2/17 Biology update and homework due 2/24

Hi folks,

Today we took the time to get deeper into evolution by really exploring the concept of natural selection.

With that in mind, we also did a very interesting lab today.  Using a paper airplane design as a model bird, we explored how random mutations and natural selection could slowly evolve a species into one that is more fit for its environment.

For homework this week please answer the following questions about today's lab.  I'll send data from each of the groups in a separate email so you can see a larger sample size.  The write up for the lab is on page 314 and 315 in your book if you wish to refer to it.

There will be a quiz next week so please be prepared.  Some possible topics on the quiz include:  Darwin's 4 postulates, natural selection, genetic drift, stressors, natural selection (see question 15 below), allele frequency, non-Mendelian genetics, blood type problem, modes of selection (see questions 5 below).

1. What was "selecting" for the successful bird?

2.  What represented the "mutations". 

3.  In each trial you used a "clone" of the previous generation.  Why is the term clone appropriate?

4.  Is this lab an example of disruptive, directive, or stabilizing selection?  (May need to use your notes or the book if you don't recall these terms.)  Why do you think so?

5.  Did each generation always progress?  In other words, did each generation get a farther flyer?

6.  How does this lab represent natural selection?

7.  In a way, there were three traits that were adapting in order to create a better flyer.  Which three traits were involved in this model?

8.  Describe two aspects of this investigation that model evolution of biological organisms.

9.  How might this lab help explain the observations Darwin made about finches on the Galapagos Islands?

10.  How would you say the term "fitness" is represented in this lab?

11.  Using this lab, give an example of each of Darwin's four postulates (DIOR).  (Hint: one of them actually is not represented in this lab.)

12.  How would you alter the lab if the environment this population of birds was in was very very windy, so that if a bird left the ground it may be blown out to sea?  What would you change to model this new scenario.

13.  This question is not based on the lab.  

In class we discussed four different "stressors".  Get food. Not be food, Reproduce, Climate.  For each stressor, give me an example of how natural selection could lead to an adaptation.  

For example, a species of bird is an insect eater.  All the birds in the population have beaks and some have beaks that are slightly longer than the others.  Those that have the longer beaks have an easier time finding food so they live longer, are stronger, and can reproduce more.  Due to that, the allele for longer beaks becomes more and more prevalent in the population.  Please give me another example of "Get Food" as well as the other three.  I highly recommend putting some thought into this as a version of this question will be on an upcoming quiz.