Struggle for Existence part 2

Question 1

contrary to some popular ideas, evolution should not be ex-pected to produce perfection. True

Answer 1

True

Question 2

Adaption through ________

Answer 2

natural selection

Question 3

Purpose of pencil to write and ear is to hear, both become better adapted through action of ________

Answer 3

selection that eliminated variants that served purpose less effectively

Question 4

Purpose there, plan absent

Answer 4

A modern biologist recognizes no element of proper planning the origin and evolution of the human ear. -Ears and other features of living or-ganisms…are perfected entirely by the trial-and-error process of natural selection proposed by Charles Darwin in 1859.
-Ears are main-tained and improved because individuals with better ears are more likely to survive and pass their genes on to future generations. This conclusion is supported by evidence that organisms can have sophisticated ad-aptations and at the same time show…features that would not be there if intelligent planning had played a role.

Question 5

natural Selection does

Answer 5

select new variants that perform a little better than the previous model and over millions of generations, accumulation of those little improvements can be sublime but imperfections give away the unplanned process of nature

Question 6

How a feature increases an organism ability to survive and pass on it genes, we call the _____ a function and feature an ________

Answer 6

1) role

2) adaption

Question 7

Human ear represent an ______ for the function hearing. Why did it arise?

Answer 7

1) adaptation
2) because animals with more acute hearing had HIGHER fitness than other.

Well functioning ears confer a fitness advantage

Question 8

In many animals, shape and orientation of pinna (external ear) is important to sharpness of hearing. Example?

Answer 8

An alert cat turns its ear to trash sounds but in humans, pinna contributes very little to hearing and certain features have no function

Question 9

In many animals, shape and orientation of pinna (external ear) is important to sharpness of hearing. Example?

Answer 9

An alert cat turns its ear to trash sounds but in humans, pinna contributes very little to hearing and certain features have no function.
Many animals can regulate body temp in addition to hearing (rabbits, elephants) = vascularized ears dump heat from body to environment through blood flow

Question 10

Natural selection weeds out the worst trait but ….

Answer 10

it takes time and does not produce perfection

Question 11

when is Maladaptive trait prominent?

Answer 11

when changing environment with new ecological challenges and opportunities change the fitness consequences of pre existing characteristic

Question 12

Example of maladaptive trait prominent:

Answer 12

Humans sting attraction to sweet and fatty foods was probably an adaptive trait in past environment where energy rich food was rare

Modern: doughnut rich environment it has become maladaptive

Question 13

Maladaptive traits can be

Answer 13

lingering holdovers form different environment, and also be mainlines by tradeoffs and constraints

Question 14

Nothing in the action of natural selection prevents traits from multitasking. True or False

Answer 14

True

Question 15

Natural Selection does not act directly upon _____ or ____ in isolation

Answer 15

1) traits or genes

Question 16

Individual organisms are the entitles that succeed or fail, so Adaptive evolution of a particular trait depends on

Answer 16

its overall effect on fitness, through all of fits function

Question 17

large eared jack rabbit encounters cool climate, small ears….

Answer 17

which smaller ears would allow to retain heat better. Thermoregulation: smaller ears might reduce having sharpness and makes rabbit vulnerable to predators

Question 18

Tradeoff

Answer 18

Rabbits ear are built, there is a negative relationship between hearing well and conserve heat well
longer ear: cool in summer and hear well but lose heat in winter
small ear: warmer in winter but cannot hear as well as with long ears and become vulnerable to predators
- hamper adaptive finetuning.

Question 19

Tradeoff

Answer 19

Rabbits ear are built, there is a negative relationship between hearing well and conserve heat well
longer ear: cool in summer and hear well but lose heat in winter
small ear: warmer in winter but cannot hear as well as with long ears and become vulnerable to predators
- hamper adaptive finetuning.
Impossible to develop ear that maximizes hearing and thermoregulation

Question 20

Life-History traits

Answer 20

Such traits concern the timing of life events (maturation and reproduction) and # of resources individual invest in such functions
- leads to proposition reproduction-survival tradeoff and size-# tradeoff

Question 21

Reproduction-Survival tradeoff

Answer 21

Investing resources in offspring means they can’t be used in maintaining the body

Question 22

Size-# tradeoff

Answer 22

if you make more seeds, they have to be smaller

Question 23

Resource-allocation tradeoff

Answer 23

• one form of evoltionary constraint
• reduce range or kind of adaptation that one might otherwise see
  Example: rabbits
• they run around in sun and open areas
• have big ears and those who live in the hottest places have largest bodies

Question 24

Relationship between ear size and environmental temp =

Answer 24

EVOLUTION in ear size has been largely unconstrained by other factors

Question 25

American Pikas

Answer 25

• do not have large ears*
• live in rocky place and sensitive large ears might get torn between rock and under rock piles
• Mountain tops are cold places (live there), they do not need to loose heat from large ears. Small ears help keep warmth

However global climate changes,

• pikas encountering more heat waves and large ears might be advantageous
• BUT NATURAL SELECTION for LARGER EARS might be countered by constraint posed by the wear and tear of pikas rocky underground style

Question 26

The Comparative Method

Answer 26

Examine how diff organisms meet environmental challenging in diff ways

Question 27

When is comparative method the strongest?

Answer 27

When we know how the species are related to each other

Question 28

Penstemon example

Answer 28

2 flowers species share many characteristics that suit them fro pollination by humming birds.
2 explanations for similarities:

1) 2 species could be close relatives
- similar because they inherited characters by descent from recent common ancestor
- cannot count the 2 bird adapted species are representing 2 separate evolutionary transitions from bee to bird pollination

2) species could be very distantly related and share characters because they have evolutionarily converged under selection exerted by humming birds
- we can infer that both had diff ancestors that were bee adapted and one represents a separate, indecent transition to bird pollination

Question 29

Phylogenetic trees

Answer 29

evolutionary relationship