Chapter 15

Question 1

evolution general definition

Answer 1

change within organisms over time, 2 types:
development
acclimation: response to changing environment conditions

Question 2

specific (biological) definition

Answer 2

change in the genetic makeup of a population over time

according to this definition, populations evolve, individuals dont

Question 3

pre darwin ideas (aristotle)

Answer 3

species dont change over time

natural order exists in the world and does not change

Question 4

plato

Answer 4

all objects can be represented by ideal forms

variation between indivduals represents a deviation from the ideal form (so is not important)

Question 5

jean lamarack

Answer 5

2 driving forces in evolution
1. linear force:
evolution towards increased complexity and perfection
this is driven by some internal force in all living things
2. lateral force: adaptation to local conditions
organisms have features that suit them to where and how they live
mechanims for adaptation is use an disuse of parts:
body part that develop in a certian way during an individual life are passed to its offspring

Question 6

charles darwin

Answer 6

sailed around the world in the 1830s as a naturlist on the beagle
proposed a mechisms for evultion in 1830s
continued to develop collect evidence for evolution for 20 years

Question 7

1858:

Answer 7

alfred wallace devlopment the same idea as darwin

Question 8

the origin of species

Answer 8

published in 1859

Question 9

darwin was influenced by two ideas

Answer 9

1. uniformitarianism: world is under constant slow change
   large changes can occur over long periods of time
   essay on population (1798, thomas malthus)
   human population grow faster than resource supplies
   when populations are stable, individuals suffer fro lack or resources

Question 10

darwins mechanims for evolution: theory of natural selection

Answer 10

observations:
1. all organisms can reproduce at an exponential rate
2. populations do not increase expontially
3. resources are limited
the ideas of malthus apply to natural population

Question 11

conclusion 1:

Answer 11

there is a struggle for existence between organisms within a species

observations:
4. indivduals in populations vary in a number of traits
5. some varibility is inheritied

Question 12

conclusion 2:

Answer 12

the ability to survive is related to variation in different traits
indivduals with traits that allow them to survive in particular situations pass these traits to their offpsring

Question 13

conclusion 3:

Answer 13

over many generations populations evolve, adapting to their enviorment
populations of the same species, in different environments, will evolve into different species

Question 14

conclusion 4:

Answer 14

applying the concept of uniformitarnisam:
all species have evolved from a common anscestral species
theory does not explain were new variation comes from

Question 15

impact of darwins ideas

Answer 15

branching pattern of evolution- all living things envolved from a common ansestor
non-constancy of species
struggle for existance is dominant force in nature
importance of variation within species

Question 16

importance of probability

Answer 16

random events:
1. new variation
2. presence of organism in particular enviornment
the success of an orgainsm is partly a random event

Question 17

evidence for evolution

Answer 17

artifical selection: organisms can be bred to look different

Question 18

biogeography

Answer 18

because they share a common ancestor, organisms from one region are more similar to each toher tha organisms from other regions

Question 19

fossil record

Answer 19

fossils are not arranged at random
fossils of recent origin, in a region resemble organisms living in the region
groups of organisms are found in similar aged rock layers in different places

Question 20

comparative anatomy

Answer 20

related organisms are built from the same basic parts
homologous structure: body parts similar in structure but can be functionally different ex) from a common ansestor
analogous stucture: body parts different in their basic in structure but functionally similar (from different anstror
vestigial (non fucntional) organs
organisms retain body parts of ansestors even when they are not used

Question 21

molecular biology

Answer 21

evolutionary reltionships can be implied from the chemical or genetic simsilarity if organisms

Question 22

co evolution

Answer 22

organisms that rely on one another show similar evolutionary patterns
ex) lice on mammals

Question 23

traditional agruements against evolution

Answer 23

there have been disagreements about:
the fact of evolution
the mechanism of evolution
does eolution occur by natrual selction

Question 24

lack of what in fossil record

Answer 24

intermediate forms

Question 25

dilution of favourable traits ex ) tall plants

Answer 25

each generation of offspring fo the tall plant becomes shorter since it crosses with short plants evolution works this way if inheritance is blending but inheritance is particuulate so, the tall trait does not become diluted

Question 26

blind watchmaker

Answer 26

1. mutation is a random process 2. complex structures require many mutations 3 it is highly (impossible for random mutations to create complex sturctures however: the evolution of complex stuctures is possible if intermediate structures are preserved

Question 27

irreducible complexity

Answer 27

incomplete stcutures are not useful and complete stcutures are too complex to evolve in a single step however, some incomplete stcuture can be useful as they envolve they may change their function

Question 28

sea vents

Answer 28

chlorophyll liek pigemtns may have evolved to detect photons from deep sea vents bacteria need to be close to vents photons coming from vents are too weak for photosynthesis

Question 29

different types of natural selection

Answer 29

selection can be classified by the traits that increase fitness for a continuous trait we expect a distrubtuion like this: moutian curve 1. stabilizing selection 2. directional selection 3. disruptive selection 4. frequncy dependant selection

Question 30

stabilizing selection

Answer 30

indivduals with average traits are selected decrease the variation in the population but does not change the avaerage value of a trait probably occurs in most populations when the enviornment is stable and organisms are adpated to where they live

Question 31

directional selection

Answer 31

individuals with higher or lower than everage traits are selected decreases variation and changes the avaerage value of a trait occurs when the anvironment changes and organisms adapt these changes

Question 32

disruptive selection

Answer 32

individuals with higher AND lower than average traits are selected creates two peaks in the abundance of a trait: occurs whem resources are unevenly distrucbuted in the enviornment

Question 33

frequency dependent sleection

Answer 33

individuals with uncommon traits are selected | tends to balance the proportion of individual with different traits

Question 34

example of frequency dependent selection

Answer 34

diease and parasite resistance: dieases envolve to infect common genotypes sex ratio: proportion of reproductive male and female tends to be equal

Question 35

other mechanisms of evolution

Answer 35

mechanisms that do not result in adaptation to the environment

Question 36

sexual selection

Answer 36

also proposed by darwin | some indivduals have traits which may decrease their ability to survive but increase their access to breeding partners

Question 37

2 forms of sexual selection

Answer 37

1. females show prefernce for males with certian traits 2. males compete with one another for access to females size differneces between males and females may be the result of sexual selection

Question 38

random selection of indivuduals in small populations

Answer 38

change in the genetic makeup of a population by random events invloves elimination of genetic info from a population

Question 39

founder effects

Answer 39

only a few individuals in a pop colonize a new habitat | by chance, these few indivdiuals have different traits compared to the parents population

Question 40

bottleneck effects

Answer 40

all but few individuals in a population are eliminated | surviving indivdiuals do not contain the same genetic stucture as the orginal population

Question 41

genetic drift

Answer 41

non adaptive change in a population over time ex) ABO blood type distribution ex 2) allele for HIV restistance

Question 42

some patterns of human genetic are a

Answer 42

mix of adaptive and non adaptive mechanisms of evolution low pigments increases vit D production pigmentation provides UV protection