1. In a stepping stone pattern, individuals migrate only to the closest populations at a constant rate. In an island pattern, individuals migrate from each population to each other populations at some constant rate.

Another answer

1. Stepping stone: migration is primarily between adjacent populations.  Island: migration is equal between all populations, regardless of distance; each population sends an approximately equal number of migrants to all other populations.
2. In the stepping stone pattern, closer populations would be more similar genetically since they can only move to close populations. In an island model, all populations would be equally similar.

2. We would see pairwise differentiation in a stepping-stone pattern.

3. No, neither migration scheme could produce this pattern. In the stepping stone, adjacent populations will always be most similar. In the island mode, no matter how far away a populations was in distance, it will exchange migrants at the same rate. All populations will be equally similar.

Another well-stated answer

3. Neither scheme could produce a pattern of divergence in neutral alleles where populations were more different over smaller differences except by chance and with small populations. Neither scheme tends towards such a pattern. Unless migrants are moving to only the far away populations, this is not possible. A stepping stone pattern is very unlikely because migrants move only to close populations.
   

2.

In convergent evolution, structures find different evolutionary pathways to resolve a common problem. The interactions between drift and selection can explain why these structures modified differently. If a population was small, then drift may have fixed an allele that coded for a specific structure to modify one structure in one population. In another population, another structure may have been fixed due to chance.

Another answer:

Different structures may have been modified in different groups for the same purpose possibly because each structure plays a different degree of importance to the organism. For example if the Passifloraceae uses its leaves to attract insects for pollination, it would be detrimental to the organism to sacrifice this structure and have it modified into tendrils. It would be more beneficial to modify the stipules instead.

Another answer:

This is an example of convergent evolution. In the different families, a different organ has been modified to perform the same function. This could have occurred because the role the environment plays on evolution. The temperature and amounts of water in different areas might make it beneficial for a leaf to be modified - in others a stipule. Since the surface area of the leaves are directly related to water loss in plants, an important part in the different strategies for adhesion in the plants would be the environmental conditions. 

3.

1. For a step like pattern, one needs to have a high difference between the fitnesses of the individuals, strong selection, a low amount of environmental variance, low mutational input, and a small populations.

For a gradual, continuous change, you need the opposite conditions: high amount of environmental variance, weak selection, large population, high mutational input to replenish genetic variation.

2. The pattern had to be due to new mutations that were fixed because the bacteria have asexual reproduction and did not under recombination.  Therefore, they could not have released any hidden genetic variation.
   
   

4.

1. Premating isolation mechanisms prevent mating from happening between two different species. In this example these mechanisms would include the Barking tree frogs which call while floating while green tree frogs call from elevated sights. The females can also recognize mates from their own species due to the differences in frequency and temporal properties. 

Another answer

1. The frogs can recognize the different types of call so mate-recognition is a very important part in keeping the species separate. The hybrids have lower fitness, so they are not effective in ending the reproductive isolation. The different areas of the pond also lead to reproductive isolation in the two species because individuals from the two species aren't in the right place to mate with each other.
2. The reproductive isolation species concept would indicate that these two groups are different species due to the decrease in fitness of the hybrids. The male recognition species concept indicates that these two groups are different species because each group has a unique call that the females can recognize. The cohesion species concept would indicate that these two groups are part of the same species because they have no intrinsic mating barriers and they exhibit genetic and ecological exchangability.

Another answer

2. Yes, in the cohesion species concept I would expect the two species to eventually unite and become one. Reproductive species concept would lead to the conclusion that they are different species. They reproduce in different conditions - some in the water, some in the vegetation. Also, the hybrids are lower in fitness. The mate-recognition concept also leads to the conclusion that they are different species. The frogs recognize the two different types of calls and probably the morphological differences as well.  This prevents, for the most part, the two different species from mating with each other.
   
   

5.

1. A2 will increase in frequency since it has the highest probability of survival (fecundity is constant), and therefore the highest fitness.
2. delta q = (p*q)(w2-w1)/mean w
3. A2 will eventually be fixed, elimination A1.
4. The average speed will be getting faster since A2A2 is favored and the fastest genotype.
5. The ratio of genetic to phenotypic variance will fall as available genetic variance is exhausted. As presented, the A2A2 will be more frequent. When A2 is fixed, Vg will be equal to zero and a muation or recombination event will be necessary for further phenotypic change.

If the initial ratio of genetic to phenotypic variance were smaller, allele frequence and running speed change would be less pronounced in the second generation on an absolute scale (rate would be slower).

Bonus:

Yes, the scheme could create a stable polymorphism because the
heterozygotes could have superiority, assuming AaBbCc was the common
genotype. But, it cannot guarantee it because the genotype AABbcc would
also have the same fitness as as others w/ 3 caps.