Darwin's finches have reached their limits on the Galapagos Islands

Press/Media: ResearchAcademic

Description

The evolution of birds on the Galápagos Islands, the cradle of Darwin's theory of evolution, is a two-speed process. Most bird species are still diversifying, while the famous Darwin's finches have already reached an equilibrium, in which new species can only appear when an existing one becomes extinct. This finding expands the classical theory on island evolution put forward in the 1960s. The study is published online on June 23 in Ecology Letters.

Islands are seen as natural laboratories for the study of evolution. They form isolated ecosystems with barriers to migration. Classical Island Theory predicts that a dynamic equilibrium will occur between immigration and extinction of species. Recent theory adds that as species diversity increases, ever more ecological niches become occupied, which has a negative effect on immigration (new immigrants from outside of the Galápagos cannot settle) and diversification (radiation into new species is blocked).

Evolutionary dynamics

'However, this has never been tested in detail, for lack of data and the right analytical tools', explains Rampal Etienne, Associate Professor of Theoretical and Evolutionary Community Ecology at the University of Groningen, the Netherlands. Together with Luis Valente (University of Potsdam, Germany) and Albert Phillimore (University of Edinburgh, UK), he developed DAISIE, a mathematical model that uses phylogenetic data on living species to reconstruct evolutionary dynamics. DAISIE stands for Dynamic Assembly of Islands by Speciation, Immigration and Extinction, and was named after famous radiations of daisy-like plants on Hawaii.

DAISIE was fed with the phylogenetic trees of existing bird species on the Galápagos Islands. These were constructed with genomic data that has become available in recent years. DAISIE then estimates diversity limits and rates of immigration, speciation and extinction per lineage.

'The analysis shows that for the finches, diversity does indeed have a negative effect. There is no more room for new species, unless one of the existing species becomes extinct, so the islands are saturated regarding finch-type species', Etienne explains. This does not mean the radiation is static. 'We found that the rates of both evolution and extinction are very high for Darwin's finches. That is probably why these birds have reached an equilibrium.'

Isolated ecosystems

Other species like mockingbirds have not yet reached equilibrium, which contrasts sharply with the current view that oceanic islands are at equilibrium. 'Our data shows that they are evolving more slowly and are still diversifying.' In a million years or so, more mockingbird species may have appeared -- granted that conditions on the islands remain the same.

The study shows that the DAISIE model -- which the authors have made available as a library* in the free and widely used R software environment -- is a valuable tool for the study of evolutionary dynamics on islands. It includes speciation and thus extends existing island theory, which is based on immigration and extinction. Etienne: 'And of course, it works for all isolated ecosystems, not just islands but also lakes or mountain tops.'

Apart from explaining evolutionary history, DAISIE also predicts future diversity. 'This could be interesting from a conservation point of view: we are not just conserving existing species, but also future diversity.'

*Link to the DAISIE programme: http://cran.r-project.org/web/packages/DAISIE/index.html

 

Story Source:

The above post is reprinted from materials provided by University of Groningen. Note: Materials may be edited for content and length.

