Islands & Other Hotspots

Question 1

Example of diversification and other island processes

Answer 1

Hawaiian islands (see slides)

Question 2

Basic geological setting

Answer 2

a hotspot for isolation. Species that arrive in here are exposed to allopatric, parapatric, and sympatric isolation

Question 3

Hot Spot Volcanism

Answer 3

1. mid-ocean ridges (MORs)
2. hot spots produce volcanos!
3. The Pacific plate moves northwest, producing a chain of islands

Question 4

Mid-ocean ridges (MORs)

Answer 4

submarine mountain ranges where new seafloor is being created

Question 5

Oceanic islands

Answer 5

never connected to mainland

Question 6

Highly varied ecological landscape & Adaptive Radiations

(fruit flies, honey creepers, & silverswords)

Answer 6

Hawaii has an incredibly adaptive landscape (rain forests, wastelands, snow-covered mountain tops, volcanic fields, etc). Landscape also causes rain shadows and orographic effects, which further diversifies the landscape (causes more natural selection).

Question 7

General evolutionary patterns & examples

Answer 7

1. Unbalanced biotas
2. High levels of Endemism, ecology, isolation
3. Particular major taxonomic groups absent or extremely under represented

Question 8

Unbalanced biotas

Answer 8

Few major taxonomic groups, but some are very rich (diverse), Coyne refers to this as unbalanced

Question 9

High levels of Endemism, ecology, isolation

Answer 9

founder effect, genetic drift, natural selection

Adaptive radiation takes place (increase in diversity within a single lineage) due to intra-specific competition (population competes amongst itself resulting in diversity within the population)

Question 10

Particular major taxonomic groups absent or extremely under represented

Answer 10

no native reptiles, amphibians, land mammals, or conifers. Whereas some bugs, birds, and seeds of small plants reached Hawaii at some point

Question 11

Dispersal to the Hawaiian Archipelago

Answer 11

Hawaiian biota evolved from about 1000 non-native species. Successful dispersal happened 1000 times over 70 million years (once every 70,000 years)

Question 12

Island Hopping, Geographic Isolation & Speciation

Answer 12

some species hopping between islands = geographic isolation (allopatric isolation) and more diversity

Question 13

Invasive species in Hawaii

Answer 13

1. Human intervention
2. Other animals introduced
3. Other factors

Question 14

Human intervention (invasive species in Hawaii)

Answer 14

hunting large, flightless geese to extinction

Question 15

Other animals introduced (invasive species in Hawaii)

Answer 15

chickens, feral pigs, mosquitoes, rats, mongooses, toads/frogs

Question 16

Other factors (invasive species in Hawaii)

Answer 16

invasive grasses, accidental wildfires

Question 17

Contributions to bird extinctions in Madagascar

Answer 17

1. Prehistoric wave

2. Historic wave

Question 18

Prehistoric wave

Answer 18

(Polynesians - 1600 years ago) resulting in extinction of large birds and flightless birds, as well as small, specialized species

Question 19

Historic wave

Answer 19

Westerners

Question 20

Basic geologic history; dispersal of mammals to Madagascar

Answer 20

1. Madagascar became an island in late Cretaceous (90 Ma)

2. Lemur ancestors arrived 40-50 Ma

Question 21

Endemic fauna

Answer 21

including geckos, chameleons, fossa, elephant birds (huge big boi birds), lemurs

Question 22

Evolution of flightless birds on islands, ratites

Answer 22

African ostriches, new zealand kiwis, south american rheas, australian emus, and elephant birds in Madagascar evolved from ancestral ratites that lived on the supercontinent Gondwana