Search results
Results from the WOW.Com Content Network
Also called functionalism. The Darwinian view that many or most physiological and behavioral traits of organisms are adaptations that have evolved for specific functions or for specific reasons (as opposed to being byproducts of the evolution of other traits, consequences of biological constraints, or the result of random variation). adaptive radiation The simultaneous or near-simultaneous ...
Neoteny in humans is the slowing or delaying of body development, compared to non-human primates, resulting in features such as a large head, a flat face, and relatively short arms. These neotenic changes may have been brought about by sexual selection in human evolution. In turn, they may have permitted the development of human capacities such ...
Generalized scheme of embryonic development. Slack "Essential Developmental Biology". Fig. 2.8. The initial stages of human embryogenesis. The sperm and egg fuse in the process of fertilization to form a fertilized egg, or zygote. [15] This undergoes a period of divisions to form a ball or sheet of similar cells called a blastula or blastoderm ...
An area of current investigation in evolutionary developmental biology is the developmental basis of adaptations and exaptations. [187] This research addresses the origin and evolution of embryonic development and how modifications of development and developmental processes produce novel features. [188]
The result of four billion years of evolution is the diversity of life around us, with an estimated 1.75 million different species in existence today. [ 71 ] [ 72 ] Usually the process of speciation is slow, occurring over very long time spans; thus direct observations within human life-spans are rare.
Evolution of ageing – Study of the evolutionary development of ageing processes Evolution of aging and mortality – Permanent end of an organism's life; Origin of programmed cell death – Death of a cell mediated by intracellular program, often as part of development; Origin of avian flight – Evolution of birds from non-flying ancestors
Morphogenesis also describes the development of unicellular life forms that do not have an embryonic stage in their life cycle. Morphogenesis is essential for the evolution of new forms. Morphogenesis is a mechanical process involving forces that generate mechanical stress, strain, and movement of cells, [ 1 ] and can be induced by genetic ...
Before its use to describe biological evolution, the term "evolution" was originally used to refer to any orderly sequence of events with the outcome somehow contained at the start. [7] The first five editions of Darwin's in Origin of Species used the word "evolved", but the word "evolution" was only used in its sixth edition in 1872. [ 8 ]