Convergent evolution News

Convergent evolution of turtle shells?

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So this abstract for AAAS’s current Science seems to imply:

Crocodiles and armadillos armor themselves in an exoskeleton of bony plates, but the turtle goes a step further with a shell that is anchored to its rib cage and spine, making it part of its internal skeleton. Just how the developing turtle embryo builds its fortress—a feat unique among vertebrates—is unclear. But two scenarios are now vying to explain this major evolutionary puzzle. Until recently, many biologists thought that the turtle shell takes shape from skin cells adjacent to the ribs that are transformed into bone in the course of development. But Japanese developmental biologists have now weighed in with a new scenario, in which the shell is a direct outgrowth of bones themselves. Researchers trying to reach consensus about how the shell develops have concluded that turtles may have more than one way to build a turtle shell.

The nice thing about convergent evolution is that they may all be right, each about his own species. The less nice thing about it for current Darwinian theory is that it is more consistent with guided evolution or some other teleological form.

Here’s one approach:

7 Replies to “Convergent evolution of turtle shells?

  1. 1
    lifepsy says:

    Compilation of examples of “convergent evolution”
    From major body types to biochemical functions.

    A Celebration of Convergent Evolution
    compiled by Connie Barlow

  2. 2
    bornagain77 says:

    lifepsy, Neat!

  3. 3
    bornagain77 says:

    Of somewhat related interest, ‘coincidental’, i.e. convergent, scientific discoveries are far more prevalent than what would be expected from a materialistic/atheistic perspective,:

    In the Air – Who says big ideas are rare? by Malcolm Gladwell
    Excerpt: This phenomenon of simultaneous discovery—what science historians call “multiples”—turns out to be extremely common. One of the first comprehensive lists of multiples was put together by William Ogburn and Dorothy Thomas, in 1922, and they found a hundred and forty-eight major scientific discoveries that fit the multiple pattern. Newton and Leibniz both discovered calculus. Charles Darwin and Alfred Russel Wallace both discovered evolution. Three mathematicians “invented” decimal fractions. Oxygen was discovered by Joseph Priestley, in Wiltshire, in 1774, and by Carl Wilhelm Scheele, in Uppsala, a year earlier. Color photography was invented at the same time by Charles Cros and by Louis Ducos du Hauron, in France. Logarithms were invented by John Napier and Henry Briggs in Britain, and by Joost Bürgi in Switzerland. ,,, For Ogburn and Thomas, the sheer number of multiples could mean only one thing: scientific discoveries must, in some sense, be inevitable.

    List of multiple discoveries
    Excerpt: Historians and sociologists have remarked on the occurrence, in science, of “multiple independent discovery”. Robert K. Merton defined such “multiples” as instances in which similar discoveries are made by scientists working independently of each other.,,, Multiple independent discovery, however, is not limited to only a few historic instances involving giants of scientific research. Merton believed that it is multiple discoveries, rather than unique ones, that represent the common pattern in science.

  4. 4
    englishmaninistanbul says:

    That Connie Barlow woman has a point you know.

    What really seals the deal is that section “Human Culture” tacked on the end. Did you know that completely distinct cultures each developed writing systems independently? And Newton and Leibniz each discovered calculus all by themselves? I mean that is totally analagous to how… life… evolved… sorry what were we trying to prove again?

  5. 5
    bornagain77 says:

    Also of note:

    The Elaborate Nanoscale Machine Called Photosynthesis: No Vestige of a Beginning – Cornelius Hunter – July 2012
    Excerpt: “The ability to do photosynthesis is widely distributed throughout the bacterial domain in six different phyla, with no apparent pattern of evolution. Photosynthetic phyla include the cyanobacteria, proteobacteria (purple bacteria), green sulfur bacteria (GSB), firmicutes (heliobacteria), filamentous anoxygenic phototrophs (FAPs, also often called the green nonsulfur bacteria), and acidobacteria (Raymond, 2008).”

    “Despite its complexity, C4 photosynthesis is one of the best examples of ‘convergent evolution’, having evolved more than 50 times in at least 18 plant families (Sage 2004; Conway Morris 2006).”

    Excerpt: Ribosomes from bacteria, archaea and eukaryotes (the three domains of life on Earth) differ in their size, sequence, structure, and the ratio of protein to RNA.

    Excerpt: The ribosome,,,, it’s the most complicated thing that is present in all organisms.,,, you find that almost the only thing that’s in common across all organisms is the ribosome.,,, So the question is, how did that thing come to be? And if I were to be an intelligent design defender, that’s what I would focus on; how did the ribosome come to be?
    George Church

  6. 6
    bornagain77 says:

    This example of convergence was particularly troublesome for Darwinists since it went all the way down to the molecular level:

    Convergence Drives Evolution Batty – Fazale Rana – September 2010
    Excerpt: The multiple, independent origin of echolocation in these animals (twice in bats and once in toothed whales) exemplifies convergence,,, When examined from an evolutionary perspective, convergence doesn’t make much sense.,,, the latest research demonstrates that—again, from an evolutionary perspective—the genetic and biochemical changes that account for the emergence of echolocation in bats and dolphins is identical. Given the random nature of the evolutionary process, this recent discovery doesn’t match what evolutionary biologists would expect to find. But both the discovery and convergence make sense if life stems from the work of a Creator.

    Bothersome Bats and Other Pests Disturb the “Tree of Life” – Casey Luskin – December 5, 2012
    Excerpt: But this is hardly the only known example of molecular convergent evolution. In his book The Cell’s Design, chemist and Darwin-skeptic Fazale Rana reviewed the technical literature and documented over 100 reported cases of convergent genetic evolution. Each case shows an example where biological similarity — even at the genetic level — is not the result of inheritance from a common ancestor.

    Common Design in Bat and Whale Echolocation Genes? – January 2011
    Excerpt: two new studies in the January 26th issue of Current Biology, a Cell Press publication, show that bats’ and whales’ remarkable ability and the high-frequency hearing it depends on are shared at a much deeper level than anyone would have anticipated — all the way down to the molecular level.

    Convergent sequence evolution between echolocating bats and dolphins – Liu et al (2010)
    Excerpt: We previously reported that the Prestin gene has undergone sequence convergence among unrelated lineages of echolocating bat [3]. Here we report that this gene has also undergone convergent amino acid substitutions in echolocating dolphins,

    Bat and Whale Echolocation Genes Point to Common Design – February 2011 – Podcast

    Here’s a figure showing bats and dolphins group together on the same tree based on Prestin sequence comparisons.

    Bats and Whales Share the Same Bio-Sonar Technology – May 2012
    Excerpt: new research shows that wild whales also increase their rate of calls or clicks during a kill – and that whales’ buzz rates are nearly identical to that of bats, at about 500 calls or clicks per second.

  7. 7
    Robert Byers says:

    It there is a common blueprint and there is mechanisms in biology to deal with needs then it follows there would be like answers to like needs.
    So convergent evolution is actually not evolution but adaptation from innate mechanisms upon need in bodies.
    I’m sure its the rule in nature.

    There is nothing strange about human discoveries coming from different people independent of each other.
    Its simply that in the past only a few people were investigating things and so it would seem this guy beat everyone else.
    Yet it was by mere months.
    Today their being so many people its just mere days and blurs the thoughtfulness that is going on in science.
    progress in the past is over hyped . It was trivial and only showed how few men were putting their minds to things.
    New inventions or discoveries could today come out of the blue but most likely will be from herds of researchers.
    The attack on evolutionism is case in point.
    Its being common to say evolutionary biology has failings.
    it will rise in numbers who say this.
    Error will be corrected by smarter folks pretty soon.

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