V. Evidence of Change Over Time
Resources
 Bozeman—Evidence for Evolution
http://www.bozemanscience.com/004-evidence-for-evolution
 Campbell Textbook
 Ch. 22.3
V. Evidence of Change Over Time
A. Fossils– show organisms in historical sequence;
show intermediate and extinct forms of organisms
V. Evidence of Change Over Time
B. Biogeography—Use of biology and geography to
describe relationships
 Closely related species tend to be found in
same geographic region; whereas, same
ecological niches tend to be occupied by very
different species (though sometimes similarlooking)
 i.e/ Marsupials vs. Eutherians
IV. Evidence of Change Over Time
C. Comparative Anatomy
i. Homologous Structures– same structure;
different function
V. Evidence of Change Over Time
Analogous Structures—same function;
different structure (i.e., butterfly and bird
wing)– doesn’t show a relationship
ii. Vestigial Structures—No longer use (i.e.,
appendix, tailbone)
Vestigial
Analogous vs
Homologous
ii.
V. Evidence of Change Over Time
iv. Embryology—similarities in embryos that
aren’t found in adult forms (i.e., gill slits in
mammal embryos)
V. Evidence of Change Over Time
C. Comparative Molecular Biology– similarities and
differences in DNA sequences and proteins
VI. Microevolution
Resources:
 Bozeman—Genetic Drift
http://www.bozemanscience.com/003-genetic-drift
 Bozeman—Solving H-W Problems
http://www.bozemanscience.com/solving-hardy-weinbergproblems
 Campbell Textbook
 Ch. 23
VI. Microevolution
A.Conditions that Result in Change in Gene
Frequency over Time
i. Mutation-Random, permanent changes
in DNA
Usually bad
Often small effects
Usually covered up by sexual
reproduction
VI. Microevolution
ii. Non-Random Mating– changes in gene
pool because some organisms mate
more/less or not all
iii. Gene Flow– change in gene pool due to
immigration/emigration
VI. Microevolution
iv.Genetic Drift– change in gene pool due
to chance
VI. Microevolution
1. Bottle Neck– population size is
drastically reduced and eliminates
certain alleles
2. Founder Effect– the “founders” of a
population contribute their alleles which
may or may not represent the entire
population
VI. Microevolution
iv. Natural Selection (Modes)– See Worksheet
B. No Evolution– Hardy-Weinberg
Equilibrium 1908—See Lab