I would say the 'Strange walking ape with sticks' will lose anyway.
The only question is whether, after the departure of the 'ape', enough of the rest of the earth's ecosystem is left, so that life can recover.
The Earth's ecosystem has survived massive global apocalypse inducing meteor strikes, super volcano eruptions, multiple ice ages even complete snowball earth and possibly a gamma ray burst. The ecosystem seems to be able to spring back from anything. It might not look like it does today but it'll spring back.