The Living World Chapters 5, 8, 9

Ecology Individual- natural selection Population- evolution Community- interacting species Ecosystem- cycling of energy & matter Biosphere- global processes Population ecology

Population Characteristics: Population Size – N # individuals Population density- volume # individuals per unit area Population Distribution Random- no pattern Uniform- evenly spaced Clumped- large groups Population sex ratio Males to females Population age structure- age categories

Influencing Population Size Density-dependent Factors: -influence an individuals’ probability of survival & reproduction Limiting resource- population cannot live without Plants  water, nutrients Animals  food, water, nest sites Carrying capacity- K limit that environment can sustain

Density Independent: -probability of being killed is not based on density of population TornadoesHurricanesFloodsFires Volcanic eruptions Climatic events

Population Changes  Population growth model- used to predict population size  Growth rate:  Intrinsic growth rate- r  Exponential growth rate (J shaped)  Logistic growth (S shaped)  Overshoot- larger than carrying capacity; followed by dieback (population crash)  Lynx/hares  Wolves/moose

Reproductive Strategies

Metapopulations  Groups  Connected by corridor  Benefits:  Better survival chances  Less vulnerable to density-independent factors  Protection against diseases  specialization

Species Interactions: Competition Resource partitioning Temporal Spatial Morphological Predation True predator Herbivore Parasite Parasitoids MutualismCommensalism

Keystone Species Role in community Low numbers Predator- mediated competition Ecosystem engineers

Community Changes Ecological succession Primary Early- successional Mid-successional Late- successional Secondary Starts with mid- successional Pioneer species- colonize new areas rapidly (aspen & cherry trees) Aquatic succession?

Matter Cycling  Biosphere- all ecosystems on Earth where life is found  Energy flow Sun  living  nonliving (emitted into space & atmosphere)

Cycles within Biosphere HydrologicCarbonNitrogenPhosphorousMacronutrients – Ca, Mg, K10% Rule

Biodiversity  Genetic diversity- variety of genes available within a species  Species richness  Species evenness

Evolution  ?  Microevolution - apples  Macroevolution – larger groups  Speciation- evolution of new species

Genetic Diversity  Genes-  Determine physical & behavioral characteristics  Genotype- Changing genes by:  Mutation  Recombination  Genotype & Phenotype

The Passing of Traits  Adaptations  Artificial selection  Natural selection  Darwin’s 5 principles  Random Evolution (nonadaptive)  Mutation  Genetic drift  Bottleneck effect  Founder effect

Speciation  Geographic isolation  Reproductive isolation  Allopatric speciation  Sympatric speciation

Successful Adaptations  Influenced by:  Rate of environmental change  Genetic variation  Population size  General time  Genetic Engineering  Examples  GMO

Ecological Roles  Range of tolerance  Fundamental niche  Realized niche =distribution  Generalist  Specialist