Natural Selection
Darwin‘s contribution was to describe the process in nature that could operate like artificial selection
The Struggle for Existence:
Darwin realize that if more individuals are produced then can survive, members of a population must compete to obtain food, living space, and other limited necessities of life.
Variation and Adaptation:
Darwin knew that individuals have natural variation among their heritable traits. Some of those variants are better suited to life and their environment than others. Any heritable characteristics that increase an organisms ability to survive and reproduce in its environment is called an adaptation. Adaptations can involve body parts or structures. Adaptations also involve behaviors.
Survival of the Fittest:
individuals with adaptations that are well-suited to their environment can survive and reproduce and have high fitness. Individuals with characteristics that are not well-suited to their environment either die without reproducing or leave few offspring. The difference in rates of survival and reproduction is called survival of the fittest.
Natural Selection:
natural selection is the process by which organisms with variations most suited to their local environment survive and leave more offspring. Natural selection occurs in any situation in which more individuals are born then can survive.
Common Descent:
Darwin proposed that living species are descended, with modification, from common ancestors. This aspect of Darwins theory implies that life has been on earth for a very long time and far enough back are the common ancestors of all living things. According to the principle of common descent, all species, living and extinct, are descended from ancient common ancestors.
The Struggle for Existence:
Darwin realize that if more individuals are produced then can survive, members of a population must compete to obtain food, living space, and other limited necessities of life.
Variation and Adaptation:
Darwin knew that individuals have natural variation among their heritable traits. Some of those variants are better suited to life and their environment than others. Any heritable characteristics that increase an organisms ability to survive and reproduce in its environment is called an adaptation. Adaptations can involve body parts or structures. Adaptations also involve behaviors.
Survival of the Fittest:
individuals with adaptations that are well-suited to their environment can survive and reproduce and have high fitness. Individuals with characteristics that are not well-suited to their environment either die without reproducing or leave few offspring. The difference in rates of survival and reproduction is called survival of the fittest.
Natural Selection:
natural selection is the process by which organisms with variations most suited to their local environment survive and leave more offspring. Natural selection occurs in any situation in which more individuals are born then can survive.
Common Descent:
Darwin proposed that living species are descended, with modification, from common ancestors. This aspect of Darwins theory implies that life has been on earth for a very long time and far enough back are the common ancestors of all living things. According to the principle of common descent, all species, living and extinct, are descended from ancient common ancestors.
