Chapter 52 Ecology o The study of how organisms interact with each other and their environment Evolution and ecology are intertwined and codependent Ecology s primary goal is to understand the distribution and abundance of organisms Ecology has 5 main levels of research work o Organismal ecology How do individuals interact with each other in their physical environment Morphological physiological and behavioral adaptations that allow individuals to live in a particular area o Like how do salmon cope with transitioning from salt to fresh water o Population ecology How and why does population size change over space and time Focus on the number and distribution of individuals in a population change over time o Use mathematical formulas to predict salmon populations will be in future o Use this to make models to see effects of dams and changes in weather patterns o Community ecology How do species interact an what are the consequences A biological community consists of populations of different species that interact with each other within a particular area Community ecologist want to see the nature of this species and the consequences of these interactions Like salmon and bears o Ecosystem ecology How do energy and nutrients cycle through the local environment An ecosystem o Consists of all the organisms in a particular region along with nonliving components o These physical and chemical or abiotic literally non living include air water and the nonliving parts of soil o Ecosystem ecology study how nutrients and energy move among organisms and through the surrounding atmosphere and soil or water o How is the biosphere affected by global changes in nutrient o Global ecology cycling and climate Biosphere Thin zone surrounding earth where all life exist the sum of all terrestrial and aquatic ecosystem This layer os only 002 percent of the diameter of earth This young field tries to quantify the effects of human impacts on the biosphere Like growing temperatures Conservation Biology o Takes these five levels and tries to presence and restore threatened genetic diversity in populations species diversity in communities and ecosystem function o Prescribe remedies for clean air soil and other things to preserve biodiversity Biogeography o The study of how organisms are distrusted geographically Abiotic factors Temperature is the biggest reason Biotic factors o You cannot thrive in both extremely high and extremely low temperatures o This is due to fitness tradeoffs which specialize us for a specific climate o Other can be water moisture The ability of a species to persist in a given area is often limited by biotic living factors meaning interactions with other organisms Such as where you breed o What attacks you o Diseases o Ticks o Misquotes The distribution of organisms is determined not only bt conditions present today but also by events in the past The history of abiotic and biotic factors o These factors influence the distribution of organisms are dynamic they are constantly changing Although mountains and lakes and what not seem to be static they are constantly changing These events are important because they impact dispersal Dispersal The movement of individuals from their place of origin to the location where they live and breed as adults The Wallace line o Alfred Wallace founded the study of biogeography Among the first to document the phenomena of the Land bridge that once existed This line separates species with Asian and Australian affinities It exists because a deep trench in the ocean maintained a water barrier to dispersal even when ocean levels dropped during the most recent glaciations As a result landforms on either side of the line remained isolated at a time when most of the other islands become connected The influence of humans o The events Wallace studied occurred before the dispersal of modern humans around the globe from Africa around 70 000 years ago o Humans transport kill and other things to infect populations o If an exotic species one that is not native is introduced into a new area spreads rapidly and competes successfully with native species it is said to be an invasive species Biotic and Abiotic factors interact o Read page 1064 on ants o Take home message the interaction of biotic and abiotic factors slowed the spread of invasive ants more than the abiotic factors alone o Argentine ants are at a competitive advantage in moist soils and a disadvantage compared to native ants in dry soils The range of every species on earth Is limited by a combination of abiotic and biotic factors that occur in the past and present The ability to survive o The ability to find food and not be eaten and the ability to disperse Climate patterns o Species are adapted to the abiotic conditions that they live in Climate Weather The long term weather of a certain area Consist of specific short term conditions in an area Why are tropics wet o Areas around the equator are wet while 30 degrees north or south is dry o This is because of the Hadley cycle o George Hadley in 1735 discovered this o Steps Air is heated by strong sunlight along the equator heat hot air rises This warm air holds a great deal of moisture because warm molecules stay in vapor form instead of condensing into droplets As air rises above the equator it radiates heat to space It also expands into the larger volume of the upper atmosphere which lowers its density and temperature As rising hot air cools down its ability to hold water declines When water vapor cools water condenses This results in high precipitation along the equator As more air is heated along the equator the cooler older air above earths surface is pushed pole ward When this mass has cooled enough its density increases so it begins to sink As it sinks it absorbs more and more solar radiation reflected from earths surface and begin to warm while being pushed to the surface by higher density air above it As the air warms ir also gains water holding capacity Thus the air approaching earth holds onto water and little rain occurs where it returns to the surface Basically o Air get hot at the bottom and holds water o Hot air holding water goers to equator and as it rises cools and drops water this happens as 6o as well o Page 1065 Why are tropics warm and poles cold o Areas of the world that receive more sunlight are hotter o Areas at the equator receive much more sunlight o At the equator the sun is at 90 degrees over the earth maximum radiation per unit o As
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