Speciation

Question 1

Natural Selection

Answer 1

process by which individuals that are better adapted to their environment tend to survive more, reproduce more offspring and therefore pass on favourable alleles. These allele become more common the population

Question 2

Stabilising natural selection

Answer 2

favours the most common phenotype as the best adapted, selects against extremes

Question 3

Disruptive natural selection

Answer 3

favours phenotypes at extremes of distribution, can lead to speciation against the mean

Question 4

Directional natural selection

Answer 4

favours phenotype at 1 end as the best adapted, bell curve shifts one way

Question 5

Speciation

Answer 5

is the process by which new species are formed from existing species as a result of becoming reproductively isolated

Question 6

Species

Answer 6

similar organism that can be reproduce in nature to produce fertile offspring

Question 7

Gene pool

Answer 7

all alleles in a population

Question 8

Gene flow

Answer 8

individuals move between populations and this allows new mutations/ new combinations of alleles to move in each population

Question 9

In order for speciation to occur

Answer 9

there must be an absence of gene flow between the populations

Question 10

Allopatric speciation

Answer 10

formation of new species which begins with a geo barrier (same origin)

Question 11

Symmpatric Speciation

Answer 11

formation of a new species that does not begin with geo brarrier, usually caused by niche differnation (a RIM) old polypodiy

Question 12

Genetic drift

Answer 12

changes to the allele freq of a pop due to chance

Question 13

Population bottleneck

Answer 13

a pop is reduced to a small no of survivors, AF of new pop of suirves not rep of OG - reduces variation in popl due to alleles being lost

Question 14

Founder effect

Answer 14

a small no of indicuals become isolated from og population - not rep sample of the gene pool

Question 15

RIM (reproductive isolating mechanims)

Answer 15

genetic barriers to gene flow

Question 16

Pre zyogotics

Answer 16

preventing a zyogtic from being made - a RIM that means feretislsiation does not even occur, temporal rim, behaviour rim, mechanical isolation, gametic rim

Question 17

Post zyogtics

Answer 17

a RIM that means fertilisation does occur but still fertile offspring does not resuly, HYBIRD INVAIABILITY, HBYRID STERLITY, HYBIRD breakdown

Question 18

Convergent eveolution

Answer 18

where simialr traits arise in unrelated species, uausally due to them experieecing smilar slection pressues, analgous features as edvience - structual feature that serve a common pruspoe in unrelated speices but have different ansercal orgins

Question 19

diveregnt evolution

Answer 19

process by which groups from the same commmon ansertor eveole and accumalte difeferences reusting in speications - homologous feature as eveidence - anataomical features that dereved from a common ancetst but have adpated for different pourpsoe (due to different slection pressures)

Question 20

adpataive radition

Answer 20

a type of DE - in which large nos of speices evoleve over a realaivek ys hsotr time from a common ancesstory. it is often the reulst of some event cretaing a large no of occumpied niches

Question 21

co eveolutin

Answer 21

interspeific relationshiop - the process by which two or more species eveolve one and another by extereting slection pressues on each other due to inetrespeci relationship they each others most sigiofcant selection pressues

Question 22

There are 2 general rates if evolutionary change

Answer 22

gradiusism and punctated equiliburm

Question 23

Gradualism

Answer 23

evo proces by small, steps over long peirods of time rather than by abdurpty major chnages

Question 24

puncated equilibrum

Answer 24

evo chnage is very slow w little or nbo chnage occuring for long periods of time (stat0 but that is puncated (interrupted0 w intervaks of rapid chnage and the follwed again by a period of stat