• Study Resource
  • Explore Categories
    • Arts & Humanities
    • Business
    • Engineering & Technology
    • Foreign Language
    • History
    • Math
    • Science
    • Social Science

    Top subcategories

    • Advanced Math
    • Algebra
    • Basic Math
    • Calculus
    • Geometry
    • Linear Algebra
    • Pre-Algebra
    • Pre-Calculus
    • Statistics And Probability
    • Trigonometry
    • other →

    Top subcategories

    • Astronomy
    • Astrophysics
    • Biology
    • Chemistry
    • Earth Science
    • Environmental Science
    • Health Science
    • Physics
    • other →

    Top subcategories

    • Anthropology
    • Law
    • Political Science
    • Psychology
    • Sociology
    • other →

    Top subcategories

    • Accounting
    • Economics
    • Finance
    • Management
    • other →

    Top subcategories

    • Aerospace Engineering
    • Bioengineering
    • Chemical Engineering
    • Civil Engineering
    • Computer Science
    • Electrical Engineering
    • Industrial Engineering
    • Mechanical Engineering
    • Web Design
    • other →

    Top subcategories

    • Architecture
    • Communications
    • English
    • Gender Studies
    • Music
    • Performing Arts
    • Philosophy
    • Religious Studies
    • Writing
    • other →

    Top subcategories

    • Ancient History
    • European History
    • US History
    • World History
    • other →

    Top subcategories

    • Croatian
    • Czech
    • Finnish
    • Greek
    • Hindi
    • Japanese
    • Korean
    • Persian
    • Swedish
    • Turkish
    • other →
 
Profile Documents Logout
Upload
BLY 303 Lecture Notes, Guest Lecture 10/27/11 (O`Brien) Patterns in
BLY 303 Lecture Notes, Guest Lecture 10/27/11 (O`Brien) Patterns in

... populations, genetic drift is a common occurrence b. Frequencies of alleles that are rare in the original population can dominate even though they offer no known selective ...
File
File

Deducing genotypes - Life is a journey: Mr. T finding his way
Deducing genotypes - Life is a journey: Mr. T finding his way

... Deducing genotypes IB Biology Jin Young Huh ...
File
File

... Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. ...
Study Guide
Study Guide

...  Today we define evolutionary change on it smallest scale as microevolution. Microevolution is change in the genetic makeup of a population from generation to generation. It refers to adaptations that are confined to a single gene pool.  New genes and new alleles originate only by mutations, which ...
Early Earth and Evolution
Early Earth and Evolution

... • May result in changes in allele frequencies and evolution of a population – Allele which increases fitness of organism becomes more common – Allele which decreases fitness of an organisms becomes less common and may ultimately ...
Natural Selection
Natural Selection

Genetics-KEY
Genetics-KEY

... Describes an organism that on being crossed with a member of the same strain always produces more organism of exactly the same strain ...
Evol unit: part 1
Evol unit: part 1

... This can result in speciation. 1.5 It can also lead to adaptive radiation, where species adapt to a variety of habitats and evolve into diverse forms ...
Chap. 23 Evolution of Populations
Chap. 23 Evolution of Populations

... phenotypes in a population  Many organisms have limited mobility and remain near their place of birth, hatching, or germination, increasing the likelihood of inbreeding  In animals, nonrandom mating can arise if individuals have preferences that influence their choice of mates  Nonrandom mating m ...
the Note
the Note

Worksheet B1a 1 - Sackville School
Worksheet B1a 1 - Sackville School

... Start by carrying out an Internet search and place any useful information into a word processing document. Then start your PowerPoint presentation. Make it colourful and include diagrams and pictures. Look at this website to get you started: http://gslc.genetics.utah.edu/features/gmfoods/ ...
Natural Selection Bio.3.4.2 Explain how natural selection influences
Natural Selection Bio.3.4.2 Explain how natural selection influences

