Paleoecology-SacramentoState.ppt

Biological Environment Predation parasitism Eliminates some species from some environments Evidence in fossil record Shell breakage Teeth holes /about/flat_stanley07.php Symbiosis Organisms live together Mutualism – for mutual benefit Zooxanthellae How does mutualism evolve? One example: Some nudibranchs retain zooxanthellae from the coral that they eat. Gut has transparent pockets that hold the chloroplasts from the algae If the nudibranch retains the entire algae and the algae is able to reproduce: mutualism Natural selection could drive the nudibranch to provide algae a safe place to live /solarpow.htm This nudibranch has lived 10 months without food in the lab, using the chloroplasts it took from the algae to photosynthesize and make sugars. This nudibranch keeps living algae in its tissues. Paleoecology Four Earth Systems Atmosphere Lithosphere Hydrosphere Biosphere Talk to your neighbor: for each arrow identify a process that is represented by that arrow Organisms interacting with their physical environment Limiting factors: determine diversity and abundance in environment Time out for vocab Diversity: Number of different kinds of organisms (e.g., # of species, # of families) Abundance Number of organisms Organisms interacting with their physical environment Limiting factors: determine diversity and abundance in environment. Determine what organisms can live in a given environment Common limiting factors in marine environments Temperature Oxygen Salinity Depth Substrate Affects Physiological rates CO2 O2 solubility (?Temp, solubility) Salt solubility (?Temp, solubility) Temperature Determined by latitude, ocean circulation, depth Usually stable – most organisms have narrow tolerances How does temperature vary Increase in latitude: Temperature Increase in depth: Temperature Relation to Ocean circulation Currents coming from equator Currents coming from poles Isolated gyres Depends on latitude – high latitude will be cold, low will be warm /mission