The theory of evolution. It gives possible explanation of how living things are influenced by the environment (adaption) and how new features are added in the process (through the process of mutation). Moths change colours not because they have decided to do so but because the environment alters the state of the fittest surving population. People living in poor conditions tend to exhibit risky behaviours so their genes can be passed on quicker (sell d to make $, have sex with multiple men/women, have many babies so at least some can survive). However, these are all after the fact ideas and it does not predict how future populations will turn out. Most mutations in genes are fatal and it is hard to imagine how many mutations a certain species must go through for it to finally survive both the environment and the mutations itself. Did we use to have eyeballs on our elbows and then somehow we died b/c our mates don't find us attractive and also it was inconvenient for hunting? What is the use of eyebrows and when eyebrows first grew above our eyes did we find that attrative? Did the cat have brainy thoughts about conquering the world but was unable to pass on his genes b/c other cats find him freaky and therefore it died and have to wait another billion years of generation until the recessive genes combined to make another brainy cat? The girl born with four arms and four legs. If we put a prestigious school in the middle of the poorest communities will the surrounding population alter to be educated legal businessmens and how long will that process take? How come that kind of change may come in a life time while having a surviving mutation takes millions of years?