Living fossils

Nurse I d like to mention a sort of half-relevant observation in coelocanths, the fish that are living fossils. When people looked at pre-Devonian fossils of these fish from 300 million years old, the cell size in sections of the fossilized bone was as much as 10 times smaller than the modern fish. The idea was that the fish have accumulated more DNA and the cells have got bigger, but the form of the fish has remained the same. 

Quinones anthraouinones Mar. Bact. Schumaker 1995,Echin. and other marine invertebr. Chang 1998 Land Liliaceae, Ang., especially in tropical and temperate/f/oe spp., and dimeric in Caesalpiniaceae, especially Cassia spp. from arid tropics AY Cassia spp. are cultivated in India and Egypt for danthron as a laxative phenanthropervleneouinones Mar. living-fossil and fossil crinoids, Echin. (likely polyket.) Land Hypericum, Theales, Ang. Pietra 1995). 

Suzuki, T. Fukuta, H. Nagato, H. Umekawa, M. Arginine kinase from Nautilus pompilius, a living fossil. Site-directed mutagenesis studies on the role of amino acid residues in the guanidino specificity region. J. Biol. Chem., 275, 23884-23890 (2000)... 

QUALITATIVE COMMENTS (with 160 mg followed at 2 h by 60 pgs LSD) The visual phenomena were extraordinary. Wc were at the beach just south of Mendocino. In anything that had ever been living, there was an endlessly deep microcosm of detail. Endless, and forever more microscopic in intricacy. A sea urchin shell, a bit of driftwood, a scrap of dried seaweed, each was a treasure of jewels. I have never had such wealth of visual eroticism and bliss before. Later, we visited the pygmy forest, but these living fossils were not as magical. 

As a living fossil which has survived for several hundred million years, the evolutionary success of the horseshoe crab attests to its strong innate immune defense ability, which it uses to thrive in microbiologically harsh habitats with abundant variety of disease-causing pathogens. 

The family of manzaddines was expanded with the isolation of manzacidine D (134) from a living fossil sponge Astrosdera wiUeyana [158] and, more recently, of compound 135, N-methyl manzacidine C, from the marine sponge Axinella brevistyla [159]. The first total synthesis of manzacidin D, in 11 steps and 16% overall yield, from commercially available glydne tert-hutyl ester hydrochloride was reported in 2004 [160]. 

Occurrence of hemocyanin related proteins in organisms. While textbooks teU that Hes occm only in arthropods and molluscs, recently Hes were also found in other phyla. The velvet worms (Onychophora) are considered living fossils and are closely related to the Euarthropoda. Onychophora possess a tracheal system for respiratory function, thus oxygen transport proteins have been considered unnecessary. In the hemolymph of the Epiperipatus sp. (Onychophora Peripatidae), an arthropod-type hemocyanin was found, demonstrating that such proteins exist outside the Euarthropoda. ... 

Complexity of an organism may be more correlated to the number and/or complexity of as yet unidentified functional ncRNA genes than to the number of genes coding for proteins. All this carefully evolved RNA system may be a glimpse of other more complex systems in junk DNA, and a living fossil of... 

Some scientists think that they have found bacteria—living fossils—that may be very closely related to the first inhabitants of earth. The bacteria thrive at temperatures higher than the boiling point of water. Some need only H2, CO2, and H2O for their metabolic processes and they quickly die in the presence of molecular oxygen. 

Jahn, T., Koning, G. M., Wright, A. D., (1997). Manzacidin D an impreeedented seeondary metabolite from the "living fossil" sponge Astrosclera willeyana. 

Smith JJ, Sumiyama K, Ameyima CT. A living fossil in the genome of a living fossil Harbinger transposons in the Coelacanth genome. Mol Biol Evol. 2012 29 985-93. 

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