evolution

Question 1

what is a scientific theory?

Answer 1

a mature, coherent body of interconnected statements based on reasoning and evidence
explains some aspects of nature

Question 2

what is evolution not?

Answer 2

not the same as natural selection
not something from the past but continuously occurring
doesn’t happen to individuals but populations

Question 3

what is evolution?

Answer 3

the change in properties of groups of organisms over the course of generations
ie descent with modification

Question 4

history of evolution thinking

Answer 4

previous thought was essentialism
relates to how everything is present of a continuum from inanimate to supernatural

led to ideas about how organisms are structured naturally

Question 5

James Hutton

Answer 5

made geology a science
wrote ‘Theory of the Earth’

Question 6

Charles Lyell

Answer 6

principles of geology
study of rock layers
influential to Darwin

Question 7

Jean-Baptiste de Lamarck

Answer 7

life had originated many times
overtime, lineages become more complex
all complexities exist at one time
- simple forms and older more complex forms

Question 8

what did Darwin and Wallace publish?

Answer 8

theory of evolution by natural selection
copublished

Question 9

similarities between Darwin and Wallace

Answer 9

evolution as a fact
common descent
changes are gradual
populations changing not individuals
caused by natural selection

Question 10

differences between Darwin and Wallace

Answer 10

Darwin emphasised competition between individuals of the same species to survive and reproduce

Wallace emphases environmental pressures on varieties and species forcing them to become adapted to their local environment

Question 11

acceptance of the theory

Answer 11

general acceptance of evolution
but rejection of natural selection
- no mechanism of inheritance ti explain traits being passed on
- blending theory of inheritance is not compatible with natural selection

Question 12

Neo-Lamarckism

Answer 12

acquired traits can be passed on

Question 13

orthogenesis

Answer 13

‘straight line’ evolution towards a fixed goal

Question 14

mutationist

Answer 14

major mutations gave rise to new phenotypes
some of which constituted a new species

Question 15

the modern synthesis

Answer 15

marriage og genetics and natural selection
mutation as raw materials for selection rather than alternative

development of mathematical theory
theory and empirical population genetics
applying concepts across fields

Question 16

developments since the modern synthesis

Answer 16

extension of evolutionary theory
- ecology, behaviour

molecular evolution
evolutionary development
macroevolution

Question 17

bias in the theory

Answer 17

scientist occurs in all societies not just western world

eg lack of representation of muslim scholars
lack of women

Question 18

eugenics

Answer 18

new understanding of evolution by natural selection opted as means of improving human society

• science of improving human stock

Question 19

examples of eugenics

Answer 19

Churchill campaigned for sterilisation of undesirables
pedigrees traced to establish inheritance of desirable and undesirable traits to purify American people

nazi laws to sterilise people such as schizophrenics and the blind

Question 20

eugenics in modern society

Answer 20

discussions of overpopulation and eco-facism
evolutionary racism as the motivation for mass shooting
white replacement theory - black outbreeding white people

Question 21

what is a mutation?

Answer 21

any change in the nucleotide sequence of DNA
can be deleterious (harmful) or neutral (no effect)

origin of genetic variation

Question 22

causes of mutation

Answer 22

DNA damage by mutagens
errors in DNA replication

Question 23

synonymous vs nonsynonymous mutations

Answer 23

synonymous - the amino acid sequence does not change

non synonymous - amino acid sequence changes

Question 24

results of mutations

Answer 24

loss of function
gain of function (rare)

Question 25

mutation rates among regions of the genome

Answer 25

base composition - transitions and transversions occur at different rates position in the genome - centromeres vs chromosome tips have different rates presence of epigenetic modification

Question 26

mutations rates among organisms

Answer 26

depends on efficiency of their DNA repair mechanisms exposure to mutagens

Question 27

relationship between genome size and mutation rate

Answer 27

viruses and prokaryotes: smaller genome so higher mutation rates multicellular organisms: larger genomes so higher mutation rates

Question 28

gene pool

Answer 28

sum of all copies of all alleles within a population

Question 29

selection

Answer 29

occurs when there is a difference in the survival and/or reproduction of individuals based on their phenotypes survival and reproduction summarised as fitness increases the frequency of the favoured trait in next generation

Question 30

natural selection

Answer 30

when the difference in fitness occurs due to conditions in biotic or abiotic environment eg peppered moth

Question 31

artificial selection

Answer 31

when the difference in fitness occurs due to human preference for traits eg selective breeding critically important process in human history - basis of crop and livestock improvement - development of breeds

Question 32

sexual selection

Answer 32

when individuals mate preferentially with particular individuals rather than at random influence fitness has power to favour traits and enhance chances of reproduction, even if reduce chance of survival

Question 33

impact of sexual selection on fitness

Answer 33

important as individuals that survive but don't reproduce make no contribution to next generation = no fitness

Question 34

how do mating patterns impact an individuals fitness?

Answer 34

survival due to natural selection reproduction relies on sexual selection limited by need for a balance between survival and reproduction eg peacock tails

Question 35

adaptation

Answer 35

characteristic that enhances the survival or reproduction of organisms process by which members of a population become better adapted to their environment

Question 36

migration

Answer 36

movement of individuals or gametes if migrants survive and reproduce then gene flow occurs

Question 37

gene flow

Answer 37

caused by migration changes allele frequencies in a population in proportion to the rate and direction of migration

Question 38

genetic drift

Answer 38

random chances in allele frequencies from one generation to the next driven by chance not selection impacted by meiosis and random survival larger impacts in smaller populations - in larger, many more generations required before allele eliminated or fixed

Question 39

mechanisms in an unstable population

Answer 39

population bottleneck founder effect

Question 40

population bottleneck

Answer 40

when a population is dramatically reduced in size by chance the small number of survivors may not be representative of the original population reduces genetic variation eg elephant seal

Question 41

founder effect

Answer 41

when a population is started by a small number of individuals they are unlikely to possess all of the alleles found in the gene pool of the source population founder population less variable than original rare alleles are likely lost reduced genetic variation

Question 42

processes in evolution

Answer 42

mutation selection (natural and sexual) gene flow genetic drift non random mating (sexual selection) all occur at the same time in a natural population