Exam 2 PPTs - 9

Question 1

(Natural selection is not the only explanation for adaptation) We should accept a … of evolutionary processes

• we need … as well as selection in a full theory of evolution
• when we are studying adaptation, it is sensible to concentrate on …

Answer 1

“pluralism”;
drift;
natural selection

Question 2

(Natural selection is not the only explanation for adaptation)

• … explains some adaptations, such as camouflage (peppered moth example)
• the problem arises in complex characters that are adapted to the environment in many … respects
• Darwin’s explanation for complex adaptations is that they …

Answer 2

selection;
interdependent;
evolved in many small steps

Question 3

(Natural selection is not the only explanation for adaptation)

• evolution is …
• if each mutation arose …., in different organisms at different times, the whole process becomes more probable
• Darwin’s … requirement is a fundamental property of evolutionary theory

Answer 3

gradual;
separately;
“gradualist”

Question 4

(Natural selection is not the only explanation for adaptation)
- In Darwin’s words, “if it could be demonstrated that any complex organ existed which could not possibly have been formed by numerous …, my theory would absolutely break down.”

Answer 4

successive slight modifications

Question 5

Climbing mount improbable by Richard Dawkins:

- the main metaphorical treatment is of a … upon which evolution can … and cannot … (that is known as an …)

Answer 5

geographical landscape;
ascend only gradually;
climb cliffs;
adaptive landscape

Question 6

(functionless, or disadvantageous, rudimentary stages)

- An organ has to be … to its bearer at all stages in its evolution if it is to be produced by natural selection

Answer 6

advantageous

Question 7

The function of an adaptation may change with …

Answer 7

little change in its form

Question 8

(the function of an adaptation may change with little change in its form)

• during the evolution of the eye, the function of the organ was … throughout
• in other cases, organs can change their … with relatively little change in …

Answer 8

relatively constant;

function; structure

Question 9

(the function of an adaptation may change with little change in its form)
- evolution of feathers and the tetrapod leg are interesting examples of … –> shift in the … of a trait during evolution

Answer 9

exaptations;

function

Question 10

evolution of feathers:

• Feathers are found in modern birds and mainly function in …, but they originally evolved got some other function
• tetrapod leg: fossil evidence, such as from Acanthostega, suggests that legs originally evolved for …

Answer 10

flight;

underwater swimming

Question 11

A new adaptation may evolve by …

Answer 11

combining unrelated parts

Question 12

(A new adaptation may evolve by combining unrelated parts)

• novelty may result when two … are …
• the mitochondria in eukaryotic cells each originated when one bacterial cell ….

Answer 12

pre-existing parts;
combined;
engulfed another bacterial cell

Question 13

(A new adaptation may evolve by combining unrelated parts)
- the mitochondria in eukaryotic cells each originated when one bacterial cell engulfed another bacterial cell. In the case of mitochondria, the combined cell was capable (or soon evolved to be capable) of … in … - a process that releases more energy than …

Answer 13

burning carbohydrates;
oxygen;
anaerobic respiration

Question 14

(Trade-Offs and Constraints)
female flower size in a begonia:
- the flowers are pollinated by …
- the male flowers offer them a …, the female flowers offer …
- the resemblance between male and female flowers is presumably …

Answer 14

bees;
reward;
nothing;
adaptive

Question 15

(Trade-Offs and Constraints)
female flower size in a begonia:
- bees avoid … flowers in favor of … flowers
- the rate at which female flowers are visited should depend on how closely they …
- the larger the flower, the more bees …

Answer 15

female;
male;
mimic male flowers;
approach and visit