Warm Up 1-31-13

1. Which process is responsible for bacteria becoming increasingly resistant to antibiotics (medicine that kills bacteria)?

(Hint: Think Darwin…)

2. Please place 4 blank graphs inside your notebook.

The Original Population Graph is First.

"nothing in biology makes sense except in the light of evolution"-Theodosius Dobzhansky (1900-1975)

Three Types of Natural Selection

•Stabilizing•Directional•Disruptive

Let’s Explore

Congratulations! You are about to analyze a population of clownfish!

Please obtain your fish population and arrange them using the large graph. Place the fish from bottom up. It must fill each bottom space before moving up.

You can make a graph with this information!

Draw a TREND LINE on your MINI-GRAPH in your notebook.

This is the ORIGINAL POPULATION.

Which species of fish are most abundant? Why could this be?

SCENARIO #1

Clownfish live in anemones to hide from predators. THE SEA TEMPERATURE CHANGES AND NOW BLUE & VIOLET anemones are taking over the coral reefs!!

What will happen to fish population?

DRAW A TREND LINE on mini-graph #1.

Directional Selection

• Neck of Giraffe• Antibiotic resistance of bacteria• Moth color (melanin) • Camouflage/Mimics• Many sexually selected traits

SCENARIO #2

A new predator arrives in the reef – chomp chomp!!

This shark can ONLY see the color YELLOW & GREEN.

WHAT WILL HAPPEN TO YOUR FISH POPULATION?

DRAW A TRENDLINE ON GRAPH #2

Disruptive Selection

• Causes divergence within the species

• Occurs when two different types of resources in one area

• Results in specialization for each branched group

• May lead to formation of new species

• E.g. Darwin’s Finches

SCENARIO #3

Pollution (YUCK!) has been dumped into the ocean and caused the yellow and green plants to outgrow the other colorful red, orange, blue, and purple plants. Now two colors of fish blend in better to its surroundings…..

WHAT WILL HAPPEN TO YOUR FISH POPULATION?

DRAW A TRENDLINE ON GRAPH #3

Stabilizing Selection• When the extremes of the

trait aren’t as well suited

Examples• bird clutch size• Elk Antlers size• Giraffe neck length• Tail length in birds

REVIEW

Examples of selection pressures...• Predators - variants with adaptations allowing them to escape

predators have more offspring- e.g. speed, defensive weapons, camouflage, mimicry

• Prey/Food - variants with adaptations allowing them to obtain food have more offspring

- e.g. Speed, senses for finding prey/food, weapons for killing prey or obtaining food, camouflage for stealth

• Climate - those who can survive new climate best have more kids- e.g. ice age, change in climate due to migration.

• Mates - variants with adaptations allowing them to attract a mate to have offspring

- e.g. strong, attractive, good provider

Make a Pyramid Foldable for the 3 types of natural selection.

Write the type on the front side. Draw the graph on the inside.