関連する実験動画
Updated: Jul 6, 2026

08:16
Experimental Protocol for Manipulating Plant-induced Soil Heterogeneity
Published on: March 13, 2014
有限な集団における協力と進化の安定の出現
Martin A Nowak1, Akira Sasaki, Christine Taylor
1Program for Evolutionary Dynamics, Harvard University, Cambridge, Massachusetts 02138, USA. martin_nowak@harvard.edu
Nature
|April 9, 2004
まとめ
自然選択は,有限な集団における協力を好むことができる. 一人の協力者でさえ,対抗策のような戦略を用いて,脱走者の集団を侵略することができ,協力の進化の道を示しています.
科学分野:
- 進化生物学の進化生物学について
- ゲーム理論はゲーム理論である.
- 人口の動態
背景:
- 自然選択による協力の進化を説明することは,長年の生物学的課題です.
- 協力者は他者を助けるために費用を負い,脱走者は互恵なしに利益を得る.
- 囚人のジレンマは,協力者と脱走者の間の相互作用をモデル化していますが,脱走者は通常,無限の集団で協力者による侵略に抵抗します.
研究 の 目的:
- 有限な集団における協力の進化的ゲームダイナミクスを調査する.
- 自然選択が協力的な戦略の出現を促す条件を特定する.
- 進化の安定性を,有限な集団の文脈で再定義する.
主な方法:
- 有限な集団における進化的ゲームダイナミクスの分析.
- 脱北者の集団に単一の協力者の侵入確率をモデル化する.
- "目と目"のような戦略の検討.
主要な成果:
- "目と目と"のような戦略を用いた1人の協力者は,脱走者の集団を侵略することができます.
- この侵入は,純選択的優位性に関連した確率で発生します.
- 有限な集団における協力を促進する自然選択の条件を特定した.
結論:
- 協力は,有限な集団で発生し,進化的に安定し,無限な集団での発見とは対照的です.
- 有限の人口動態は,協同戦略の初期拡散のためのメカニズムを提供します.
- この研究は,有限な集団の進化的安定性を再定義し,協力の起源に関する新しい洞察を提供している.
関連する概念動画
Formation of Species
Speciation describes the formation of one or more new species from one or sometimes multiple original species. The resulting species are discrete from the parent species, and barriers to reproduction will typically exist. There are two primary mechanisms, speciation with and without geographic isolation—allopatric and sympatric speciation, respectively.Allopatric SpeciationIn allopatric speciation, gene flow between two populations of the same species is prevented by a geographic barrier, like...
Speciation Rates
Speciation can proceed at markedly different rates, and evolutionary biologists commonly describe these differences through the models of gradualism and punctuated equilibrium. Both patterns explain how new species arise, but they differ in the tempo and continuity of evolutionary change. In both cases, evolutionary change arises from heritable variation within populations, with natural selection often shaping traits that improve survival and reproduction under specific environmental conditions.
Types of Selection
Natural selection influences the frequencies of particular alleles and phenotypes within populations in several different ways. Primarily, natural selection can be directional, stabilizing, or disruptive. Directional selection favors one extreme trait and shifts the population towards that phenotype while selecting against individuals displaying alternate traits. Stabilizing selection favors an intermediate trait with a narrow range of variation. Deviation from the optimal phenotype towards an...
Mutation, 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,...
Competition
When organisms require the same limited resources within an environment, they may have to compete for them. Competition is a net-negative interaction. Even if two competing individuals or populations do not interact directly, the overall fitness of both competitors is lowered as a result of not having full access to the limited resource.Intraspecific competition, which occurs between individuals of the same species, serves as a natural mechanism for regulating population size. Too much...
Hybrid Zones
Hybrid zones are narrow regions where two closely related species interact, mate, and produce hybrids. Relative to either parent species, hybrids may possess distinct phenotypic or genetic differences that impact their survival and reproductive success. The genetic variances introduced by hybridization influence species diversity and speciation processes within the hybrid zone.Gene flow and natural selection are evolutionary mechanisms that shape the outcome of a hybrid zone. Gene flow...

