Islands and Other Hotspots Flashcards Preview

GeoSci 110 (Exam 2) > Islands and Other Hotspots > Flashcards

Flashcards in Islands and Other Hotspots Deck (11):

Basic Geological Setting of Hawaii

- Hawaiian islands are the most isolated major archipelago in the world

- species that arrive here experience allopatric, parapatric and sympatric isolation


Hot Spot Volancanism (Hawaii)

formed the islands;

Mid-Ocean Ridges: submarine mountain ranges where the new seafloor is being created

- hot spots produce volcanoes!

- the Pacific plate moves northwest, producing a chain of islands


Highly Varied Ecological Landscape (Hawaii)

Hawaii's landscape is hella diverse and adaptive

- rainforests, wastelands, snow-covered mountain tops, volcanic fields, etc.


Adaptive Radiation (Hawaii)

a large increase in the morphological and ecological diversity within a single lineage

- being the first to arrive on a new volcanic island means encountering a completely "empty" ecological landscape

- survival of new individuals will depend on availability of resources and intra-specific competition

- geometric increase in population will quickly make competition a dominant force


General Evolutionary Patterns (oceanic Islands/Hawaii)

1.) compared to continental biotas, islands have fewer major taxonomic groups (some are very rich and diverse)
- Coyne calls this unbalanced

2.) high levels of endemism among flora and fauna

3.) missing many major groups (i.e. amphibians, reptiles, mammals) or are extremely underrepresented whereas some bugs, birds, and seeds of small plants reached Hawaii at some point


Invasive Species (Hawaii)

1.) Human Intervention (boooooo) hunting and building airports that take away land

2.) other animals introduced
- i.e. chickens, feral pigs, mosquitoes, rats, mongoose

3.) Other Factors
- i.e. invasive grasses, accidental wildfires


Contributors to Bird Extinctions (Hawaii)

- explosion of rat and mongoose populations


Basic Geological History (Madagascar)

became an island after it broke off from Africa


Dispersal of Mammals to Madagascar

lemurs arrived from floating broken tree parts


Endemic Fauna (Madagascar)

geckos, chameleons, fossa, elephant birds, lemurs


Evolution of Flightless Birds on Islands

African Ostriches, NZ Kiwis, South American Rheas, Australian Emus, and Elephant birds in Madagascar evolved from Ratities that lived on the supercontinent Gondwana