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Mechanisms of Evolution
Mechanisms of Evolution

...  Allelic frequency: % of a specific allele in the gene pool.  Genetic Equilibrium: This exists when the frequency of alleles remains the same over generations. The population is not evolving. ...
5.5 Variation and Evolution
5.5 Variation and Evolution

... selection as an outcome. It is as simple as that. ...
Genetics revision for learners
Genetics revision for learners

... Meiosis produces gametes with half the number of chromosomes. This means that pairs of alleles are separated at meiosis. During meiosis matching chromosomes cross over (swap sections of the chromosome) which adds variation. Independent assortment also increases variation as the chromosome pairs rand ...
Variation handout - University of Leicester
Variation handout - University of Leicester

... In natural populations, the organisms that are best suited to their environments are the ones that are most likely to survive and pass their genes onto the next generation. This is natural selection; the fittest organisms are selected and live long enough to reproduce. For one organism to be selecte ...
Genetic Evolution Lecture
Genetic Evolution Lecture

... percentage of one allele in a gene pool. For example, 50% of the alleles might have been B’s, but after the change, it might have dropped to 10%. Recall that only GROUPS can evolve, not individuals. If this is true, then genetic evolution can only occur if there is a change in the allele frequency o ...
BAN 6: Evolution within our Species
BAN 6: Evolution within our Species

... and how they relate to underlying cultural and biological process, and evidence for recent cultural influences on human phenotypes. The Lent term will cover life history variation and how it relates to human adaptability, and the genetic evidence for adaptation within our species, both due to introg ...
Introduction vs Rationale, Writing
Introduction vs Rationale, Writing

... A fundamental and yet unresolved problem in evolutionary biology is the extent to which variability in molecular genetic markers such as allozyme and DNA polymorphisms can be used to estimate genetic variation in ecologically significant traits[i]. This problem is emphasised by geneticists and ecolo ...
Ear Points - also called Darwin`s Point
Ear Points - also called Darwin`s Point

... Check for tiny hairs in this area of your fingers, above the knuckle. ...
Population Genetics 2
Population Genetics 2

... their alleles to next generation, others by chance pass on more than their “fair share” • This effect causes changes in allele frequency between generations - genetic drift • The effect is particularly pronounced in small populations • Given enough time, any allele frequency can drift to 1 (fixation ...
Microevolution involves the evolutionary changes within a population.
Microevolution involves the evolutionary changes within a population.

... reduction in total genetic diversity of the original gene pool. The cheetah bottleneck causes relative infertility because of the intense interbreeding when populations were reduced in earlier times. ...
Evolution Hardy-Weinberg Equilibrium Model
Evolution Hardy-Weinberg Equilibrium Model

... parents: B = .92 and b = .08; in their offspring B= .90 and b = .10 ...
BI0152: Genetic engineering
BI0152: Genetic engineering

... a specific gene can be selected & transferred we don’t need to wait for a mutation to happen naturally to a particular gene- saves time and reduces dependence on ‘chance’ Genes between species can be selected and ...
Biology or Genes?
Biology or Genes?

... • As the size of the founding population increases, the magnitude of the founder effect decreases – A recent estimate of the founding population of Native ...
Mader/Biology, 11/e – Chapter Outline
Mader/Biology, 11/e – Chapter Outline

... a. Gene flow can increase variation within a population by introducing novel alleles produced by mutation in another population. b. Continued gene flow decreases diversity among populations, causing gene pools to become similar. c. Gene flow among populations can prevent speciation from occurring. G ...
Presentation
Presentation

... Genetic Variations are promoted by: mutations gene flow ...
Gene Pools
Gene Pools

... different ways. • You might be able to predict which traits natural selection would favor if you think about the demands of an organism’s environment. ...
12A.G - Illinois State Board of Education
12A.G - Illinois State Board of Education

... REFLECTION DIRECTIONS ...
Sex-Linked Genes
Sex-Linked Genes

... then be wider, for it will intervene between man in a more civilized state, as we may hope, even than the Caucasion, and some ape as low as a baboon, instead of as now between the negro or Australian [aborigine] and the gorilla.” • Charles Darwin, The Descent of Man (New York: A.L. Burt, 1874, 2nd e ...
Gene Pool
Gene Pool

... • DNA can _____________ and these changes are nearly impossible to predict. – DNA mutations are caused by: crossing over, sexual reproduction, basepair changes, mutagens. – Mutations can _________________ or ______________ an individual’s chance of survival. 5) Natural Selection • Allows for the mos ...
Meiosis and Genetic Variation
Meiosis and Genetic Variation

... section ...
The Evolution of Populations
The Evolution of Populations

... EQUILIBRIUM ...
Exam 2 Practice Questions
Exam 2 Practice Questions

... genetic variability from place to place. Viscous populations have low gene flow and high genetic variability across entire range. *Note that inbreeding in a viscous population may lead to reduced genetic variability. ...
BIO 373 Exam 2 Practice Questions
BIO 373 Exam 2 Practice Questions

... genetic variability from place to place. Viscous populations have low gene flow and high genetic variability across entire range. *Note that inbreeding in a viscous population may lead to reduced genetic variability. ...
NAME_______________________________ EXAM
NAME_______________________________ EXAM

... How- Isolation by distance (IBD) shows a pattern of FST values between population pairs show positive correlation with geographic distance between the pairs (i.e) plot FST vs distance Haplotype trees How- IBD shows a pattern of older haplotypes having a larger geographic distributions than younger h ...
Natural Selection and Variation
Natural Selection and Variation

... 8. Struggle for ______. ...
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Human genetic variation



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. On average, in terms of DNA sequence all humans are 99.9% similar to any other humans.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.Causes of differences between individuals include the exchange of genes during meiosis and various mutational events. There are at least two reasons why genetic variation exists between populations. Natural selection may confer an adaptive advantage to individuals in a specific environment if an allele provides a competitive advantage. Alleles under selection are likely to occur only in those geographic regions where they confer an advantage. The second main cause of genetic variation is due to the high degree of neutrality of most mutations. Most mutations do not appear to have any selective effect one way or the other on the organism. The main cause is genetic drift, this is the effect of random changes in the gene pool. In humans, founder effect and past small population size (increasing the likelihood of genetic drift) may have had an important influence in neutral differences between populations. The theory that humans recently migrated out of Africa supports this.The study of human genetic variation has both evolutionary significance and medical applications. It can help scientists understand ancient human population migrations as well as how different human groups are biologically related to one another. For medicine, study of human genetic variation may be important because some disease-causing alleles occur more often in people from specific geographic regions. New findings show that each human has on average 60 new mutations compared to their parents.Apart from mutations, many genes that may have aided humans in ancient times plague humans today. For example, it is suspected that genes that allow humans to more efficiently process food are those that make people susceptible to obesity and diabetes today.
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