What are the 2 main sources of genetic variation? Why is this genetic variation important?


The main sources of genetic variation are mutation and gene flow. AnswerParty.

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Genetic variation, variation in alleles of genes, occurs both within and among populations. Genetic variation is important because it provides the genetic material for natural selection. Genetic variation is brought about by mutation, which is a permanent change in the chemical structure of a gene. Polyploidy is an example of chromosomal mutation. Polyploidy is a condition wherein organisms have three or more sets of genetic variation (3n or more). The mutation is started off by a parent, as the parent mates the offspring now has a chance to receive that mutation trait also. Now when that mutated offspring is ready to mate they now have the chance of passing on that trait to their offspring. This process begins the first generation of mutated offspring.

Population genetics is the study of allele frequency distribution and change under the influence of the four main evolutionary processes: natural selection, genetic drift, mutation and gene flow. It also takes into account the factors of recombination, population subdivision and population structure. It attempts to explain such phenomena as adaptation and speciation.

Population genetics was a vital ingredient in the emergence of the modern evolutionary synthesis. Its primary founders were Sewall Wright, J. B. S. Haldane and R. A. Fisher, who also laid the foundations for the related discipline of quantitative genetics.


Evolutionary biology is a sub-field of biology concerned with the study of the evolutionary processes that produced the diversity of life on Earth. Someone who studies evolutionary biology is known as an evolutionary biologist. Evolutionary biologists study the descent of species, and the origin of new species.

The philosophy of biology is a subfield of philosophy of science, which deals with epistemological, metaphysical, and ethical issues in the biological and biomedical sciences. Although philosophers of science and philosophers generally have long been interested in biology (e.g., Aristotle, Descartes, and even Kant), philosophy of biology only emerged as an independent field of philosophy in the 1960s and 1970s. Philosophers of science then began paying increasing attention to biology, from the rise of Neodarwinism in the 1930s and 1940s to the discovery of the structure of DNA in 1953 to more recent advances in genetic engineering. Other key ideas include the reduction of all life processes to biochemical reactions, and the incorporation of psychology into a broader neuroscience.


Human genetics is the study of inheritance as it occurs in human beings. Human genetics encompasses a variety of overlapping fields including: classical genetics, cytogenetics, molecular genetics, biochemical genetics, genomics, population genetics, developmental genetics, clinical genetics, and genetic counseling.

Genes can be the common factor of the qualities of most human-inherited traits. Study of human genetics can be useful as it can answer questions about human nature, understand the diseases and development of effective disease treatment, and understand genetics of human life. This article describes only basic features of human genetics; for the genetics of disorders please see: Medical genetics.

A scientific controversy may be a fundamental disagreement among scientists about the validity of a major theory, a secondary scientific controversy, i.e., "scientists disagreeing about a less central aspect of a scientific idea."

A true scientific controversy involves a sustained debate within the broader scientific community (McMullin, 1987). In other words, a significant number of people must be actively engaged in research that addresses the controversy over time.


Human genetic variation is the genetic differences both within and among populations. There may be multiple variants of any given gene in the human population (genes), leading to polymorphism. Many genes are not polymorphic, meaning that only a single allele is present in the population: the gene is then said to be fixed.

No two humans are genetically identical. Even monozygotic twins, who develop from one zygote, have infrequent genetic differences due to mutations occurring during development and gene copy number variation. Differences between individuals, even closely related individuals, are the key to techniques such as genetic fingerprinting. Alleles occur at different frequencies in different human populations, with populations that are more geographically and ancestrally remote tending to differ more.

The relationship between race and genetics is relevant to the controversy concerning race. In everyday life many societies classify populations into groups based on phenotypical traits and impressions of probable geographic ancestry and socio-economic status - these are the groups we tend to call "races". Because the patterns of variation of human genetic traits are clinal, with a gradual change in trait frequency between population clusters, it is possible to statistically correlate clusters of physical traits with individual geographic ancestry. The frequencies of allelles tend to form clusters where populations live closely together and interact over periods of time. This is due to endogamy within kin groups and lineages or national, cultural or linguistic boundaries. This causes genetic clusters to correlate statistically with population groups when a number of alleles are evaluated. Different clines align around the different centers, resulting in more complex variations than those observed comparing continental groups.

For example if a person has light skin, light hair and blue eyes, a combination of traits that seems to have evolved in Northern Europe and is found at a high frequency there, it is probable that person has some recent European ancestry. And by extension, according to the racial categories in use in North America that person is likely to be classified by others, and to self-identify, as "white". In a similar way, Genetic analysis enables us to determine the geographic ancestry of a person pinpointing the migrational history of a person's ancestors with a high degree of accuracy, and by inference the probable racial category into which they will be classified in a given society. In that way there is a distinct statistical correlation between gene frequencies and racial categories. However, because all populations are genetically diverse, and because there is a complex relation between ancestry, genetic makeup and phenotype, and because racial categories are based on subjective evaluations of the traits, it is not the case that there are any specific genes, that can be used to determine a person's race.

Science of drugs including their origin, composition, pharmacokinetics,
pharmacodynamics, therapeutic use, and toxicology.

Pharmacology (from Greek φάρμακον, pharmakon, "poison" in classic Greek; "drug" in modern Greek; and -λογία, -logia "study of", "knowledge of") is the branch of medicine and biology concerned with the study of drug action, where a drug can be broadly defined as any man-made, natural, or endogenous (within the body) molecule which exerts a biochemical and/or physiological effect on the cell, tissue, organ, or organism. More specifically, it is the study of the interactions that occur between a living organism and chemicals that affect normal or abnormal biochemical function. If substances have medicinal properties, they are considered pharmaceuticals.


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