Principles of Ethology and Ecology: Behavior and Evolution

Fundamentals of Ethology

Ethology is the study of animal behavior, considering the what, how, and why. A key method in this field is observation, while avoiding anthropomorphism—the projection of human emotions or motivations onto animals.

• Proximate questions: Ask how and consider the mechanics of an animal's body.
• Ultimate questions: Ask why and consider the benefits versus the costs to fitness.
• Cost-Benefit Analysis: Evaluates the fitness benefits of a behavior against its risks (e.g., health, survival, and reproductive output).

Biological Fitness and Behavior

Biological fitness is your contribution to the gene pool of future generations. Adaptive behavior increases this fitness. Natural selection acts on behavior just as it does on physical traits; adaptive behaviors that allow individuals to pass on their genes increase in the population.

Altruistic behavior involves risking the individual for the sake of others, such as meerkats acting as guards.

Kin Selection and Fitness

• Direct fitness: Your own contribution to the next generation’s gene pool.
• Indirect fitness: Your relatives’ fitness improves yours because you share genes (alleles).
• Kin selection: Selection for behaviors that benefit relatives (e.g., humans giving larger presents to closer relatives).
• Inclusive fitness: The sum of direct and indirect fitness.

Learning and Communication

Behaviors like living in groups, babysitting, monogamy, and mate cannibalism are subject to cost-benefit analysis. Learning mechanisms include:

• Habituation: Adjusting to not respond to a stimulus.
• Associative Learning: Relating two events.
• Classical Conditioning: Associating two previously unrelated things.
• Operant Conditioning: Associating a behavior with consequences (can lead to superstition).
• Imprinting: Quickly learning who will care for you.

Communication methods include auditory (hearing, vibration), visual (eyes), chemical (smell, taste), and tactile (skin receptors).

Principles of Ecology

Ecology is the study of the interactions of organisms with other living things (biotic) and non-living things (abiotic).

Population Dynamics

Populations exhibit different distribution patterns: random, uniform, or clumped. Growth phases include lag, exponential, deceleration, environmental resistance, and stable equilibrium. Factors affecting populations are either density-dependent or density-independent.

Survivorship Curves

• Type I: Longer-living.
• Type II: Steady decline.
• Type III: Short-lived.

Species strategies include opportunistic (high hazard risk, high biotic potential) and equilibrium. Opportunistic strategies are often found in less developed areas with lower education and fewer resources, while equilibrium strategies are common in developed areas with larger ecological footprints.

Community Ecology

Coevolution occurs when the interaction between two species influences their reproductive success (fitness), causing natural selection to shape the interaction.

Ecological Succession

• Primary succession: No soil remaining.
• Secondary succession: Soil remains.
• Pioneer species: Opportunistic annual plants, grasses, and perennials that are eventually outcompeted by equilibrium species.
• Intermediate species.
• Climax community.