Genetic Variance Between And Within Species

Over the millions of years organisms have been present on earth, there has been many forms of evidence to suggest animals are evolving through natural selection. However, the question still remains as to whether homo sapiens are still evolving through natural selection. Through the nature of science being subject to change and many new discoveries being made each day, it is difficult to make clear confined theories and conclusions, which will not be impacted on in the future.

"New standards pointed out about that discrepancies in a molecular evidence has challenged the evolutionary theory of common ancestry of all living things and that whether microevolution can be extrapolated to explain macro evolutionary changes is controversial".(LeBeau, 2007)

Discovering the origins and timeline of our species genetics is an essential component of our history. The majority of research into this topic has been relatively recent within the past many years. Scientists are consistently providing new findings and new information for this rising area of interest. Through widespread learning of this material can we collectively make sound judgements based on our own past.

“If no such variations exist, the population rapidly goes extinct because it cannot adapt to a changing environment” (O’Neil, 1998-2013). Scientists call this reproductive success. “Within a specific environment context, one genotype will be better than another genotype in survival or reproduction for certain reasons having to do with the way its particular features relate to the environment or relate to other organisms within the population” (Futuyma, 2000-2014). The theory of evolution is explicable through various kinds of scientific research.

The biological findings of Charles Darwin contributed to revolutionizing modern understanding of evolution and genetics through the comparison of biodiversity and the trending similarities and differences among members of shared lineage. Darwin's observation of how the environment impacted the evolution of species as they adapted to their surroundings led to the understanding of how new environments may influence new divergent characteristics between members of shared ancestry. This scientific study on heredity contributed to a universal understanding of genes, alleles, chromosomes, and the recombination they incur during reproduction. But what

2) How should stabilizing and disruptive selection affect the magnitude of phenotypic variation from one generation to the next? (Ch. 7)

In the case of ring species, natural selection and sexual selection each play a role in the divergence of ring species. Selective pressures allowed one phenotype to survive better than others in a certain area; sexual selection could cause divergence because organisms choose mates based on phenotypes. In the case of salamanders, natural selection affected divergence because organisms with certain coloration survived better in coastal or inland environments. In warblers, sexual selection and natural selection seem to play a part in the divergence of the ring species, as forest density and migration distance is variable and affects survival of the species. Molecular and morphological evidence can be used to support multiple species by showing

Natural selection is considered to be the primary mechanism by which Evolution happens. Darwin posited that because any species can exceed the resources necessary to sustain life, a struggle for existence develops. In this struggle, “individuals with heritable traits that increase survival and reproductive success will pass on those traits to their offspring while those that do not will tend to be eliminated.” It is interesting to note that Darwin’s thoughts on natural selection were heavily influenced by Edward Blyth. Blyth, however, viewed natural selection as a conservative process whose goal was to keep organisms essentially unchanged.

After completing the experiment, it was evident that the wild allele would result in higher chances in survival and reproduction. When comparing the genders, females were more likely to be in larger numbers. The data was analyzed using the chi-squared value that was calculated for each week. It was determined that on week 3 that it did follow Hardy- Weinberg equilibrium; however, by week five and seven it did not. This proves that our hypothesis was right and the Drosophila melanogaster population did undergo evolution.

Natural selection is considered one of the most important processes for a variety of species and the environment which allows the fittest organisms to produce offspring. To prevent a species from extinction, it is necessary for them to adapt to the surrounding environment. The species which have the ability to adapt to new surroundings will be able to pass their genes through reproduction. Within the process of natural selection, it is possible for the original genetic make-up of a species to become altered. The team will report on the different processes of basic mechanisms of evolution, how natural selection results in biodiversity and why biodiversity is important to continued evolution. The sources of genetic

The purpose of the Population Genetics Lab was to use the Hardy Weinberg theory of genetic equilibrium and examine the relationship between evolution and allele frequencies. Additionally this lab allowed us to examine how microevolution factors such as natural selection, heterozygote advantage, and genetic drift affected the genotype and allele frequencies. Finally the population genetics lab permitted us to become masters of finding allele frequencies and establishing a better knowledge on evolution in populations and how we can calculate if that occurred using the Hardy-Weinberg equations. This experiment is relevant because

BBC - GCSE Bitesize: Evidence for natural selection. (2017). Bbc.co.uk. Retrieved 29 September 2017, from http://www.bbc.co.uk/schools/gcsebitesize/science/ocr_gateway_pre_2011/environment/4_survival_of_fittest5.shtml

What is evolution and how does it happen? There are two ways of evolution taking place. There is microevolution and macroevolution. Microevolution is gene frequency. Macroevolution is speciation. There are two types of barriers that can be formed that would cause speciation to occur. Allopatric speciation is a physical barrier that separates a species long enough for speciation, such as a dam that was built. Sympatric speciation is speciation occurs without a geographic separation, such a mutation that caused a bird to sing a different song. Mutation can happen in many different ways. There is chromosomal alterations such as deletion, duplication, inversion,

Genetic diversity can help a species survive. The greater the number of different alleles that all members of a species possess, the greater the genetic diversity of that species.

Several alternatives to panselectionism are presented and are generally all a variation on the neutral theory of molecular evolution (printing should pend inquiry regarding the lack of credit to Motoo Kimura for development of said theory). This hypothesis proposes that random genetic drift plays a dominant role in genetic evolution with selection playing a minor supporting role. In the section titled Telling Stories, the authors criticize scientists who ignore and/or marginalize the more likely explanation of neutral theory in favor of the archaic approach of justifying every identifiable characteristic of an organism as beneficial and inventing an often completely untestable hypothesis for its utility. I heartily agree with this objection- I have long felt that the field of evolutionary biology is weakened every time the phrase “over millions of years” is uttered (and it is uttered far beyond the point of cliché), and every time a biologist duplicitously represents that selection happens without values and judgment (of course), and then proceeds to describe the various features in terms of survival value and utility. As the authors point out, “the mere existence of a good fit between organism and environment is insufficient evidence for inferring the action of natural selection (593).”