Is there evidence that genetic variation in wild populations is caused by natural selection - Essay Example

This adjustment may be structural, behavioral or functional which increases the individual’s ability to survive in the ecological niche. The process of natural selection happens through random genetic variations. The beneficial variations are carried to the progeny. Under the similar environment the process is extended to the entire population of the species in the ecological niche. The new alleles and genes are responsible for genetic variations. Mutations can create new genes and alleles.

In the process of gene duplication morphology of chromosomes may undergo changes which would alter the genetic structure in the evolutionary process. Barett R.D.H. and Schluter state “Compared with new mutations, adaptation from standing genetic variation is likely to lead to faster evolution, the fixation of more alleles of small effect and the spread of more recessive alleles. There is potential to distinguish between adaptation from standing variation and that from new mutations by differences in the genomic signature of selection.

” When we consider sudden alterations by way of mutation as against existing genes, where the changes were induced on account of adaptability to environment filtered for benefits with regard to survival, we can understand the concept of adaptation and natural selection in evolution in the latter case. However, it is also established that beneficial mutations create new alleles to aid an organism in its struggle for existence. Natural selection has been rather well established and reveals increase in the frequency of these alleles.

An example is given with reference to Adaptation to High and Low Temperatures by E. coli.  ‘A single clone of E. coli was cultured at 37 C (that is 37 degrees Celsius) for 2000 generations. A single clone was then extracted from this population and divided into replicates that were then cultured at either 32 C , 37