Ecology and Biodiversity Overview

Biodiversity: Origins and Interactions

• Biodiversity arises from interactions between biotic (living) and abiotic (non-living) factors within ecosystems.
• Natural selection drives the development of biodiversity.
• Organisms possess both adaptive (beneficial) and maladaptive (harmful) traits.

Ecology and Populations

• Populations have the potential for exponential growth under ideal conditions.
• This is a positive feedback loop, but populations are typically stable due to limited resources.
• Not all offspring survive and reproduce, maintaining population stability.
• Genetic variability within populations is critical for survival.

Heredity and Genetic Variation

• Individuals within a population have differing genetic makeup.
• This variation arises from mutations during an organism's lifespan, including during DNA replication.
• Reproduction recombines parental DNA, further increasing genetic variation in offspring.
• Some mutations are neutral, others harmful, and some beneficial.
• Adaptive traits enhance survival and reproduction; maladaptive ones reduce these chances.

Types of Selection

• Stabilizing selection: Favors the intermediate form of a trait, such as the optimal number of eggs.
• Directional selection: Favors one extreme of a trait, as seen in the peppered moth response to industrial pollution.
• Diversifying selection: Favors both extremes of a trait, often driven by changing environmental conditions. (e.g. rabbits adapting distinct coat colors for camouflage)

Environmental Conditions and Evolution

• Divergent evolution: Related species evolve different traits in response to varying habitats, like Hawaiian honeycreepers.
• Convergent evolution: Unrelated species develop similar traits in similar environments, like cacti adapted to arid regions.

Types of Biodiversity

• Genetic diversity: Variability in genes within a population, crucial for adaptability.
• Species diversity: Measured by species richness (total number) and abundance (population sizes).
• Functional diversity: Explores how each species contributes to the ecosystem.
• Ecosystem diversity: Examines the variety of habitats and ecological processes within an area.

Species Extinction and Speciation

• Speciation: The formation of new species through sufficient adaptation.
• Allopatric speciation: New species form from geographic isolation, such as the separation of eastern and western gorilla populations.
• Sympatric speciation: New species emerge from the same geographic area through diversification of niches, without geographic isolation.
• Extinction: Complete disappearance of a species from Earth.
• Extirpation: Local extinction of a species while existing elsewhere.
• Endemic species: Found only in specific regions; extinction means permanent loss.

Island Biogeography

• Island biodiversity is affected by location from the mainland. Closer islands have greater biodiversity.

Biodiversity Case Study: Bobcats

• Bobcats exhibit high adaptability, inhabiting diverse habitats including forest and urban areas.
• Genetic analysis of bobcats in different locations revealed varied genetic diversity.
• Geographical barriers, like highways, can restrict gene flow among populations.
• Reduced genetic diversity was observed near urban areas.
• A disease outbreak (e.g. mange) showed how genetic diversity influences survival.
• Human activities can affect wildlife populations.

Protected Areas and Reintroductions

• Protected areas: Include parks, sanctuaries, and wilderness areas, serving diverse purposes. Their formation can involve displacement of local populations.
• Canada’s park system prioritized recreational use but increasingly emphasizes ecological preservation, using 39 physiographic regions to guide protection efforts.
• Reintroductions: Introduce species previously present but extirpated.
• Careful planning and monitoring are critical; considerations involve cost-benefit analysis, removal of threats, and ensuring a species' success in the introduced area.

This quiz explores the fundamental concepts of biodiversity and ecology, focusing on the origins of biodiversity, population dynamics, and genetic variation. Understand how biotic and abiotic factors influence ecosystems and the role of natural selection in shaping biodiversity.