Aim: How does adaptative variation lead to the

survival of an organism?

How is Kevin Costner different form everybody else in Water

World?

He had webbed feet and gills

ADAPTIVE VARIATION

Variation

DIFFERENCES (in structure and or behavior) within a population

What produces variations?

• Sexual reproduction recombination of genes

• Meiosis• Crossing over• Independent

assortment – different gametes made by one parent

• Mutations

Why are variations important to a population?

• Variation in a species increases the chances that some members will survive an environmental change.

• Why is this important?

For example: The peppered moth

Adaptation

A variation that allows an organism to survive in it’s environment

Adaptive VariationA variation that allows you to

survive a changing

environment

What would happen to a population with variation if the environment changed?

• Those who had an adaptive variation would survive. Those that don’t will die. This would lead to ….

EVOLUTIONEVOLUTION

What would happen to a population that did not have

variation?• If they don’t posses

a trait that allows them to adapt to a changing environment, they will die out:

EXTINCTIONEXTINCTION

What is the theory of evolution?

• Theory – well tested conclusion that has been accepted by the scientific community.

• Evolution :1) The process by which

species change over time.

2) Present day species are related to ancient species.

Summary Questions:

1) The driving force behind evolution is the interaction between the individual organisms andthe __________.

2) In your own words, define what an adaptivevariation is?

3) Explain what the following statement means, “Individual organisms do not evolve, species do”.

A certain species has little genetic variation. The rapid extinction of this species would most likely result from the effect of

(1) successful cloning

(2) gene manipulation

(3) environmental change

(4) genetic recombination

The least genetic variation will probably be found in the offspring of organisms that reproduce using

(1) mitosis to produce a larger population

(2) meiosis to produce gametes

(3) fusion of eggs and sperm to produce zygotes

(4) internal fertilization to produce an embryo

In an environment that undergoes frequent change, species that reproduce sexually may

have an advantage over species that reproduce

asexually because the sexually reproducing

species produce

(1) more offspring in each generation

(2) identical offspring

(3) offspring with more variety

(4) new species of offspring in each generation

In a group of mushrooms exposed to a poisonouschemical, only a few of the mushrooms survived.The best explanation for the resistance of thesurviving mushrooms is that the resistance

(1) was transmitted to the mushrooms from thepoisonous chemical(2) resulted from the presence of mutations inthe mushrooms(3) was transferred through the food web to themushrooms(4) developed in response to the poisonouschemical