The evidence for the one designer scenario are mainly these:
1) Signatures (dna etc): all living organisms require dna & or rna to determine their distinguishing features, live and adapt....Including rna viruses. Imagine taking away dna from every living thing....what organisms will these kinds of viruses be left with to reproduce & survive?
2) Noticed similarities (common design): Everything requires mechanisms to utilize water & or sunlight to live.
3) The intricacy of the ecosystem: All Organisms depend upon each other to both regulate the environment in which they live and survive.
I'm having trouble seeing how any/all of these negate multiple designers.
As for #1: if DNA is a signature, since we know there are at least three different structures for DNA does this evidence three designers?
For #2: I fail to see how the fact that most cars have wheels, lights, windshields, engines, seats and radios equates to there only being one designer of cars. Isn't similarity of design rather than exact replication of design a hallmark of additional designers?
#3: This seems to me to have PCC (Project Coordinating Committee) written all over it. How does the complexity and intricate interweaving of an ecosystem evidence one designer over a coordinated effort of many?
... It is more likely that if there were many designers they would all think of different mechanisms (other than dna) in several living things.
It is more likely that if there were many designers they would all think of different mechanisms for sustenance in several living things.
The complex and intricate interweaving of the ecosystem (i.e. Life sustains life.) serves as a another sign of "common thought" in relation to the first two points.
So the theme here is that common principles, common energy sources and common thoughts or ideas give evidence to there being only one designer.
The problem is that our experiences with designs and designers negate this theme.
One example among thousands. There are literally hundreds of disperate designs of internal combustion engines by hundreds of different designers all using the same principles, energy sources and common ideas for turning gasoline into motive power.
I cannot see where any of your three points is exclusive to a one-designer hypothesis when our own experiences indicate otherwise.
It is not 'definitive' evidence of a single designer, but the odds / probabilities are in favor of these exhibited commonalities being the idea of solely one designer.
Is this your opinion or are these odds/probabilities demonstrable in some manner?
Sorry to keep dragging this out, SavageD, but your answers seem to be no more than suppositions without any separation of what would be 0ne- or multiple-designer evidence. Again, taking the human design/designer experience as our guide there doesn't seem to be anything in your points that in any way negates a multi-designer scenario.
Unless there is something compelling in the odds/probability analysis you mentioned then I'm afraid your evidence for a one-designer hypothesis is not sufficient.
Do you have a probability analysis you could share? Though not stellar in all areas, my math is more than sufficient to comprehend probability theory. Feel free to get as detailed as you think is necessary.