Bio1b Summer 2008 Eric Harris Evolution Lecture 2 Page 1 of 3 EVOLUTION LECTURE 2 DARWIN AND THE GENETIC BASIS OF EVOLUTION Reading 7th ed 443 453 251 260 8th ed 457 467 262 271 A Recap of Pre Darwinian ideas of Evolution B The argument presented in On the Origin of Species 1859 i Artificial selection ii Variation in natural species iii Struggle for existence iv Natural selection C Problems for Darwin s Theory i Blending theory of inheritance ii How can selection recognize such small differences iii Is the earth old enough iv Lack of transitional forms D Evidence of Evolution i Artificial selection ii Systematics iii Geographical Distributions Biogeography iv Comparative Anatomy Homology Vestigial Structures Rudimentary organs v Comparative Embryology vi Fossils Updated on 06 17 08 Bio1b Summer 2008 Eric Harris Evolution Lecture 2 Page 2 of 3 vii Molecular biology in recent years Darwin presented overwhelming evidence for evolution having occurred and a specific mechanism natural selection to explain how it occurred Remember i Individuals do not evolve populations do ii Natural selection can only amplify HERITABLE variation iii Not all variation is heritable much of it is environmental E Mendelian genetics terms to remember character true breeding trait P F1 F2 homozygous heterozygous genotype phenotype monohybrid cross dihybrid cross test cross i Mendel s law of segregation using modern terminology Allele pairs segregate during gamete formation meiosis and the paired condition is restored by the random fusion of gametes at fertilization ii Mendel s law of independent assortment using modern terminology Each allele pair segregates independently of other gene pairs during gamete formation iii Mendelian genetics involve the application of these two simple laws and two basic laws of probability Rule of multiplication the probability that independent events will occur simultaneously is the product of their individual probabilities Updated on 06 17 08 Bio1b Summer 2008 Eric Harris Evolution Lecture 2 Page 3 of 3 Rule of addition the probability that an event can occur in two or more independent ways is the sum of the separate probabilities of the different ways Updated on 06 17 08
View Full Document
Unlocking...