What is Evolution? Fact or Theory?

Evolution is the process in which organisms change or adapt to better fit their environment and/or cohabitate/survive with the other organisms in their environment. I add the second part because organisms can evolve together. Last semester I took Organismic Biology, and I learned that moths and bats constantly evolve to outwit one another -- moths to stop bats from eating them, and bats to keep being able to eat the moths. Bats have developed echolocation to be able to find moths in the darkness of night. The echolocation sends sound pulses which bounce off objects/organisms and allow the bat to determine what the sound waves hit and its position. Moths came up with the ability to emit their own sonar to either block the bat’s waves or confuse it, and some moths developed the ability to send sounds that signaled that they were poisonous or would taste bad. This is an example of behavioral evolution, and the moths and bats have coevolved. Here is a link to a youtube video with more information about the bats and moths. It's pretty good.

    I know of parallel, divergent, and convergent evolution. Parallel evolution is kind of like the bat/moth example above. Where the bats and moths informs each other’s evolution, parallel evolution is when two different organisms evolve around the same time due to a common factor, like their environment. Divergent evolution occurs when organisms from the same ancestor evolve different traits. There is convergent evolution, which is when organisms from different predecessors evolve similar traits in order to better survive in their environments. An example of this could be dolphins and sharks. Both have evolved fins, but dolphins are warm blooded and use their spine to pump their bodies up and down to swim. Sharks are cold blooded and move their bodies side to side to swim. I’m pretty sure there is additional evidence that supports the statement that they evolved from different ancestors, but they both evolved similar structures like their fins. 

    Evolution is a theory. There are many, many facts that support the theory of evolution, but there is nothing substantial or direct enough in which we can say that evolution itself is a fact. An example of this is the homologous structures of mammal appendages. Observing the bone structures of whale fins, bat wings, and human arms shows that we have similar bone patterns and structures. This supports the theory that we all descended from a common ancestor and then evolved in our own way. This is known as divergent evolution. However, there is nothing conclusive that says for a matter of fact that this is the case. We can’t go back in time and view the common ancestor nor watch its descendants change form and function. We can only hypothesize with this evidence. Evolution takes a long time to observe, and that’s part of the reason why we cannot deem it a fact.