Flashcards
Lecture 3
Flashcards do conjunto (26)
- 1What is a species?A group of living organisms consisting of similar individuals capable of exchanging genes or interbreeding/producing fertile offspring.
- 2what is a morphological species?Organisms are classified in the same species if they appear identical by morphological (anatomical) criteria.
- 3What are Phylogenetic Species?Share one morphological or molecular trait. Increase species by 48%.
- 4What proportion of species are vertebrates?1%
- 5How many new species are discovered a year?15,000
- 6What percentage of known species have now become extinct?99%
- 7what percentage of present day species are predicted to go extinct>20%
- 8how many of the worlds' species of birds that could go extinct?2000
- 9What is the Bonarelli Event /Anoxic Event?occurs when the earth's oceans become completely depleted of O2 below the surface levels, may have caused mass extinction.
- 10What is the Mega-Funa extinction? And what was the cause of it?It was the mass extinction of large land based mammals. The main cause is thought to be human hunting (74-86%)
- 11In Madagascar, what species went extinct due to human hunting?15 species of lemur
pigmy hippo
flightless elephant bird
13 species of Moas - 12Why have African Mega-fauna survived?Perhaps because animals coevolved with humans
Animals evolved counter-adaptations to human predation - 13Why are islands so vulnerable?Evolved in the absence of predators
Humans introduced competitors, diseases
Island populations are usually small which increases their risk for extinction
Rescue effect
Relaxed anti-predator behavior, loss of herbivore defenses and reduced dispersal in plants - 14What has happened to the rate of extinction in the last 150 years?It has increased.
- 15what percentage of vertebrates could become extinct by the end of the year?66%
- 16What is the increased percentage of the worlds birds that have become critically endangered?8%
- 17Why is this mass extinction notable?It is the only such event triggered by a single species (Homo sapien)
A few million years is a long time to wait for recovery
It is not clear that biodiversity will rebound this time
Humans are utilizing resources that new species would need to evolve - 18What is an endemic species?species found naturally in only one geographic area and no place else
Occupy restricted ranges - 19Give some examples of an endemic species?Komodo dragon lives only on a few islands
Mauna Kea Silversword only lives in a single volcano crater on the island of Hawaii - 20If we protected 1.4% of the worlds land surface, what would that preserved?44% of the worlds vascular plants, 35% of its terrestrial vertebrate can be preserved.
- 21What percentage of human population are located in hotspots?20%
- 22Why are species going extinct in hotspots?High rates of habitat destruction
Land cleared for agriculture, housing, economic development
More than 70% of the original area of each hotspot has already disappeared
Only 15% or less of original habitat remains in 14 hotspots
95% Brazilian forest lost
90% Madagascar forest lost - 23what are some of the causes of extinction (direct or indirect)?Overexploitation
Habitat loss
Introduced species
Disruption of ecosystem interactions
Pollution
Loss of genetic variation
Catastrophic disturbances - 24What is happening to the frog population around the world?Frog populations that had once been abundant are now decreasing or entirely gone
2005: 43% of amphibian species experienced decreases in population size
1/3rd are threatened with extinction - 25Why have some frog species declined although they live in pristine, well protected habitats?The water they have lived in are tainted in chemicals, which passes though their skin into their skin into their bodies.
- 26What are some of the other reasons why frogs are declining in populations?Global environment is deteriorating, habitat loss and Chytrid fungus.
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- University Bangor year 2 FlashCards sobre Lecture 3, criado por sammibeard em 10-11-2014.
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