Notes on Evolution and Ecology PDF

notes science Notes on Key Concepts in Evolution and Ecology Natural Selection Definition: A process where organisms with favorable traits are more likely to survive and reproduce. Key Components: Variation:...

notes science Notes on Key Concepts in Evolution and Ecology Natural Selection Definition: A process where organisms with favorable traits are more likely to survive and reproduce. Key Components: Variation: Differences in traits among individuals in a population. Heritability: Traits must be heritable to be passed on to the next generation. Differential Survival: Individuals with advantageous traits are more likely to survive and reproduce. Example: Peppered moths changing color during the Industrial Revolution due to pollution. Variation Definition: The differences in physical or behavioral traits among individuals of a species. Sources of Variation: Genetic Mutations: Changes in DNA that can introduce new traits. Environmental Factors: Influences such as climate, food availability, and habitat can affect traits. Importance: Provides the raw material for natural selection to act upon. Adaptation Definition: Traits that enhance an organism's ability to survive and reproduce in a specific environment. Types of Adaptations: notes science 1  Structural: Physical features (e.g., beak shape in birds). Behavioral: Actions taken by organisms (e.g., migration patterns). Physiological: Internal processes (e.g., temperature regulation). Example: Cacti have adaptations like thick skin and spines to conserve water in arid environments. Evolution Definition: The change in inherited characteristics of biological populations over generations. Mechanisms of Evolution: Natural Selection Mutation: Random changes in DNA that can introduce new traits. Genetic Drift: Random changes in allele frequencies, especially in small populations. Gene Flow: Movement of genes between populations through migration. Outcome: Can lead to speciation, where new species arise from existing ones. Artificial Selection Definition: The intentional breeding of organisms by humans for specific traits. Examples: Domesticated animals (e.g., dogs bred for specific behaviors or appearances). Crop plants selected for yield, taste, or disease resistance. Contrast with Natural Selection: Driven by human choice rather than environmental pressures. Competition Definition: The struggle between organisms for limited resources such as food, space, and mates. notes science 2  Types of Competition: Intraspecific Competition: Competition within the same species. Interspecific Competition: Competition between different species. Effects on Populations: Can lead to adaptations, resource partitioning, or changes in population dynamics. Predator-Prey Relationship Definition: An ecological interaction where one organism (the predator) hunts another (the prey). Dynamics of the Relationship: Predators help regulate prey populations, preventing overpopulation. Prey develop adaptations (e.g., camouflage, speed) to evade predators. This relationship can drive co-evolution; as prey evolve defenses, predators may evolve better hunting strategies. Example: Wolves hunting deer; an increase in wolves may lead to a decrease in deer population and vice versa. notes science 3