Evolution of Character Displacement in Darwin's Finches

@article{Grant2006EvolutionOC,
  title={Evolution of Character Displacement in Darwin's Finches},
  author={Peter R. Grant and Barbara Rosemary Grant},
  journal={Science},
  year={2006},
  volume={313},
  pages={224 - 226}
}
Competitor species can have evolutionary effects on each other that result in ecological character displacement; that is, divergence in resource-exploiting traits such as jaws and beaks. [] Key Result The observed evolutionary response to natural selection was the strongest recorded in 33 years of study, and close to the value predicted from the high heritability of beak size. These findings support the role of competition in models of community assembly, speciation, and adaptive radiations.
Reproductive isolation of sympatric morphs in a population of Darwin's finches
TLDR
It is demonstrated that the two morphs show strong positive assortative pairing, a pattern that holds over three breeding seasons and during both dry and wet conditions, and provides strong support for the central role of ecology during the early stages of adaptive radiation.
Fission and fusion of Darwin's finches populations
  • B. Grant, P. Grant
  • Biology
    Philosophical Transactions of the Royal Society B: Biological Sciences
  • 2008
TLDR
It is proposed that introgression has the largest effect on the evolution of interbreeding species after they have diverged in morphology, but before the point is reached when genetic incompatibilities incur a severe fitness cost.
Experimental demonstration of ecological character displacement
TLDR
This accordion-like dynamic provides direct experimental evidence that competition for resources can cause evolutionary shifts in resource-related characters.
Disruptive selection in a bimodal population of Darwin's finches
TLDR
Analysis of patterns of selection in the medium ground finch of El Garrapatero, Santa Cruz Island, Galápagos suggests a dynamic tug of war among factors such as selection and assortative mating, which may alternatively promote or constrain divergence during adaptive radiation.
Character Displacement and the Origins of Diversity
TLDR
The empirical support for Darwin’s principle of divergence of character is examined, specifically that (1) competition promotes divergent trait evolution, (2) the strength of competitively mediated divergent selection increases with increasing phenotypic similarity between competitors, (3) divergence can occur within species, and (4)competitively mediated divergence can trigger speciation.
Evolutionary Dead End in the Galápagos: Divergence of Sexual Signals in the Rarest of Darwin's Finches
TLDR
Striking differences in mating signals, morphology and genetics between the two remnant populations of Darwin's mangrove finch Camarhynchus heliobates are reported, and it is shown that territorial males exhibited strong discrimination of sexual signals by locality.
Rapid evolution of a native species following invasion by a congener
TLDR
On small islands in Florida, it is found that the lizard Anolis carolinensis moved to higher perches following invasion by Anolis sagrei and, in response, adaptively evolved larger toepads after only 20 generations, illustrating that interspecific interactions between closely related species can drive evolutionary change on observable time scales.
Ecological and morphological determinants of evolutionary diversification in Darwin's finches and their relatives
TLDR
Analysis of the evolutionary dynamics of speciation and trait diversification in Thraupidae illustrates how the exploitation of ecological opportunity by contrasting means can produce clades with similarly high diversification rate yet strikingly different degrees of ecological and morphological differentiation.
Darwin's finches and their diet niches: the sympatric coexistence of imperfect generalists
TLDR
The results together suggest that the ground finches are ‘imperfect generalists’ that use overlapping resources under benign conditions, but then retreat to resources for which they are best adapted during periods of food limitation, which likely promote local and regional coexistence.
A beak size locus in Darwin’s finches facilitated character displacement during a drought
TLDR
A genome-wide analysis in finches identifies loci associated with parallel size variation in the Galápagos and discovered a genomic region containing the HMGA2 gene that varies systematically among Darwin’s finch species with different beak sizes.
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Character displacement resulting from interspecific competition has been extremely difficult to demonstrate, but a study of Darwin's ground finches provides strong evidence for character displacement.
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