Mammals phylogenetic tree

Another way of obtaining indirect information on molecular evolution was offered by the study of phylogenetic trees. A typical example, in this field, is the comparison between amphibians and mammals. Both groups derived from a common aquatic ancestor, but amphibians evolved much more slowly. They share so many anatomical characters that a single order comprises most of them, while mammals differentiated into as many as sixteen distinct orders. Mammals clearly underwent a much faster phenotypic evolution than amphibians, and it seemed logical to conclude that, at the molecular level, the mutation rate has been much faster in mammals than in amphibians. 

Fig. 2. A sample phylogenetic tree for mammals (numbers are only approximate). Because proximities are multiplicative, the proximity of chimp to LCA (the last common ancestor, or the root of the tree), for example, is 0.85 x 0.6 =...

FIGURE 23.1 Organisms discussed in this chapter and their positions on the phylogenetic Tree of Life. Mammals are marked by a bar labeled M. Animals are divided into Vertebrates and Invertebrates, and also divided into five physiological groups, D = Deuterostomes, L = lx)photrochozoans, E = Ecdysozoans, C = Cnidarians, and P = Poriferans. The three domains (supraphyla) are Eukaryotes, Archaens (A), and Bacteria (B). 

Fibrinopeptides the two pairs of peptides (A and B) cleaved from the /V-termini of the 2a and 2P chains of fibrinogen by thrombin. F. arise by cleavage of Arg-GIy bon so that Arg is the C-terminal end of the F, and Gly is the A/-terminal end of the a and P chains of fibrin. Human FA. is Ala-Asp-Ser-Gly-Glu-Gly-Asp-Phe-Leu-Ala-Glu-(Gly)3-Val-Arg, and human F.B. is Pyr-Glu-Gly-Val-Asn-Asp-Asn-(Glu)2-Gly-(Phe)2-Ser-Ala-Arg. F.A. ranges in size from 14 amino acids (horse, lizard) to 19 (cattle), and F.B. from 9 (rhesus monkeys) to 21 (cattle, elk and kangaroo). The sequences of the F. have been used to establish a detailed phylogenetic tree for mammals which is very similar to the classical one. The F. have a vasoconstrictive effect which serves to keep the coagulation principles from being removed too quickly from an injury site. 

Fig. 5. Phylogenetic analysis of NRF family amino acid sequences. The amino acid sequences of known or predicted members of the NRF family in zebrafish and pufferfish were obtained from the GenBank or genome databases and aligned with the human NRF family sequences. The tree was inferred using maximum parsimony within PAUP 4b 10. The results illustrate the conservation of NRF proteins in mammals and fish as well as the additional diversity in NRF3 forms present in pufferfish. Danio rerio (Dr), Takifugu (Fugu) rubripes (Fr), Homo sapiens (Hs).

This Amnlota page from the Tree of Life Project shows the phylogenetic relationships of reptile groups, birds, and mammals... 

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