Biodiversity and Evolution New

Biodiversity and Evolution Biodiversity Definition: Biological diversity, referring to the variety of life on Earth. Indicator of Biodiversity: Species as the most apparent indicator. Species: Groups of similar organisms capable of mating and producing fertile offspring. Components of Biodiversity Four Main Components: Genetic Diversity Variety of genetic material within a species or population. Species Diversity The number and abundance of different species within an ecosystem. Ecosystem Diversity Variety of terrestrial and aquatic ecosystems in a region. Functional Diversity Biological and chemical processes essential for survival, such as energy flow and matter recycling. Understanding Functional Diversity Describes processes that maintain ecosystems. Involves: Decomposers (bacteria, fungi) Chemical nutrients (carbon dioxide, oxygen, nitrogen) Energy (solar energy, producers, consumers) Species Diversity Definition: Refers to the number and abundance of different species in an ecosystem. Includes concepts like species richness, which measures the number of different species present. Genetic Diversity in Specific Species Genetic diversity example: Caribbean snail variations in shell color and patterns. Genetic diversity impacts include variations in chemical makeup and behavior. Ecosystem Diversity Refers to various biological communities (e.g., deserts, grasslands, forests, oceans). Functional Diversity Variety of processes within ecosystems (energy flow, matter cycling). Importance: Essential for ecosystem functioning and stability. Ecological Niche Definition: The role species play within their ecosystem. Different organisms occupy various niches, impacting ecological balance. Habitat Definition: Environment where organisms live and obtain necessary resources. Kinds of Niches Generalists: Species that thrive in varied environments and consume diverse food sources. Specialists: Species adapted to specific habitats and limited food sources. Importance of Biodiversity Economic Services Medicinal Value: Diversity in organisms contributes to drug development (e.g., aspirin from willow bark). Fuel: Biofuels derived from plants (corn, sugarcane). Timber: Economically crucial for energy and construction. Food: Wide variety of food resources from plants and animals. Ecological Services Balance: Biodiversity maintains ecosystem balance. Biological Productivity: High biodiversity correlates with biological productivity. Climate Regulation: Biodiversity aids in carbon sequestration and mitigating climate change. Degradation of Waste: Microorganisms recycle nutrients and decompose waste. Pest Control: Natural species act as pest control agents. Other Benefits Recreation: Biodiversity provides opportunities for leisure activities. Education and Research: Diverse life forms are crucial for scientific study. Traditional Value: Cultural significance of plant and animal species. Species Roles in Ecosystems Native Species: Naturally found and thriving in specific ecosystems. Nonnative Species: Species introduced into ecosystems, either accidentally or intentionally. Indicator Species: Provide warnings of environmental changes. Keystone Species: Critical for sustaining ecosystem structure and diversity. Evolution Biological Evolution: Changes in genetic characteristics of populations over time. Natural Selection: Process where organisms with advantageous traits survive and reproduce. Charles Darwin and Alfred Russel Wallace Proposed natural selection, observing struggles within environments for survival and reproduction. Steps in Biological Evolution Genetic Variability: Arises from mutations in DNA. Natural Selection: Populations evolve based on environmental pressures. Mutation and Its Role Definition: Random genetic changes that can occur spontaneously or due to external factors (e.g., UV radiation). Adaptation Definition: Heritable traits that enhance survival and reproduction in changing conditions. Limits to Adaptation Adaptation restricted to existing genetic traits and reproductive capacity of populations. Common Myths about Evolution Survival of the Fittest: Measured by reproductive success, not just physical strength. Traits Developed by Need: Traits are already present in populations’ genetic makeup. Goal of Perfection: Evolution is not about perfect adaptation; it has no predetermined direction. Factors Affecting Biodiversity Speciation Process where one species evolves into multiple species under certain circumstances (e.g., natural selection). Geographic Isolation Groups of the same species become isolated, leading to evolution of distinct species. Reproductive Isolation Result of genetic differences preventing successful reproduction between isolated populations. Artificial Selection and Genetic Engineering Artificial Selection: Selecting desirable traits through breeding practices. Genetic Engineering: Manipulating genes to create traits not found naturally. Synthetic Biology Involves creating sequences of DNA to develop organisms not found in nature. Extinction Biological Extinction: Complete disappearance of a species due to environmental changes. Endemic species are particularly vulnerable due to their limited geographical distribution. Background Extinction Rate Natural, low rate of extinction versus mass extinction events caused by drastic environmental changes.