Convergent evolution News

Convergent evolution: Animal only looks like a sea anemone

Spread the love
sea anemone/Bernard Picton, U Northern Ireland

It belongs to a different, new order, researchers say.

“Anemones are very simple animals,” Rodríguez said. “Because of this, they are grouped together by their lack of characters — for example, the absence of a skeleton or the lack of colony-building, like you see in corals. So it wasn’t a huge surprise when we began to look at their molecular data and found that the traditional classifications of anemones were wrong.”

The researchers compared particular sections of DNA of more than 112 species of anemones collected from oceans around the world. Based on genetic data and the organization of their internal structures, the scientists reduced the sub-orders of anemones from four to two.

They also discovered that one of species that they analyzed is not a sea anemone at all. This animal, previously called Boloceroides daphneae, was discovered in 2006 in the deep east Pacific Ocean and labeled as one of the largest sea anemones in existence. But the new study shifts it outside of the tree of life for anemones. Instead, the researchers placed it in a newly created order — a classification equal to carnivoria in mammals or crocodilia in reptiles — under the sub-class Hexacorallia, which includes stony corals, anemones, and black corals. The new name of the animal, which lives next to hydrothermal vents, is Relicanthus daphneae.

Relicanthus daphneae is a classic example of convergent evolution, the independent evolution of similar features in species of different lineages.

“Even though this animal looks very much like a sea anemone, it is not one,” Rodríguez said. “Both groups of animals lack the same characters, but our research shows that while the anemones lost those characters over millions of years of evolution, R. daphneae never had them. Putting these animals in the same group would be like classifying worms and snakes together because neither have legs.”

This is the creature, doing business under the old name:

Follow UD News at Twitter!

33 Replies to “Convergent evolution: Animal only looks like a sea anemone

  1. 1
    Robert Byers says:

    Aha. So classification by looks or by DNA is bumping into each other.
    As predicted.
    this is because both ways are based on mere lines of reassoning of trait comparison. There is no evidence or relationships except this way.
    HOW did the scientists make this mistake about this thing? What happened to their science? who screwed up?
    Could this be going on all the time?
    YUP

  2. 2
    Acartia_bogart says:

    Robert, taxonomy started centuries before natural selection was proposed. And natural selection was proposed decades before DNA was discovered. Yet, DNA analysis corresponds remarkably well with what was done using taxonomy centuries before. As predicted.

  3. 3
    Querius says:

    Robert Byers,

    Yes, exactly. DNA is used only to try to resolve embarrassingly bogus classification based on morphology.

    But . . . I just had an idea!

    Just as the sea anemone and Relicanthus daphneae was discovered to be “a classic example of convergent evolution,” as the researchers put it, what about humans?

    It seems to me that a case can be made that humans and primates (chimps, orang-utans, and gorillas) are also “a classic example of convergent evolution.”

    It makes sense considering some of the puzzling DNA analysis that variously shows humans closer to chimps in some cases, oran-utans in others, and even gorillas in others. The explanation is that we don’t have a common ancestor, we are . . . converging!

    Unfortunately, I will have to predict that this novel insight will be rejected out-of-hand due to its incompatibility with the current narrative. 😉

    -Q

  4. 4
    Querius says:

    Acartia_bogart claimed:

    Yet, DNA analysis corresponds remarkably well with what was done using taxonomy centuries before. As predicted.

    No, it doesn’t. DNA corresponds remarkably well only when you cherry pick the data. Otherwise the proteins would also match up, which they don’t.

    Conversely, modern-looking animals are found in nearly every fossil layer.

    In some cases, modern animals are termed “living fossils” in the belief that evolutionary change magically stopped for some reason. And as always, predicted in retrospect.

    -Q

  5. 5
    Piotr says:

    It makes sense considering some of the puzzling DNA analysis that variously shows humans closer to chimps in some cases, oran-utans in others, and even gorillas in others. The explanation is that we don’t have a common ancestor, we are . . . converging!

    Those analyses consistently show humans to be most closely related to the chimp/bonobo clade, then to gorillas and more distantly to orangutans. In the few cases when DNA analysis seems to group humans with gorillas rather than chimpanzees, it’s the consequence of the fact that what actually evolves, diverges and undergoes speciation is populations, not the “average” chimp, human or gorilla.

