Understanding this phenomenon allowed him to develop his concept of “natural selection” which, in turn, became a core element of his theory of evolution. Darwin observed that with such abundance, ...

Change can also occur by genetic drift or gene flow. What does ‘survival of the fittest’ mean? In terms of evolution, an animal that is ‘fit’ is one that’s adapted to its environment. This concept is ...

A classic example of natural selection at work is the origin of giraffes’ long necks. The ancestors of modern giraffes were animals similar to deer or antelope, with necks of ordinary length.

The proportion of well-adapted organisms in a population can increase over the generations by the process of evolution by natural selection.

Edelaar, P. & Weissing, F. J. On the origin of species by natural and sexual selection. Science 326, 1704–1707 (2009). Via, S. Sympatric speciation in animals: The ugly duckling grows up.

New alleles produced by mutations can result in plants and animals becoming better adapted to their environment. Variation within a population makes it possible for a population to evolve over ...

Discover the science behind natural selection and evolution. Get the facts on survival of the fittest with ExtremeTech’s ...

Natural selection is a mechanism of evolution—not ... This is true of any living thing, from animals and plants to fungi and single-celled organisms such as algae. A mammal that dies before ...