Isaac Arthur is an engineer, so not exactly an expert on biology or anthropology. He does to a lot of futurology, but thats unrelated to the origins of life on earth and any speculation he does there is just that.

As a former astrobiologist, I respectfully disagree. The future and past are intimately related, and our planet's future may be examined through other planets' pasts (e.g. Venus). Other than genetics, we have zero evidence about life 3.5 billion years ago, so everything is speculation, and an engineer can do that as well as a biologist.

Thanks, I'll check that out also!