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Author Topic:   The ancestry of some "living fossils"
Lithodid-Man
Member (Idle past 1005 days)
Posts: 504
From: Juneau, Alaska, USA
Joined: 03-22-2004


Message 1 of 3 (528289)
10-05-2009 3:19 PM


In the thread Living fossils expose evolution Calypsis4 presented a number of photos depicting fossil lifeforms and their modern equivalents. The point seemed to be that since no appreciable evolution occurred the ToE is compromised. Another claim made, deemed off topic, was that these living fossils (representing a 'kind') are orphaned in time with no ancestors. The claim is they appeared suddenly, and remain unchanged to this day having spawned no descendants that are not their 'kind'

I would like to discuss the origin and diversification of the specific 'kinds' Calypsis presented without introducing any others. As there were so many, I think it would be useful to discuss them in order a few at a time, moving on after a few posts. With the wide variety of expertise here I think we could get a good overview of what is or isn't known about the paleontology and molecular phylogenies of some of these. Those who disagree could present their critiques (if more can be said than "Is not!").

So the order of discussion. I really think that the bats have been beaten to death in the original thread, so is of little value repeating it here.

So to start off: Magnoliacea (family, magnolia trees), Astacidacea (infraorder, crayfish and clawed lobsters), and Lagomorpha (order, hares, rabbits, and pika).

Then Triconodonta (subclass, extinct mesozoic mammals), Mecoptera (order, scorpionflies and relatives), and ?water insects (Calypsis posted two completely unrelated orders of insect, water striders are true bugs, Hemiptera, while Chresmoda is definitely not but may be a paraplecopterid), then Nautiloids (family, shelled cephalopods)

Finally Felidae (family, cats. Pretend instead of a hyena skull it was any number of extinct felines instead), the Ginkgophyta (division, ginkgos and their extinct relatives) and finally the Odonata (order, dragonflies and relatives).

So starting with the first three. Ignore the slippery definition of 'kind' and just take it as presented, equivalent to the taxonomic ranking I gave with each. Does this 'kind' have a fossil history? Does this 'kind' have any descendants that are not the same 'kind'? Do genetics or other molecular phylogenies tell us anything? What are the creationist explanations for the evidences presented?

Biological evolution seems appropriate.

Edited by Lithodid-Man, : Forgot the dragonflies


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Elim Garak: "My dear Doctor, they're all true"
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AdminNosy
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Message 2 of 3 (528303)
10-05-2009 5:33 PM


Thread Copied from Proposed New Topics Forum
Thread copied here from the The ancestry of some "living fossils" thread in the Proposed New Topics forum.
  
Lithodid-Man
Member (Idle past 1005 days)
Posts: 504
From: Juneau, Alaska, USA
Joined: 03-22-2004


(2)
Message 3 of 3 (528948)
10-07-2009 4:15 PM


Well, I will try to get this started by discussing the Astacidea (crayfish and clawed lobsters) and their evolutionary history. I am hoping someone with a botanical flair will discuss the Magnoliacea, I understand they have a fair paleontological history and there has been some great molecular systematics with basal angiosperms.

The approach to deciphering the history of the crayfish and clawed lobsters is based upon a combination of morphology, fossils, biogeography, and molecular systematics. This group has proven to be more difficult than other decapods as one unifying feature of most members of the group is a retention of basal decapod characters (elongate body, well-developed abdomen, claws on first three walking legs, etc.).

Unfortunately, the fossil evidence for the evolution of astacids is scarce. The few known Triassic forms are very primitive but recognizable Protoastacidea, Erymoidea, and Glyphoidea (note, in the most recent pub I could find the Glyphoidea are removed from the Astacidea and combined with the Erymoidea as a new infraorder Glypheidea (de Grave et al. 2009). I have not yet found the origin or basis for that change, so am leaving this with the older classification). By the Jurassic of the extant superfamilies are found. Standing as an anomaly is a fossilized burrow from the Carboniferous that resembles the burrow type seen in many groups of astacoids.

Molecular phylogenies indicate that the Astacidea as a clade are monophyletic if the Glyphoidea are removed or if some thalassinids are included (a related froup, called mud shrimp or yabbies). It is likely that this and some other work I have not encountered yet are the basis for the reclassification I mentioned above. This confirms the close relationship of these two infraorders based upon morphology.

The bigeography of this group is disjointed and confusing. Schram (2001) shows that if the current distribution of astacoid superfamilies is superimposed on a map with the continents in the Triassic configuration, the disjointed distributions within the freshwater superfamilies disappear. Centralized distribution for all groups based upon the Triassic map strongly suggests an earlier radiation, and consistent with the Carboniferous trace fossil mentioned above.

Breinholt, J, Pérez-Losada M, and Crandall KA (2009) The timing of the diversification of the freshwater crayfishes. In: Martin, J.W., K.A. Crandall, and D.L. Felder (eds.) Decapod Crustacean Phylogenetics. Crustacean Issues. Koenemann, S. (series ed.) Vol. 18. Boca Raton, London, New York: CRC Press, Taylor & Francis Group. 343–355 pp.

De Grave S, Pentcheff ND, Ahyong ST, Chan TY, Crandall KA, Dworschak PC, Felder DL, Feldmann RM, Fransen CHJM, Goulding LYD, Lemaitre R, Low MEY,Martin JW, Ng PKL, Schweitzer CE, Tan SH, Tshudy D, and Wetzer R (2009) A classification of living and fossil genera of decapod crustaceans. The Raffles Bulletin of Zoology Supplement No. 21: 1-109.

Schram FR (2001) Phylogeny of decapods: moving towards a consensus, Hydrobiologia 449 (2001), pp. 1–20.

Tshudy D, Robles R, Chan TY, Ho KC, Chu KH, Ahyong ST, and Felder DL (2009) Phylogeny of marine clawed lobster families Nephropidae Dana, 1852, and Thaumastochelidae Bate, 1888, based on mitochondrial genes. In: Martin, J.W., K.A. Crandall, and D.L. Felder (eds.) Decapod Crustacean Phylogenetics. Crustacean Issues. Koenemann, S. (series ed.) Vol. 18. Boca Raton, London, New York: CRC Press, Taylor & Francis Group. 357–368 pp.


Doctor Bashir: "Of all the stories you told me, which were true and which weren't?"
Elim Garak: "My dear Doctor, they're all true"
Doctor Bashir: "Even the lies?"
Elim Garak: "Especially the lies"
    
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