Briefly summarize the modern version of Darwin's theory of evolution by natural selection?

Answer 1

1. DNA in an individual mutates. This happens all the time in everyone, otherwise we´d all be exactly the same! Mutation account for differences between people.

2. If a mutation is beneficial to an animal, for instance helps it survive by making it better at catching prey, more attractive to the other sex, or capable of having more young, it will be passed on to the next generation because the animal lived longer and had more young. This is simple inheritance. Natural selection selects the animals best at surviving and lets them pass on the succesful genes.

3. If this goes on for long enough the mutation will become fixed and the population will have changed. It can be as small a change as slightly longer teeth, slightly better camouflage or more potent venom.

4. After a long time, say millions of years, small changes will accumulate and together they will have changed the species very much, probably into a new species or lots of new species. A lot of microevolution piled up makes macroevolution.

Answer 2

Basically what evolution by natural selection means is "survival of the fittest". Whatever organisms have the traits that are best suited to their environment, for example a desert animal that doesn't need to drink much water, will survive, while those that are less adapted will die. Also, if an environment changes, those that develop new traits or abilities that help them survive have "evolved". So, whichever animal is most evolved has the highest chance of surviving, and therefore will continue on.

Answer 3

Called the modern synthesis, or the neo-darwinian synthesis.