Biology Exam 2: #2

Question 1

Allopatric Speciation

Answer 1

occurs when populations are separated geographically; GENE FLOW IS NOT POSSIBLE

Question 2

Ways Allopatric Speciation can occur

Answer 2

Dispersal and Vicariance

Question 3

Dispersal

Answer 3

population splits, with one part moving to a new location; they remain separated which allows for reproductive isolation and genetic divergence to occur

Question 4

Example of dispersal

Answer 4

founder effect lead to allopatric speciation; some finches moved from a large population from Island A to B, resulting in them breeding and forming a new population; starting to diverge genetically even though same species

Question 5

Vicariance

Answer 5

physical splitting of habitat causes splitting of single population into two or more populations

Question 6

Examples of vicariance

Answer 6

river changing course, continental drift, volcanic action, forest fragmentation, agriculture roads

Question 7

Example of Vicariance

Answer 7

South American trumpeters found strictly in forest in South America; Birds do not like to fly over water, and water changed course(new pathways) multiple times overtime, causing multiple splits and multiple species with NO gene flow

Question 8

Sympatric Speciation

Answer 8

populations living in the area but with NO GENE flow

Question 9

Ways Sympatric Speciation can occur

Answer 9

Mutation, Chromosomal Events, Adaptive Radiation, and Extinction

Question 10

Mutation

Answer 10

prevents breeding between population

Question 11

Example of Mutation

Answer 11

Snail shells have left-hand vs right-hand orientation, the opposites cannot mate together; PLAYS MAJOR ROLE

Question 12

Chromosomal Events

Answer 12

differences in chromosome number between parents and offspring(Polyploidy)

Question 13

Types of Chromosomal Events

Answer 13

Polyploidy, Auto-polyploidy, Allopolyploidy

Question 14

Auto-polyploidy

Answer 14

can occur when there are errors during meiosis in hermaphrodite species(STUDY IMAGE TO HELP)

Question 15

Allopolyploidy

Answer 15

parents from a different species(that have different chromosome numbers) attempt to breed(STUDY IMAGE TO HELP)

Question 16

Example of Allopolyplody

Answer 16

Diploid plants species introduced to North America(view image)

Question 17

Adaptive Radiation

Answer 17

single species that rapidly evolves into multiple descendent species; takes 50-100 years(NOT LONG); occurs only under INTENSE COMPETITION FOR RESOURCES

Question 18

Examples of Adaptive Radiation by Ecological Opportunity

Answer 18

Hawaiian silverswords evolved from a single species of tarweed that is found in all possilbe habitats(diff. in soil, moisture, sunlight, growth forms) after only a few million years

African cichlid fish split from landslides creating dams between river waterways; whole ecosystem changed, causing pressures, living conditions to change, and INTENSE competition; allowed from potential for reproductive isolation and speciation(such as feeding approach/where they feed and jaws)

Question 19

Describe Adaptive Radiation occurring when new Key Traits Evolved through Mutation

Answer 19

new traits allow the organism to move to and use new habitats, change their food selection, and/or change their mate selection/reproduction habits

Question 20

Example of Adaptive Radiation occuring through Mutation

Answer 20

Feathers of Osprey vs. Regular Bird vs. Hummingbird; flight at different ranges, feather insulation in different habitat, altered predation from different escape tactics

Flowers; get variety of modes of reproduction and isolation; altered distribution allows successful reproduction in new habitats

Question 21

Extinction

Answer 21

large reduction in species number/biodiversity; can occur in days to thousands of years; species die out due to harsh, rapid changes in environment

Question 22

Examples of extinction Events

Answer 22

asteroids, volcanic eruptions, significant deforestation

Question 23

Local Immediate Effects vs. Global Long-term effects of Extinction

Answer 23

Death destruction, and change in local conditions(change habitat links and reduce habitat size) vs chain reaction of organisms in an ecosystem causing death and decline(yet creates potential for new habitat and a species to thrive there)

Question 24

Local Immediate Effects vs. Global Long-term effects of Extinction

Answer 24

Death destruction, and change in local conditions (change habitat links and reduce habitat size)
vs
chain reaction of organisms in an ecosystem causing death and decline; ALTER FOOD WEBS;(yet creates potential for new habitat and a species to thrive there)