Interactions of Living Things Chapter 18 Interactions of Living Things

What is Ecology? The study of the interactions between organisms and their environment Interactions between organisms is not simply who eats who but varied, some good some bad

2 parts of ecology Biotic aspect The living part of the environment Animals, plants, insects, humans Abiotic aspect The non-living part of the environment Physical factors Rocks, water, soil, light, temperature

Organization in the Environment Organism Populations Communities Ecosystems Biosphere Single animal Group of the same animal Different populations in the same area Includes the abiotic factors Earth where life exists

The Energy Connection All living things need energy to survive Organisms are divided into groups based on how they get energy Producers Consumers Scavengers Decomposers

Make their own food/energy Producers Make their own food/energy Use the sun to go through the process of photosynthesis Includes plants, algae and some bacteria

Consumers Primary consumer – eats the producer Can’t make their own energy, get it by eating producers or other consumers Primary consumer – eats the producer Secondary consumer – eats a consumer Herbivore – eats only plants Carnivore – eats only animals Omnivores – eats both plants and animals

Scavenger vs. Decomposer Scavengers eat dead animals for energy Examples include turkey vultures Decomposers get energy by breaking down the remains of dead organisms Recyclers, bacteria and fungi

Food Chains and Webs Food chains represent how energy flows from one organism to the next Rare in nature because animals usually eat more than one organism Food webs represent many pathways that energy flows in an ecosystem

Represents the loss of energy by each organism in a food chain or web Energy Pyramids Represents the loss of energy by each organism in a food chain or web

Habitat vs. Niche Habitat – the environment in which an organism lives When things like deforestation, building of roads and buildings occur, habitats are being destroyed Niche – organisms way of life in the ecosystem Includes its habitat, food, predators, competitors and abiotic factors

Niche of the Gray Wolf Consumers Carnivores, eating moose, deer, reindeer, sheep and small animals such as birds and snakes Social Structure – hunt in packs Nurture and teach their young Important in population control

Interactions Most living things produce more offspring than will survive but abiotic and biotic factors will control the population size Example: frogs

Limiting factors Populations cannot grow indefinitely because the environment contains only so much food, water, living space and other resources When one or more becomes scarce, it becomes a limiting factor

Carrying Capacity The largest population that a given environment can support over a long period of time When the population gets larger than carrying capacity, limiting factors will cause the population to get smaller

Can occur among individuals within a population or between populations Competition Can occur among individuals within a population or between populations Competition for resources, mates, space

Prey – the organism that is eaten Predator and Prey Prey – the organism that is eaten Predator – the organism doing the eating Adaptations Predator – speed or ambush prey Prey – run away, camouflage, poisonous, bright colors, groups

Long term, association between two or more species 3 types Symbiosis Long term, association between two or more species 3 types Mutualism Commensalism Parasitism

Both organisms benefit Insects pollinating flowers Mutualism Both organisms benefit Insects pollinating flowers

Commensalism One organism is benefiting and the other is unaffected Clown fish and sea anemone

One organism is harmed and the other is benefiting Parasitism One organism is harmed and the other is benefiting Parasite- benefits Host - harmed

Herbivores evolving with the plants they eat Coevolution Long term change that takes place in two species because of their close interactions with each other Herbivores evolving with the plants they eat Flowers and their pollinators