Download Evolution - El Camino College

EL CAMINO COLLEGE
INSTRUCTOR: K.VILLATORO
LAB
STUDENT’S NAME: ________________
EVOLUTION LAB: MICROEVOLUTION
PART 1: TOXIC NEWTS
- Go to the website: http://www.pbs.org/wgbh/evolution/library/01/3/quicktime/l_013_07_56.html
- Listen to this video clip and use the information presented here to answer the following questions.
1. Why has the newt evolved a level of toxicity much higher than that necessary to kill most predators?
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2. What is the trade-off (disadvantage) for the snake in developing greater resistance to toxicity?
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PART 2: EVOLUTION OF SALAMANDERS IN ACTION
- Go to the website: http://www.pbs.org/wgbh/nova/evolution/evolution-action-salamanders.html
- Click on “Launch Video”
- Listen to this video clip and use the information presented here to answer the following questions.
1. Pair each population of California salamanders with its adaptation:
a. population in the forest
_____ Mimicry of poisonous newts
b. population on the coast
_____ Blending with their surroundings
2. Which of the mechanisms of evolution is at work on this species of salamander?
a. mutation
b. genetic drift
c. gene flow
d. natural selection
3. What is the prediction of the fate of these two populations?
a. they are both evolutionary dead ends and will die out
b. they will keep hybridizing and will stay as one species
c. they will become two distinct species
d. they will migrate back to the north
PART 3: GENETIC VARIATION HELPS RESCUE ENDANGERED PANTHERS
- Go to the website: http://evolution.berkeley.edu/evolibrary/news/101201_panthers
- Read the article and answer the following questions
1. The reduction in size (and genetic diversity) of Florida panthers, due to hunting and habitat loss, is an example of:
a. mutation
b. genetic drift
c. gene flow
d. natural selection
2. The introduction of 8 Texas panthers to this population, in hopes of increasing genetic diversity, is an example of
which mechanism of evolution:
a. mutation
b. genetic drift
c. gene flow
d. natural selection
3. How does increased genetic variation affect a population's ability to survive attacks by pathogens and parasites?
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PART 4: SURVIVAL OF THE SNEAKIEST
- Go to the website: http://evolution.berkeley.edu/evolibrary/article/0_0_0/sneakermales_01
- Read the comic strip presented here and answer the following questions.
How does natural selection favor the “caller crickets”?
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How does natural selection favor the “no caller crickets”?
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PART 5: EVOLUTION IN HUMANS
For around 10% of Americans, 10% of Africa's Tutsi tribe, 50% of Spanish and French people, and 99% of Chinese, a
tall cold glass of milk means an upset stomach and other unpleasant digestive side effects. In fact, most adults in the
world are lactose intolerant and cannot digest lactose, the primary sugar in milk. And yet, regardless of our ancestry,
most of us began our lives happily drinking milk from a bottle or breast — so what happened in the intervening time?
Why do so many babies enjoy lactose and so many adults avoid it? Lactose is broken down by a protein called lactase,
which acts as a pair of molecular scissors, snipping the lactose molecule in two. Anyone who drank milk as a baby
carries a working version of the gene that codes for lactase. In lactose tolerant individuals, that gene keeps working
into adulthood, producing the protein that digests lactose and makes eating ice cream a pleasant experience. But in
people who are lactose intolerant, that lactase gene is switched off after weaning.
- Go to http://www.hhmi.org/biointeractive/natural-selection-lactose-tolerance
- Watch the animation and answer the following questions
1. Explain how a lactose tolerance mutation would spread through a human population that herds cattle. Make sure to
include the concepts of variation, selection, and inheritance in your explanation.
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2. Now imagine that the population described in the question above lived during the Paleolithic before any animals
were domesticated. How would that change your answer to the question above?
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3. Which of the mechanism has given as a result populations that are predominantly lactose intolerant and
populations that are predominantly lactose tolerant?
a. mutation
b. genetic drift
c. gene flow
d. natural selection
PART 5: REVIEW QUESTIONS
Circle the correct answer, based on your understanding of microevolution
Some head lice are now resistant to all commonly used pesticide shampoos used to kill them. Which is the better
explanation for this observation?
A. Frequent contact with pesticide shampoos caused mutations that allowed the lice to become resistant so resistant
lice became more and more common.
B. Some lice carried genes for resistance to the pesticide before contact with the shampoos and their numbers
increased after lice shampoos became common.
Which statement describes the swallow with the greatest evolutionary fitness?
a.
A swallow that lives to be 3 years old and has four offspring, two of which survive to reproduce themselves
b.
A swallow that lives to be 5 years old and has five offspring, one of which survives to reproduce
c.
A swallow that lives to be 2 years old and has four offspring, all of which survive to reproduce themselves
d.
A swallow that lives to be 7 years old and has three offspring, all of which survive to reproduce
e.
All are equally fit
The more we expose bacteria to antibiotics, the harder they will try to adapt.
a.
agree
b.
disagree