Phylogeny

Linnaeus, Georges L. L., Comte de Buffon and other pre-evolutionary taxonomists were aware that some species may have changed since their creation, but Jean-Baptiste de Lamarck (1809) was the first to emphasize that all biological forms or taxa develop by Evolution and represent a historical continuum or Phylogeny (Simpson, 1961:50-51). He believed that there were no breaks in an evolutionary lineage and that taxa were arbitrary subdivisions of a lineage. Gaps in the fossil record are thus gaps in knowledge but not a reflection of a break in a lineage. "Phylogeny" was soon coined by Ernst Haeckel in order to describe the evolutionary development of lineages or organisms (Ghiselin, 1972:131). 

Charles Darwin (1859) incorporated the ideas of Lamarck into his volume and also laid the basis for contemporary evolutionary Taxanomy. He believed that shared anatomical features could be interpreted as due to common ancestry and that many related contemporary taxa shared common ancestry and intermediate forms (Simpson, 1961). In addition, he believed that the temporal succession of fossil forms is the actual record of Phylogeny.

The evolutionary tree of Phylogeny is derived from an analysis of both distributional and functional data. Distributional information includes the fossil record, biogeography, and aspects of comparative ecology. The fossil evidence is analyzed in a number of ways. It often includes a character analysis in which homologous anatomical traits are identified and then a Cline and direction (polarity) are inferred. Functional data are used to infer the historical changes in terms of biological laws and principles. Ghiselin (1972) has reviewed many of the expectations and "rules" for this kind of analysis. Finally, controversy over neo-Darwinian theory has led to explicit discussions of method in phylogenetic reconstruction.

Questionnaire:

• Explain About Phylogeny.
•  What is Phylogeny?
• Who coined term Phylogeny?
•  Explain about the evolutionary tree of Phylogeny.