The Natural FishThe Natural Fish

What is Biological Evolution?

Change over time

Descent with modification from a common ancestor

University of California Museum of Paleontology's Understanding Evolution (http://evolution.berkeley.edu)

Descent with ModificationGenetic material is passed on from parent to

offspring. The offspring is not identical to either parent.Those differences determine how well adapted

the individual is to its environment.

Natural Selection

If the brown allele is dominant, what will be the color of the offspring’s Mohawk?

Mother (yy) Father (BB)

What color will my

mohawk be?

If the brown allele is dominant, what will be the color of the offspring’s Mohawk?

Mother (yy) Father (BB)

What color will my

mohawk be?

In this example the allele combinations are not dominant or recessive. What will be the color of the offspring’s mohawk?

What color will my

mohawk be?

Mother (yy) Father (rr)

In this example the allele combinations are not dominant or recessive. What will be the color of the offspring’s mohawk?

What color will my

mohawk be?

Mother (yy) Father (rr)

Fish Genotypes and PhenotypesTABLE 1

ALLELE COMBINATION GENOTYPEPHENOTYPE

(fish scale color)

Green (G) + Green (G) GG Green

Green (G) + Yellow (y) Gy Green

Green (G) + Red (r) Gr Green

Yellow (y) + Yellow (y) yy yellow

Red (r) + Red (r) rr red

Red (r) + Yellow (y) ry orange

What to Do:

• Follow the directions from your teacher to complete Generation 1.

• Complete Table 2 as you go along.

• Use Table 3 to tally phenotypes from Table 2.

The Pond

Generations 2-4• Repeat the process for generations 2-4.

• Complete Table 2 as you go along.

• Use Table 3 to tally your phenotypes.

• At the end of each generation, remember to remove all yellow fish (any fish with yy genotype)

• When you complete Generation 4 – DO NOT REMOVE THE YELLOW FISH:

The Pond After an Environmental Disaster

Environmental Change• DO NOT remove any yellow fish.

• The environment has changed: now green fish are easily spotted by predators and can’t survive or reproduce.

• Remove any green fish (any fish with a green phenotype/ with genotypes GG, Gr, or Gy).

• Count the remaining numbers of each phenotype and record them on Table 3.

• Report your totals for the class chart.

Review Questions How did the population size change over the generations?

Looking at Table 2, did any allele(s) disappear from the population? What is more important to look at the phenotype or genotype when determining if an allele has disappeared? Why?

Was the population in Generation 4 Survivors different form earlier generations? If so how was it different? Explain in your own words why this occurred.

List the earth spheres that were important to the simulation, and explain in your own words how they interacted?

Give an example of another change in an earth sphere could affected the fish population?

The protein for brown eyes contains melanin which will always mask the protein for blue eyes.

brown eyes(melanin)

blue eyes