BIOL2050 Ecology Organisms And Environmental Variation PDF

Organisms and environmental variation Bowman Ch. 4, 5 BIOL2050 Ecology NOT FOR SALE OR DISTRIBUTION PROPERTY OF YORK UNIVERSITY By Hannes Grobe, AWI - Own work, CC BY-SA 2.5, https://commons.wikimedia.org/w/i...

Organisms and environmental variation Bowman Ch. 4, 5 BIOL2050 Ecology NOT FOR SALE OR DISTRIBUTION PROPERTY OF YORK UNIVERSITY By Hannes Grobe, AWI - Own work, CC BY-SA 2.5, https://commons.wikimedia.org/w/index.php?curid=2978170 By Luca Galuzzi (Lucag) http://www.galuzzi.it, CC BY-SA 2.5, https://commons.wikimedia.org/w/index.php?curid=2121532 NOT FOR SALE OR DISTRIBUTION PROPERTY OF YORK UNIVERSITY Performance curves Species performance Reproduction Growth Survival Intensity of condition (e.g. Temp., pH, salinity) NOT FOR SALE OR DISTRIBUTION PROPERTY OF YORK UNIVERSITY  Posted Only Performance curves For most conditions, there is a range within which an organism can survive; a narrower range within which an organism can grow; an even narrower range within which an organism can reproduce NOT FOR SALE OR DISTRIBUTION PROPERTY OF YORK UNIVERSITY Conditions = physical / chemical features of the environment E.g. temperature, humidity, pH, salinity, etc. NOT consumed Resources = things that are consumed Plants: sunlight, water, mineral nutrients Animals: food organisms, nesting sites Once used, resources are no longer usable by other organisms → competition NOT FOR SALE OR DISTRIBUTION PROPERTY OF YORK UNIVERSITY  Posted Only Condition vs. resource Some things that are consumed may behave like a condition or a resource, depending on the circumstances E.g. oxygen – Terrestrial environment: can’t be depleted; behaves like a condition – Aquatic environment: can be depleted by respiration; behaves like a resource NOT FOR SALE OR DISTRIBUTION PROPERTY OF YORK UNIVERSITY Response on the level of an individual (i.e. within an individual’s lifetime) Acclimatization: Adjusting to stress through behavior or physiology. short-term, reversible process e.g. Acclimatization to high elevations involves higher breathing rates, greater production of red blood cells, and higher pulmonary blood pressure NOT FOR SALE OR DISTRIBUTION PROPERTY OF YORK UNIVERSITY  Response on the population level Adaptation: Over time, natural selection can result in adaptation of a population to environmental stress. Individuals with traits that enable them to cope with the stress of a particular environment are favored; over time, these genetic traits become more frequent in the population. e.g. Some indigenous populations that have lived at high altitudes for 1000s of years show genetically based adaptations to high altitudes Andean populations have high red blood cell concentrations and large lung capacity. Tibetans have faster breathing rates and higher blood flows. Adaptation is a long-term, genetic response of a population! NOT FOR SALE OR DISTRIBUTION PROPERTY OF YORK UNIVERSITY