関連する実験動画
Updated: Jul 11, 2026
06:03
Procedure for Adaptive Laboratory Evolution of Microorganisms Using a Chemostat
Published on: September 20, 2016
ダーウィンのフィンチの30年間の研究における予測不能な進化
Peter R Grant1, B Rosemary Grant
1Department of Ecology and Evolutionary Biology, Princeton University, Washington Road, Princeton, NJ 08544-1003, USA. prgrantprinceton.edu.
Science (New York, N.Y.)
|April 27, 2002
まとめ
短期的な進化は予測可能ですが,長期的な進化軌道は環境の変動により予測不可能です. ダーウィンのフィンチに関するこの研究は,30年間にわたって予測可能と予測不可能の両方の進化的変化を示しています.
科学分野:
- 進化生物学の進化生物学について
- エコロジー エコロジー エコロジー
- 鳥類学 鳥類学とは,鳥類学である.
背景:
- 進化の変化は,選択と遺伝に基づいて短期的に予測することができます.
- 長期進化は,選択圧力に影響を与える変動する環境条件のために本質的に予測不可能です.
研究 の 目的:
- 30年間の進化の予測可能と予測不能の側面を調査する.
- 環境の変化に反応するダーウィンのフィンチの体サイズとの特徴の変化を記録する.
主な方法:
- ダフネ・メジャー島にある2種のフィンチ (Geospiza fortisとGeospiza scandens) の長期的な生態学的モニタリング.
- 体のサイズとの形状における現象的変化の分析.
- ハイブリダイゼーションを含む自然選択現象の観察と,その集団遺伝学への影響.
主要な成果:
- Geospiza fortisとGeospiza scandensの両方とも,30年以上にわたり,体サイズとの特徴に大きな変化を示した.
- 自然淘汰は方向と強度によって様々であり,単方向から振動性,エピソード性から漸進性まで様々であった.
- 希少なハイブリッド化イベントは,ゲオスピザスカンデンの現象的変異の増大との形の変化をもたらした.
結論:
- この研究は,短期的な選択の知識があるにもかかわらず,長期的な進化的結果の予測不可能性を強調しています.
- 継続的な長期的な生態学的研究は,希少な進化的現象と非均一な進化的変化を理解するために不可欠です.
- 環境の予測不能性は,ダーウィンのフィンチにおける長期的な進化の予測不能性の主要な原動力である.
関連する概念動画
01:49Hardy-Weinberg Principle
Diploid organisms have two alleles of each gene, one from each parent, in their somatic cells. Therefore, each individual contributes two alleles to the gene pool of the population. The gene pool of a population is the sum of every allele of all genes within that population and has some degree of variation. Genetic variation is typically expressed as a relative frequency, which is the percentage of the total population that has a given allele, genotype or phenotype.In the early 20th century,...
01:38Limits to Natural Selection
Organisms that are well-adapted to their environment are more likely to survive and reproduce. However, natural selection does not lead to perfectly adapted organisms. Several factors constrain natural selection.For one, natural selection can only act upon existing genetic variation. Hypothetically, redtusks may enhance elephant survival by deterring ivory-seeking poachers. However, if there are no gene variants—or alleles—for redtusks, natural selection cannot increase the prevalence of...
03:33Genetic Drift
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 events like this can...
02:05Gene Evolution - Fast or Slow?
The genomes of eukaryotes are punctuated by long stretches of sequence which do not code for proteins or RNAs. Although some of these regions do contain crucial regulatory sequences, the vast majority of this DNA serves no known function. Typically, these regions of the genome are the ones in which the fastest change, in evolutionary terms, is observed, because there is typically little to no selection pressure acting on these regions to preserve their sequences.
In contrast, regions which code...
In contrast, regions which code...
02:05Gene Evolution - Fast or Slow?
The genomes of eukaryotes are punctuated by long stretches of sequence which do not code for proteins or RNAs. Although some of these regions do contain crucial regulatory sequences, the vast majority of this DNA serves no known function. Typically, these regions of the genome are the ones in which the fastest change, in evolutionary terms, is observed, because there is typically little to no selection pressure acting on these regions to preserve their sequences.
In contrast, regions which code...
In contrast, regions which code...
01:24Evolution of New Traits in Microbes
Microorganisms evolve rapidly due to their large population sizes and short generation times, often exhibiting measurable changes within days under laboratory conditions. Natural selection acts on standing genetic variation, enabling the retention and amplification of beneficial traits that confer fitness advantages in changing environments.Adaptive Pigment Regulation in RhodobacterIn Rhodobacter, a genus of purple non-sulfur bacteria, light-harvesting pigments such as bacteriochlorophyll and...