1. Week 33
Mechanics of Evolution
What’s behind the curtain?
 Ch. 15.2 pg 404

2. gene pool gene
All the genes (alleles) in a DNA segment that controls
population Darwin Award video protein production and
cell cycle

3. allelic frequency
 The percentage of an allele
in the gene pool

4. genetic equilibrium
 When the frequency of alleles remains the
same over generations

5.  The change of allelic
genetic drift frequencies by unusual events,
disrupting a population’s
genetic equilibrium
 ex. extra fingers and toes due
to inbreeding

6. stabilizing selection
 natural selection that favors average
individuals in a population

7. directional selection
 natural selection that favors individuals
with an extreme variation of a trait

8. disruptive selection
 natural selection that favors individuals
with either extreme variation of a trait,
eliminating intermediate phenotypes

9. speciation
 Evolution of a new species
extinct

10. geographic isolation
 Occurs whenever a physical barrier
divides a population

11. reproductive isolation
 Occurs when formerly interbreeding organisms
can no longer mate and produce fertile offspring,
due to change in genetic material or behavior

12. polyploidy
 multiple of the
normal set (2n) of
chromosomes due
to mistakes in
mitosis or meiosis
Tetraploid (4n)
Examples of Polyploid Crops
Triploid (3n) crops: banana, apple, ginger, watermelon, citrus[11]
Tetraploid (4n) crops: durum or macaroni wheat, maize, cotton,
potato, cabbage, leek, tobacco, peanut
Hexaploid (6n) crops: chrysanthemum, bread wheat, oat, kiwifruit
Octaploid (8n) crops: strawberry, dahlia, pansies, sugar cane

13. gradualism
 Idea that
species
originate
though a
gradual
change of
adaptations

14. punctuated equilibrium
 Idea
speciation
occurs
relatively
quickly in
rapid bursts
with long
periods of
genetic
equilibrium in
between

15. adaptive radiation
 When an
ancestral
species
evolves into
an array of
species to fit
number of
diverse
habitats

16. divergent evolution
 species that once were similar to an
ancestral species diverge (become
increasingly DIFFERENT)

17. convergent evolution
 When unrelated species evolve similar
traits

18. Report on
an example of
convergent evolution
and divergent evolution
or
examples of
stablizing, directional, and disruptive
selection

19. And now the quiz

20. 1. ___________ selection
 natural selection that favors individuals
with an extreme variation of a trait

21.  The change of allelic
2 frequencies by unusual events,
disrupting a population’s
genetic equilibrium
 ex. extra fingers and toes due
to inbreeding

22. 3 _________ selection
 natural selection that favors average
individuals in a population

23. 4 _________ selection
 natural selection that favors individuals
with either extreme variation of a trait,
eliminating intermediate phenotypes

24. 5_________ isolation
 Occurs whenever a physical barrier
divides a population

25. 6________ isolation
 Occurs when formerly interbreeding organisms
can no longer mate and produce fertile offspring,
due to change in genetic material or behavior

26. 7 ____________ radiation
 When an
ancestral
species
evolves into
an array of
species to fit
number of
diverse
habitats

27. 8 __________ evolution
 The pattern of evolution in which species that
once were similar to an ancestral species
diverge (become increasingly district)

28. 9_________ evolution
 When unrelated species evolve similar
traits

29. 10
 Evolution of a new species
extinct

30. 11 _________ ________
 The percentage of an allele
in the gene pool

31. 12 ______ ______
 When the frequency of alleles remains the
same (equal) over generations

32. 13
 multiple of the
normal set (2n) of
chromosomes due
to mistakes in
mitosis or meiosis
Examples
Triploid (3n) crops: banana, apple, ginger, watermelon, citrus[11]
Tetraploid (4n) crops: durum or macaroni wheat, maize, cotton,
potato, cabbage, leek, tobacco, peanut
Hexaploid (6n) crops: chrysanthemum, bread wheat, oat, kiwifruit
Octaploid (8n) crops: strawberry, dahlia, pansies, sugar cane

33. 14
 Idea that
species
originate
though a
gradual
change of
adaptations

34. 15
All the genes (alleles) in a DNA segment that controls
population Darwin Award video protein production and
cell cycle

35. 16
 Idea
speciation
occurs
relatively
quickly in
rapid bursts
with long
periods of
genetic
equilibrium in
between