system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:How did the Neanderthals die off ?

And how did Homo Sapiens contribute to their extinction.
gpt
They were gradually assimilated and outcompeted by Homo Sapiens. They had a lower brain capacity, and were less adaptable, and natural selection favored humans, who outcompeted them for food and living space. We do know that humans also interbred with them though, and it is estimated that up to 4% of our genome material is Neanderthal.