# Evolution - Natural Selection

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Darwin's Theory of Evolution
Darwin's Theory of Evolution states that groups of organisms will undergo genetic changes over time due to the process of natural selection. Darwin's theory says that organisms which are most fit for their environment survive while unfit organisms die, changing the genetics of a species until that species is well adapted for its environment. Variations in a species' genetics that lead to evolution often come from mutations.

A look at Darwin's Theory of Evolution.
Natural Selection
Natural selection is a theory conceived by Charles Darwin that states that in a population, organisms with a genetic trait that increases the chance of having offspring will pass on their genes to the next generation more than those without it. Natural selection ultimately leads to evolution after many successive generations. Mutation, migration and genetic drift are some factors that significant impact heritable traits in a group of organisms and potentially influence natural selection.
Understanding the process of natural selection.

Evolution of Populations
The evolution of populations is defined as the changes populations undergo when organisms change over time as predicted by Darwin's Theory of Evolution. Over time, organisms which are most fit for their environment survive while unfit organisms die, changing the genetics of a species until that species is well adapted for its environment. These changes are often caused by natural selection or genetic drift.
How populations evolve?
Hardy-Weinberg
The Hardy-Weinberg Law is an equation for calculating the frequencies of different alleles and genotypes in a population in genetic equilibrium and expressed by the formula p + q = 1 where p is the frequency of the dominant allele and q is the frequency of the recessive allele. For genotypes the equation is p^2+pq+q^2 = 1 in which p^2 is the frequency of the homozygous dominant genotype, 2pq is the frequency of the heterozygous genotype and q^2 is the frequency of the homozygous recessive genotype.
Predicting allele frequency in Hardy Weinberg equilibrium.

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