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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 ...
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]
Evolutionary developmental biology is primarily concerned with the ways in which evolution affects development, [2] and seeks to unravel the causes of evolutionary innovations. [ 3 ] The approach is relatively new, but has roots in Schultz's The physical distinctions of man, from the 1940s.
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 ...
The idea of evolution by natural selection was proposed by Charles Darwin in 1859, but evolutionary biology, as an academic discipline in its own right, emerged during the period of the modern synthesis in the 1930s and 1940s. [19] It was not until the 1980s that many universities had departments of evolutionary biology.
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.
In the so-called modern synthesis of the early 20th century, between 1918 and 1930 Ronald Fisher brought together Darwin's theory of evolution, with its insistence on natural selection, heredity, and variation, and Gregor Mendel's laws of genetics into a coherent structure for evolutionary biology. Biologists assumed that an organism was a ...
A number of other changes have also characterized the evolution of humans, among them an increased reliance on vision rather than smell (highly reduced olfactory bulb); a longer juvenile developmental period and higher infant dependency; [180] a smaller gut and small, misaligned teeth; faster basal metabolism; [181] loss of body hair; [182] an ...