1.
Rock Pocket Mouse – Macroevolution
If you missed school and didn’t see the video shown in class, here is the web address:
http://www.hhmi.org/biointeractive/making-fittest-natural-selection-and-adaptation
Explain the difference in microevolution and macroevolution.
2.
The rock pocket mice shown in the video clip is an example of allele frequency change in a population
(they are still the same species). Is this an example of microevolution or macroevolution? Explain.
3.
The creation of any new species requires reproductive isolation in a population. Define all of the following
terms relating to reproductive isolation.
a. Reproductive isolation
b.
Prezygotic barrier
c.
Postzygotic barrier
4.
The reproductive isolation seen from the rock pocket mice is that dark mice are found in different
geographic locations than light mice because each is camouflaged to a particular area (dark mice to the lava
rock and light mice to the sandy areas). Is this a prezygotic or postzygotic barrier? Explain.
5.
As mentioned, these rock pocket mice are still the same species even though they have different
phenotypes. Explain how we know if 2 organisms are the same species?
6.
If these 2 populations of mice (dark and light) continue to be reproductively isolated, macroevolution will
eventually occur creating 2 new species. Explain how reproductive isolation and mutations both eventually
result in new species.
7.
Answer the following questions concerning the scenario in which rock pocket mice could eventually evolve
into 2 different species (as described in number 6).
a. Would this be an example of divergent or convergent evolution? Explain.
b.
Would the 2 new species have homologous or analogous structures? Explain.
c.
Would this be an example of sympatric or allopatric speciation? Explain. (Hint: Even though the
populations aren’t separated by a typical geographical barrier [ex. mountain, river, etc.], the
different colors of their environments would still create a situation where the populations are
found in geographically different areas.)
d.
The rock pocket mice shown have been tan for thousands of years with very little change. Even so,
we are rapidly seeing them become dark in certain areas that could eventually result in new
species relatively rapidly. Would this type of evolution represent punctuated equilibrium or
gradualism? Explain.