    If the ancestral population was variable in some respect (had two alleles of some chromosome fragment, say, A and A’), the variation continued to undergo fixation in the descendants. Gorillas eventually fixed A, while the common Homo/Pan ancestor was still polymorphic and retained both A and A’. A was fixed in proto-humans, and A’ in chimps, producing a phantom “sister” relationship between Homo and Gorilla. Such mismatch between the genealogy of populations and individual genes is not only possible but predicted by evolutionary theory.

    It doesn’t mean that “anything goes”: the species in question must be closely related (calculations show that neutral polymorphisms in primates can be retained for one or two million years, but not tens of millions), and mismatches are exceptions, not the rule. That’s why in order to establish the structure of relationships you have to look at the total evidence, not at a few selected genes.

  6. 6
    gpuccio says:

    Piotr:

    I think you are essentially right here.

    However, even if I am not really any expert of these things, I believe that in the general field of tree of life evaluation there are certainly some big discrepancies, between morphology and molecular data, but especially between different types of molecular data (for example, miRNAs), which seem to be something more than isolated “exceptions”, and deserve more attention.

    I say that not as a generic criticism to CD (you know I absolutely accept the idea), but out of genuine scientific curiosity.

  7. 7
    Acartia_bogart says:

    Querius claimed:

    “DNA corresponds remarkably well only when you cherry pick the data. Otherwise the proteins would also match up, which they don’t.”

    Actually, it is only when you cherry-pick that they don’t match up. Taxonomy was used long before DNA to suggests relatedness of different species. This was primarily based on comparative anatomy. What is most amazing is that when comparisons are made using molecular biology (i.e., DNA, proteins, etc.) rather than visible morphology, a very similar pattern is seen. Yes, there are many examples of some species not being as closely related molecularly as was expected based on morphology, but, relatively speaking, these are very few.

  8. 8
    Querius says:

    Piotr explained,

    If the ancestral population was variable in some respect (had two alleles of some chromosome fragment, say, A and A’), the variation continued to undergo fixation in the descendants. Gorillas eventually fixed A, while the common Homo/Pan ancestor was still polymorphic and retained both A and A’. A was fixed in proto-humans, and A’ in chimps, producing a phantom “sister” relationship between Homo and Gorilla.

    Speaking in conceptual generalities, I don’t want to dismiss possible explanations when the data are available, but I would like to point out that conclusions have been made about the convergent evolution of some fossils based on the morphology alone. And when genomic data is available to settle controversies regarding contemporary species, the data often seems to indicate a more complex relationship, unless a lot of the genomic data is excluded from consideration.

    Such mismatch between the genealogy of populations and individual genes is not only possible but predicted by evolutionary theory.

    But only predicted in retrospect, which beggar’s the term predicted. In other words, it was “predicted” only as a possibility in response to the genomic data, and not in specific instances.

    FWIW, what I think is needed is a reset button on the tree (or bushes or grass lawn) of life, starting with genomic data on extant species, and then use what we learn to carefully apply it to fossils for which only morphology is available. While incremental change is not apparent in the fossil record (bats, for example), it should be available in contemporary species.

    Also, I think a lot can be learned from outlying phenomena, such as the Frankenstein-like qualities of the platypus genome.

    (And no, Acartia, the protein data lined up poorly, so that initial method was pretty much abandoned as a result.)

    -Q

  9. 9
    Robert Byers says:

    Acratia
    I note they bump into it not working often enough.
    Anyways like dna should equal like looks
    creationism would predict this.

  10. 10
    Robert Byers says:

    Querius
    human dna would look like ape dna because wqe look alike. Almost a perfect match by my looking.
    however the bible says we are a special case.
    We do not have a body type to represent us and so we are renting another creatures body type. WE uniquely don’
    t have our own body. all other creatures do or did at creation week.
    Looking alike is not biological scientific evidence for common descent.
    Its just looking alike evidence.
    Science methodology should be used in these complicated matters.

  11. 11
    wd400 says:

    But only predicted in retrospect, which beggar’s the term predicted.

