JoVE - Journal of Visualized Experiments
JoVE Visualize
Contact Us
このページは機械翻訳されています。他のページは英語で表示される場合があります。 View in English

人類時代における遺伝的多様性の減少

  • 0Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA.
Clinical Neuroscience (new York, N.y.) +

|

2022年9月22日

PubMedで要約を見る

まとめ

この要約は機械生成です。

関連する概念動画

Threats to Biodiversity 01:50

22.7K

There have been five major extinction events throughout geological history, resulting in the elimination of biodiversity, followed by a rebound of species that adapted to the new conditions. In the current geological epoch, the Holocene, there is a sixth extinction event in progress. This mass extinction has been attributed to human activities and is thus provisionally called the Anthropocene. In 2019 the human population reached 7.7 billion people and is projected to comprise 10 billion by...

Mutation, Gene Flow, and Genetic Drift 01:09

59.3K

In a population that is not at Hardy-Weinberg equilibrium, the frequency of alleles changes over time. Therefore, any deviations from the five conditions of Hardy-Weinberg equilibrium can alter the genetic variation of a given population. Conditions that change the genetic variability of a population include mutations, natural selection, non-random mating, gene flow, and genetic drift (small population size).

Mechanisms of Genetic Variation

The original sources of genetic variation are...

Genetic Drift 03:33

40.5K

Natural selection—probably the most well-known evolutionary mechanism—increases the prevalence of traits that enhance survival and reproduction. However, evolution does not merely propagate favorable traits, nor does it always benefit populations.

Life is not fair. A deer grazing contentedly in a field can have her meal cut tragically short by a bolt of lightning. If the doomed doe is one of only three in the population, 1/3 of the population’s gene pool is lost. Random...

Biodiversity and Human Values 01:24

13.3K

Human civilization relies on biodiversity in many ways. Sudden changes in species biodiversity result in environmental changes that can modify weather patterns and therefore human civilizations.

Humans are dependent on agriculture, which developed when ancestral humans found species that made suitable foods. At least 11,000 years ago, humans started to select plant and animal species to be cultivated on farms. Going back for thousands of years, humans have been artificially selecting species...

Gene Flow 02:39

35.4K

Gene flow is the transfer of genes among populations, resulting from either the dispersal of gametes or from the migration of individuals.

This phenomenon plays a significant evolutionary role in all organisms, and depending on the rates of gene flow, the mechanism either induces genetic diversity or generates genetic homogeneity among populations. When the rate of gene flow is low, the introduction of new alleles into a population generates genetic diversity. On the other hand, a high rate of...

Genetic Variation 01:25

362

Genetic variation is the diversity in DNA sequences found among individuals of the same species. This diversity is crucial for a species' survival because it helps organisms adapt to environmental changes. Genetic variation begins with fertilization, where an egg and sperm cell merge. Each of these cells carries 23 chromosomes, up to 46 in the fertilized egg. Chromosomes are long DNA strands that contain genes, the basic units of heredity.
Genes exist in different versions called alleles,...