Interactions Among living Things

Natural selection Remember natural selection- individuals better suited for environment will survive and reproduce Adaptations- the behaviors and physical features that allow organisms to live successfully in their environment

Niche Every organism has a variety of adaptations that are suited to its specific living conditions Niche- role of an organism in its habitat or how it makes its living –Type of food –How it gets food –How other organism use it as food –How it reproduces

ON pg. 694, compare and contrast the three different birds and their niches.

What are the types of interactions that occur in an ecosystem?

Competition There are three major types of interactions among organism; competition, predation, and symbiosis Competition - It is a struggle between organism to survive with the same limited resources Many organisms compete for food, water, shelter, mates

How is it that trees and grass complete? Sunlight, water, minerals, space

Predation Predation - The interaction where one organism kills another for food Predator- one that does the killing Prey- one that is eaten If an increase in predators, what will happen? –Prey population will decrease-  lower food supply will cause the predator population to decrease

Pg. 695 Math Analyzing Data 1.What variable is plotted on the x-axis? What two variables are plotted on the y-axis? 2.How did the moose population change between 1965 and 1972? What happened to the wolf population from 1973 through 2976? 3.How might the change in the moose population have led to the change in the wolf population? 4.What is one likely cause of the dip in the moose population between 1974 and 1981?

Predator and Prey Adaptations Predators- help kill prey –speed, tentacles Prey- avoid being killed –mimicry- looking like something else that is dangerous –false coloring- looks like something bigger –protective covering- porcupine –camouflage- chameleon, walking leaf insect –warning colors- certain colors often are warning of poisonous.

Symbiosis A close relationship between two species that benefits at least one of the species. The three types of symbiotic relationships are mutualism, commensalisms and parasitism.

Mutualism Both species benefit Some species could not survive without the other Pg 30. read caption on figure 17 –Why are these birds sitting on the hippo? To feed and hitch a ride

Commensalism One species benefits and other is neither helped or harmed Some birds with trees- birds have home and the tree is neither helped or harmed Hawk and cactus Your bugs-- tiny mites(demodex folliculorum) live on the base of eyelashes and live on dead skin

Parasitism Parasite - One organism living in or on another organism causing it harm Host- provides the home and food for the parasite Parasite usually smaller than host Doesn’t usually kill host Example- flees, ticks, worms

Review What are adaptations –Behaviors and characteristics that help organism be successful How are a snake’s sharp fangs and adaptation? –Enable the snake to bit into its prey What are the three main ways in which organisms interact? –Competition, predation, symbiosis –Watch Discovery Educations Life: Hunters and Hunted