| > humans are extremely adaptable This is a strange claim I see repeated over and over, but it has very little evidence to justify it. The only piece of evidence people present is: > people had colonized the whole planet, except for Antarctica This is true of a fairly large number of organisms on Earth. On top of this humans have only been around for ~200,000 years, that's not long at all. Humans have not survived a single mass extinction event. So far we've seen humans travel around a planet that has been relatively stable for that period of time. There have been plenty of species that have traveled around with us that didn't even need to rely on extra tools, clothing or the use of energy to survive. Humans share several vulnerabilities with other megafauna that have all gone extinct. A major one is a fairly long gestation, plus small number of offspring per generation. Human young likewise need tremendous amounts of care and energy to raise to mature adulthood. Additionally human have fairly high energy requirements to support their complex brains. We've seen exponential rise in human population only because humans have had access to excessive amount of non-renewable, high-energy density sources of energy. It just happens that humans have lived on a planet that has mostly been within survivable temperature changes, with historic climate changes happening on time scales that lead to easy migration. As you pointed out, the one continent that does not have an environment that supports human life remains empty. Humans can't survive a wet bulb temperature of 35C. Until just recently we never saw that temperature on this planet. As we see more and more places reach that temperature more often, I suspect we'll see how frail human adaptability is. |
That is because we possess multiple different ways of adapting to our enviroment:
genetic
during childhood
acclimatization
culture and technology
This link provides a nice summary: https://www2.palomar.edu/anthro/adapt/adapt_1.htm