Diversity and Evolution

December 8 & 9

Do Now

• Begin working on warm-up• REMEMBER – EXAM NEXT WEEK!

Objective

• By the end of class, students will be able to explain how population size and diversity affects a population’s ability to evolve

Agenda

• Warm-Up review• Natural selection video• Diversity and evolution notes• Diversity and evolution simulation• Biodiversity video• Florida panther reading• Exam review• Exit ticket

Why is answer “b” wrong?

1. 1. A fungus destroys most of a wheat crop, but a few plants survive. A few years later, the same fungus attacks the wheat crop again. This time, most of the wheat plants survive. The most likely reason for the survival of the second wheat crop is

a. the fungus caused a mutation in the wheat’s DNAb. the wheat became immune to the fungusc. the wheat immune to the fungus lived and produced

offspringd. the fungus evolved to be more deadly

Environmental changes do not CAUSE random mutations

(That’s what makes them random; they just happen for no reason)

Natural selection acts on the variation that already exists

Natural Selection Video

What is the role of population diversity in natural selection?

Where does diversity come from?

• Mutations in DNA• Sexual reproduction

Mutations in DNA

DNA is a code It gives instructions for building proteins

Those proteins build you!

Sexual reproductionproduces new combinations

Can natural selection occur without diversity?

More diverse populations are more able to evolve.

Also: size matters.Bigger populations are more likely to

evolve

What is the benefit of owning many different pairs of shoes?

Card Simulation

• Split into 4 groups• Each group will get a deck of cards which

represents a population of animals– Small deck, low diversity– Small deck, high diversity– Large deck, low diversity– Large deck, high diversity

Card Simulation

• Different environmental conditions will select for different variations

• If your group has the variation in its population, everyone in the group gets a piece of a candy

Card Simulation

• Which deck did you get?

Card Simulation 1

• A disease kills all the red cards.• Any group with black cards gets candy!

Card Simulation 2

• A predator has evolved a new hunting strategy. Only kings can avoid being eaten.

• Any group with kings gets candy!

Card Simulation 3

• The cards’ main food source goes extinct. Only red 3s are able to eat another food.

• Any group with a red three gets candy!

Card Simulation 4

• Spring comes late this year. Only the 5 of clubs emerges from hibernation late enough that it doesn’t starve before the plants start growing.

• Any group with the 5 of clubs gets candy.

Card Simulation 5

• Humans start applying a chemical to the environment that kills cards. Only the 2 of hearts is unaffected by the chemical.

• All groups with a 2 of hearts get candy!

Card Simulation Analysis

• Which group had a card that met the criteria most often?

• Is there any situation that this group would not be able to handle?

Large, diverse populations are most likely to have one member who meets environmental

challenges

Biodiversity

• Diversity with a population is called genetic diversity

• Diversity within a population is a component of biodiversity.

Biodiversity video

Genetic diversity in Florida panther population

Exam Review

Evolutionary

Exit ticket

• Which population is most likely to evolve in response to a change in its environment?– A small population with low diversity.– A small population with high diversity– A large population with low diversity– A large population with high diversity