Questions for Those Who Accept (Universal) Common Descent
OK if you accept universal common descent how do you test it to the exclusion of all alternatives?
How many mutations does it take to get a eukaryote starting with populations of prokaryotes- you can use each alleged symbiotic event as one genetic change/ mutation?
How many mutations does it take to get a chordate starting with populations of invertabrates?
How many mutations does it take to get a fish-a-pod starting with populations of fish? What genes are involved? Are any new genes required? If "yes" how many?
Science says that genes control traits- traits being eye color, hair color, ear-lobe style, etc. What is your evidence that being human is just a collection of traits?
And the killer question:
What makes an organism what it is? Without knowing that no one can say one type can evolve into another.
In his book (English title) “Why is a Fly not a Horse?”, the prominent Italian geneticist Giuseppe Sermonti, tells us the following:
Chapter VI “Why is a Fly not a horse?” (same as the book’s title)
”The scientist enjoys a privilege denied the theologian. To any question, even one central to his theories, he may reply “I’m sorry but I do not know.” This is the only honest answer to the question posed by the title of this chapter. We are fully aware of what makes a flower red rather than white, what it is that prevents a dwarf from growing taller, or what goes wrong in a paraplegic or a thalassemic. But the mystery of species eludes us, and we have made no progress beyond what we already have long known, namely, that a kitty is born because its mother was a she-cat that mated with a tom, and that a fly emerges as a fly larva from a fly egg.”
The bottom line is people accept universal common descent for personal, not scientific, reasons. And the comments will bear that out.