Unit 3

Study Guide 2012

Microevolution and Speciation

Microevolution

• Learn the terms in the glossary.

• Questions 1- 26

Question 1

• 1. ____?____ is genetic change in a line of descent through successive generations

Answer 1

1. Evolution is genetic change in a line of descent through successive generations.

Question 2

• 2. _______ _______ practices yield evidence that heritable changes do occur.

Answer 2

2. Selective breeding practices yield evidence that heritable changes do occur.

Q - 3

3. Results of artificial selection show that extremes in _____ and _____ are universally attainable in a relatively short time period.

Answer 3

• 3. Results of artificial selection show that extremes in size and form are universally attainable in a relatively short time period.

Question 4

• 4. The selective breeding of dogs began about ______ years ago.

Answer 4

• 4. The domestication of dogs began about 14,000 years ago.

Question 5

• 5. Which Greek philosopher developed the concept, the “great chain of being”?

Answer 5

• 5. Which Greek philosopher developed the concept, the “great chain of being”?

• Aristotle

Question 6

• 6. The notion that “all aspects of nature can be traced to their underlying causes” is attributed to _______ ?

Answer 6

• 6. The notion that “all aspects of nature can be traced to their underlying causes” is attributed to Hippocrates ?

Question 7

• 7. Cite two types of “confounding evidence” that the great chain of being does not explain.

Answer 7

• 7. Cite two types of “confounding evidence” that the great chain of being does not explain.

• Biogeography

• Comparative anatomy

• Geologic discoveries

Question 8

• 8. _________ is the study of the geographical patterns of plant and animal species.

Answer 8

• 8. Biogeography is the study of the geographical patterns of plant and animal species.

Question 9

• 9. Name two biorealms and state where they are located.

Answer 9

• 9. Name two biorealms and state where they are located.

• Palaeartic …… Europe - Siberia• Nearctic ……… North America• Neotropical …… Central and South America• Afrotropical ……. Africa• Indomalayan …… S.E. Asia• Oceanian ……….. Pacific oceanic islands• Australian ……….. Australia• Antarctic ………….. Antarctica

Question10

• 10. Cite a “puzzling problem” from comparative anatomy.

Answer 10

• 10. Cite a “puzzling problem” from comparative anatomy.– Animals as different as whales and bats

have similar bones in forelimbs

or

– Some parts seem to have no function

Question 11

• 11. Why is the Grand Canyon an excellent laboratory for geologic studies?

Answer 11

• 11. Why is the Grand Canyon an excellent laboratory for geologic studies?

• The mile deep canyon provides access to many layers of rock representing about a billion years of earth history.

Question 12

• 12. ______ (shallow/deeper) layers contain _______(simpler/more complex) fossils than shallow layers.

Answer 12

12. Deeper layers contain simpler fossils than shallow layers.

Question 13

• 13. Some fossils seem to be related to known ________.

Answer 13

• 13. Some fossils seem to be related to known species.

Question 14

• 14. Georges Cuvier posited the idea of ________ ________ to explain multiple extinction events (such as the Flood).

Answer 14

• 14. Georges Cuvier posited the idea of ________ ________ to explain multiple extinction events (such as the Flood).

• Georges Cuvier - multiple catastrophes

Question 15

• 15. Lamarck was responsible for the concept of the “______ of _______ characteristics”.

Answer 15

• 15. Lamarck was responsible for the concept of the “inheritance of acquired characteristics”.

Question 16

• 16. The English geologist,______, posited the theory of Uniformity.

Answer 16

• 16. The English geologist,Lyell, posited the theory of Uniformity.

Question 17

17. What was the name of the ship on which Darwin sailed? (On a recent Georgia State – wide test, this was the only question concerning Darwin!!!).

Answer 17

17. What was the name of the ship on which Darwin sailed? (On a recent Georgia State – wide test, this was the only question concerning Darwin!!!).

HMS Beagle

Question 18

18. What group of organisms most influenced Darwin’s shaping of his theory of natural selection? Why?

Answer 18

18. What group of organisms most influenced Darwin’s shaping of his theory of natural selection? Why?

Galapagos finches

They were well isolated from the mainland and seemed to be related through a line of common descent.

Question 19

• 19. What is the “Malthusian catastrophe”?

Question 15

• 15. Lamarck was responsible for the concept of the “______ of _______ characteristics”.

Answer 19

• 19. what is the “Malthusian catastrophe”?

This occurs when a population exceeds its available resources.

Question 20

20. Of the following which is an inference?

Potential exponential increase in populations (superfecundity)

Heritability of much of the individual variation

Differential survival and reproduction i.e. natural selection

Answer 20

20. Of the following which is an inference?

Potential exponential increase in populations (superfecundity)

Heritability of much of the individual variation

Differential survival and reproduction i.e. natural selection

Question 21

• 21. Biological evolution does not change individuals/populations.

It changes individuals/ populations.

Answer 21

• 21. Biological evolution does not change individuals/populations.

It changes individuals/ populations.

Question 22

• 22. Genetic resource that is shared (in theory) by all members of population is the ______ _____.

Answer 22

• 22. Genetic resource that is shared (in theory) by all members of population is the gene pool.

Question 23

• 23. What determines alleles in new individual? (state three)

Answer 23

• 23. What determines alleles in new individual? (state three)

• Mutation • Crossing over at meiosis I• Independent assortment

• Fertilization

• Change in chromosome number or structure

Question 24

24. When is a population not evolving?

Answer 24

24. When is a population not evolving?

• When it is in genetic equilibrium (that is the gene frequencies are constant, not changing).

Question 25

• 25. What is the mathematical model that measures genetic equilibrium?