... Bio.3.4.2 Explain how natural selection influences the changes in species over time • Develop a cause and effect model for the process of natural selection:  Species have the potential to increase in numbers exponentially.  Populations are genetically variable due to mutations and genetic recombin ...
Homework outline
Homework outline

... Describe why evolution applies to and acts upon populations of organisms and not individuals. ...
word - marric.us
word - marric.us

Take Home Quiz- Genetics 1. A partial Punnett square is shown
Take Home Quiz- Genetics 1. A partial Punnett square is shown

... D. One parent is homozygous dominant and the other parent is heterozygous. 2. In fruit flies, the gene for eye color is located on the X chromosome, and the red eye allele (R) is dominant to the white eye allele (r). A female fly with genotype XRXr is mated with a male fly with genotype XrY. Which o ...
Boissinot - QC Queens College
Boissinot - QC Queens College

... genetic elements called transposable elements or “jumping genes”. Although most transposable elements impose a genetic load on their host they can also be a rich source of evolutionary novelties. However, it is unknown why some species like human have more than 3 millions of these elements whereas m ...
abt.2017.79.2.128
abt.2017.79.2.128

... 2. Mutation occurs when there is a change in DNA sequence. This can result in change from one allele to another. 3. Natural selection occurs when individuals with one phenotype survive and reproduce at a greater rate than individuals with a different phenotype. 4. Random genetic drift is the effect ...
File - Bunse Biology
File - Bunse Biology

Genetics Notes
Genetics Notes

... Ex: Purple-flowering plant only has purpleflowered offspring ...
Exam 3 Review material
Exam 3 Review material

Evolution - Fall River Public Schools
Evolution - Fall River Public Schools

... Natural selection is not the only source of evolutionary change. Mutations, migration, genetic drift, and nonrandom mating can also result in evolution. In small populations, individuals that carry a particular allele may leave more descendants than other individuals, just by chance. Over time, a se ...
Chapter 15: Temporal and Spatial Dynamics of Populations
Chapter 15: Temporal and Spatial Dynamics of Populations

... success non-random. The conditions set up by the Hardy-Weinberg Law allow for variability (the existence of different alleles) and inheritance, but they eliminate natural selection. The fact that no evolution occurs in a population meeting these conditions proves that ...
01 Microevolution Unique Gene Pools and Genetic Variation NMSI
01 Microevolution Unique Gene Pools and Genetic Variation NMSI

... Microevolution is simply a change in gene frequency within a population. • Evolution at this scale can be observed over short periods of time such as from one generation to the next. • Example: The frequency of a gene for pesticide resistance in a population of crop pests increases. • Such a change ...
Genetic Justice
Genetic Justice

... will be realised; - the severity of these harms • - the likelihood that intervention will have the desired results; - the costs of intervention and the magnitude of benefits (if realised) • - the safety, efficacy and costs of other forms of ...
< 1 ... 392 393 394 395 396 397 398 399 400 ... 511 >

Genetic drift



Genetic drift (or allelic drift) is the change in the frequency of a gene variant (allele) in a population due to random sampling of organisms.The alleles in the offspring are a sample of those in the parents, and chance has a role in determining whether a given individual survives and reproduces. A population's allele frequency is the fraction of the copies of one gene that share a particular form. Genetic drift may cause gene variants to disappear completely and thereby reduce genetic variation.When there are few copies of an allele, the effect of genetic drift is larger, and when there are many copies the effect is smaller. In the early twentieth century vigorous debates occurred over the relative importance of natural selection versus neutral processes, including genetic drift. Ronald Fisher, who explained natural selection using Mendelian genetics, held the view that genetic drift plays at the most a minor role in evolution, and this remained the dominant view for several decades. In 1968, Motoo Kimura rekindled the debate with his neutral theory of molecular evolution, which claims that most instances where a genetic change spreads across a population (although not necessarily changes in phenotypes) are caused by genetic drift. There is currently a scientific debate about how much of evolution has been caused by natural selection, and how much by genetic drift.
  • studyres.com © 2026
  • DMCA
  • Privacy
  • Terms
  • Report