Period22-Jun-2015 → 24-Jun-2015

Media coverage

15

Media coverage

  • TitleDarwinvinken 'klaar met evolutie'
    Degree of recognitionNational
    Media name/outletNational Geographic
    Media typePrint
    Country/TerritoryNetherlands
    Date24/06/2015
    Producer/AuthorJamie Schemkes
    URLwww.nationalgeographic.nl/artikel/darwinvinken-klaar-met-evolutie
    PersonsRampal Etienne
  • TitleDarwinvink bereikt limiet op Galápagoseilanden
    Degree of recognitionNational
    Media name/outletOuderen journaal
    Media typeWeb
    Country/TerritoryNetherlands
    Date24/06/2015
    URLwww.ouderenjournaal.nl/home/2015/06/24/darwinvink-bereikt-limiet-op-galapagoseilanden/
    PersonsRampal Etienne
  • TitleGalápagos: as ilhas de Darwin vão ver nascer novas espécies de aves
    Degree of recognitionInternational
    Media name/outletPublico
    Media typeWeb
    Country/TerritoryPortugal
    Date24/06/2015
    DescriptionAs ilhas são territórios pequenos e os cientistas perguntam-se quantas espécies diferentes é que podem existir nestes lugares. Um estudo mostra que as aves terrestres das Galápagos continuam a evoluir e, no futuro, poderá haver novas espécies. Mas há uma excepção, os tentilhões de Darwin.
    Producer/AuthorNicolau Ferreira
    URLwww.publico.pt/ciencia/noticia/galapagos-as-ilhas-de-darwin-vao-ver-nascer-novas-especies-de-aves-1699907
    PersonsRampal Etienne
  • TitleDarwinfinken sind Schnell-Entwickler
    Degree of recognitionInternational
    Media name/outletVBiO
    Media typeWeb
    Country/TerritoryGermany
    Date24/06/2015
    DescriptionDie Evolution der Spezies verläuft auf den Galapagos-Inseln, dem Geburtsort von Darwins Evolutionstheorie, unterschiedlich schnell. Während etliche Vogelfamilien nach wie vor neue, weitere Arten hervorbringen, haben die berühmten Darwinfinken offenbar eine besondere Form des Gleichgewichts erreicht: So entstehen zwar neue Arten, aber nur wenn andere aussterben. Zu diesem überraschenden Schluss kommt ein Forscherteam um Dr. Luis Valente, der derzeit als Humboldt-Stipendiat an der Universität Potsdam zu Gast ist. Die Studie, deren Ergebnisse die klassische Theorie zur Evolution auf Inseln infrage stellen, wird jetzt in Ecology Letters veröffentlicht.
    URLhttps://www.vbio.de/aktuelles/darwinfinken-sind-schnell-entwickler/
    PersonsRampal Etienne
  • TitleEvolutionstheorie von Darwinfinken infrage gestellt
    Degree of recognitionInternational
    Media name/outletPotsdamer Neue Nachrichten
    Duration/Length/SizeGermany
    Date24/06/2015
    Producer/AuthorPNN
    URLwww.pnn.de/campus/980003/
    PersonsRampal Etienne
  • TitleEvolução de pássaros segue ritmos diferentes em Galápagos
    Degree of recognitionInternational
    Media name/outletO Globo
    Media typeWeb
    Country/TerritoryBrazil
    Date23/06/2015
    DescriptionPesquisa indica que enquanto populações dos simbólicos tentilhões-de-Darwin atingiram equilíbrio, outras espécies de aves ainda passam por transformações no arquipélago
    Producer/AuthorCesar Baima
    URLoglobo.globo.com/sociedade/ciencia/evolucao-de-passaros-segue-ritmos-diferentes-em-galapagos-16520917
    PersonsRampal Etienne
  • TitleDarwin’s finches reach their limits on Galápagos
    Degree of recognitionInternational
    Media name/outletRedOrbit
    Media typeWeb
    Country/TerritoryUnited States
    Date23/06/2015
    DescriptionDarwin's finches are a group of 15 different bird species that Charles Darwin famously based his theories of evolution on. However, there's no more room on the island for the development of new species.
    Producer/AuthorBrett Smith
    URLwww.redorbit.com/news/science/1113405097/darwins-finches-reach-their-limits-on-galapagos-062315/
    PersonsRampal Etienne
  • TitleDarwin's finches have reached their limits on the Galápagos
    Degree of recognitionInternational
    Media name/outletEurekAlert!
    Media typeWeb
    Country/TerritoryUnited States
    Date23/06/2015
    DescriptionThe evolution of birds on the Galápagos Islands, the cradle of Darwin's theory of evolution, is a two-speed process. Most bird species are still diversifying, while the famous Darwin's finches have already reached an equilibrium, in which new species can only appear when an existing one becomes extinct. This finding expands the classical theory on island evolution put forward in the 1960s. The study is published online on June 23 in Ecology Letters.
    Producer/AuthorUniversity of Groningen
    URLwww.eurekalert.org/pub_releases/2015-06/uog-dfh062215.php
    PersonsRampal Etienne
  • TitleDarwin’s finches offer fresh insights
    Degree of recognitionInternational
