• Explain The Role Of Hormones In Early Birth

11. Define the following: Genetic drift: unpredictable fluctuations in allele frequencies, reduces genetic variation over time through such losses of alleles

Natural selection involves the adaptation of a species to better survive in their designated environment. When organisms reproduce, they pass down their DNA to their offspring. For example, a child that is tall is the result of their parent being tall as well. Parents pass down traits to their children. When it comes to survival, some organisms are better at it than others based on the traits that they have acquired. Some organisms can camouflage from predators while members of the same species do not obtain that same trait. With that in mind, the ones that can camouflage will most likely survive in certain environments and they will then pass on that trait when they reproduce. Since these traits are advantageous, they are passed on to more and more offspring through time and it will eventually overcome any original traits that species first started out with. It’s kind of like the current state of sexual misconduct in Hollywood. We have our directors, actors, agents, and so forth. However, as time goes on, some do not survive in the business based on their inherently evil traits and they get weeded out just like some species in the wild. As generations pass, these organisms have then adapted to fit the environment and better survive based on their inherited traits.

Natural selection is nature’s way of revising and changing to aid in the constant pursuit of survival. And genetics are the key to finding favorable traits in nature. The more diverse a population, the more likely the species will continue on in the future. The way this works is not very complex. Those that have traits better suited for the environment, will survive and pass on those genes. The genes they pass on, will change the population and make it better suited for the ever changing environment. It’s not always the biggest and strongest that pass on their genes however. Since genetic variations are completely random, some organisms get favorable variations and survive while some get less favorable variations and die.

Likewise, genetic drift is the change of amount of a gene in a population from different generations. This is by chance or accident. For example,

It is the change in inherited traits of a population through a process called natural selection in which only the strongest traits are appropriately adapted to the environment, thus those traits from parents who live longer and are healthier are passed down to future generations. Evolution is the product of two opposing forces: variation in traits and mutation (Futuyma, Evolution). Darwin's views convinced the scientific, and many others, that the world was not static. Instead, life is and has been continually evolving. One cannot imagine how much of a paradigm shift this was it turned religion and philosophy around to the point that even in the 20th and 21st centuries the idea is considered so dangerous that it should be regulated in its dissemination, especially to children. Some see this explanation of life as the central organizing force that allows for complexity. Darwin's natural selection is such a process that accounts for evolution to the point of both human minds and societies. Philosopher and cognitive scientist Daniel Dennett, in his 1995 book Darwin's Dangerous Idea, says that:

A mutation is the act or process of being altered or changed. Mutations are very dangerous to the human body. The good thing is that not all mutations can be inherited. In some cases where a mutation occurs in sperm cells, a mutation can be passed on which often most likely leads to genetic variation. A mutation that is possible to receive is called a germ line mutation.

Natural selection is the process in which individual organisms with more adaptive alleles have reproductive fitness and are able to pass their genes to their offspring while organisms with unsuccessful alleles do not survive.

Genetic drift is a natural phenomenon that occurs due to the randomness of natural breeding and reproduction within populations. Normally this occurs in smaller populations and leads to a fixation of alleles over time. Frequencies of the alleles change because of sampling error within a population and their reproduction from generation to generation. Genetic drift also tends to change populations a lot in a very quick amount of time. The amount of inbreeding and homozygotes increases in populations where genetic drift is present and the rate at which genetic drift occurs is not proportion to population size but is more common in smaller populations because there is already a smaller pool of alleles than in a larger population. Any population

By comparing the single-nucleotide polymorphisms(SNPs) and examining the genetic sequence within a population, researchers can determine if the genetic diversity is caused by natural selection or mutation (Kawabe et al., 2014). As mentioned above, genetic diversity is caused by many factors such as mutations, natural selection, genetic drift and migration (PCG-Denver, 2006). Mutations change the nucleotides in DNA sequence through radiation, chemicals or error during DNA replication while natural selection allows organisms with the fitted allele to survive and spread (“What is Genetic Diversity?” n.d.). In addition, genetic drift changes the gene of a population over time which may lead to loss of beneficial genes and migration enhances gene flow as genes are transferred among populations (Star, B. & Spencer, H. G., 2013). Thus, genetic diversity may be detrimental or beneficial, but it is important for its occurrence because it helps regulate the lifespan of a population by providing gene resistance to diseases and environmental pressures (“What

Genetic Drift (Allelic Drift) is a change in the genetic structure of a population because of random events such as floods, earthquakes or fires, which leads to changes in allele frequencies (the frequency of an allele at a specific locus in a population (Gillespie, 1998) over time which influences its survival. The impact of genetic drift seems to be smaller in bigger populations and larger in small populations due to the lower number of individuals, and small size of a gene pool. Consequently, it may lead to disappear in gene variants and thereby limits the genetic variability (DeBenedictis, 2014).

selection and one sort of random drift can correspond to different aspects of such a population-

A genotype is the different allele combination that an individual has that causes a particular trait or disorder. It is the alleles that are present in an individual.

The former includes mutations, allelic differences (i.e., any one of a number of alternative forms of a gene occupying a given position on a chromosome), genetic drift (i.e., changes in gene frequencies in isolated populations over time), natural selection and cultural selection. Although many variables are at least partially determined or affected by genetic factors, few of them are controlled solely by simple Mendelian inheritance (i.e., a single gene being entirely responsible for a trait). Rather, most are polygenic (i.e., controlled by multiple genes) or are determined by a complex combination of genes and prenatal

Darwin’s theory of natural selection states that evolutionary change comes through the production of variation in each generation and differential survival of individuals with different combinations of these variable characters. [2]

genetic drift. Genetic drift is a random change in a small gene pool due to