Question: how did people first come on to this planet?

SarahJayne Boulton answered on 25 Jun 2012:

Hey Brooklynne, I answered this question a little bit just earlier, I thought you might like to read the little bit I wrote about evolution:

Charles Darwin put forward the first scientific arguments for the theory of evolution, and published a book on the subject called ‘The Origin of Species’ in 1859.

Part of the Darwin’s argument is concerned with a thing called ‘Natural Selection. You might have heard of people talking about ‘survival of the fittest’ before – it’s to do with that. Without going too deep, the theory is that if within a group of individuals, one develops a skill or a physical ability that makes that individual more likely or capable of surviving longer, then that individual is more likely to have babies and pass on the beneficial feature.

Over millions of years and after millions of little beneficial changes occur little independent species can occur as the difference between the original individuals and the developed individuals becomes greater and they separate out. Humans coming from apes is part of the theory, that there were great apes that developed the ability to walk upright either through mutation or a change in behavior, and that the thumb was another beneficial mutation that was preserved due to the individuals with the more dexterous hands were better suited for long survival.

It’s pretty much the best theory we have to explain how humans came about on the planet!

Louise Leakey gave a great talk back in 2008 about our ancestral origins – you can see the video here:

Hope this helps! Like Gem said it’s a massive theory, and real complex to boot!