Human evolution is the evolutionary process within the history of primates that led to the emergence of Homo sapiens as a distinct species of the hominid family that includes all the great apes. This process involved the gradual development of traits such as human bipedalism, dexterity, and complex language, as well as interbreeding with other hominins, indicating that human evolution was not linear but weblike. The study of the origins of humans, variously known by the terms anthropogeny, anthropogenesis, or anthropogony, involves several scientific disciplines, including physical and evolutionary anthropology, paleontology, and genetics.
Notharctus tenebrosus, American Museum of Natural History, New York
Reconstructed tailless Proconsul skeleton
Reconstruction of "Lucy"
Reconstruction of Turkana boy who lived 1.5 to 1.6 million years ago
Evolution is the change in the heritable characteristics of biological populations over successive generations. It occurs when evolutionary processes such as natural selection and genetic drift act on genetic variation, resulting in certain characteristics becoming more or less common within a population over successive generations. The process of evolution has given rise to biodiversity at every level of biological organisation.
White peppered moth
Black morph in peppered moth evolution
Male moor frogs become blue during the height of mating season. Blue reflectance may be a form of intersexual communication. It is hypothesised that males with brighter blue coloration may signal greater sexual and genetic fitness.
The common garter snake has evolved resistance to the defensive substance tetrodotoxin in its amphibian prey.