Natural selection News

Birds don’t “sacrifice” song for showy plumage, as Darwin thought

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From ScienceDaily :

A study of one of the world’s largest and most colorful bird families has dispelled a long-held notion, first proposed by Charles Darwin, that animals are limited in their options to evolve showiness. The study – the largest of its kind – was published today in the Proceedings of the Royal Society B.

According to the theory,

“Animals have limited resources, and they have to spend those in order to develop showy plumage or precision singing that help them attract mates and defend territories,” said Nick Mason, the paper’s lead author. “So it seems to make sense that you can’t have both. But our study took a more detailed look and suggests that actually, some species can.” Mason did the research as a master’s student at San Diego State University. He is now a Ph.D. student at the Cornell Lab of Ornithology.

Mason and his colleagues tested the idea of trade-offs by looking at a very large family of songbirds from Central and South America, the tanagers. This group consists of 371 species – nearly 10 percent of all songbirds. It includes some of the most spectacularly colorful birds in the world such as the Paradise Tanager as well as more drab birds such the Black-bellied Seedeater. The group also includes both accomplished and weak songsters alike.

And guess what?

The study puts a significant dent in the idea of evolutionary trade-offs between plumage and song. It’s still possible that trade-offs take place at the level of genus, Mason said, or that they influence species relatively fleetingly as evolutionary pressures appear and disappear. But as a broad effect on an entire family of birds, a voice–plumage tradeoff doesn’t seem to exist. One possibility is that the resources needed to develop fancy plumage are different from the ones required for complex songs, freeing tanagers to invest in both forms of showiness simultaneously.

Another possibility is that continuing to rely on Darwin and his followers for insights is a good way to get it wrong.

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4 Replies to “Birds don’t “sacrifice” song for showy plumage, as Darwin thought

  1. 1
    bornagain77 says:

    Birds have been challenging basic Darwinian precepts more and more lately:

    Darwin ‘Wrong’: Species Living Together Does Not Encourage Evolution – December 20, 2013
    Excerpt: Charles Darwin’s theory of evolution set out in the Origin of Species has been proven wrong by scientists studying ovenbirds.
    Researchers at Oxford University found that species living together do not evolve differently to avoid competing with one another for food and habitats – a theory put forward by Darwin 150 years ago.
    The ovenbird is one of the most diverse bird families in the world and researchers were looking to establish the processes causing them to evolve.
    Published in Nature, the research compared the beaks, legs and songs of 90% of ovenbird species.
    Findings showed that while the birds living together were consistently more different than those living apart, this was the result of age differences. Once the variation of age was accounted for, birds that live together were more similar than those living separately – directly contradicting Darwin’s view.
    The species that lived together had beaks and legs no more different than those living apart,,,
    ,,,there is no shortage of evidence for competition driving divergent evolution in some very young lineages. But we found no evidence that this process explains differences across a much larger sample of species.,,,
    He said that the reasons why birds living together appear to evolve less are “difficult to explain”,,

    When Dinosaurs Flew – February 4, 2014
    Excerpt: A study published online by PeerJ on Jan. 2 detailed the examination of a startlingly complete and pristine specimen of an ancient, dinosaur-era bird: Hongshanornis longicresta, which flapped throughout what is now China roughly 125 million years ago during the early Cretaceous Period.
    This particular specimen, discovered a few years ago in rocks from northeastern China, is the latest example of the unexpected diversity of primitive birds that have been unearthed from that part of the world.,,,
    Roughly 90 percent of the skeleton is complete, with wings and tail so finely preserved that the outlines of feathers and what may be dark color bands on the tail can still be seen. That high level of preservation — particularly around the wings and tail — has allowed the team to perform an aerodynamic analysis of the bird, revealing how it likely flew.
    Michael Habib, assistant professor of research at the Keck School of Medicine of USC, analyzed the shape of the wings and tail and determined that the bird “flitted about,” bouncing through the air with bursts of flapping.
    The flying style is far closer to that found in modern birds than what was supposed of ancient flyers — which have been thought to rely more on gliding due to a lack of enough muscle mass in flying appendages to achieve flapping bursts.
    “This isn’t a mode of flight we expected from Cretaceous birds,” Habib said, adding that its small size and overall shape are comparable to that of modern birds. “It was pretty much a Cretaceous starling with a larger tail like a mockingbird.”
    Transported to the modern world, it wouldn’t look like anything special to the casual observer, until a closer examination revealed claws at the end of the bird’s wings and tiny teeth in its beak.,,,

    News for the Birds – May 7, 2014
    Excerpt: Yanornis is called an ancestor of birds, but PhysOrg reported on April 18 that a fossil found in China shows that “the digestive system of the ancestors to modern birds was essentially modern in all aspects.”,,,
    But if it was already “essentially modern” in the ancestors, and already integrated with the flight systems, where is the time for natural selection to have supposedly produced it?