    No. Here’s Pamilo and Nei talking about exactly the process Piotr was talking about in 1988, when it was already “well known”. So the imcomplete lineage sorting in human-chimp-gorilla is hardly “puzzling” (there is almost no ILS when we look at organgs, btw)

  12. 12
    wd400 says:

    Sorry, here, in face it Pamilo and Nei

    http://mbe.oxfordjournals.org/content/5/5/568

  13. 13
    Querius says:

    LOL, I can do it too. Face this:

    http://news.nationalgeographic.....lated.html

    Must more of that selective amnesia. It’s treatable, you know. 😛

    -Q

  14. 14
    wd400 says:

    What?

    Schwartz and Grehan are kooks, but even they don’t claim there is much incomplete lineage sorting among Orangs and African apes. (They, and they alone, thing orangs are closer relatives to humans because, among other reasons, they have mustaches.

  15. 15
    Querius says:

    And what do Dr. Jeffrey Schwartz (Ph.D., Physical Anthopology) and Dr. John Grehan think of you? Have you ever met them?

    By contrast, humans share at least 28 unique physical characteristics with orangutans but only 2 with chimps and 7 with gorillas, the authors say.

    Face it, the characteristics they list are observable evidence. You would probably have to agree that a lot of paleontology is based on characteristics just like these.
    You choose your list; they choose theirs.

    -Q

  16. 16
    wd400 says:

    Mustaches dying fossilize well. When anyone other than these two looks at morphological data they find the human-chimp group.

    But none of this has anything to do with your claim that dna studies sometimes place Orangs with humans, or that incomplete lineage sorting was an adams hockey response to genomic data, rather than a direct prediction of population Hindus

  17. 17
    Joe says:

    Until someone figures out what makes a chimp a chimp and a human a human, grouping different types of organisms together is a fool’s errand.

  18. 18
    Querius says:

    Joe,

    Apparently, there are a lot of volunteers. 😛

    Do you understand what wd400 was trying to say in 16? I don’t want to be unkind, but why would he bring up Hindus?

    -Q

  19. 19
    wd400 says:

    Autocorrect fail there,

    Mustaches don’t fossilize well.

    But none of this has anything to do with your claim that dna studies sometimes place Orangs with humans, or that incomplete lineage sorting was an ad hoc response to genomic data, rather than a direct prediction of population genetics (that predates genomics).

  20. 20
    Querius says:

    Whew. I thought you might have blown a fuse or something!

    So, do you think that Dr. Jeffrey Schwartz (Ph.D., Physical Anthopology) and Dr. John Grehan claim that they have fossilized mustaches?

    Personally, I’d imagine that physical anthropology has a broader scope. Although, there is indeed serious evolutionary research being conducted on this subject:

    http://www.ehbonline.org/artic.....6/abstract

    -Q

  21. 21
    wd400 says:

    I think it isn’t true that ” a lot of paleontology is based on characteristics just like these.” I think despite their credentials Schwartz and Grehan are kooks of the sort every discipline has a couple of, and to pretend they provide proof for a viable alternative to what we know of primate phylogeny would be an extreme case of cherry picking.

  22. 22
    Querius says:

    wd400,

    Schwartz and Grehan hypothesized a dental hominoid clade—and nowhere in their paper was any reference to beards or mustaches. Perhaps your source was dyslexic, confusing pongo with pogon. 😉

    I took the time to read their paper here:
    http://www.blackwellpublishing.....i_2141.pdf

    Perhaps you would consider reading it without prejudice.

    A gutsy challenge to the related molecular studies is also presented, suggesting that the molecular studies essentially cherry-picked the genetic data.

    The overwhelming morphological evidence in
    support of a human–orangutan sister relationship is dis-
    counted as ‘false’ because it is not consistent with the
    interpretation of molecular similarity, but when molecular
    data yield phylogenies that are in conflict with traditional
    taxonomic groupings of primates, these molecular data are also rejected as ‘false’ (Ruvolo, 1997; Patterson et al., 2006)

    To be fair, here’s a critique by Lehtonen et al of Schwartz and Grehan’s paper in the same journal:
    http://onlinelibrary.wiley.com.....2354.x/pdf

    And here’s Schwartz and Grehan’s response to their critics:
    http://onlinelibrary.wiley.com.....577.x/full

    But even in an evolutionist’s blog critical of Schwartz, the author admits that

    Schwartz is still a renowned expert in orang-utans whose research has made many important contributions to our understanding of human evolution.

