Understanding

Question 1

What are the three requirements for adaptation

Answer 1

They must have a genetic basis, they must increase fitness in the given environment, and they must have evolved for the purpose they are being used now

Question 2

An example of adaptation must have a genetic basis

Answer 2

The fact that you know how to drive CANNOT be an adaptation because that is a phenotype you got from your environment. You didn’t have it in your DNA when you were born

Question 3

What are the three components of fitness?

Answer 3

How good you are at surviving, finding a mate and having offspring

Question 4

Adaptations must have evolved for the purpose it is currently serving example:

Answer 4

Bird feathers are thought to have originally evolved to keep birds warm but now they are used to help birds fly

Question 5

Adaptation evolve due to natural and sexual selection

Answer 5

Natural selection leads to adaptations

Ex: mice that live on the lava rocks have dark fur because it’s an adaptation to their environment

Question 6

Adaptation examples

Answer 6

Some fish have antifreeze proteins that are an adaptation that allow them to survive in very cold water

Question 7

Some of the best evidence for adaptation comes from convergent evolution

Answer 7

This is because species experienced similar environments. So they evolved independently similar traits to handle their environments

Question 8

Convergent evolution is almost an opposite to homólogy

Answer 8

In homology species have the same trait due to a common ancestor but in convergent evolution species have similar traits because they evolved independently

Question 9

Examples of convergent evolution

Answer 9

Two plants can look similar due to adapting to similar environments

Question 10

What are examples of traits that aren’t adaptations

Answer 10

1. Traits that evolved as side effects (pleiotropy)
2. An outdated adaptation
3. An exaptation
4. Traits that evolved due to genetic drift
5. Traits that no longer serve a function

Question 11

1. Traits that evolved as aide effects example

Answer 11

We give birth to small babies because when we started walking in two legs. Our pelvis got smaller. So we started to give birth early in pregnancy so the baby can still fit through the pelvis.

Question 12

2. Trait that are outdated adaptations

Answer 12

Example the calabash tree has large hard shelled fruits. It was thought because of gomphothere that could easily move the fruit. But then they went extinct and the fruits kept the hard shell.

Question 13

3. Traits that are an exaptation

Answer 13

Birds used to use feather to keep warm but now they use them to help fly

Question 14

4. Traits that evolved due to genetic drift and non random mating (inbreeding) example

Answer 14

Royal families with big jaws evolved due to inbreeding

Question 15

5. Traits that no longer serve a function example

Answer 15

Vestigial traits

Wisdom teeth or human tail bone

Question 16

Why don’t all adaptations evolve?

Answer 16

1. Physical constraints
2. Pleiotropy
3. No variation
4. Trade offs

Question 17

1. Physical constraints examples

Answer 17

Plants can’t have skinny stems and big leaves or else they will fall over

Question 18

2. Pleiotropy examples

Answer 18

Sometimes the pleiotropic effects of an adaptation trait are so bad that the trait cannot evolve
Ex: human babies can’t be born earlier unless we go back to walking on 4 limbs

Question 19

3. No variation

Remember the three conditions for natural selection

Answer 19

Variation in population, variation is heredity, and variation leads to higher fitness

Question 20

3. No variation

In order to see evolution you have to have variation in the trait

Answer 20

Ex: humans can’t have wings until a mutation arises that leads to wings on our back

Question 21

4. Tradeoffs

Organisms have a limited amount of energy

Answer 21

Ex: if you spend more energy on reproduction (making babies) you will have less energy to spend on surviving.
Tradeoffs prevent some adaptations from evolving

Question 22

An adaptation does not lead to a perfect fit in the environment

Answer 22

Sometimes the environment changes and the population doesn’t evolve fast enough to adapt to it

Question 23

Examples of evolutionary mismatch

Answer 23

Snowshoe hares (bunnies) change colors eight the seasons so they camouflage better. With climate change and changing seasons, they are sometimes color mismatch, leading to easy pickings

Question 24

What is the difference between adaptation and phenotypic plasticity?
The key is the environment

Answer 24

Adaptation is passed down while phenotypic is when an individuals phenotype changes because of the environment

Question 25

Example of adaptation plasticity

Answer 25

Human populations that live in high elevations (mountains) have evolved to have proteins that can deal with less oxygen

Question 26

Example of phenotypic plasticity

Answer 26

If you live in low elevation and go to high elevation. You can get used to it but once you go back you lose it and your offspring won’t be adapted to live in high elevations

Question 27

Review of phenotypic plasticity

Answer 27

When the same genotype in different environments leads to different phenotypes. They are not adaptations

Question 28

Is phenotypic plasticity reversible?

Answer 28

Yes , you go back to normal once you leave the environment or the environment changes

Question 29

How does phenotypic plasticity happen?

Answer 29

The environment changes

Question 30

How do we study adaptations?

Answer 30

First need to make sure the trait has a genetic basis. Then, figure out what function the trait might have for the organisms. Then we can either do:
•experiments
• reciprocal transplant experiments, specifically
• comparative studies

Question 31

How do We study if a trait has a genetic basis? Think back at the three conditions of natural selection

Answer 31

How do test if trait is heritable? We measure parents phenotypes and organisms phenotypes and check if parents phenotype predicted child phenotype
Another approach is to change the environment of the organism. See if the phenotype stays the same. If it changes it could be due to phenotypic plasticity.

Question 32

How do we do experiments to test if a trait is An adaptation?

Answer 32

1. We figure out what the function provides
2. We have to hypothesize how that function increases fitness
3. We have to test to see if the function actually increases fitness
   Tricky thing: measuring fitness is hard so instead we measure something similar like body size, mass or survival

Question 33

What is a reciprocal transplant experiment?

Answer 33

When closely related species have adapted to different environments. You switch the species/ populations around to the other environment and see what their fitness is in the new environment.

Question 34

What is comparative method?

Answer 34

When you see how a trait ( that might be an adaptation) has evolved on a phylogeny

Question 35

Special topics in adaptation

Answer 35

Evolution of sex
Evolution of life history
Evolution of behavior
Co-evolution

Question 36

Is sexual reproduction adaptive

Answer 36

There are two main ways to make a baby. Clone yourself (asexual) or mate with someone(sexual). The main hypothesis is that it is an adaptation

Question 37

Sexual reproduction increases fitness

Answer 37

Sexual reproduction increases genetic diversity which lets species respond to changing conditions more quickly. Sexual reproduction also makes it easier to get rid of bad mutations.