Species Area Curves
• Species area curve predicts that larger islands will have more species than smaller islands.
• S=cAz where– S = number of species– c = a constant measuring the number of
species per unit area– A = area of island (in square units)– z = a constant measuring the slope of the line
relating to S and A
Island Biogeography
• Number of species (on a plot or island) is a balance between immigration and extinction.
• If immigration exceeds extinction, then the number of species will increase.
• Number of species usually at equilibrium
Island Biogeography
• Immigration rates on islands are related to the distance from the mainland.– Close islands have greater immigration rates
than far islands• Extinction rates on islands are related to
the size of the island.– Extinction rates are greater for small islands
than for large islands
Island Biogeography
BryozoanAquatic Colonial Animals.
Mostly marine, but some freshwater.
Reproduce by budding Corals are also colonial animals.
Individual animals are called zooids.
Colony is situated in a gelatinous mass that is firm, but 99% water.
http://www.civgeo.rmit.edu.au/bryozoa/default.html
Zooid Anatomy