Joined: Sep. 2006
To create a quote box around someones quoted phrase type [quote] first. Insert (or copy/paste) the message then type [/quote}. (except replace the last } with a ]). All the words/phrases/references between the typed "quotes" will be contained in a quote box.
|Quote (Cornelius Hunter @ Jan. 28 2007,13:11)|
|...My question was, how is it that similarities such as the pentadactyl pattern are such powerful evidence for evolution, in light of equal and greater levels of similarity in distant species, such as displayed in the marsupial and placental cousin species? |
This was my question. There are many, many more examples of similarities that do not fit the common descent pattern. Why are those that can be fitted to the common descent pattern cited as such powerful evidence? Without some justification, this fundamental claim of evolution appears to be selective. Unfortunately, good justification is hard to come by. The vast majority of the responses simply avoided the question and made up their own.
What we have here are a vast number of similarities across the spectrum in biology, often arising via different genes and development pathways, and often showing up in distant species. Whereever possible, they are ascribed to common descent. Otherwise they are said to have evolved independently. So far so good. But the former do not qualify as particularly powerful, objective, evidence for evolution.
So the bolded question is your present claim. And the following paragraphs focus your question. I think I can work with this now that a clear and concise question is put forward.
First, the evolutionary claim is made that pentadactyl pattern found within mammals is the result of common descent. You do know that this means the common ancestor of mammals had pentadactyl pattern limbs. And that this trait is carried by ALL mammals.
Second, the evolutionary claim is made that the morphological similarities between thylacine and wolves are developmental in nature because of similar environmental influences during each evolutionary event. You do know that this means that an environmental niche was "available" for evolution to "fill" by RM+NS+time (+other factors) and that the "available" niche was duplicate at seperate and isolated geographic locations. And that the resident species "eligible" to fill this niche within these geographic locations were different.
I dispute your analogy here because without further explanation about how pentadactyl limb development is comparable to thylacine/wolf morphological development. You need to show either...
How did available environmental niche influence the development of pentadactyl limbs.
What genetic similarities were developed between thylacine and wolf as a result of environmental nich development.
You can parse and rephrase this objection as you see fit.
I see the "challange" you've made as a conflation of two seperate examples of evolutionary change. Both changes occur, but you have to make a logical link somewhere between the two for your "challange" to have any meaning.