1) The graph below shows allele frequency over time of new mutations that appear in a population. Label each curve in the graph with the scenario that it corresponds to ( A F ) : (A) The new mutation is dominant and is selected against. (B) The mutation is favored by selection but is recessive. (C) The mutation is very strongly favored by selection. (D) The mutation is recessive and s < 0 . (E) The mutation is dominant and s > 0 . (F) The mutation is co-dominant (additive) and favored by selection. .

1. 1)Prior to the discovery of transitional forms, scientists proposed a relationship between fish and
amphibians. What features might indicate an evolutionary relationship between the two groups?
2) If you were a paleontologist looking for a transitional fossil linking fish and amphibians, what
would you expect that animal to look like? Why?
3) The rocks that contain fossils (sedimentary rocks) are closely linked to the environment in
which they are formed (like forests, rivers, lakes, or oceans). If you were looking for this
transitional animal, what environment would you focus on? Why?
4) Tiktaalik, which is a famous transitional fossil. The first specimen was collected in the
Canadian Arctic in 2004 and a few additional specimens have been discovered since then. What
features does this organism share with fish? What features does this organism share with
amphibians? Why is this organism considered transitional?
5) Remember, organisms do not evolve features to be successful in the future, instead they
evolve features to help them in that instant. How could these features that are considered
amphibian-like help an animal that had an aquatic lifestyle?