EVOLUTION In biology Evolution refers to the process

EVOLUTION

In biology, Evolution refers to the process through which species change over time. The change results from a change in the genetic material of an organism and is passed from one generation to the next.

Charles Darwin 12 February 1809 – 19 April 1882 Darwin was an English naturalist who is best known for his contributions to theory of evolution. He established that all species of life have descended over time from common ancestors and that evolution resulted from a process that he called natural selection. There is grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved. ”

The Voyage of the Beagle The Galapagos Islands Darwin spent 5 years in his mid 20’s aboard the Beagle exploring and collecting specimens. It was his time visiting the volcanic island chain off the coast of Ecuador that he began to notice that each island had a different environment and that plants and animals that were similar differed from island to island. Finches

Darwin’s Finches

Darwin wondered…Had these birds evolved from a similar species? From one common ancestor? ? ?

Darwin’s finches are an example of evolution as well as adaptation. An Adaptation is any inherited trait that gives an organism an advantage in it’s particular environment.

Artificial Selection (Breeding) Natural Selection: Members of a species that are best suited to their environment survive and reproduce at a higher rate than other members of the species.

Natural Selection: Members of a species that are best suited to their environment survive and reproduce at a higher rate than other members of the species.

The process of natural selection 1. Over production: When a plant or animal reproduces, it usually makes more offspring than the environment can support. Some will die of disease or due to predation. Others will live to adulthood and even fewer will successfully reproduce and pass on their genetics. 2. Variation: Within a species there are natural differences, or variations, in traits. Many of these differences among individuals result from differences in the genetic material of the fish. Sometimes a mutation occurs causing new variation to come about. As individuals with the new variation reproduce, the trait gets passed on to its offspring. *Therefore, genetic variations are passed on from one generation to the next. 3. Adaptation: Sometimes a mutation occurs that makes an individual better able to survive than other members of the group. This would be an adaptation that gives an organism an advantage in its particular environment. Helps it to survive illness or predators…or helps it to hunt more efficiently. 4. 4. Selection: Individuals with a beneficial adaptation are most likely to survive long enough to reproduce. As a result, the adaptation becomes more common in the next generation. As this process repeats from generation to generation, more members of a species show the adaptation.

Adaptation Selection

A New Species Arises 1. 4. Selection: Individuals with a beneficial adaptation are most likely to survive long enough to reproduce. As a result, the adaptation becomes more common in the next generation. As this process repeats from generation to generation, more members of a species show the adaptation. Speciation: Is the evolution of new species from an existing species.

Isolation: The separation of two populations of the same species by a physical barrier, such as a mountain or body of water. Geographical isolation may ultimately lead to the populations becoming separate species.

It is not the strongest of the species that survives, nor the most intelligent that survives. It is the one that is most adaptable to change.