natural selection and modern synthesis

Question 1

what does natural selection say about species?

Answer 1

species are not immutable

Question 2

what analogy did darwin draw about natural selection?

Answer 2

he drew analogy between natural selection and artificial selection

Question 3

what are the 4 principles of natural selection?

Answer 3

variability, heritability, non-random survival and reproduction, surplus offspring

Question 4

what is variability?

Answer 4

species mate to produce viable offspring, gives natural selection something to act on

Question 5

what is heritability?

Answer 5

variability is transmitted generation to generation, traits come from genes

Question 6

what is lamarkism?

Answer 6

we inherit acquired traits, traits dont come from genes

Question 7

what is non-random survival and reproduction?

Answer 7

those with traits better suited to the environment are more likely to survive on average

Question 8

what does non-random survival and reproduction say about complexity?

Answer 8

it doesnt happen by chance

Question 9

what is surplus offspring?

Answer 9

there are more offspring than the environment can support (carrying capacity), species have a cap on growth

Question 10

what are the 4 F’s of fitness?

Answer 10

feeding, fighting, fleeing, reproduction

Question 11

what is fitness?

Answer 11

the differential survival and reproduction of individuals

Question 12

are species perfectly adapted to their environment?

Answer 12

no, as the adaptive landscape (environment) changes

Question 13

what happens when the adaptive landscape changes?

Answer 13

the optimum solution changes

Question 14

what happens when the optimum solution changes?

Answer 14

there is a reduction in fitness when getting from one strategy to the other

Question 15

what are 3 other sources of evolution?

Answer 15

genetic drift, founder effect, population bottlenecks

Question 16

what is genetic drift?

Answer 16

genes move randomly due to chance

Question 17

what is the founder effect?

Answer 17

loss of genetic variation in small population

Question 18

what are population bottlenecks?

Answer 18

populations shrink massively

Question 19

what is Mendel’s theory of inheritance?

Answer 19

genes are inherited without blending

Question 20

what is mendelian inheritance?

Answer 20

traits are controlled by discrete particles (genes), they are dominant or recessive

Question 21

what is mendel’s 1st law of segregation?

Answer 21

1. everyone has 2 copies of particles for a trait
2. pairs segregate and pass into different sex cells (gametes)
3. they unite with another particle after fertilization to form a zygote

Question 22

what is mendel’s 2nd law of independent assortment?

Answer 22

particles for different traits assort randomly

Question 23

how does mendelian inheritance effect variation?

Answer 23

it doesnt destroy variation, unlike blending

Question 24

what are 3 reasons why some traits appear blended?

Answer 24

1. more than one gene for a trait (polygenic)
2. co-dominance/incomplete dominance
3. recessive traits are hard to eliminate as they are hidden from natural selection

Question 25

what is the main theory of molecular genetics?

Answer 25

chromosome theory

Question 26

what are genes carried on in chromosome theory?

Answer 26

chromosomes

Question 27

what do gametes do in chromosome theory?

Answer 27

they carry single copies of parental chromosomes

Question 28

what happens when gametes are formed in chromosome theory?

Answer 28

variants of genes are equally likely to be transmitted

Question 29

what are alleles?

Answer 29

variants of genes

Question 30

what do genes do on a chromosome (locus)?

Answer 30

they occupy unique positions

Question 31

why is it difficult to understand a phenotype?

Answer 31

one gene can have multiple effects and multiple genes can have one effect

Question 32

what do genes do?

Answer 32

they code specific sequences of amino acids

Question 33

what are the 4 protein functions?

Answer 33

structural, enzymes, hormonal, regulatory proteins

Question 34

what is epigenetics?

Answer 34

how behaviour and environment can affect how genes work

Question 35

what is the modern synthesis?

Answer 35

neo-darwinism, blend of natural selection and mendelian inheritance

Question 36

what is the theory of the modern synthesis?

Answer 36

populations evolve and evolution acts on genes

Question 37

what are 6 forces for changing allele frequencies in populations?

Answer 37

genetic drift, natural selection, gene flow, mutation, non-random mating, meiotic drive

Question 38

what is meiotic drive?

Answer 38

selfish genes are passed on more than is predicted from random assortment

Question 39

how is an organism described by the modern synthesis?

Answer 39

it is a genes way of making more genes

Question 40

what are analogies?

Answer 40

traits that appear similar but evolved independently (convergent evolution)

Question 41

what are homologies?

Answer 41

traits that share evolutionary history but look different

Question 42

what does adaptive radiation produce?

Answer 42

homologous traits

Question 43

what are vestigial traits?

Answer 43

traits that have no purpose (eg human tailbone)

Question 44

what are exaptations?

Answer 44

traits that serve a different purpose than they were adapted for

Question 45

what are developmental byproducts?

Answer 45

expressed traits that have no purpose in certain members of a species (eg male nipples)

Question 46

what is maladaptation?

Answer 46

failure to adapt to an environment

Question 47

what are 2 reasons not all traits can evolve?

Answer 47

1. phylogenetic inertia 2. genetic or physical constraints

Question 48

what is evolvability described as being?

Answer 48

adaptive

Question 49

what are eugenics?

Answer 49

breeding desired traits

Question 50

what is a misunderstanding about the nature of natural selection?

Answer 50

natural selection doesnt act for the good of the species

Question 51

what is hume's is-ought fallacy?

Answer 51

just because something is evolved the way it is, it doesnt mean it ought to be that way

Question 52

what is the naturalistic fallacy?

Answer 52

not everything naturally evolved is good (eg desires)