Answer 25

• 25. What is the mathematical model that measures genetic equilibrium?

• Hardy-Weinburg Rule

p2 AA + 2pq Aa + q2 aa = 1

Frequency of allele A = pFrequency of allele a = q

p + q = 1

Question 26

26. What are two types of natural selection models? (there are three).

Answer 26

• 26. What are two types of natural selection models? (there are three).

• Stabilizing

• Directional

• Disruptive

Speciation

• Learn the terms

• Questions 1 - 17

Terms

• Learn the terms found in the glossary, Speciation.

Q -1

1. The process by which species are formed is known as _______.

A - 1

1. The process by which species are formed is known as __speciation_______.

Q – 2 and 3

• __________ is an accumulation of differences in separated pools of alleles.

• The evolution of reproductive _______ __________ pave the way for genetic divergence and speciation.

A 2 and 3

• Genetic divergence______ __________ is an accumulation of differences in separated pools of alleles. The evolution of reproductive ___isolating mechanisms_______ __________ pave the way for genetic divergence and speciation.

Q 4

• Be able to briefly define the major categories of prezygotic and postzygotic isolating mechanisms.

A 4• Be able to briefly define the major categories of prezygotic and postzygotic isolating mechanisms.• Prezygotic mechanisms take effect before or during fertilization.• a. Behavioral Isolation: patterns of

courtship may be altered to the extent that sexual union is not achieved (for example: albatross courtship rituals).

• b. Temporal Isolation: different groups may not be reproductively mature at the same season, or month, or year (for example: periodical cicadas).

• c. Mechanical Isolation: two populations are mechanically isolated when differences in reproductive organs prevent successful interbreeding (for example: floral arrangements in sage plants discriminate between different bee pollinators).

• d. Ecological Isolation: potential mates may be in the same general area by not in the same habitat where they are likely to meet (for example: different species of manzanita shrubs live at different altitudes and habitats).

• e. Gametic Mortality: incompatibilities between egg and sperm prevent fertilization (for example: signals to pollen grains to begin growing toward the egg).

• Postzygotic mechanisms take effect after fertilization.

• a. Sometimes fertilization does occur between different species, but the hybrid embryo is weak and dies.

• b. In some instances the hybrids are vigorous but sterile (example: mule produced by a male donkey and a female horse).

Q 5, 6, 7, and 8

• ______ speciation occurs when daughter species form gradually by divergence in the absence of gene flow between geographically separate populations.

• In _______ speciation, daughter species arise, sometimes rapidly, from a small proportion of individuals within an existing population.

• There is evidence that polyploid animals are rare because of a failed ________ compensation.

• When daughter species form from a small proportion of individuals along a common border between two populations, it is called _________ speciation

A 5, 6, 7, and 8

• ____Allopatric______ speciation occurs when daughter species form gradually by divergence in the absence of gene flow between geographically separate populations.

• In ___sympatric_______ speciation, daughter species arise, sometimes rapidly, from a small proportion of individuals within an existing population.

• There is evidence that polyploid animals are rare because of a failed __dosage________ compensation.

• When daughter species form from a small proportion of individuals along a common border between two populations, it is called _parapatric_________ speciation

Q 9

• Explain why sympatric speciation by polyploidy is a rapid method of speciation.

•

A 9

• Explain why sympatric speciation by polyploidy is a rapid method of speciation.

• Polyploidy is the inheritance of three or more of each type of chromosome due to improper separation of chromosomes during meiosis or mitosis.

• Speciation is instantaneous for plants that are polyploidy because they can only pair up their chromosomes with other identical polyploids (prophase I).

Q 10, 11, 12, and 13

1. In some cases of parapatric speciation, gene exchange between two species is confined to a _________ zone.

• Explain why branches on an evolutionary tree that have slight angles indicate the ________ model of speciation.

• Branches on an evolutionary tree that turn abruptly with 90-degree turns are consistent with the ________ model of speciation.

• An adaptive radiation is a burst of ________ from a single lineage that give rise to many new species, each adapted to an unoccupied or a new habitat or to using a novel resource.

A 10, 11, 12, and 13

1. In some cases of parapatric speciation, gene exchange between two species is confined to a _hybrid_________ zone.

• Explain why branches on an evolutionary tree that have slight angles indicate the __gradual________ model of speciation.

• Branches on an evolutionary tree that turn abruptly with 90-degree turns are consistent with the __punctuated________ model of speciation.

• An adaptive radiation is a burst of __divergences________ from a single lineage that give rise to many new species, each adapted to an unoccupied or a new habitat or to using a novel resource.

Q 14

• Distinguish cladogenesis from anagenesis.

A 14

• Distinguish cladogenesis from anagenesis.

• Cladogenesis applies to populations that become isolated from one another and subsequently diverge in different directions.

• Anagenesis is a pattern of descent in which species form within a single, unbranched line.

Q 15

• Be able to explain the use of evolutionary tree diagrams and the symbolism used.

•

A 15

• Be able to explain the use of evolutionary tree diagrams and the symbolism used.

• Evolutionary trees summarize information about the continuity of relationship among species.

• The gradual model of speciation is represented by tree diagrams with branches at slight angles to each other to show slow change over time.

• The punctuation model of speciation is drawn with short, horizontal branches that represent abrupt periods of speciation followed by stable periods.

Q16

• Cite examples of adaptive zones.

A 16

• Cite examples of adaptive zones.

• An adaptive zone is a set of ecological niches that may be occupied by a group of species that exploits the same resources in a similar manner. Examples: The sandy beach, the brook bottom, etc

Q 17

The fossil record shows twenty or more ________ extinctions.

A 17

• The fossil record shows twenty or more __mass ________ extinctions.