Search results
Results from the WOW.Com Content Network
They also believed that human history was progressive, which was another idea becoming increasingly popular in the 18th century. They saw progress in human history as being mirrored by the development of life from the simple to the complex over the history of the Earth. This connection was very clear in the work of Erasmus Darwin and Robert ...
Lev Berg proposed a combination of mutationism and directed (orthogenetic) evolution in his 1922 book Nomogenesis; or, Evolution Determined by Law. He used evidence from paleontology, zoology, and botany to argue that natural selection had limitations which set a direction for evolution. He claimed that speciation was caused by "mass ...
The Baldwin effect compared to Lamarck's theory of evolution, Darwinian evolution, and Waddington's genetic assimilation. All the theories offer explanations of how organisms respond to a changed environment with adaptive inherited change. In evolutionary biology, the Baldwin effect describes an effect of learned behaviour on evolution.
The evolution of biological complexity is one important outcome of the process of evolution. [1] Evolution has produced some remarkably complex organisms – although the actual level of complexity is very hard to define or measure accurately in biology, with properties such as gene content, the number of cell types or morphology all proposed as possible metrics.
Evolutionary biology, in particular the understanding of how organisms evolve through natural selection, is an area of science with many practical applications. [1] [2] Creationists often claim that the theory of evolution lacks any practical applications; however, this claim has been refuted by scientists.
Ohno presented the first version of the 2R hypothesis as part of his larger argument for the general importance of gene duplication in evolution.Based on relative genome sizes and isozyme analysis, he suggested that ancestral fish or amphibians had undergone at least one and possibly more cases of "tetraploid evolution".
Controversy exists as to whether Charles Darwin recognized a true geographical-based model of speciation in his publication On the Origin of Species. [5] In chapter 11, "Geographical Distribution", Darwin discusses geographic barriers to migration, stating for example that "barriers of any kind, or obstacles to free migration, are related in a close and important manner to the differences ...
The Holocene extinction, also referred to as the Anthropocene extinction, [3] [4] is an ongoing extinction event caused by human activities during the Holocene epoch. This extinction event spans numerous families of plants [ 5 ] [ 6 ] [ 7 ] and animals, including mammals , birds, reptiles, amphibians , fish, and invertebrates , impacting both ...