1A. Two different species that posses the homologous trait are a frog and a rabbit because they both posses forelimbs and they look very different. The animals forelimbs look so different because they have evolved differently in response to the evolutionary pressures on each animal.
1B. Each of these species have a forelimb but they look different and they each use them very differently to. For example, a frogs forelimb is short and stubby and they use it to swim and jump and push themselves forward and to also eat and bring food to its mouth. A rabbit is small and skinny and hey use their forelimb to hold themselves up, run, hop and sleep. The forelimb is different in both of the species because of the size of the animal its self and the size of the actual animal and its  functions.
1C. The common ancestor of these two species could possibly be the human because our arms posses a similar setup as the frogs and rabbits with multiple bones in the forelimb. Also the arm of a human has a much different skeletal setup compared with the legs and the same goes for a frogs arms and legs.

2A. Two different species that posses the analogous trait are a snack and a worm because they have very similar body shapes and there is no evolutionary link between the two. The fossil records show that the snack descend from a burrowing lizard. Snakes have evolved to burrow and eventually became smooth-scaled and developed  eye coverings to avoid injury to their eyes while diggings and they ultimately lost their limbs leaving them with a body similar to the worm.
2B. Snakes have evolved to burrow and eventually became smooth-scaled and developed  eye coverings to avoid injury to their eyes while diggings and they ultimately lost their limbs leaving them with a body similar to the worm. Snakes do not have eye so they can see or sense something is coming using by its vibrations. Worms do not have eyes either but they have light receptors and can tell when they are in the dark or the light. 
2C. I do not think that the common ancestor could have possessed the analogous trait because the snake adapted into its body shape it has now. These traits are analogous and not genetically related because the snake and the worm have different functions of their bodies and they are not identical at all meaning their traits could not have come from something or someone. 

1. I would agree that Thomas Malthus had the most influence over Charles Darwin and his development over natural selection. His theory was that things like dieses, warfare and the scarcity of food was necessary to control population size. This caught Darwin's eye and he added onto that with an evolutionary twist. Darwin said that the constant battle between the ones who are more and  less likely to survive would have a constant change in the organism otherwise known as natural selection.
2.  Thomas contributed by giving Darwin an added idea to his theories of evolution and natural selection. Darwin was already thinking of population and the role it played. He said that population would grow until it matched up with all of the existing resources and from there it would stay the same and not grow anymore. Malthus work helped Darwin get a better look on natural selection because he showed how two of the same species can be in competition.
3. The point that was most affected by is the one that states that  our resources are limited because according to Malthus it is survival of the fittest and whoever wins gets those resources. Another point is that organisms with better access to resources will be successful in their reproductive efforts because those humans who are successful in achieving those resources can better provide for their family or anyone else.
4. I believe Darwin could have developed his theory without help because all of the others theories are just helping Darwin further his theories and add important points to them.
5. Darwin's theory went complete against what the church believed in and it was the opposite. It was hard for him to publish his theory because he would get so much backlash and it would be the center or debate from those who believed in god.