Natural Selection - Survival of the Fittest Flashcards
What is natural selection?
The idea that some characteristics aid survival and other characteristics don’t.
What important points did Darwin take into account?
- organisms have more offspring than are required
- some characteristics aid survival
- characteristics are inherited
What did Darwin suggest?
He suggested that those characteristics that aided the survival of the organism so that it reproduced its genes are bound to be the characteristics for survival.
What would happen to characteristics that didn’t help survival?
They would die out.
Why would characteristics that don’t help survival die out?
Because the organism with that characteristic wouldn’t survive to reproduce. So if it didn’t reproduce its genes, those genes would die out.
What does natural selection mean about us as organisms?
We are the best that we could be in terms of how we have evolved, as all our inherited characteristics are those that helped our ancestors to survive and reproduce.
Why is the idea of natural selection referred to as ‘survival of the fittest’?
Because it is survival of the fittest - i.e. most suitable - genes.
Survival of the fittest refers to…
… how organisms that suit their environment will survive long enough to reproduce so their genes will continue, whereas organisms not suited to their environment will not survive so their genes won’t continue.
Natural selection only works if there is?
Sufficient variation in the species for certain genes to lead to characteristics that help the organism to survive and other genes that give characteristics not useful for survival.
When won’t natural selection work?
When there is very little variation in the species.
What are variations?
Differences between the genes of organisms in a species.
Where do variations come from?
Mutations.
