関連する実験動画
Updated: Jun 23, 2026
06:01
Collecting Hair Samples for Hair Cortisol Analysis in African Americans
Published on: June 10, 2018
アフリカ人とアフリカ系アメリカ人の遺伝的構造と歴史
Sarah A Tishkoff1, Floyd A Reed, Françoise R Friedlaender
1Department of Biology, University of Maryland, College Park, MD 20742, USA. tishkoff@mail.med.upenn.edu
Science (New York, N.Y.)
|May 2, 2009
まとめ
アフリカにおける遺伝的多様性は,14の祖先集団を明らかにし,ほとんどの集団は,歴史的な移住による混合祖先を示しています. この研究は,アフリカとアフリカ系アメリカ人の進化の歴史を明らかにします.
科学分野:
- 人間の起源と進化について
- 人口遺伝学 人口遺伝学
- アントロポロジー人類学
背景:
- アフリカは,すべての現代人の起源ですが,その人口の遺伝的多様性と,人口間の関係については,まだ完全に理解されていません.
- アフリカの集団における遺伝的多様性を特徴づけることは,人間の進化史と移住パターンを理解するために極めて重要です.
研究 の 目的:
- アフリカの多様な集団における遺伝的多様性と人口構造を包括的に特徴づけること.
- アフリカ人とアフリカ系アメリカ人の祖先と混合パターンを調査する.
- アフリカにおける人類の起源の複雑な進化の歴史についての洞察を提供するためです.
主な方法:
- 121人のアフリカ人,4人のアフリカ系アメリカ人,60人の非アフリカ人集団の1327人の核マイクロサテライトと挿入/削除マーカーの分析.
- 集団遺伝的方法を用いた祖先集団のクラスターの識別.
- アフリカ系アメリカ人における添加物比の定量化.
主要な成果:
- アフリカの14の異なる祖先の集団を特定し,民族と言語的/文化的特性と相関する.
- 歴史的な移住の指標であるアフリカの人口全体に広範囲にわたる混合祖先の観察.
- 地理的に分散した狩猟採集者集団 (ホエサ語話者とピグミー族) の共通の祖先の証拠.
- アフリカ系アメリカ人における支配的な祖先の決定: ~71%のニジェール・コルドーファニア人, ~13%のヨーロッパ人, ~8%の他のアフリカ人,個々の違いが大きい.
結論:
- この研究は,アフリカの人口の複雑な遺伝的景観とその歴史的関係を解明します.
- この発見は,アフリカの進化史,移住,混合のより深い理解に貢献します.
- このデータは,アフリカ人およびアフリカ系アメリカ人の人口の詳細な遺伝的枠組みを提供することによって,人類学および遺伝的疫学研究をサポートしています.
関連する概念動画
01:27Principles of Pharmacogenetics: Types of Genetic Variants
The human genome is over 99.9% identical between individuals, yet genetic differences exist at millions of bases. The human genome contains approximately 3 million variant positions per individual, many of which are heterozygous, contributing to genetic diversity and individual traits. Genetic variations include single-nucleotide polymorphisms (SNPs), insertions, deletions, and copy number variations (CNVs).SNPs, the most common variation, involve single-base changes in DNA. These can be...
02:31Synteny and Evolution
John H. Renwick first coined the term “synteny” in 1971, which refers to the genes present on the same chromosomes, even if they are not genetically linked. The species with common ancestry tend to show conserved syntenic regions. Therefore, the concept of synteny is nowadays used to describe the evolutionary relationship between species.
Around 80 million years ago, the human and mice lineages diverged from the common ancestor. During the course of evolution, the ancestral chromosome underwent...
Around 80 million years ago, the human and mice lineages diverged from the common ancestor. During the course of evolution, the ancestral chromosome underwent...
02:54Evolutionary Relationships through Genome Comparisons
Genome comparison is one of the excellent ways to interpret the evolutionary relationships between organisms. The basic principle of genome comparison is that if two species share a common feature, it is likely encoded by the DNA sequence conserved between both species. The advent of genome sequencing technologies in the late 20th century enabled scientists to understand the concept of conservation of domains between species and helped them to deduce evolutionary relationships across diverse...
01:25Genetic Variation
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, which...
Genes exist in different versions called alleles, which...
01:09Mutation, Gene Flow, and Genetic Drift
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 VariationThe original sources of genetic variation are mutations,...
01:25What is Population Genetics?
A population is composed of members of the same species that simultaneously live and interact in the same area. When individuals in a population breed, they pass down their genes to their offspring. Many of these genes are polymorphic, meaning that they occur in multiple variants. Such variations of a gene are referred to as alleles. The collective set of all the alleles within a population is known as the gene pool.While some alleles of a given gene might be observed commonly, other variants...