ANT203Y1 Lecture Notes - Lecture 3: Fleeming Jenkin, Blending Inheritance, Noncoding Dna
Document Summary
Convergence: evolution of similar adaptations in unrelated groups of animals: marsupial faunas in australia and south america, lens in aquatic organisms. Adaptations occurred 8 different times (in each animal or in 8 animals?) Darwin had difficulty explaining source of variation. Fleeming jenkin: blending inheritance leads to little or no variation. Tall mom, short dad, blended together to create medium-sized offspring: selection works to remove variants. New types of variants have to be acquired from outside initial range. E. g. , elephants evolving from a shrew type creature requires some mechanism for such drastic change. Majority of unknown dna discovered to have the purpose of controlling what happens to our genes/what is done with them/where they go/their function. Still some junk dna; the purpose of which remains unknown. Understand how genes work and how traits are transmitted from one generation to the next: human evolution, adaptation, variation.
