Macroevolution

Question 1

Biological species concept

Answer 1

a population or group of population in nature whose individual members can interbreed to produce viable, fertile offspring that can also interbreed

Question 2

example of biological species concept

Answer 2

Grey’s zebra (endangered) and plains zebra (widespread) are different species- can’t interbreed

Question 3

speciation occurs when..

Answer 3

population become isolated over time

Question 3

speciation

Answer 3

when some members of a sexually reproducing population change so much that they are no longer able to reproduce

Question 4

speciation causes formation…

Answer 4

of new species from existing species

Question 5

what’s the most common form of speciation?

Answer 5

allopatric speciation

Question 6

allopatric speciation occurs when…

Answer 6

populations of a species are geographically isolated

Can no longer exchange genetic information

Question 6

in allopatric speciation, over many generation the populations…

Answer 6

gradually become less and less alike

Question 7

in allopatric speciation, eventually two populations evolve…

Answer 7

some sort of reproductive isolating mechanism

Question 8

What is a form of allopatric speciation?

Answer 8

Adaptive radiation

Question 8

example of allopatric speciation

Answer 8

the isthmus of Panama arose some 3 million years ago, populations of snapping shrimp have diverged into seperate species

Question 9

Sympatric speciation occurs….

Answer 9

gradually or suddenly

Question 9

In plants sympatric speciation occurs mostly because of…

Answer 9

chromosomal changes

ex. Polyploidy

Question 9

How does sympatric speciation evolve?

Answer 9

new species evolves from within a large population

Question 9

In animals sympatric speciation occurs because of…

Answer 9

non-random mating, ex, Squirrels mate at sunset and sunrise results in 2 new species

Ex. Diane Dodd maltose vs starch flies

Question 10

where does sympatric speciation occur?

Answer 10

occurs in species in within the same geographical area

Question 11

how does adaptive radiation occur?

Answer 11

When members of a single species occupy a variety of distinct niches within with different environmental conditions

Question 12

what does adaptive radiation describe?

Answer 12

describes the rapid evolutionary diversification of a single ancestral line

Question 13

example of adaptive radiation

Answer 13

beak types in finches of the Galapagos Islands

Question 14

In adaptive radiation, members evolve…

Answer 14

different morphological features (adaptations) in response to the different selection pressures

Question 15

What are pre-zygotic isolating mechanisms?

Answer 15

barriers that either impede mating between species or prevent fertilization

Question 16

What are the 5 pre-zygotic isolating mechanisms

Answer 16

behaviour, habitat, temporal (timing) , mechanical, gametes

Question 17

examples of behavior

Answer 17

bird songs, courtship rituals of elk, insect pheromones

certain groups of birds will only respond to species-specific mating calls

Question 17

Behaviour

Answer 17

any special signals or behaviours that are species specific

prevent interbreeding with closely related species

Question 18

Habitat

Answer 18

two species may live in the same general region but different habitats rarely encounter each other

Question 19

example of temporal (timing)

Answer 19

three tropical orchid species time lapse between weather stimulus and flowering is 8,9, and 10 days respectively

Question 19

Temporal (timing)

Answer 19

two species may occupy the same habitat but mate or flower at different times of day, seasons or years

Question 20

examples of habitats

Answer 20

common garter snake found near water whereas northwest garter snake found in open areas (like meadows)

Question 21

another example of temporal

Answer 21

frogs will live same pond but breed during different seasons (spring vs summer)

Question 22

Mechanical

Answer 22

closely related species may attempt to mate but fail to achieve fertilization between they are anatomically incompatible

Question 23

example of mechanical

Answer 23

genitalia specificity in insects certain breeds of dog are morphologically incapable of mating due to size

Question 24

Gametes

Answer 24

egg and sperm meet but rarely fuse to form a zygote

Question 25

example of gametes

Answer 25

sperm of one species cannot survive in the environment of the female reproductive tract of another species

Question 26

what are post-zygotic isolating mechanisms?

Answer 26

barriers the prevent hybrid zygotes from developing into viable fertile individuals

Question 27

what are the three post-zygotic isolating mechanisms?

Answer 27

hybrid inviability, hybrid sterility, hybrid breakdown

Question 28

what is hybrid inviability?

Answer 28

embryo dies in early development before birth genetic incompatibility prevents normal mitosis after fusion

Question 29

example of hybrid inviability

Answer 29

sheep and goats

Question 30

what is hybrid sterility?

Answer 30

hybrid offspring is sterile meiosis fails to produce normal gametes in the hybrid because chromosomes of the tow different species differ in number of structure

Question 31

example of hybrid sterility

Answer 31

mule offspring between female horse and male donkey n

Question 32

examples of hybrid breakdown

Answer 32

hybrids between the cotton species Gossypium barbadense, G.hirsytum and G.tomentosu The offspring of hybrid copepods have less potential for survival or reproduction

Question 32

what is hybrid breakdown?

Answer 32

Hybrids can mate with each other but produce either weak or sterile offspring in the next generation

Question 33

where does hybrid breakdown occur?

Answer 33

in plants

Question 34

Divergent evolution

Answer 34

common ancestor diverge to produce homologous structures species appearance becomes more different over time species are closely related (share genetic homology)

Question 35

example of divergent evolution

Answer 35

pentadactyl limb structure (vertebrates)

Question 36

convergent evolution

Answer 36

different ancestor converge to produce analogous structures species appearance becomes more similar over time species are unrelated (genetically different)

Question 37

2 models of speciation

Answer 37

phyletic gradualism punctuated equilibrium

Question 37

example of convergent evolution

Answer 37

wings in insects, birds and bats

Question 38

what is phyletic gradualism?

Answer 38

speciation occurs uniformly steady and gradual transformation of whole lineages

Question 39

What is punctuated equilibrium?

Answer 39

species remain stable for long periods before undergoing abrupt and rapid changes (speciation)

Question 39

example of phyletic gradualism

Answer 39

fossil record of horse shows many intermediate forms connecting ancestral to modern species

Question 39

In punctuated equilibrium, speciation is seen as...

Answer 39

periodic process (big changes occur suddenly followed by long periods of no change)

Question 40

punctuated equliibrium is supported by...

Answer 40

general lack of transitional fossils (such absences could be because fossilization conditions are rare)