Common descent

The genes coding for CETP and PLTP belong to one gene family, which also includes lipopolysaccharide-binding-protein (LBP) and bactericidal/permeability-increasing-protein (BPI). This common descent not only becomes clear from a considerable sequence similarity (45-65% homology at the cDNA level), but also from substantial conservation of exon/intron transitions. 

Clearly this means a complete rejection of the fundamental Darwinian principle of common descent. Also, he rejects mutation and natural selection as the mechanisms that produced species. Is this view also contrary to the universality of biochemistry, and in particular the monophyletic origin of life, to which most biochemists today would subscribe Probably yes but of course if one assumes an absolute determinism, then the laws of chemistry and physics would produce the same products at each different start. This goes against the notion of frozen accident and the unique origin of the genetic code. So, there was never a time on Earth with only one kind of species, and the development of species was parallel rather than sequential. Of course all these ideas are substantiated by arguments and data - for these, the reader should refer to the original sources. 

The Hypothesis of Common Descent with Deeper Phylogenetic Roots... 

Darwin did propose, however, some truly original ideas, and perhaps the most extraordinary of all is the concept of common descent, the theory that all living creatures of our planet derive from a single stock of primordial forms. In Darwin s times, the fixity of species was still the official theory of biology, and generations of past naturalists had built, within that reference system, a grandiose classification scheme that appeared capable of revealing, as Linnaeus put it, the Plan of Creation . 

Evolutionary thought and theory since the time of Darwin have created a new function for taxonomic classification to provide a framework for the study of evolutionary relationships. The overwhelming evidence we have that all organisms on Earth are related by common descent from some of the first cells, has led to different methods for tracing the family trees or phylogenetic trees of living and fossil organisms. 

In simpler wordings natural affinity is common descent John and Peter look similar, because they have the same parents. And, analogous Portulaca oleracea and Portulaca ouadrifida look more similar to each other than any of them to Talinum trlanculare because the first mentioned two species are supposed to have been descended from a more r.cent common ancestral species. 

Schardl CL, Leuchtmann A, Chung K-R, Penny D, Siegel MR. Coevolution by common descent of fungal symbionts (Epichloe spp) and grass hosts. Mol Biol Evol 14 133-143, 1997. 

Thus it is clear that evolutionary theory or evolutionary biology is not just historical (see Bock and von Wahlert, 1963) and indeed that most aspects of evolutionary theory are not historical, but nomological-deductive. Many evolutionary biologists, especially system-atists, work in area b (common descent) dealing with historical evolutionary theory. This paper emphasizes historical evolutionary theory and how this is based on nomological evolutionary theory. 

Common ancestry, 208 Common descent, implication of, 51 Common sense philosophei 58 Community of descent, 198 Comparative anatomy, 166 Competing h3 tfaeses, preferred hypothesis ove 82... 

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