Intro to Ecology and Symbiotic Relationships

Ecology: How individual organisms interact with each other and with their environment How individual organisms interact with each other and with their environment

Levels of Organization Ecologists organize the world into different biological levels:Ecologists organize the world into different biological levels: – Individual – a single member of a species – Populations – group of individuals of the same species living in the same place – Communities – interacting populations of different species –Ecosystems – interacting populations + abiotic factors –Biomes - group of ecosystems (same climate, etc.) –Biosphere – the part of Earth that can support life

Abiotic vs. Biotic factors Abiotic factors: the nonliving parts of the environmentAbiotic factors: the nonliving parts of the environment –Ex. air, temperature, moisture, light, soil –These often determine which species survive in a particular environment Biotic factors: the living parts of the environmentBiotic factors: the living parts of the environment

Ecosystem Interactions The place where an organism lives (including both abiotic and biotic factors) is called its habitatThe place where an organism lives (including both abiotic and biotic factors) is called its habitat

Ecosystem Interactions If an organism’s habitat is its address, its niche is its occupation.If an organism’s habitat is its address, its niche is its occupation. A niche is the role that the organism plays in its habitat; how does it fit in?A niche is the role that the organism plays in its habitat; how does it fit in?

Ecosystem Interactions A fundamental rule in ecology is the competitive exclusion principle, which states that no two species can occupy the same niche in the same habitat at the same time.A fundamental rule in ecology is the competitive exclusion principle, which states that no two species can occupy the same niche in the same habitat at the same time. Why?Why?

Ecosystem Interactions A fundamental rule in ecology is the competitive exclusion principle, which states that no two species can occupy the same niche in the same habitat at the same time.A fundamental rule in ecology is the competitive exclusion principle, which states that no two species can occupy the same niche in the same habitat at the same time. Why?Why? When organisms share habitats, it creates competition – therefore each organism must find its own niche in order to have enough resources to surviveWhen organisms share habitats, it creates competition – therefore each organism must find its own niche in order to have enough resources to survive

Community Interactions Most species survive because of their relationships with other speciesMost species survive because of their relationships with other species Species benefit from one another, harm one another, and are dependent on one anotherSpecies benefit from one another, harm one another, and are dependent on one another

Symbiosis – any relationship in which two species live closely together –Competition –Predation –Mutualism –Parasitism Community Relationships

Community Interactions Competition – organisms fight for resources that they need to survive (food, water, mates)Competition – organisms fight for resources that they need to survive (food, water, mates)

Community Interactions Predation – when one organism (a predator) captures/feeds on another (prey)Predation – when one organism (a predator) captures/feeds on another (prey)

Community Interactions Q: How do predator-prey relationships maintain stability in an ecosystem?Q: How do predator-prey relationships maintain stability in an ecosystem?

Mutualism – both organisms benefit from the relationship

Mutualism examples: - plants + pollinators (birds/ bees) - sea anemones and clown fish - algae and fungi (lichens) - plants and fungi (mycorrhizae)

Parasitism Parasitism only one organism benefits from the relationship Filarial worms (causes Elephantitis)

Parasitism Parasitism one organism lives on/inside another and harms it (one helped, one harmed) Filarial worms (causes Elephantitis)

Parasitism examples: - athlete’s foot (fungi on human feet) - mosquitos and animals - cuckoos and cowbirds - tapeworms and dogs

What kind of community interaction is described here? A mountain lion pounces and attacks a hare for dinner A tapeworm lives and feeds in the intestine of a dog A bee feeds on the nectar of a honeysuckle flower E. coli live in the human gut and aid in digestion

What kind of community interaction is described here? A mountain lion pounces and attacks a hare for dinner PREDATION A tapeworm lives and feeds in the intestine of a dog PARASITISM A bee feeds on the nectar of a honeysuckle flower MUTUALISM E. coli live in the human gut and aid in digestion MUTUALISM

Other Social Interactions… Communication behaviors Aggressive/defensive behaviors Courtship behaviors

Communication Why??? Examples:

Communication Why??? Examples: –Pheromones in insects

Aggressive/Defensive Behavior Why??? Examples: –Fighting fish

Aggressive/ Defensive Behavior Why??? Examples:

Courtship Behaviors Why??? Examples: –Bird dances/displays

Courtship Behaviors Why??? Examples: –fruit fly courtship