Breeding Bunnies

On thursday's biology class, we learned that, to evolve, a population needs some sort of genetic variation, memory of previous generations, and a selecting factor. We looked at the example of a population of bunnies that lived in the middle of a mountain. It was neither at the very top nor at the very bottom. Then, a hurricane came and took some bunnies to the bottom and some to the top. What genes would allow the most bunnies to survive at each location, FF (dominant, thicker hair), Ff (heterozygous, thicker hair), or ff (recessive, thinner hair)?
Our group explored the possibilites of survival of those rabbits at the very top of the mountain. Here is what we did. Our group recieved 5 plastic cups. One had fifty beans; 25 black and 25 red, the others were marked; "FF", "Ff", "ff" and ":(". We should draw two beans at a time, placing them at the corresponding plastic cup. Each set of two beans stood for an individual, where black beans meant dominant alleles and red beans meant recessive alleles. Every time we picked a "Ff" bean couple, we flipped a coin to see whether this individual would live or die. If it lived, the beans would go to the "Ff" cup, and if it died, they would go to the ":(" cup. At the end of a generation, we "killed off" the beans in the "ff" cup, since the rabbits with thin hair would not survive in the cold climate of the mountaintop. All the beans that were of surviving individuals went back to the clear cup and were drawn to find the statistics of the next generation.
Before starting to experiment we came up with a hypothesis:
"If a population of rabbits with equal number of dominant and recessive alleles is placed at the top of a mountain, then those with thicker hair (dominant alleles) will survive more than those with thinner hair (recessive alleles)."
If our hypothesis were right, we wrote that the rabbits of "ff" alleles would die off and the ones with "FF" alleles would live on after 10 generations.
Here is our data chart.

As one can observe, the "ff" individauls completely died off at the 5th generation.
Here are the questions we were supposed to answer after completing the experiment:

• What was your original hypothesis?

Our hypothesis stated that FF bunnies would survive and dominate over ff bunnies when placed on a mountaintop (see above).

• Based on your lab data, do you need to change your hypothesis? Explain

No, we do not have to change our hypothesis because it was correct.

• Compare the number of alleles for the dominant characteristic with the number of alleles for the recessive characteristic.

By the second generation, the FF bunnies already had a 4:1 ratio over the ff bunnies, and by the fifth, the ff bunnies had already died off.

• Compare the frequencies of the dominant allele to the frequencies of the recessive allele.

The dominant allele was more common because it was the one that was best suited for that enviornment.

• In a real habitat new animals often come into the habitat (immigrate), and other s leave the area (emigrate). How might emigration and immigration affect gene frequency of F and f individuals in this population of rabbits? How might you simulate this effect if you were to repeat this activity?

In our population, immigration and emmigration would have an impact only on the generation directly after that, due to the fact that new alleles would be added into the gene pool, but, in the long run, they would not present much difference, since the thick-hair alleles would dominate. The rabbits with "FF" genes would survive the most because they would be the most adapted to the enviornment, regardless of immigration and emigration.

• How do your results compate with the class data? If significantly different, why were they different?

Our results were different because we gathered information while selecting for FF bunnies, against ff bunnies. Some other groups were selecting for either ff or FF alleles, and therefore our results vary. However, the first generation was very similar in all the groups in our class.

• How are the results of this simulation an example of evolution?

Our results are an example of evolution because our mock population adapted to conditions exterior to themselves (which was the weather at the peak of the mountain). Eventually the population grew thicher fur in order to adapt to its conditions. There was variation (genes: FF, Ff. and ff), memory of the previous generation (the gene pool was changed over the years) and a selecting factor (weather, which selected for FF genes). Therefore, this experiment is a simulation of evolution!

Arm Vs. Leg Length in relationship to Flexibility

Some classes ago, we worked on measurements regarding two body parts of children and how they could have an advantage based on the ratio of those body parts. My group worked with the ratio of arm length to leg length and how that could give them an advantage in flexibility. We measured the arm and leg length of 31 second graders. Here are the graphs for our group's research:

This graph shows the relationships of leg length and arm length in our sample.

This graph shows the arm vs. leg ratio in second graders in relationship to their skill.

This is a histogram concerning the frequency of each arm to leg ratio of second graders. 

Did you know?

Did you know that the Chrysalidocarpus lutescens is one of the trees most used today for interior decoration?
That is so because it grows well in places with lots of light, even if it is not natural light. Even a light bulb generates enough light energy for the Chrysalidocarpus lutescens to grow well! Also, it is a beautiful plant and is known for "purifying" the air.

THE TREE

My tree is a palm tree, one of the many we find in Brazil, but this particular one is the Chrysalidocarpus lutescens, or Areca bambu as it is most commonly known here in Brazil. It is a perennial angiosperm plant, originally from Madagascar. It is fast-growing, and grows best under partial or total sunlight.
The tree I chose is about 3 to 3.5 m tall, and has 8 parallel trunks that sprout out of the same root structure, whith a few other smaller trunks starting to grow. I can tell that there is a different rate of growth between trunks, since there are taller ones and shorter ones. Also, the tree grows in such a way that the leaves are coming out of a spike that sits on the very top of the tree. It is the greenest, and the newest leaves are growing out of there. As the leaves get old, they become gradually more yellow, then orange, and finally they become reddish brown and fall off. The falling generates some "scar tissue", which creates a ring on the palm's trunk. This causes the tree to grow away from the older scar tissues. When one pulls off a leaf it is noticeable that the inside of the leaf, where it touches the trunk, has a waxy sort of covering. This has the purpose of  keeping the water inside the plant, so that it does not dehydrate. Another sort of covering can be seen in the trunk and some leaves, where they have a white, furry substance growing. It also has a series of leaves that sprout out of the trunk, one tree having up to 20 leaves growing at the same time. It serves to keep the water in as well. It propagates with seeds, which it sheds every 2-6 weeks, or through the division of the root structure.
My palm sits right in front of the drama room, in front of the gymnasium.
I chose this plant because palm trees in general remind me of going to the beach, a thing I love doing. Also, I like this particular type of palm tree because my dad planted a palm like that one to celebrate my birth, so I am obviously drawn to this tree.

This tree does not have any change of color or structure, therefore I expect that on the next 9-21 months it will continue growing, until it reaches its maximum height (its species can get up to 9 meters tall!) and then it will continue the same. However, the leaves will continue falling, generating the scar tissue, and the trunk will eventually enlarge, but no greater scale changes will be seen. Also, the root structure will have more palm tree trunks growing out of it if it is allowed to grow.
I noticed small things on this plant that I had not seen at first after observing it for about 20-30 minutes. Firstly, the waxy inside of the plant's leaves, the whitish covering on the trunk, the fact that the fibers are clear and distinct in the trunk and leaves, the fact that the leaves become yellowish where it has more exposed contact with sunlight, and the fact that the trunk is not entirely cylindrical, but actually has a difference in its diameter, and is thicker in some places and thinner in others.
So this is it for my first "blogging the tree", tune in later this week for more!

Hello and Welcome!

Hello!

Well, this is my first post for my tree-reporting blog. Here, I will apply all my knowledge of biology, which I still am to learn in this year's AP Bio class, onto nothing more, nothing less than a tree! There is a tree outside the drama room at my school and that will be the one I will "follow". All that I learn concerning trees/nature/plants in general will be applied to that beauiful palm tree.

This seems like an interesting assignment and I am looking forward to it.

Check online soon (around the 11th, to be more precise) for the actual first impressions on the tree and more about what I observed that a common passerby would not notice!

For now, I sign out with a goodbye for this hello,

Arminda Sesana