat meat that human really began to evolve. Human brains use about 20% of the body’s energy, so we needed meat rather than plant matter to give our brains enough food to grow and develop.
Modern human beings did not evolve from Neanderthals, and Dr Stringer made the case that it is unlikely that Neanderthals and early Homo Sapiens interbred. Neanderthals should be viewed, then, as an experiment in different ways to be human, and that they should be viewed as ‘another type of human’, and not our ancestors.
In terms of explaining non-shared, regional features of modern humans, Dr Stringer said he agreed with Darwin; that the best explanation for people coming in ‘different shapes, sizes and colours’ was sexual, rather than natural selection. In fact, it is likely that most of the visual differences we see between different regional groups of people, such as facial features, have evolved in just the last 50,000 and genetically, the variation between people is tiny.
Where now for humans? As a sobering end to a lively lecture, Dr Stringer argued that, although human beings are still evolving, our fate is dependent more on our environment than sexual or natural selection, and that we must address issues such as climate change urgently, if we are to continue our amazing story of evolution.
Notes
The BHA hosted the lecture in conjunction with the South Place Ethical Society, at Conway Hall, Red Lion Square, London, WC1R 4RL.
The Darwin Day Lecture is part of the BHA’s annual lecture programme, which also includes the Voltaire, Holyoake and Bentham lectures.
For information about future BHA events, visit humanists.uk/meet-up/events
Read about our Darwin Day campaign.
The British Humanist Association (BHA) is the national charity representing and supporting the non-religious and campaigning for an end to religious privilege and discrimination based on religion or belief.