HOMO SAPIENS - THE ONLY SURVIVOR

In my previous posts, I briefly mentioned the once incredible diversity of the human family tree and I looked at the possible reasons behind the disappearance of the Neanderthals. But what about all the other hominin species that did not make it, although at some time in the past they were thriving? Searching for answers is extremely hard. Entire populations who lived for thousands of years left behind only a few incomplete fossils on which we base our speculations.

As an example let’s take Homo florensiensis – also nicknamed ‘the hobbit’.  Homo florensiensis lived on the island of Flores in Indonesia, measured a little bit more than a metre in height and a brain of a size of an orange (Brown: 2012). There are numerous theories on the emergence of the species, but I want to focus on its disappearance which took place approximately 12,000 years ago. There are numerous theories on the emergence of the species, but I want to focus on its abrupt disappearance which took place very recently - approximately 12,000 years ago. One of the popular theories states that H. florensiensis (as well as Stegodon, the pygmy elephant which constituted the main source of food for the hobbit) went extinct because of a volcanic eruption at ca. 12,000 years ago. Some scientists say it could have been the arrival of Homo sapiens that put an end to the millennia of H. florensiensis presence on the island. However, there is some evidence suggesting that changes in climate could have played their part too. The stalagmite records from Indonesia show a sharp increase in rainfall, following a long arid period and coinciding with the H. florensiensis extinction (Westaway et al.: 2007). Unfortunately, due to the lack of complete evidence it is still impossible to tell for sure which of the possible causes had a major part in the vanishing of the hobbit.

With the demise of H. florensiensis, the diversity of Homo lineage finished. We are not entirely certain why H. habilis, H. erectus and other species of the genus Homo disappeared. Environmental stress? Competition?  Interbreeding? Climate change? Or combination of all the factors? Due to that uncertainty, in my next post I would like to focus not on the reasons for extinction of the other species, but on the factors making Homo sapiens the only survivor of the Homo family. I will also look at what the story of our success can mean for our future under the rapidly changing climate.