The observation that Galapagos finch species possessed different beak shapes to obtain different foods was central to the theory of evolution by natural selection, and it has been assumed that this form-function relationship holds true across all species of bird. (photo at right: puffin finds a use for sand eels,/Stef Bennett, Fotolia)
However, a new study published in the journal Evolution suggests the beaks of birds are not as adapted to the food types they feed on as it is generally believed.
An international team of scientists from the United Kingdom, Spain and the US used computational and mathematical techniques to better understand the connection between beak shapes and functions in living birds.
By measuring beak shape in a wide range of modern bird species from museum collections and looking at information about how the beak is used by different species to eat different foods, the team were able to assess the link between beak shape and feeding behaviour.
Professor Emily Rayfield, from the University of Bristol’s School of Earth Sciences, and senior author of the study, said: “This is, to our knowledge, the first approach to test a long-standing principle in biology: that the beak shape and function of birds is tightly linked to their feeding ecologies.” Paper. (paywall) – Sam Van Wassenbergh, Simon Baeckens. Evolution of shape and leverage of bird beaks reflects feeding ecology, but not as strongly as expected. Evolution, 2019 DOI: 10.1111/evo.13686
Actually, it doesn’t matter what’s true about Darwin’s finches at all. They are a Textbook Icon of Evolution, demonstration natural selection (Darwinism). Now they have even been raised to the status of zombies in school systems:
Response: Darwin’s finches!
Congratulations, you just PASSED the Evolution section in Biology class! 20% of your mark! Just think of all you don’t need to know now…
It may be worth keeping in mind that eating is central to an animal’s staying alive. We might expect that birds would adapt, to whatever extent they can, to foods not especially suited to their beaks when the alternative is starvation. A study of urban wildlife whose ecology revolves around dumpsters and bird feeders will likely provide much evidence for that. See “Can cities serve as cauldrons of evolution (speciation)?”
See also: Researchers: Darwin’s Finches Not Typical Example Of Evolution At All
Darwin’s finches not a good example of Darwinian evolution, but of hybridization
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