    Darwin’s Finches Show Rule-Constrained Variation in Beak Shape – June 10, 2014
    Excerpt: A simple yet powerful mathematical rule controls beak development, Harvard scientists find, while simultaneously preventing beaks from evolving into something else.,,,
    We find in Darwin’s finches (and all songbirds) an internal system, controlled by a non-random developmental process. It is flexible enough to allow for variation, but powerful enough to constrain the beak to its basic form (a conical shape modulated by scaling and shear) so that the rest of the bird’s structures are not negatively affected. Beak development is controlled by a decay process that must operate at a particular rate. It’s all very precise, so much so that it could be modeled mathematically.,,,
    The very birds that have long been used as iconic examples of natural selection become, on closer examination, paragons of intelligent design.

    As to the concept of evolutionary ‘tradeoffs’, that idea has always seemed to be a two-edged sword which cuts both ways for Darwinists, for instance,

    “This is the issue I have with neo-Darwinists: They teach that what is generating novelty is the accumulation of random mutations in DNA, in a direction set by natural selection. If you want bigger eggs, you keep selecting the hens that are laying the biggest eggs, and you get bigger and bigger eggs. But you also get hens with defective feathers and wobbly legs. Natural selection eliminates and maybe maintains, but it doesn’t create….
    (Quoted in “Discover Interview: Lynn Margulis Says She’s Not Controversial, She’s Right,” Discover Magazine, p. 68 (April, 2011).)

    Darwin tried rather unsuccessfully to solve the problem of the contradictions between his model of random variability and the existence of constraints. He tried to hide this complication citing abundant facts on other phenomena. The authors of the modern versions of Darwinism followed this strategy, allowing the question to persist. …However, he was forced to admit some cases where creating anything humans may wish for was impossible. For example, when the English farmers decided to get cows with thick hams, they soon abandoned this attempt since they perished too frequently during delivery. Evidently such cases provoked an idea on the limitations to variability,,,
    The problem of the constraints on variation was not solved neither within the framework of the proper Darwin’s theory, nor within the framework of modern Darwinism.”

    The problem of constraints (i.e. trade offs) on Darwinian evolution, feeds right into the concept of Irreducible Complexity, in that ‘plasticity of form’, as Darwinists imagine all life to have originated, requires multiple simultaneous changes to be implemented and the same time.

    K´necting The Dots: Modeling Functional Integration In Biological Systems – June 11, 2010
    Excerpt: “If an engineer modifies the length of the piston rods in an internal combustion engine, but does not modify the crankshaft accordingly, the engine won’t start. Similarly, processes of development are so tightly integrated temporally and spatially that one change early in development will require a host of other coordinated changes in separate but functionally interrelated developmental processes downstream” (1)

    And as Behe, Axe, and Gauger etc.. have shown, such multiple coordinated mutations are far beyond the reach of Darwinian processes.

    Supplemental video on ‘colorful’ birds

    Rare Glimpses of Amazing Birds-of-Paradise Courtship Rituals – video playlist

  2. 2
    Dionisio says:

    “One possibility is that the resources needed to develop fancy plumage are different from the ones required for complex songs, freeing tanagers to invest in both forms of showiness simultaneously.”

    How many PhDs and years of research does it take to arrive at such an obvious conclusion?
    Oh, well. What else is new?

  3. 3
    Dionisio says:

    “A study of […] has dispelled a long-held notion, first proposed by Charles Darwin, that…”

    What else is new? Haven’t we read similar statements recently? They might want to use the above quoted text as the standard ‘fill in the blank’ form to issue their research conclusions in the future.
    Anyway, who cares? We mainly enjoy reading the actual information resulting from the research. That’s priceless. Everything else they can charge it on Visa or MasterCard. 😉

  4. 4
    Dionisio says:

    “The study – the largest of its kind – was published today in the Proceedings of the Royal Society B.”

    They just don’t understand ‘n-D evo’ 😉
    They might want to contact “the 3rd. way” for an explanation on the origin of all that stuff. 😉
    In the meantime scientists continue to research the mechanisms behind all those interesting phenotypic features.

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