Evolution is the change in the inherited characteristics of biological populations over successive generations (process of biological change over time). Evolutionary processes give rise to diversity at every level of biological organization, including species, individual organisms and as well as the molecular level (DNA and proteins). The mechanisms driving evolution include the following: mutation, migration (gene flow), genetic drift, and natural selection. Modern evolutionary theory incorporates these following concepts: species change over time; genetic mutations are responsible for the changes; individuals with beneficial genetic mutations will survive preferentially compared with their competitors, in a process known as natural selection; those successful individuals more numerous offspring will spread the beneficial genetic constructs throughout the population; when enough genetic changes reproductively isolate a population, that population has become a new species (i.e., speciation, great example can be found in the cichlids of Lake Victoria, Africa). Evolution requires genetic variation, and these variations or changes (mutations) can be beneficial, neutral or deleterious. In general, there are two major types of evolutionary mechanisms, those that act to increase genetic variation, and mechanisms that operate to decrease genetic mechanisms. Mechanisms that increase genetic variation include mutation, recombination and gene flow. Mechanisms that decrease genetic variation include genetic drift and natural selection. Adaption is one of the many terms used in the Group by creationists and is accepted by Creationist, who then turn around and state they dont accept evolution. Adaptation is a change in a population in order to fill a niche or survive in a changing environment and provides an improved function. Adaptations add up over time to drive Natural Selection, thus if one accepts adaption (a mechanism of evolution), one accepts evolution. An example of adaption is the mimicry of leaves for evading predators, ambush tactics, etc., Photo 1, Leaf-mimicking grasshopper, Africa Photo 2, Satanic Leaf-tailed gecko, Madagascar Photo 3, Leaf-tailed gecko on bark, Madagascar Photo 4, Leaf-tailed gecko, Madagascar Photo 5, Leafy Sea dragon, Indonesia evolution.berkeley.edu/evosite/evo101/IIIMechanisms.shtml livescience/topics/evolution
Posted on: Fri, 23 Jan 2015 11:42:15 +0000
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