Describe the Charles Darwin's theory of natural selection and survival of the fittest?

Answer 1

These are the basic steps of his logic:

1. Organisms produce more offspring than can possibly survive.
2. The offspring are not all alike; they have variations.
3. Some variations help individuals survive and reproduce when other individuals die without reproducing.
4. Their offspring are more likely to have the favorable variation.
5. After many generations, the favorable variation will be common in the population.

Answer 2

I dont think i have the room or the attention span to explain the whole theory, but here is the basic principle:

Natural selection is a term which says only those organisms that have some distinguished trait, such as a large beak to break seeds, or great strengths or speed to catch prey, will most likely pass on their genes to the next generation since their trait helps to prolong the survival of that species. For instance.....the famous Moth example:

before the industrial revolution in england the ratio of white moths to black moths was very high,,,, lets say 10:1. This was because black moths were much easier to be located by predetors that ate the moths as oppose to the white ones which could blend in easierly. Thus why more White moths existed. Now, after the industrial revolution, where all the soot and what not was put into the atmosphere, it litterly dirtied the trees in which moths lived in to the point where black ones could now blend in with the surroundings, and white ones stood out and where therefore hunted until black moths were the majority of the species. So, in this example you can see how genes are passed on through natural stressors, or in some cases unnatural (industrial revolution), which may promote one trait but discriminate against another. Thus the stronger survives.

Answer 3

Maybe it's beter to illustrate with an example. Let's say birds with a certain kind of beak fly to a remote island, and try to make a living there. Let's say that the bugs they were accustomed to finding on the mainland aren't so easily found. Instead, they either can get at the bugs in crevices in some trees, or they can crack some small nuts. So, birds that happen to be born with slightly longer beaks have a better chance in finding bugs in the trees, and birds with a slightly thicker and stronger beaks have a better chance in being able to crack the nuts, and meanwhile, the birds with the original kind of beak tend to die from starvation. After a while, we find birds that are almost like the ones from the mainland, but either they have long thin beaks good for probing tree trunks, or stout ones good for cracking nuts. Hence, it's the "fittest ones" that have survived the migration to the remote islands, and this would be an example of "natural selection", as in "selected by hard realities of living in nature".

Answer 4

http://en.wikipedia.org/wiki/Natural_selection