Isthmus of Panama Flashcards
Pangea breakup
last continents to move NA and SA, change ocean currents- but ocean could still move between NA and SA- isthmus formation changed ocean
Isthmus formation
circulation of tropical warm water blocked, in Atlantic water deflected north- Gulf Stream; salinity of two oceans altered
Ocean Circulation
Driven by temperature and salinity differences- density differences; also impacted by trade winds and land masses
Water Density
warm and low salinity water less dense; warm water stays at surface; dense water stays deep- as density changes it rises/ falls in water column
Upwelling
water rising
downwelling
water falling
Gulf stream
formed with isthmus, impacts weather patterns in NA and Europe- brings heat
Biotic effects
barrier to marine; corridor for land; indirect effects of altering climate and changes in distribution, ecology
Marine species and barrier
isolation of populations, speciation; differences in marine environments on either side
Pacific Marine Environment
Deep; high production; low construction- deep basin, winds push water away from land, upwelling of nutrients ;, upwelling of cold water; greater nutrients favors organisms with faster lifecycles, deep water does not favor photosynthesis
Production
growth and multiplication
construction
development of more permanent biological materials (like coral)
Caribbean (Atlantic) Marine Environment
Shallow; low production; high construction- shallow waters support growth of photosynthetic organism, no upwelling, favors slower growing organisms with low nutrient input- biotic interactions as opposed to nutrient availability
Terrestrial species corridor
Similar ecological niches on both continents- can’t have exact same niche (can’t have more than one apex predator), almost entirely different species before connection (convergent evolution), species mix- only good dispersers and can survive dry environment
convergent evolution
unrelated species evolve similar traits due to similar environmental and ecological conditions
Convergent mammals
marsupials vs. placental mammals
Heralds
south moves up (sloths), north moves down (raccoons)
Legions of the north
lots move south, those that moved south persist in south
legions of the south
idk not really important basically most immigration from north to south- outcompete marsupials
Changing climates
mountain formation and rain shadow, ecological barrier
Human changes
panama canal maybe some species exchange across ocean
