Unit III: Interaction Among Living Things Review from last week: - Natural Selection Organisms in an ecosystem have unique characteristics that help them survive. Over time the characteristics that make organisms better suited to the environment become common place. Natural Selection leads to adaptations. - Adaptations The behaviors and physical characteristics that allow organisms to live successfully in their environment. An organisms adaptations will fit it’s specific role in the ecosystem. - Niche The specialized role of an organism in an ecosystem. This is how the organism makes its living. Review from last week: - Natural Selection Organisms in an ecosystem have unique characteristics that help them survive. Over time the characteristics that make organisms better suited to the environment become common place. Natural Selection leads to adaptations. - Adaptations The behaviors and physical characteristics that allow organisms to live successfully in their environment. An organisms adaptations will fit it’s specific role in the ecosystem. - Niche The specialized role of an organism in an ecosystem. This is how the organism makes its living.

Types of Interactions Remember, all living things need food, water, shelter, in order to grow and reproduce. Organisms do not live alone in their environments, and interact constantly with living and non-living things in their community. There are 3 major types of interactions within an ecosystem: Competition: the struggle between organisms to survive as they attempt to use the same limited resources Predation: an interaction in which one organism kills another for food Symbiosis: close relationship between 2 species that benefits at least one of the species

Competition There are 2 types of competition in an ecosystem: Interspecies Competition: Competition between organisms of different species. i.e. Wolf and Bear competing for Elk or Birds and Squirrels competing for nesting sites Intraspecies Competition: Competition between organisms of the same species. i.e. Male Deer fighting for a mate or Chimpanzees defending their territory from intruding Chimps

Competition Why can’t we be friends?

Competition Because all living things need food, water, shelter to reproduce and grow. There is a limited amount of these resources (limiting factors?), and the most/best quality resources go to the organism that can edge out the competition. However, Mother Nature attempts to break up the fight: Niches reduce competition. By specializing how you obtain food/water/shelter, what you call food, water, shelter, or where you find it, etc… But if two organisms share the same niche, one will eventually over-power the other. Turn to page 27 in your books and answer Qs about Warblers

Competition Not just for Animals

Predation (definitely not friends) Predation = an interaction in which one organism kills another for food The organism that does the killing is the predator The organism that is killed is the prey

Predation Still Not just for Animals…

Predation Predators have adaptations that help them catch and kill their prey Example Cheetahs can run very fast for a short amount of time Jellyfish have poisonous tentacles Some plants have sticky bulbs that catch flies Owls can see at night Bats can hunt without seeing at all

Predation Prey also have adaptations that help them avoid being lunch. Along with such attributes such as acute senses, Strength and Speed, and ability to hide, prey may also use Mimicry False Coloring Camouflage Protective Covering Warning Coloration (Aposematism, Batesian mimicry, and Müllerian mimicry) Find the definitions to these words in your text book. Maybe they will be extra credit questions on a quiz…

Symbiosis Symbiosis = close relationship between 2 species that benefits at least one of the species The three types of symbiotic relationships: 1.Mutualism 2.Commensalism 3.Parasitism

Symbiosis Mutualism = A relationship in which both species benefit Examples: Saguaro and the long-eared bats Cactus provide food for bats Bats carry pollen to another plant Acacia trees and stinging ants Ants nest in acacia trees, whose thorns discourage the ants predators, and the tree provides food Ants attack other animals that approach the tree and clear competing plants away from base

Symbiosis Commensalism = A relationship in which one species benefits and the other species is neither helped or harmed Examples: Red-tailed hawks’ and saguaro cactus Hawks build their nest in the cactus Cactus is not affected by the hawks

Symbiosis Parasitism = one organism living on or inside another organism and harming it The organism that benefits is called the parasite The organism it lives on or inside is the host

Symbiosis Ok, one more plant video

Python v. Gator

Homework Copy these questions into your notebook and answer for homework tonight. How have pythons adapted to living in the everglades? What are some reasons that the pythons and alligators are competing? Do they occupy the same niche? According to natural selection, do you think the pythons will increase or decrease in size over time?