Island Biogeography (Week 9 Lecture 12) Flashcards
Since islands are isolated, and in many cases the species found on them are ______.
Endemic
______ has been particularly common on islands.
Extinction
What percent of the bird species whose extinction has been recorded since 1600 have been island species.
93%
Who CoauthoredThe Theory of Island Biogeography.
Edward O Wilson and Robert H Macarthur
True or False: The biota of an island is simpler than that of a continental area, and the interactions are easier to understand.
True
What are the three types of Islands?
Islands that were originally part of a nearby continent
Islands that are part of a volcanic island arc.
Seamount chains
What type if island is formed over geological hotspots?
Seamount chains
What type of island was separated by rising sea level?
Land-bridge Islands
True or False: Islands formed by isolation from continents would not have a biota which would be a subset of that on the continent.
False, they would have similar biota
Islands formed by isolation from continents would have changed, however, as the result of independent ______ and ______.
evolution and extinction
The biota of island arcs and hotspot island chains originally arrived by ______.
Tran-ocean dispersal
True or False: If several islands exist at one time it creates the possibility for inter-island dispersal and a more complex pattern of evolutionary change.
True
What one factor restricts the diversity of life on islands?
Organisms share adaptation that allow them to get to the island rather than to live on it.
What type of animal is capable of reaching very distant islands.
Flying animals
What type of animal rely on dispersal mechanisms to reach islands?
Iguanas
Is long distance more likely to happen in plant sor animals?
Plants,can typically be accomplished by a single spore or seed, where in animals it typically requires a pair of organisms or a pregnant female.
True or False: On very remote islands the number of species may be less because of the great difficulty in dispersing to these islands.
True
For conifers and flowering plants in the Pacific diversity is much ______ (lower/higher) in the more isolated island groups of the central and eastern Pacific.
lower
True or False: The more isolated islands have fewer genera than less isolated islands of the same size.
True
Is island life more hazardous than mainland life?
Yes, catastrophic events have more severe effects.
What are three reasons why island population are more likely to extinct than those on mainlands?
Populations are typically smaller.
They have less genetic diversity.
They were not originally adapted to the island habitat.
True or False: when a species is lost by extinction, it is more difficult to replace it by immigration than in a mainland situation.
True
True or False: Islands tend to support the same amount species than mainland areas of similar size.
False, islands tend to support fewer species.
______ stated that islands are less diverse because they have not had sufficient time to accumulate species by immigration.
Nonequilibrium theory of island biogeography
True or False: Islands are high species richness relative to mainland areas of comparable size.
False, low in species richness
The ______ proposed that the lower number of species on islands was not the result of insufficient time, but rather the result of an equilibrium process peculiar to all islands.
equilibrium theory of island biogeography
In the equilibrium theory of island biogeography, The theory is based on the idea that, at any given time, the number of species on an island is the result of a balance between two processes: ______ and ______.
extinction and colonization
True or False: Colonization rates however should be greater for the island near the mainland than for the more distant island.
True
True or False: Extinction should be greater on a smaller island.
True
True or False: Small islands have a greater degree of habitat heterogeneity, and therefore greater diversity.
False, large islands
what did E. Wilson And Daniel Simberloff find during their experiment?
They found that species increased for a while, then reached to a number approximately equal to the original number.
True or False: Oceanic islands confirm pretty closely to the patterns predicted by island biogeographic theory,
True
______ ______ is the term referring to when a land bridge island has more species than to be expected on an island of that size and the number of species diminishes.
Relaxation fauna
______ island region of suitable habitat that is surrounded by uninhabitable area that serves as a barrier to dispersal.
Habitat
What are the two important phenomena of habitat islands?
Habitat diversity may be more important than area.
The formation of a habitat island in a mainland area creates an “edge effect”.
______ ______ refers to a change in physical and biological characteristics of a habitat as one moves from the edge to the interior.
Edge effect
One of the most significant anthropogenic influences on natural habitats has been the ______ of habitats
Fragmentatio
True or False: These fragmented habitats do not show relaxation effects like some islands.
False, the often do
Mammal diversity in Mt. Rainier National Park has decreased by ______ between 1920 and 1976 due to ______.
26%, fragmentation of forest habitats
In what two ways can Island biogeography theory can assist in solving practical conservation problems.
Predict the effect of anthropogenic habitat fragmentation.
Using our knowledge of species-area effects and relaxation faunas to design nature preserves that will maximize long-term species diversity.