    Media name/outletDeadline News
    Media typeWeb
    Country/TerritoryUnited Kingdom
    Date23/06/2015
    DescriptionA bird family that helped Charles Darwin devise his famed theory has offered new insight into island biodiversity thanks to a study from Edinburgh University.
    Producer/AuthorJoe Stenson
    URLwww.deadlinenews.co.uk/2015/06/23/darwins-finches-offer-fresh-insights/
    PersonsRampal Etienne
  • TitleDarwinfinken sind Schnell-Entwickler
    Degree of recognitionInternational
    Media name/outletInnovations Report
    Media typeWeb
    Country/TerritoryGermany
    Date23/06/2015
    DescriptionDie Evolution der Spezies verläuft auf den Galapagos-Inseln, dem Geburtsort von Darwins Evolutionstheorie, unterschiedlich schnell. Während etliche Vogelfamilien nach wie vor neue, weitere Arten hervorbringen, haben die berühmten Darwinfinken offenbar eine besondere Form des Gleichgewichts erreicht.
    Producer/AuthorMatthias Zimmermann - Universität Potsdam
    URLwww.innovations-report.de/html/berichte/biowissenschaften-chemie/darwinfinken-sind-schnell-entwickler.html
    PersonsRampal Etienne
  • Title Darwin's finches have reached their limits on the Galapagos Islands
    Degree of recognitionInternational
    Media name/outletPhys.org
    Media typeWeb
    Country/TerritoryUnited Kingdom
    Date23/06/2015
    DescriptionThe evolution of birds on the Galápagos Islands, the cradle of Darwin's theory of evolution, is a two-speed process. Most bird species are still diversifying, while the famous Darwin's finches have already reached an equilibrium, in which new species can only appear when an existing one becomes extinct. This finding expands the classical theory on island evolution put forward in the 1960s. The study is published online on June 23 in Ecology Letters.
    Producer/AuthorUniversity of Groningen
    URLphys.org/news/2015-06-darwin-finches-limits-galapagos.html
    PersonsRampal Etienne
  • TitleDarwin's finches have reached their limits on the Galapagos Islands
    Degree of recognitionInternational
    Media name/outletSciFeeds
    Media typeWeb
    Country/TerritoryUnited States
    Date23/06/2015
    DescriptionThe evolution of birds on the Galapagos Islands, the cradle of Darwin's theory of evolution, is a two-speed process. Most bird species are still diversifying, while the famous Darwin's finches have already reached an equilibrium, in which new species can only appear when an existing one becomes extinct. This finding expands the classical theory on island evolution put forward in the 1960s.
    Producer/AuthorUniversity of Groningen
    URLscifeeds.com/news/darwins-finches-have-reached-their-limits-on-the-galapagos/
    PersonsRampal Etienne
  • TitleDarwin's finches have reached their limits on the Galapagos Islands
    Degree of recognitionInternational
    Media name/outletScienceDaily
    Media typeWeb
    Country/TerritoryUnited States
    Date23/06/2015
    DescriptionThe evolution of birds on the Galapagos Islands, the cradle of Darwin's theory of evolution, is a two-speed process. Most bird species are still diversifying, while the famous Darwin's finches have already reached an equilibrium, in which new species can only appear when an existing one becomes extinct. This finding expands the classical theory on island evolution put forward in the 1960s.
    Producer/AuthorUniversity of Groningen
    URLhttps://www.sciencedaily.com/releases/2015/06/150623072242.htm
    PersonsRampal Etienne
  • TitleDarwin's finches have reached their limits on the Galapagos Islands
    Degree of recognitionInternational
    Media name/outletScience Newsline
    Media typeWeb
    Country/TerritoryUnited States
    Date23/06/2015
    DescriptionThe evolution of birds on the Galapagos Islands, the cradle of Darwin's theory of evolution, is a two-speed process. Most bird species are still diversifying, while the famous Darwin's finches have already reached an equilibrium, in which new species can only appear when an existing one becomes extinct. This finding expands the classical theory on island evolution put forward in the 1960s.
    Producer/AuthorUniversity of Groningen
    URLwww.sciencenewsline.com/summary/2015062314370040.html
    PersonsRampal Etienne
  • TitleEvolução de pássaros segue ritmos diferentes em Galápagos
    Degree of recognitionInternational
    Media name/outletPortal do Holanda
    Media typeWeb
    Country/TerritoryBrazil
    Date22/06/2015
    URLwww.portaldoholanda.com.br/ciencia/evolucao-de-passaros-segue-ritmos-diferentes-em-galapagos
    PersonsRampal Etienne

Media contributions

1

Media contributions