A Neanderthal Extinction Hypothesis: Birth Complications due to
Megaloencephaly
- Ugur Bilge,
- Safak Olgan,
- Battal Ciplak,
- Metin Ozbek,
- Hilmi Uysal
Abstract
Homo neanderthalensis is the closest relative to Homo sapiens in the
tree of human evolution. It is estimated that the Neanderthals became
extinct around 30 thousand years ago. Several hypotheses have been put
forward to explain this extinction. Larger brains hence larger heads
were favoured by evolution among the Hominids for over two million years
but stopped being an advantage due to trade-offs between bipedal
walking, larger brains and birth. Our hypothesis states that H.
neanderthalensis became extinct as a result of their larger head
circumference, compared with H. sapiens, leading to birth complications.
We use population dynamics to demonstrate that a small difference in the
rate of mortality during birth can cause extinction of one population.
We simulate two populations with an Agent Based Simulation technique to
show that in the case of interbreeding between two populations,
unexpected results can emerge depending on random events in simulations.
We demonstrate that sharing the same habitat with capacity constraints
over thousands of years, with a relatively higher death rate during
birth could be the main cause of the slow decline in the H.
neanderthalensis population, and its eventual extinction.