October 26, 2006 | David F. Coppedge

Fossil Lamprey Changed Little in 360 Million Years

Lampreys, fish that consist of little more than a mouth with a tube-like body and fin, don’t usually fossilize well because they lack bones and hard cartilage.  A small two-inch fossil lamprey has been found in South Africa and reported in Nature1 (see also National Geographic, Live Science and EurekAlert based on a press release from University of Chicago Hospitals).
    The news reports are calling this a “living fossil” but it’s really more of a “reverse living fossil.”  Most living fossils are live animals found that had been thought long extinct.  This is a dead fossil that shows similarity to living lampreys, with little change for 360 million years according to evolutionary dating: e.g., according to Gess et al in Nature, “lampreys as a whole appear all the more remarkable: ancient specialists that have persisted as such and survived a subsequent 360 million years.”  The conclusion of their paper states:

The discovery of Priscomyzon within a Late Devonian marginal marine estuarine environment pushes the minimum date of lamprey-like fishes back by some 35 million years, and provides a new minimum date for molecular-clock-based estimates of the cyclostome crown node.  The well developed oral disc, annular cartilages and circumoral teeth of Priscomyzon suggests the evolutionary long-term stability of a highly specialized parasitic feeding habit.  Lampreys have long been recognized as highly apomorphic but only now is it possible to appreciate just how ancient these specializations are.  In this particular sense, lampreys might be described as ‘living fossils’, and Priscomyzon adds new phylogenetic perspective to studies using modern agnathans as model systems for deriving insight into primitive vertebrate conditions.

The authors built a new phylogenetic tree including the new species, a member of the cyclostomes (circle-mouths).  Philippe Janvier, however, commenting in Nature2 on this find, was not convinced the fossil helps the tree:

The relationships between living hagfishes, lampreys and jawed vertebrates are hotly debated, because of conflicting distributions of morphological and physiological traits on the one hand, and of DNA and RNA sequence data on the other.  The morphological and physiological aspects suggest that lampreys (but not hagfishes) are the sister group of jawed vertebrates, whereas gene sequences generally suggest that lampreys and hagfishes are sister groups.  Fossils sometimes help to resolve such conflicts, by revealing combinations of traits in an extinct species that better support a particular relationship.  Frustratingly, Priscomyzon does not help in resolving the problem of lamprey relationships, because it provides no new informative combinations of characteristics compared with post-Devonian and extant lampreys.
    Morphology-based evolutionary trees of living and fossil vertebrates have long been prone to change.

Later, Janvier asked, “So, it is not too surprising that lampreys turn up in the Devonian period, 360 Myr ago.  What is surprising is that they are already very similar to modern lampreys.  What, then, did earlier or more primitive lampreys look like?”  All he could do was speculate.
    Another discovery was announced from this geological epoch.  A press release from University of Ohio announced finding organic molecules in 350 million year old fossil crinoids.  That makes these the oldest such molecules found.  The researchers think this provides a new way to trace animal evolution.  See also Science Daily.

1Gess et al, “ Nature 443, 981-984(26 October 2006) | doi:10.1038/nature05150.
2Philippe Janvier, “Palaeontology: Modern look for ancient lamprey,” Nature 443, 921-924(26 October 2006) | doi:10.1038/443921a.

The researchers performed some tree-building magic with their new lamprey to give it the illusion of fitting into an evolutionary ancestry somehow, but clearly finding one so early, so little evolved, was a surprise.  Their unwieldy chart now has to place lampreys 35 million years farther back, where its unique morphology was already well-developed.  Then they have to claim that very little changed for 360 million years.  During that same amount of time, all the varieties of reptiles, birds, mammals, and land plants supposedly emerged: an embarrassment of riches for the fecund process of evolution.  Why did lampreys miss the party?  May as well add to the story; in the absence of fossils, National Geographic speculates, “When the fossilized lamprey lived, there were probably many types of jawless vertebrates.  Except for the lamprey and hagfish, all of them seem to have died out.”
    Interestingly, Janvier pointed out that we cannot assume a parasitic lifestyle just from the morphology.  It may look like this fossil lamprey used its mouth to suck blood, “Yet only 19 living lamprey species (out of 38) feed this way,” he said.  “Other lampreys mainly use their sucker to either secure themselves while at rest or carry stones for nest building.”  This opens the possibility that parasitism was a degenerate behavior for structures that had another purpose.
    The overarching theme, though, was the surprise of finding a nearly modern lamprey so far back in time; it means that any alleged common ancestor had to be pushed even farther back: “lamprey morphology has been astonishingly stable for 360 Myr,” Janvier said.  Thinking inside the Darwinian box, he said this “proves that lampreys and hagfishes had already diverged by late Devonian times, earlier than previously thought.”
    So there you have Darwinists experiencing the surprise effect of anomalies again, yet with no prospect of thinking outside the box.  (In fact, the same issue of Nature had several tirades against those close-minded, evil creationists.)  Finding organic molecules in fossils 350 million years old does little to jar the evolutionists, nor does finding living fossils virtually unchanged for hundreds of millions of years.  The gumby Darwinists are masters at turning every falsification into confirmation.  The evolution talk is all in future tense, as usual: this “may give us insight” into evolution (yawn).  We’ve been waiting a long time for said insight, and all we keep getting is outdark.  It makes us downright ready to upchuck.

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Categories: Fossils

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