BIOL 117 Lecture Notes - Lecture 4: Thylacine, The Selfish Gene, Richard Dawkins
28 Apr 2016
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Document Summary
Heritability of specific phenotypes is the key to understanding what charles darwin meant when he described natural selection as descent with modification . Darwinian evolution requires heritability of phenotypes from one generation to the next. Without heritability, the variants that are selected for or against by the environment would be lost and evolution would not take place. In his book: on the origin of species, darwin acknowledged that his hypotheses lacked a mechanism by which variation could arise and how traits are passed from parent to offspring. Interestingly, the mechanism for inheritance was described within a few years after darwin"s book was published, but the world did not notice. This, and the following few lectures will cover those details. We now know that phenotypes (measurable traits) are caused by genotypes (genes that code for traits) (however, you don"t always get a predictable phenotype from a specific genotype. And it is that genetic variation that encodes for phenotypic variation.
