BIOL 102 Lecture Notes - Lecture 3: Noncoding Dna, Selective Breeding, Directional Selection
Document Summary
Epigenetics- change in gene expression (active versus inactive genes) that do not involve changes to the underlying dna sequence. Effectively change in phenotype without a change in genotype. Which genes are activated can be influenced by the environment, lifestyle and disease state. 98% is noncoding dna or junk dna. Believed that over time the neck of the giraffe had to stretch in order to reach the trees. The ones who could not stretch to reach the trees died off. Darwin argued that complexity evolved simply as a result of life adapting to its local conditions from one generation to the next. Co(cid:374)du(cid:272)ted (cid:373)ouse studies that resulted i(cid:374) the (cid:272)oi(cid:374)ed ter(cid:373) (cid:862)weis(cid:373)a(cid:374) (cid:271)arrier(cid:863) He cut mouse tails off expecting for the offspring not to have tails however he realized that even though the mouse had no tail its offspring had a tail. Further proved that evolving had to occur naturally.
