M.Sc. / The current dogma that dictates that Natural Selection is the driving force behind evolutionary change, is finally being challenged - what with the upsurgence of evidence provided by molecular and developmental biologists. This genetic and ontogenic evidence points towards a far more holistic approach (such as the involvement of the cell as a whole, the external environment as well as a flexible genome) to evolution, in contrast to the previously accepted DNA-centric Mendelian hypothesis. This new wave of thought, together with the re-discovery of 18th and 19th century evolutionary thought that complies with current findings, was the motivation to expose other biological mechanisms that are able to induce evolutionary change. New concepts were introduced (that contradict Neo- Darwinian thinking), with the intention of placing Natural Selection in its rightful position as an adaptive mechanism. Concepts introduced, were firstly, a chapter on how genes produce their effects, and, that by simply reinserting or duplicating existing genes, drastic (macro-evolutionary) change would result. Here the genome is portrayed as a static and dynamic system. The phenomenon of repetition or duplication of existing genes provides evidence of common ancestry, as well as reinforcing the idea of regularity in evolution. Abundant evidence in nature reveals trends of regularity or constraint. Anything is not possible in evolutionary development. The search for laws of form and the reasons for their constraining variables are discussed. The most interesting evolutionary events are those that have led to major changes in the anatomical organisation of animals. These changes are associated with the formation of new phyla. All that remains of such highly significant events are the time-locked tales of fossils. However, the fossil record cannot begin to reveal how these events occurred. The final chapter speculates on how life may have begun in the primordial waters and ends at a hypothesis on the origin of eukaryotes. The scription was an attempt to nudge the prevailing "Darwin" orientated evolutionary paradigm, in order to create space for the arrival of an "Epigenetic" orientated evolutionary paradigm, that is completely able to explain evolutionary procedure.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:uj/uj:10203 |
| Date | 12 September 2012 |
| Creators | Van der Walt, Merrill |
| Source Sets | South African National ETD Portal |
| Detected Language | English |
| Type | Thesis |
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