Macroevolution

Question 1

What is macroevolution?

Answer 1

Evolution on a scale at or above the level of species.

Question 2

What is microevolution?

Answer 2

Refers to smaller evolutionary changes of allele frequencies within a species or population.

Question 3

What was the Neo-Darwinism evolutionary theory from 1895?

Answer 3

Combination and integration of natural selection and genetics, Darwin’s theory and Mendel’s theory, refers to modern synthesis, unified theory.

Question 4

Patterns of biodiversity?

Answer 4

Processes generating biodiversity, biodiversity pump, processes reducing biodiversity, cull biodiversity.

Question 5

Characteristics of speciation?

Answer 5

Geological and environmental changes, natural selection favour particular aleles, separation due to mountains lakes etc, populations different, no interbreeding, different species.

Question 6

Characteristics of extinction?

Answer 6

Species completely dies out, new competition predators disease, changes in environment, lack of adaptation, volcanoes earthquakes, cyclical nature of speciation, taxonomic change.

Question 7

Sympatric evolution?

Answer 7

Evolution of a new species from surviving ancestral species, both same geographic region.

Question 8

Parapatric evolution?

Answer 8

New species evolve in contiguous spatially segregated habitats.

Question 9

Peripatric speciation?

Answer 9

Speciation in which new species formed from isolated peripheral population.

Question 10

Allopatric speciation?

Answer 10

Geographic of vicariant speciation, biological populations become geographically isolated.

Question 11

Cladogenesis?

Answer 11

Evolutionary splitting of a parent species into two distinct species, forming a clade.

Question 12

Anagenesis?

Answer 12

Evolution within a lineage.

Question 13

Genetic drift?

Answer 13

Change in composition of a gene pool as a result of a random or change event.

Question 14

Selection?

Answer 14

Change in gene pool as a result of differentially selective environmental pressues.

Question 15

What is adaptive radiation?

Answer 15

Event in which lineage rapidly diversifies with newly formed lineages evolving different adaptations, different factors may trigger adaptive radiations but each is a response to an opportunity.

Question 16

Pros of island systems?

Answer 16

No competition, reduced predation, less food increase inbreeding, founder effect, selective pressures.

Question 17

Characteristics of Hyracotherium?

Answer 17

Earliest horse like form, more dog like, pads for feet, 3 hind toes, 4 front toes, small brain case, herbivory teeth, browser not grazer (tooth crown), common in Miocene.

Question 18

Why did Hyracotherium have separate evolutionary paths?

Answer 18

Consequence of the isolation of continents resulting from continental drift - speciation.

Question 19

Characteristics of Miohippus?

Answer 19

Evolution of Hyracatherium, not quite horse, larger, big brain case, different forefeet, loss of little digit, lateral digits reduced, several lineages existed, one branch gave rise to true horse.

Question 20

Characteristics of Merychippus?

Answer 20

True horse line, larger bodied, premolars and molars like modern horse, long high crowned teeth, lengthened enamel ridges, ridges filled with cement, major change in teeth.

Question 21

Reasons why grass shaped horse evolution?

Answer 21

Tough, high silica, apical meristem close to ground, adaptations against herbivory.

Question 22

Reasons why teeth shaped horse evolution?

Answer 22

High crowned, adaptation against wear from silica, merychippus grazer and deeper skull, accommodate lengthened teeth.

Question 23

Characteristics of spring foot?

Answer 23

Hoofed feet, elastic ligaments, more efficient, better mechanism, foot bent upon impact, suspensorio ligament provides lift, adaptation to running.

Question 24

What is convergent evolution?

Answer 24

Organisms that are not closely related evolve similar features or behaviours.

Question 25

Characteristics of convergent evolution?

Answer 25

Same traits evolved independently, solutions to same problems, lead to adaptive radiations, similar habitat selection pressures.

Question 26

Total number of described species?

Answer 26

2 million.

Question 27

Total number predicted species?

Answer 27

15 million.

Question 28

Characteristics of Coelacanth (living fossil)?

Answer 28

Example of species persistence, carnivorous fish, live up to 60 years, up to 2 meters length, lobed fins, extinct.

Question 29

Examples of extinct animals due to human infleunce?

Answer 29

Pleistocene megafauna - sabre toothed cat, giant ground sloth, woolly mammoth.

Question 30

Example of a type of species badly affected?

Answer 30

Island species.

Question 31

How old is the Earth?

Answer 31

4.55 billion years old.

Question 32

How long has life been on Earth?

Answer 32

3.8 billion years.

Question 33

How long did bacteria dominate Earth for first?

Answer 33

3.1 billion years.

Question 34

Composition of primitive atmosphere?

Answer 34

Nitrogen, CO2, hydrogen, water vapour.

Question 35

Why did the primitive atmosphere favour prokaryotes?

Answer 35

Environment creates a primordial soup where prokaryotes developed a range of metabolic adaptations.

Question 36

Bacteria vs Cyanobacteria?

Answer 36

Cells small vs large, flagella vs none, autotrophic and heterotrophic vs only autotrophic, anoxygenic vs oxygenic, aerobic and anaerobic vs aerobic, reserve food glycogen vs cyanophycean starch.

Question 37

Characteristics of atmospheric revolution?

Answer 37

Arrival of Cyanobacteria, oxygen released, initially soaked up by iron dissolved in oceans, starts building up in atmosphere, arrival of atmospheric oxygen and mass extinction.

Question 38

When did mitochondria evolve?

Answer 38

After great oxygenation event (GOE).

Question 39

What happened during Cambrian?

Answer 39

Diversity gradually increased and exploded.

Question 40

What is the rate of accumulation of diversity like?

Answer 40

Not constant, periods of diversification followed by stable periods and mass extinction.

Question 41

What was the K-T event?

Answer 41

End of Cretaceous, excitation of dinosaurs etc, due to meteorites near Mexico and Ukraine, also mantle plume eruption on Indian subcontinent, volcanic eruption.

Question 42

What did K-T mass extinctions result from?

Answer 42

Short term acid rain, long term atmospheric barrier to solar radiation.

Question 43

Why would early mammals likely survive K-T adverse conditions?

Answer 43

Burrowing habits.

Question 44

Rate of current extinction?

Answer 44

Sixth mass extinction, increasing global temps.

Question 45

When did large animal extinctions coincide with?

Answer 45

Arrival of modern humans.

Question 46

The Holocene extinctions?

Answer 46

Describes ongoing extinction events of species during present Holocene epoch due to human activity.

Question 47

Consequences of climate change resulting in species extinctions?

Answer 47

Decline of amphibians, rising temps and acidification, coral reef communities predicted extinct.

Question 48

What do alien species do?

Answer 48

Become pests and arrive to colonise area they’re not supposed to be.

Question 49

What has spread of chytridiomycosis been attributed to?

Answer 49

Trade in amphibians.

Question 50

Characteristics of Alfred Wefener’s hypothesis?

Answer 50

Inspired by unexpected distributions of plants and animals, due to continental drift.

Question 51

Wallace’s line?

Answer 51

Imaginary line used to delineate faunas among islands, similar lines applied to mammals.

Question 52

Why do we get distinctive distributions?

Answer 52

Continental drift and lower sea levels (due to ice age).

Question 53

Genetic consequences of Pleistocene ice age?

Answer 53

5 ice ages have occurred, currently warm interglacial, glaciation, 18,000-20,000 years, altered landscape.

Question 54

Effects of ice age?

Answer 54

Extinction of species, formation of barriers, splitting of populations, speciation.

Question 55

Genetic consequences of ice age?

Answer 55

Recolonisation, subpopulations bottlenecked, less genetic diversity.