Search results
Results from the WOW.Com Content Network
Vestigial structures are often homologous to structures that are functioning normally in other species. Therefore, vestigial structures can be considered evidence for evolution, the process by which beneficial heritable traits arise in populations over an extended period of time. The existence of vestigial traits can be attributed to changes in ...
Arrows show the vestigial structure called Darwin's tubercle. In the context of human evolution, vestigiality involves those traits occurring in humans that have lost all or most of their original function through evolution. Although structures called vestigial often appear functionless, they may retain lesser functions or develop minor new ones.
The two theories; non-adaptive, and adaptive, are used to explain the evolution of senescence, which is the decline in reproduction with age. [8] The non-adaptive theory assumes that the evolutionary deterioration of human age occurs as a result of accumulation of deleterious mutations in the germline. [8]
In such a case, a shift in the time a trait is allowed to develop before it is fixed can bring forth an ancestral phenotype. [5] Atavisms are often seen as evidence of evolution. [6] In social sciences, atavism is the tendency of reversion: for example, people in the modern era reverting to the ways of thinking and acting of a former time.
Ageing (or aging in American English) is the process of becoming older. The term refers mainly to humans , many other animals , and fungi, whereas for example, bacteria, perennial plants and some simple animals are potentially biologically immortal .
Trait theory suggests that some natural behaviours may give someone an advantage in a position of leadership. [2] There are two approaches to define traits: as internal causal properties or as purely descriptive summaries. The internal causal definition states that traits influence our behaviours, leading us to do things in line with that trait.
Gerontology (/ ˌ dʒ ɛr ən ˈ t ɒ l ə dʒ i / JERR-ən-TOL-ə-jee) is the study of the social, cultural, psychological, cognitive, and biological aspects of aging.The word was coined by Ilya Ilyich Mechnikov in 1903, from the Greek γέρων (gérōn), meaning "old man", and -λογία (), meaning "study of".
Thus the zoologist Newman stated in the Scopes Trial: "There are, according to Wiedersheim, no less than 180 vestigial structures in the human body, sufficient to make of a man a veritable walking museum of antiquities." Some of the vestigial organs or organs containing evolutionary vestigial structures, as listed on the article about him: Adenoids