Iguanas original environment

lifestyle

• Green Iguanas are forest dwelling lizards that live high in the tree canopy of the South American rainforest.

• Young iguanas stay in areas lower in the forest canopy. Mature iguanas live higher in the tree tops. Iguanas rarely leave the trees. The only real exception to this is when the female iguanas must come down from their sky high home in order to dig burrows in which the female iguanas lay their eggs.

• Iguanas prefer to have water around them as iguanas are excellent swimmers and will often dive beneath the water to avoid oncoming predators.

JUNGLE IGUANA ( Green ) well adapted to heavy tropical forest

In the Jungle…Nature selects Climbing feet. Not webbed

Jaguars prey on iguanas

Nature selects the fear instinct. Instinct is to Seek safety in trees when frightened

Good Camoflage

Tsunami enters jungle environment

Tsunami floods jungle lowlands could wash groups of iguanas out to sea

Many trees wash out to sea… some perhaps with iguanas in the branches

MUTATIONS… all are super-dominant

• 1. no mutation • 2. “N” Nostril genes mutate during meiosis. The

new gene causes glands in the nose to collect extra salt from the blood and to expel that salt.

• 3. “B” mutation of skin pigment gene causes black pigment instead of green

• 4. “S” Mutation of foot shape gene on chromosome 2 causes webbed feet

• 5. “C” The “calm gene” is a Mutation of the fear reaction gene on chromosome 3. The calm gene causes fear reaction to dissapear.

The new environment. Which traits will be selected here ?

Galapagos islands

That was a long trip !

Stranded !! Algae is your food now !

IF you missed it

• The iguana tsunami activity is designed to get your thinking about how a population of iguanas might change over time if they are “dropped” into a new environment.

FLY TEST

• 1. Your Conclusion: Based on your observations…what causes long and short wings in fruit Flies? ( worth 0 points )

• 2. Give all evidence you can to support your answer.

• 3. Explain how you used “IF THEN “ predictions to disprove 3 other hypotheses