Thanks to correspondent Laurence Clark Crossen, I need to add another newly discovered species, the enigma moth of Australia's Kangaroo Island. The tiny, handsome gold and purple moth is referred to (inaccurately) as a "living dinosaur moth." What's special about it? It carries many "primitive" traits that go tens of millions of years back in moth evolution. So scientists are very happy to see it alive. (I don't know what a "living dinosaur moth" would actually look like - maybe like Mothra in the Godzilla movies? )
13 comments:
This would make it a lazarus taxa as that concept is broadly defined. I think it also argues against the easy presumption that early creatures have necessarily gone extinct. Did you know that the idea that extinction is utter and absolute originated in Cuvier's cyclical concept of earth history? His idea was that the biblical Flood was the last of a series of complete and absolute destructions of all life on earth, after which God made a whole new creation. This is why Agassiz, a pupil of Cuvier's, insisted on the Ice Age covering the whole earth and destroying all life. See Bolles, The Ice Finders. It was Lyell who turned the Ice Age into a uniformitarian "glacial" change. Lyell scoffed at the idea that the ice covered the whole earth.
It is called, Enigmatinea glatzella. Maybe the should have called glatzilla?
One lesson here is that uniformitarians do not think extinctions have been quite so absolute and complete and final as catastrophists do. I'm with Lyell.
Clark, I made a mistake in the posting. This species is a new discovery, not a rediscovery. Sorry about that.
If that is how you like to define lazarus taxa. I think the points are just as pertinent either way. I don't think these issues depend on such a definition. That was why I mentioned that the phrase is always poorly or broadly defined. After all, how can the idea really be defined in a very meaningful way? One of the real points about lazarus taxa are that so-called primitive or elementary features are not confined to early Earth history. As Niles Eldredge points out, evolution has not been a linear progressive process. If there could be and are very "primitive" forms flourishing today undiscovered, then obviously such forms in the fossil record could easily still be found. I think you dodged another issue. Is your aversion to the idea that lazarus taxa as you define them a product of your catastrophist viewpoint? Are you a catastrophist? I am a uniformitarian.
I left out a phrase from one sentence. Here is the complete thought:
Is your aversion to the idea that lazarus taxa, as you define them, are likely, a product of your catastrophist viewpoint?
No aversion to Lazarus taxa - just that this particular find may not be an example.
You are not in bad company if you agree with George Gaylord Simpson's criticisms of cryptozoology (Mammals and Cryptozoology 1984). He said the okapi was not a lazarus taxa because it was not a Samotherium. It is a short necked forest giraffe and they were all thought to be extinct. So I disagree with him.
According to Wikipedia, "In paleontology, a Lazarus taxon (plural taxa) is a taxon that disappears for one or more periods from the fossil record, only to appear again later."
A taxon is a biological group of any rank. Why would anyone want to define it so narrowly that only the exact species counts?
Maybe we can understand better if we relate this to the extant cow-deers or boselaphines. Only one species still exists today, the nilgai. If none existed that would be very significant for ecology and evolution.
In his book, Evolutionary Trends in Flowering Plants (Columbia University Press 1991), Armen Takhtajan discusses the "significance of 'living fossils'(p.10)." Here he says that "many undoubtedly archaic flowering plants with a number of primitive characters... are still preserved as 'living fossils'." This shows that professional specialists do describe living forms with archaic characteristics as lazarus taxa even when they are not the exact forms once thought extinct in the fossil record.
Actually, Simpson mentioned Helladotherium and not Samotherium. But I think my point remains, that some prefer to define lazarus taxa in a more narrow and some in a more broad sense depending on how averse they are to acknowledging their significance. Simpson said, "Okapia is not a survivor of
a known fossil genus, subfamily, or family." It is an unexpected surviving short necked forest giraffe. Would you call that a lazarus taxa?
Clark, it gets awfully technical, I suppose, because everyone can establish their own definition. To me, okapi doesn't count if it's an "unexpected" rather than a "survivor."
I have been trying to say that it is not the definition but the significance that matters. I do not think such finds are merely curiosities. I think they have great significance. For example, it is true that this find shows there is a good chance we will continue to find many more creatures with "primitive" traits including exact matches with the fossil record and closely similar creatures.
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