Having the good-old creation V evolution debate with one of my aunts (back-and-forth via Facebook).
Her claim of the moment is that there have been no observations of evolution, only speculation from fossils; thus the theory of evolution fails the scientific method.
I've got a couple good counters and links in mind, but was hoping to get some additional responses from all my fine friends here on Think Atheist. I could quote pages of research and tons of examples, but I'm sure it will overwhelm her if I just give her a wall of text; and if she is overwhelmed she will just dismiss it. So I'd like to make it a list and keep each entry fairly brief; so I'm looking for single-line examples, and internet links.
When your aunt says that "evolution has never been observed", a claim commonly made by those I've talked to that support a creationist view, she is most likely referring to macroevolution. Macroevolution involves large evolutionary changes, usually morphological, and most often results in what was one species now being classified taxonomically as two distinct species. This is what most people think of when they think of evolution. What many fail to take into account is the second, and arguably more important, facet of evolution: microevolution. This is the changes in allele frequencies in a population over time, and is what, ultimately, drives the process of macroevolution along. Speciation is a slow process, but it can be observed. Evidence of speciation occurs in the form of organisms that exist only in environments that did not exist a few hundreds or thousands of years ago.
That being said, there are many examples that one could use to show evolution has occurred. One of my favorite examples is that of the Apple Maggot Fly. The fly's originally used Hawthorne trees, which are native to NA, to mate on and then laid their eggs in the fruits of the trees. When apple trees were first brought over to NA by colonists around 300 years ago, people noticed that some of the same flies were now using the apple trees instead of the Hawthorne trees. Since apple trees produce fruit earlier in the fall than the Hawthorne trees do this causes the pupae to be exposed to greater numbers of warmer days prior to emerging than those laid in the Hawthorne fruit later in the season. The extra days of warmth causes the flies that hatch from the apples to have far less of Acon-2 gene present in their populations when compared to the allele frequency in the Hawthorne population. These changes at the genetic level are enough to allow the two populations to diverge from one another. BTW - this is an especially good argument for the young earth creationists since this speciation didn't take millions of years to come about.
Sorry about the lengthy post. I am currently in grad school getting my PhD in Evolutionary Biology and had to jump on the chance to spread some knowledge around. I don't know if this will help you at all with your aunt, but at the least you may have learned something new. Cheers!
Thanks for the addition Kevin. The fly does provide a good example.
Personally I avoid using "macro" and "micro" whenever possible. I'm not positive, but I'm fairly sure she believes strictly that no evolution has occurred. She is Seventh-Day Adventist, and all her points and arguments so far appear to be from a "young earth" creationist perspective. We'll see though, I sent her the three questions (that I posted above) last night.