BIOGRAPHY & DIVERSITY & HUMANS

Lecture 26

Biogeography

The distrubution of organism and ecosystems in a space and time

Abitotc and Biotic Factors

Both Abiotic and Biotic factors can drive unquie pattern of species distrubution ( climate,geological vs speciation and physiology )

Wallace Lines

There is a distint break in fanuans between Oriental and Australi Biogeographic Zones; can use these sides to speak about species diversity on each side; can be calucted using index of similarity ( C/N1 )

Biogeographic Realms

Each ream has very distinct biotic enviroments, meaning each realm must have unqiue evoluntionary history 

Endemic

Organism restricted to speflic geographic area

Cosmopolitan

Species that have a world-wide distrubution

Disjunct

Species found in two or more areas

Vicariance

A splitting event that seperate gene pools

Disperal

Movement of individuals of one species from one area to another

Isthumus of Panama

The formoation of the Isthmus of Panama is an example of an variance event as this spilt marine organism gene flow, however it also provided an gene flow for terrestrial organism acting as a bridge ( The Great American Interchange )

Center of Diversity

A geographic area where a group of organsims have signifcant genetic diversity