Natural Selection

Competition and

Blobfish image courtesy of Biology: A Battle for Survival.

King Penguins image courtesy of Life in the Fast Lane.

Resource Competition

• when two or more organisms need the same resource. – Competition can occur between two different species

or between two individuals of the same species . • The ___________ items include all living

organisms in an ecosystem • The ___________ items include all non-living

materials in an ecosystem • A unique role of an organism within an

ecosystem is known as a — – Niche

biotic biotic

abiotic abiotic

Think – Pair- Share

• What are some biotic and abiotic factors that organisms might compete for?

• Why do some organisms end up surviving while others die off?

Natural Selection• Charles Darwin- studied finches (bird species) on the Galapagos islands.

–Natural Selection • (“Survival of the fittest”)

– a natural process resulting in the evolution of organisms best adapted to survive in their environment

image courtesy of MedioAmbiente.net

image courtesy of University of Washington Libraries

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Traits and Adaptations

• Traits- characteristics that can be passed down from parent to offspring.

• Examples: eye color, height, hunting instincts

• Adaptations- characteristics that help an organism survive better in its environment; inherited OR learned

1. What adaptations does this tree frog have?

2. How is this anteater adapted for survival?

image courtesy of World of Reptiels.

image courtesy of Mammals R Us.

• What factors might these giraffes be in competition for?

• What adaptations do these giraffes have?• Why didn’t the short-necked giraffe disappear

from time period A to B?• How did natural selection change this population

from time period A to C?