CH. 4 (Geography of Life)

Question 1

What and where is the Juan Fernandez Archipelago?

Answer 1

4 land masses totalling 40 square miles 400 miles west of Chile. Home of marooned sailor Alexander Selkirk for four years. Home to many rare and endemic flora and fauna.

Question 2

endemic

Answer 2

found nowhere else in the world

Question 3

What does Juan Fernandez lack?

Answer 3

any native species of amphibian, reptile, or mammal

Question 4

biogeography

Answer 4

study of distribution of species on earth

Question 5

What can be used to estimate divergence time of species?

Answer 5

DNA, fossil records, and geography and plate movement (knowing where land masses were connected and how it coincides with fossils)

Question 6

convergent evolution

Answer 6

species that live in similar habitats will experience similar selective pressures and will thus adapt in similar way (converging adaptation) even though they are unrelated

Question 7

examples of convergent evolution

Answer 7

• sugar glider (marsup.) vs flying squirrel (placental)
• banded anteater vs anteater
• marsupial mole vs. mole
  (each can thrive in the others environment)

Question 8

How did marsupials get to Australia?

Answer 8

oldest marsupial fossils are in North America, they evolved and spread to SA (40 million years ago), crossed over Antarctica to Australia when they were connected (meaning there are marsupial fossils dating between 30-40 mil years old.

Question 9

What is the Bering Land Bridge?

Answer 9

Connected Asia and NA (during ice age, ocean levels dropped and revealed land bridge that connected continents)

Question 10

Where did humans evolve? What evidence do we have of this?

Answer 10

Humans evolved in Africa (Darwin made this prediction), fossils of earliest ape human transitional species in Africa.

Question 11

continental island

Answer 11

island once connected to a continent but were later separated by rising sea levels that flooded land bridges or moving plates

Question 12

Oceanic Islands

Answer 12

Islands never connected to a continent, arose from sea floor as growing volcanoes or coral reefs

Question 13

Examples of continental islands and oceanic islands

Answer 13

cont. - Australia, Madagascar, British Isles, Sri Lanka, Japan, Tasmania

oceanic - Hawaiian Islands, Galapagos archipelago, St. Helena, Juan Fernandez

Question 14

What happens when mammals, fresh water fish, and reptiles are introduced to oceanic islands and why?

Answer 14

They do extremely well and often wipe out native species. They are well suited for life on oceanic islands but the island ecosystems developed without predators and thus collapse

Question 15

Adaptive radiation

Answer 15

process by which organisms rapidly diversify from ancestral species into multitude of new forms (especially when environment changes or niche opens up).

Question 16

Examples of adaptive radiation?

Answer 16

• galapagos finches (of 28 species of bird on the islands, 14 of them are finches)
• Hawaiian honeycreepers (finch like bird)

Question 17

What do oceanic islands have and what do they lack?

Answer 17

They have plants, insects, arthropods, birds (in short anything that can colonize over water or through long-distance dispersal) but do not have land mammals, reptiles, amphibians, or freshwater fishes (exception bats and seals which are mammals that can fly/swim)

Question 18

Characteristic of plants and animals on oceanic islands?

Answer 18

Most similar to species found on nearest mainland (climates/environments might be different but the species evolve from others nearby)

Question 19

What happens when you have a very old continental island?

Answer 19

Features of both oceanic and continental islands combine in very old continental islands. We see endemic species on very old continental islands because they’ve spent enough time geographically isolated.

Ex. Madagascar (lemurs most closely related to african species) and New Zealand (flightless birds like giant moa, kiwi, fat parrot, only a few endemic reptiles and two native mammals both bats)