For the past two days in Biology, we have been working on a web quest our teacher sent us. This web quest was about guppies, species, and microevolution. Below is the web quest with the links. If you would like to read about it click on the first link. The second link takes you to learn about guppies and their spots. We needed to answer questions and define a few words.
PART 1: EVOLUTION 101
--Go to http://evolution.berkeley.e
1. How do the authors of this page define microevolution?
They define microevolution to be evolution on a small scale—within a single population. That means narrowing our focus to one branch of the tree of life.
2. How do they define a population?
They define population as a group of organisms that interbreed with each other—that is, they all share a gene pool.
--Read the section “Mechanisms of Microevolution”
3. Summarize each of the 4 mechanisms of microevolutionary change that are discussed.
1) Mutation- Where a gene randomly mutates and causes a change in the alle frequency.
2) Migration- Where a species with a certain gene immigrates from one population and enters a group with a different gene.
3) Genetic Drift- When a species mates a certain gene from the immigrated group shows up more than the common gene in the emigrated group.
4) Natural Selection- A species with a certain gene that can camaflauge them from preditors survive better than those who are bright and easily seen.
--Under “Explore further” at the bottom of the page, click on “examples of microevolution” and read the examples provided.
4. Summarize the 3 examples of microevolution on this page.
1) The first example was dicussing the body size of the sparrows. The colder the climate the larger the body the sparrow has. The warmer the climate the smaller the body of the sparrow. Evolutionists say this was due to Natural Selection.
2) In the second example the scientists discussed the affect of global warming and how it was causeing the environment to change. It would make the summers longer and hotter and the winters colder.
3) Example 3 was very short and it talked about building resistance. The evolutionists say it was also by natural selection. They say that many different kinds of bacteria have built a resistance to some antibiotics and pestisides.
--Go to the link “Artificial selection in the lab” and read about experiments with the evolution of guppies.
5. Summarize the results of the two different experiments (with and without predators).
With Predators- The scientists set up a pond to test the spot on guppies. The spots are meant to hide them from predators. The first set of ponds had predators. After less than 15 generations the number of spots seemed to diverge as a result of natural selection.
Without Predators- Without the predators the sexual selection of the guppies kicked in. The males attracted the attention of females with their many spots.
6. What types of selection were demonstrated in each experiment? Are these experiments truly cases of artificial selection? Explain your answer.
There was Natural selection, sexual selection, and artificial selection. Yes they are cases of artificial selection because each pond had fewer than 15 generations and the ponds were tampered with to get results.
--Click on the quick quiz link to go to the quiz.
7. Pick your three favorite questions from the quiz and write how you would answer them if you were teaching this class.
1) What are species and how do new ones evolve?
Species are different types of animals and they evolve over time. For example the dinosaur teridactly is supposed to have evolved into today’s birds.
2) What is macroevolution?
Macroevolution is basically evoultion, but on a bigger scale. We look at the over-arching history of life.
3) What is an evolutionary trend?
An evolutionary trend is a directional change within a single lineage or parallel change across lineages, in other words, several lineages undergoing the same sort of change.
PART 2: SEX AND THE SINGLE GUPPY
Use the simulation to test different hypotheses about why some guppies are very brightly colored even thohat makes them easy for predators to find.
1. Why do some guppies tend to be drabber than others?
To hide from predators
2. Why do some guppies tend to be more colorful?
To attract a mate to pass on there genes
3. What role does color play in guppy survival?
The more colorful a guppy is the better chances it has to
reproduce, the more drabber a guppy is the better chance it has to
survive
4. Explain the push and pull that the environment (including predators) has on the coloration of guppies in Endler’s pools.
Places that have a lot of predators have less colorful guppy as
they are usually eaten. This results in the male guppy being more
drabber as it is pushed toward camouflage.
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