    This is hardly the kook that you ungenerously portrayed him. In addition, I think your deprecatory dismissal of Schwartz and Grehan, based on imaginary references to mustaches ill-informed at best and deceptive at worst. Unfortunately, these falsehoods simply reinforce the perception that your posts are unreliable.

    -Q

  23. 23
    wd400 says:

    Here’s their data table:

    http://johngrehan.net/files/16.....lished.pdf

    Hair direction, moustaches, female-initiated mounting, mechanical ability and on and on.

    Do you care to apologise for accusing me of deception or being misinformed? Or to admit you were wrong about dna evidence sporting a human-orang clade, and about incomplete lineage sorting?

  24. 24
    Piotr says:

    Querius:

    You need to see Appendix S1 to their article,

    Character states for extant large bodied hominoids comprising the great ape genera (Gorilla, Pan, Pongo) and humans (Homo) with lesser apes (Hylobates) and monkeys (Catarrhini and Platyrrhini) as the outgroup.

    Beard & moustache are listed there, among other curiosities.

  25. 25
    Piotr says:

    Oops, wd400 beat me to it, soI’ll just add “flexed rectum”.

  26. 26
    Joe says:

    wd400- You are misinformed if you listen to “mainstream” evo biologists. The only people who put humans and chimps in the same clade are the people who are ignorant of what makes a chimp a chimp and a human a human. Science via ignorance is not science.

  27. 27
    Querius says:

    But if you had read their papers, you would see that Schwartz and Grehan’s comparisons hypothesized a dental hominoid clade.

    But I guess you wouldn’t know that.

    -Q

  28. 28
    Piotr says:

    Querius:

    You must have read their publications very carefully indeed, since you have seen therein things that nobody else can see. Here is the supporting information from their first article, with the datasets they used:

    http://onlinelibrary.wiley.com.....x/suppinfo

    Please cite the fragments of any of “their papers” where they identify Pongo/Homo as a dental clade.

    No apology forthcoming? Eh bien, c’est la vie.

  29. 29
    wd400 says:

    Querius,

    If you understood the their papers, you would see that Schwartz and Grehan use the name “dental clade” to refer to a group in one of their trees (estimated from all their data, not just teeth). The “dental” bit is just the one character they could find to describe the group after they found it (“… wwhich we refer to as the ‘dental hominoid clade’ in reference to their relatively thick molar enamel. “).

    So, thus far you’ve been wrong about DNA often supporting a human-orang relationship, wrong about incomplete lineage sorting being an ad hoc solution to genomic data, wrong about mustaches not being used in these papers, wrong about whether I’d read the papers and (it seems) wrong about what was meant by dental clade.

    Do you want to perhaps reconsider which of us is “unreliable”?

  30. 30
    Querius says:

    Actually, I don’t see anything wrong with Schwartz and Grehan’s scholarship, notwithstanding your objections to their considering a very large number of possible physical characteristics from which to consider.

    The breadth of the physical characteristics that they were willing to consider is apparently repugnant to you, perhaps because it’s what some have been termed, “openmindedness” to any observable data.

    Your apparently randomly chosen criticism that they based their hypothesis on the presence or absence of mustaches turned out to be a blatant falsehood. Imagine that! And they chose aspects of dentition based on considering and rejecting the others for various reasons.

    So I have to ask myself, what sort of person would deliberately misrepresent the views of qualified evolutionary scientists published in a peer-reviewed scientific journal, with whom they disagree, and furthermore, resorting to an ad hominem attack, calling them “kooks?”

    The answer is plain as day.

    Goodbye.

  31. 31
    wd400 says:

    Full marks for the flounce, quite impressive to be able muster so much indigance after making so many false claims here.

    I don’t believe I have misrepresented the papers here. These two really are alone in thinking humans and orangs are sister species, they really do include the presence or absence of mustache as a character in their paper and as you see in the supplementary data that this is pretty representative of strange lengths you need to go to get that relationship.

    I guess I’ll give up on the apology though.

  32. 32
    wd400 says:

    I should add, I hardly “resorted to” an ad hominem attack. The my point of my post was to point that even if these two were right, it would be irrelevant to your claim about DNA and orangs. If their conclusions had been relevant to your claims I might have spent more time on their paper, but not much because it is really pretty strange.

  33. 33
    Mung says:

    wd400, I apologize.

Leave a Reply