Speciation full Flashcards

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1
Q

Evolution

A

change of gene pool of a pop over tine

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2
Q

Gene Pool

A

All genetic alleles present in a population

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3
Q

Allele Frequency

A

The occurrence of allele/total amount of allele present
How common an allele occur in a population

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4
Q

Mutation

A

It is a permanent change in the base sequence of DNA that may result in new alleles being formed. The only way new alleles are formed.

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5
Q

I can discuss the relationship between allele frequency and evolutionary change

A

it is influenced when the enviro changes and it will affect mutant alleles. For instance, if an evolutionary change leads to the emergence of a mutant allele and it undergoes natural selection, successful survival boosts the mutant allele’s reproductive success and frequency. Conversely, if the mutant allele doesn’t survive, the opposite occurs.

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6
Q

I can define genetic drift

A

Random change in allele frequency of population over time

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7
Q

I can discuss how genetic drift changes a gene pool

A

due to certain alleles caused by random events made them less common in a population over time - less genetic diversity.

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8
Q

I can define the founder effect

A

Founder effect is when a small number of a population moves and establishes a new population carrying small amount of genetic variation present in the original population - more gd

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9
Q

I can define the founder effect
I can explain how the founding population will likely have a different gene pool to the large population

A

as the new population is isolated from the larger population, founder effect occurs, meaning that the genetic makeup of the new population is not an representative of the orginal population therefore different genepool with different allele frequencies.

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10
Q

I can explain how migration changes allele frequency in a population

A

individuals mirgating out of a population will have lesser alleles compared to the orginal population causing both population to be unstable with less alleles with a reduced gv.

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11
Q

I can explain what stabilising selection is

A

is when the middle range is more favoured and the outer two extreme like the left and right extreme are selected against

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12
Q

Directional selection

A

is when there are two extreme, the favoured phenotype will be selected for and the allele frequency will shift in one direction.

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13
Q

Two types of polyploidy:

A

Autopolyploidy
Individuals with more than 2 sets of chromosomes from the same species, this occurs through failure of cell division during meisosi/mitosis (chromosome doubling)n

Allopolypoidy
individuals has more than 2 sets of choromsomes from different species occurred through hybrization between two different species (chromosome doubling)

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14
Q

I can discuss how polyploidy can result in instant speciation/non-disjunction.v

A

opccurs when meiossi spindles pulls incorrect numer of number of chromosomes to the wrong end of the pole resulting in gamates having more or less chromosome than normal. This result in non-disjuntion and may cause gamtes having 2n. The fusion of
diploid gametes is a form of instant speciation.

The offspring have different chromosome numbers than their parents, so are unable to breed with their parent species due to not having homologous pairs.

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15
Q

Disruptive selection

A

an natural selection where the middle extreme is selected against and the two outer extremes are more favoured:

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16
Q

I can define reproductive isolating mechanisms [23]

A

Is a mechanism factor that prevents interbreeding between different population and species.

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17
Q

Hybrid inviability

A

Hybrid offspring dies in early development
due to genes of both parents are incompatible)

18
Q

Hybrid sterility

A

the hybrid offspring reaches maturity but is infertile so cannot breed.

19
Q

Hybrid breakdown

A

Hybrid or springs arefertile now by as generation passes by there be less fertile due to birth defects in embrtoytic stage

20
Q

What are advantages of polyploidy?

A
  1. increased fitness of hybrid offsprings compared to the fitness of their parent- more larger
  2. increased Genetic Diversity - get beneficial traits and pass on { wider range of traits and adaptations advantageous in changing environment.
21
Q

Allopatric Speciation/ 2 things required and the impacts.

A

Speciation occurs due to geographical barriers, or geographical isolation.
1. No inbreeding between populations
2. Gene pool must stay isolated

impact:
Populations in different geographical locations will have different selection pressure to faceOvertime heritable traits in each population will change until populations are different and distinct.

22
Q

Sympatric Speciation

A

formation of a new species from parent species in the same location / different niche.

23
Q

Convergent

A

is when two or more unrelated species develop similar functions due to selection pressurees

24
Q

Analogous structure

A

different orgins but similar
functions

25
Q

Divergent evolution

A

Evolutionary process in which an ancestral species is split into 2 or more species due to different selection pressures.

26
Q

Homologous structure

A

are structure that are similar and are from similar orgins but different functions

27
Q

Adaptive radiation

A

A type of divergent evolution where one ancestral species splits into many new species rapidly adapted to several new niches.

28
Q

co evolution

A

Is when two or more species evolve in response to each others selection pressure, contributing to GD

29
Q

Puncuated Equilbirum

A

A rate of evolution, where periods of rapid evolution interrupted by periods of little change/stasis

30
Q

Gradualism

A

slow changes between populations over time where small changes accumulate over time to produce major evolutionary transition

31
Q

How can polploidy lead to speciation

A

polyploidy inviduvals may be reproductively isolated from their parent species due to differences in chromosome number preventing successful mating and reproductions leading to new species being reproductively isolated from its parent species.

32
Q

(aka reproductive isolation)
How does isolation of populations creates new formation of species:

A

If two populations are isolated, individuals from one population cannot migate to the other population. This prevents the possibility of breeding and therefore gene flow; the two factors needed for the formation of a new species. Selection pressures ARE unique to one population and would affect that gene pool only. Isolation of populations + different selection pressures = formation of a new species.

33
Q

Parrell evolution

A

species share a common ancestor (but not related) but envovlve in similar ways independent of other species )

34
Q

Post-zygotic RIMS?

A

Reproductive isolating mechanisms which prevent gene flow by acting when the egg is fertilised.

35
Q

What is behavioural isolation?

A

Reproductive barriers due to difference in mating behaviours.

36
Q

What is temporal isolation?

A

Difference in breeding behaviour, such as time for breeding and breeding seasons.

37
Q

What is Ecological Isolation

A

The difference in the habitat within the same geographical location that prevents populations from coming into contact

38
Q

What is Gametic isolation?

A

Eggs from one population are incompatible with the sperm of the other, preventing fertilisation from occurring.

39
Q

Pre-zygotic RIMS?

A

Reproductive isolating mechanisms

which prevent gene flow before the egg is fertilised (before the zygote is formed).

40
Q

speciation

A

The formation of new species as a result of evolution