forgive me for being a little slow on this series, my next posts on this series will hopefully be more frequent.
Anyway this one is about homologous structures; the "evolutionist" myth is apparently that it proves evolution. Their counter-argument is that physical or genetic similarities does not prove two organisms are related anymore then the fact that two phones are alike means they are related. One person actually denied that the similar characteristics can also prove common design. I don't think the argument is invalid; it also logically follows that organisms without the the same structures would have greater genetic differences then organisms that do have the same structures and vice verca. The problem with this argument is deciding which similarities are due to common design and which are due to common descent. Mainstream creationists (AiG, ICR, and CMI mainly) think that all species come from larger more diverse kinds, so obviously you would have some organisms which are similar also due to common descent, so two different breeds of dogs being genetically similar due to common descent is not a problem for creationists. But what about say, chimpanzees and humans who are about as similar as two breeds of dogs? A theologically consistent special creationist would have to say that humans were of a different kind then chimpanzees, even though his scientific definition of a kind says otherwise. The question is how far can you go back in animals before you the kind level? If
If this aspect of creationist genetics were correct then should be large gaps in genetic similarity between two species from different kinds. For example; chimpanzees should be more like 90% or even 80% similar, not 98% similar.
My point here is while the common design argument is valid as far as logic goes, but it fails in the fact that the genetic similarities are more consistent with a non-creationist interpretation of the data. As far back as we go back largely unrelated organisms (such as dogs and bears) become more and more genetically similar to the point where they would classify as being in the same creationist kind. Following a creationist interpretation we have to make an arbitrary cut off point which has no other then a weak theological justification for it.