Adaptations

Question 1

What is an example of an evolutionary anachronism?

Answer 1

Many neotropical plants with large, tough seeds are not adapted for seed dispersal now because they relied on large herbivore dispersers that are now extinct

Question 2

How can adaptation be a part of sexual selection?

Answer 2

Mate attraction or competition. Adaptations to draw in a mate or to fight to get access to mates

Question 3

What data supports the human eye being a complex adaptation?

Answer 3

Computer simulation showed it took 400,000 generations for an eye to evolve to a complex vertebrate eye

Question 4

Linkage among traits

Answer 4

Pleiotropy

Question 5

What is poor design evidence of?

Answer 5

Natural selection

Question 6

What is an example of a genetic constraint to adaptation?

Answer 6

Heterozygote advantage

Question 7

Things from a different time that existed due to selective pressures then that don’t exist now

Answer 7

Evolutionary anachronisms

Question 8

How are adaptation, fitness, and natural selection related?

Answer 8

All three are linked to each other

Question 9

Why is it not advantageous to get rid of vestigial structures?

Answer 9

Flightless bird wings are a good example. Getting rid of the wings gets rids of the genes and getting rid of the genes is a bad idea

Question 10

What is needed to show a correlation is an adaptation?

Answer 10

Fitness data is needed to support it

Question 11

What is the only known explanation for adaptations?

Answer 11

Natural selection. Natural selection leads to adaptations

Question 12

Share the same development patterns but are modified for specific species through selection

Answer 12

Homologous structures

Question 13

Are complex adaptations related to the best solution?

Answer 13

No. Complex doesn’t mean best and simple doesn’t mean worst

Question 14

Feeding specializations and crypsis (allowing organisms to blend in) are examples of what?

Answer 14

Adaptations (noun)

Question 15

Can individuals adapt?

Answer 15

No

Question 16

What are adaptations the result of?

Answer 16

They are the result of evolution by natural selection

Question 17

Why do developmental constraints exist for adaptations?

Answer 17

Certain morphologies are impossible developmentally

Question 18

What are products of convergent evolution?

Answer 18

Analogous structures

Question 19

An existing structure modified to serve a new function

Answer 19

Preadaptation

Question 20

What do trade offs lead to?

Answer 20

Stabilizing selection. Finding the balance between what you’re selecting for and the other function compromised as a result

Question 21

What can a significant shift in phenotype cause for an organism?

Answer 21

It could push the organism off and over the adaptive peak

Question 22

Example of a trade off

Answer 22

Longer legs = faster but more fragile bones

Question 23

How is poor design proof of selection?

Answer 23

Mutation is random and selection can only act on what exists so if the mutation is poor but functional, selection will still act on it

Question 24

Something is this if it scales with size

Answer 24

Allometry

Question 25

Adaptation for one function may compromise another function

Answer 25

Trade offs

Question 26

The process by which features that enhance fitness are fixed in a population or species

Answer 26

Adaptation (verb)

Question 27

What happens when you go up a peak ("decide" on a solution) in the fitness landscape?

Answer 27

You cant go back down to get to an optimal peak, you are stuck with the one you have

Question 28

Functionally similar but structurally and historically different. Have independent evolutionary origins

Answer 28

Analogous structures

Question 29

Why is it difficult to determine what selection has selected for, thus making it hard to determine whether something is an adaptation?

Answer 29

Linkage of traits (pleiotropy) and passage of time

Question 30

What is heterozygote advantage?

Answer 30

The form with the highest fitness cant breed true. A heterozygote crossed with a heterozygote doesn't produce all high fitness heterozygotes, it produces 50% homozygotes that are lower in fitness

Question 31

Valleys in the fitness landscape represent this

Answer 31

Low fitness

Question 32

What are two types of constraint to adaptation?

Answer 32

Genetic and developmental

Question 33

When are adaptations most apparent?

Answer 33

Most apparent from comparisons of related species specialized for different niches

Question 34

What is an example of poor design in humans but selection still acting on it?

Answer 34

The eye. The blind spot and having muscles stretch to focus are not optimal. The male urogenital system also is not optimal.

Question 35

Way of visualizing adaptations in potential solutions

Answer 35

Fitness landscape

Question 36

An adaptation that has arisen via preadaptation

Answer 36

Exaptation

Question 37

What makes adaptation unique from usually occurring selective evolution?

Answer 37

Adaptation occurs gradually with directional selection over several generations

Question 38

These two are the effects of differences in fitness

Answer 38

Differential reproductive success and survival

Question 39

What two things must be present for something to be considered an adaptation?

Answer 39

1. Improve fitness such that organisms with the trait have higher fitness than those without (all other things being equal) 2. Show correlation between the presence of the feature and the hypothesized selective pressure (ex: larger beaks survive food shortage from drought)

Question 40

Structures with little or no current function but are retained due to common ancestry

Answer 40

Vestigial structures

Question 41

Peaks in the fitness landscape represent this

Answer 41

High fitness

Question 42

Specialized features that enhance fitness

Answer 42

Adaptations (noun)

Question 43

How does selection act in an adaptive landscape?

Answer 43

Selection cant look across the landscape and choose the path to the highest peak. Selection operates on existing variation and chooses the local peak, it probably won't cross a non-adaptive valley

Question 44

What can be products of divergent evolution?

Answer 44

Homologous structures

Question 45

How does adaptation occur over time?

Answer 45

It is usually gradual. Slight adjustments over multiple generations

Question 46

What is an example of a developmental constraint to adaptation?

Answer 46

Allometry. Animals with antlers, selection exists for large body size but large body size comes with large antlers which are unfavorable (neck cant support it) so it is against it

Question 47

Structurally similar but can be functionally different. Have evolutionary shared ancestry

Answer 47

Homologous structures

Question 48

What is an example of convergent evolution in cave dwelling animals? How does this occur?

Answer 48

Loss of sight and pigmentation is the convergent evolution. This occurs due to the absence of selective pressures for these things