EOC Evolution and Ecology

Evolution

Creationism vs. Evolution Creationism Belief that a divine creator created the earth and all its life forms Evolution Belief that all modern life forms have descended from older life forms

Charles Darwin Scientist that contributed the MOST to our understanding of evolution

Darwin's Beliefs about Evolution 1) Struggle for Existence 2) Natural Selection 3) Descent with Modification 4) Common Descent

Struggle for Existence Animals with the STRONGEST traits will have an easier time obtaining food, living space and other necessities of life Example: Faster cheetah will get more prey than slower cheetah

Terminology to Understand Natural Selection Fitness The ability of an organism to survive and reproduce in its specific environment Question: Which animal would have a high level of fitness? low level of fitness? Polar bear living in the arctic with thick fur Polar bear living in the arctic with thin fur

Terminology to Understand Natural Selection Adaptation Any inherited characteristic that increases an organism's chance of survival Categories of Adaptations Include: Anatomical Behavioral Structural Physiological processes or function

Natural Selection Organisms with favorable adaptations that enable a high level of fitness, survive and reproduce MOST successfully * Occurs NATURALLY*

Descent with Modification Over LONG PERIODS OF TIME natural selection produces organisms different than their ancestors. Examples: 1) different structures 2) different niches 3) different habitats

Common Descent All species, living and extinct, were derived from a COMMON ANCESTOR they DID NOT EVOLVE Example:

Evidence of Evolution 1) Fossil Record 2) Geographical Distribution 3) Homologous Body Structures 4) Similarities in Embryology 5) Biochemical

Fossil Record Shows how different groups of organisms have changed over time

Homologous Body Structures Structures that have different mature forms but develop from the same embryonic tissues

Homologous Body Structures The limbs of each of these organisms have the same basic bones which supports the theory that at some point they shared a common ancestor

Vestigial Organs Body part that has little or no function Rabbit Human

Similarities in Embryology Embryonic cells develop in the same order to produce the tissues and organs of all vertebrates

Example of Biochemical Evidence for Evolution Trait: Hemoglobin Gorilla: Asp Val Asp Val Gly Gly Glu Horse: Asp Val Glu Val Gly Gly Glu

Adaptive Radiation When species all deriving from a common ancestor adapt to their own environment

Convergent Evolution When unrelated organisms resemble each other because they live in similar environments

Coevolution Two species change in response to each other Ex: flowering plants and pollinators

Punctuated Equilibrium LONG periods of NO CHANGE interrupted by brief periods of RAPID change

Ecology

Abiotic vs. Biotic Abiotic Nonliving part of an ecosystem Ex: rocks, soil, air Biotic Living part of an ecosystem Ex: animals, plants

Decomposition Organisms die at ALL LEVELS of the food chain Decomposed organisms provide producers with organic material to grow

Trophic Levels

Food Chain ONE WAY flow of energy in an ecosystem Example: Grass Insect Bird Hawk

Food Web Network of interconnecting food chains Represents ALL the possible feeding relationships in an ecosystem

Energy Pyramid Tertiary Consumers 10 kcal Secondary Consumers 100 kcal Primary Consumers 1,000 kcal Producer 10,000 kcal Sunlight 1,000,000,000 kcal 10% of energy is transferred from one trophic level to the next. This excludes sunlight.

Where the lost energy in an Energy Pyramid Goes Used up by the organism in the form of: 1)Heat 2)Producing new cells 3)Regulating body temperature 4)Moving

Biomass Mass of all the biological organisms in one trophic level

How Energy Loss Affects an Ecosystem 1)Fewer animals at higher trophic levels 2)Limits the number of trophic levels in an ecosystem

Greenhouse Effect Heat from the sun heats the earth Heat from the earth goes back into the troposphere and warms the air Greenhouse gases in the troposphere absorb the heat and send it back to the Earth

Greenhouse Gases Water Vapor Carbon Dioxide Chlorofluorocarbons Methane Nitrous oxide Largest amount of Greenhouse Gases

Global Warming Definition: The average temperature at the Earth's surface has increased due to greenhouse gases Prediction: Scientists believe that temperatures will rise more rapidly in coming decades (2.5º F to 10.4º F)

Consequences of Global Warming Severe Weather Events Melting ice and snow Ecosystem shifts and species extinction Human Health

Ozone Layer Location: Within the Stratosphere Contains: Ozone

Role: Absorbs ultraviolet light from the sun (acts like sunscreen for the earth)

Ozone 3 oxygen atoms OOO

Chemicals Causing Ozone Depletion CHLOROFLUOROCARBONS

Chemical Being Used to Replace CFCs HYDROFLUOROCARBON (HFC)