Lecture #2 Flashcards
Biogeography
studies the distribution of species and how and why they have specific distributions (what causes them to settle in certain areas?)
Why is biogeography important?
the distribution, movement, and connectivity of species among habitats drives species interactions and thus changes ecosystems
3 primary factors for physical environment
temperature, salinity, productivity
Importance of temperature
Impacts adult performance: metabolism, growth, larval duration (time spent as plankton), and feeding
Impacts species interactions: greater metabolic demand, greater feeding rate → greater effect on prey
Impacts survival: too high or too low can threaten organism’s survival (ex: coral)
Planktonic/Pelagic Larvae
time spent as plankton, unable to swim against the ocean current, thus movement is at the mercy of currents
How can an organism be dispersed farther?
stronger current and longer planktonic larval stage
Range Size
the distance (measured by degrees latitude) that a species is distributed and commonly found; it is a function of how far larvae disperse for some feeding and direct developers
What does it mean to be “well connected”?
GENETIC SIMILARITY; offspring of individuals from different geographic locations have a high likelihood of successful recruitment to the many locations
Means that distant populations are genetically similar, and added together they form larger populations
Benefits of larger populations
More resistant to extinction
Greater genetic variation
Higher likelihood of evolutionary adaptation
Fst value of 0
very well connected, minimal genetic differences between populations
Fst value of 1
totally isolated, many genetic differences between populations
What is a large Fst value?
> 0.25
What is a small Fst value?
<0.05
