What is natural selection? Natural selection is the process of organisms adapting to their environment and producing more offspring. Let take look at the environment on the right.
Here, you can see a variation of coloured frogs. Variation is any difference between individuals of the same species. It could be an advantage, neutral or disadvantage.
In this photo, the environment has changed. Now, darker green frogs are able to camouflage unlike the light green frogs, creating selective pressure. Selective pressure is a change in the environment which could be could be beneficial or detrimental to species.
As you can see, most of the darker green frogs were able to survive. While only a small portion of light green frogs lived on.
Green coloured frogs will pass down their heritable traits. Heritable traits are traits that have been pass on to the next generation.
As time goes by, differential reproduction will happen. This means the dark colour green frogs will produce more offspring than the other colour coloured frogs. The other coloured frogs are easier to spot, so they produce less.