L2: Evolution and man
Prof. Graham
Describe evidence from fossils, living animals and molecular biology that supports the theory of
evolution
Evolution - Change in the hereditary characteristics of groups of organisms over the course of
generation - Descent with modification from a common ancestor.
Supported by the fossil record, comparative studies of living animals showing similarities,
molecular biology studies.
Cetacean evolution - gradual reduction in the hindlimbs, Increased mobility of the back. The
most recent fossils resemble organisms alive today, whereas the increasingly older fossils
are progressively different.
All organisms use the same molecular code to translate DNA base sequences into protein
amino acid sequences- shows interrelatedness of living things.
DNA: source of change and continuity in evolution. Mutations create variation. Selection
works on the genetic variation that is already present in any new generation. There is no
direction to evolutionary processes.
Describe the concepts of variation, natural selection and selective pressures and give examples
that illustrate these from man and other animals
Natural selection: works on heritable change favouring better adapted individuals. Variation
exists in a population.
Changes in genes controlling development can have major effects on adult morphology e.g.
in the Drosophila Melonogaster- mutation in ultrabithorax = ectopic set of wings (grow in
abnormal position).
Prof. Graham
Describe evidence from fossils, living animals and molecular biology that supports the theory of
evolution
Evolution - Change in the hereditary characteristics of groups of organisms over the course of
generation - Descent with modification from a common ancestor.
Supported by the fossil record, comparative studies of living animals showing similarities,
molecular biology studies.
Cetacean evolution - gradual reduction in the hindlimbs, Increased mobility of the back. The
most recent fossils resemble organisms alive today, whereas the increasingly older fossils
are progressively different.
All organisms use the same molecular code to translate DNA base sequences into protein
amino acid sequences- shows interrelatedness of living things.
DNA: source of change and continuity in evolution. Mutations create variation. Selection
works on the genetic variation that is already present in any new generation. There is no
direction to evolutionary processes.
Describe the concepts of variation, natural selection and selective pressures and give examples
that illustrate these from man and other animals
Natural selection: works on heritable change favouring better adapted individuals. Variation
exists in a population.
Changes in genes controlling development can have major effects on adult morphology e.g.
in the Drosophila Melonogaster- mutation in ultrabithorax = ectopic set of wings (grow in
abnormal position).
