Statements And Poor Extrapolations:
1. All life (bacteria, viruses, plants, fungi, and animals) descend from a single organism.
2. Natural selection can act upon a diverse type of organism to cause species-wide changes, or cause two divided groups of a species to change relative to one-another.
3. The alterations that occurred, causing the entire diversity of life we see today, were solely due to random mutations and natural selection.
Notice, these three claims are independent. Proving one to be true does not validate the other two.
Scientifically, we can confirm that number 2 is valid. We observe changes occurring through mutations, and natural selection either weeding out, our ensuring dominance for those changes. This does not prove 1 or 3 however.
I find number 3 hardest to justify, it would be impossible to prove that these mechanisms are the only thing driving change. So even if we accepted the first two, that doesn't rule out that God could have supernaturally intervened in the history of life on earth to cause changes.
Of course, most evolutionary biologists are atheists and agnostics. Thus having no reason to insert God into the mix. But if there really is a sovereign God over the whole world as Christians believe, why is it so laughable to believe that God intervened in the history of life on earth?
After all, so many evolutionists *cough* Neil Degrasse Tyson *cough* claim to have no issues with religious people. If true, why then are you so devoted to getting them to accept number 3? Surely you must have some evidence that God could not have intervened in natural history to cause alterations? Don't be shy, show it please!
So, I would say the fact that we observe changes occurring today through mutations and natural selection is not evidence *in the slightest* that either all life descends from a common ancestor or that the diversity of life derives *just* from natural selection and random mutations. The latter is, in fact, *impossible* to confirm.
Surely, it is at the very least *plausible* that evolution has a limit to how much change it can cause? After all, we can see that artificial selection, like humans used to create Great Danes, German Shepherds, and Poodles from Wolves has proven to be *far* more powerful than natural selection, yet we do encounter a limit. We can't breed a dog that has venom. We can't breed a dog that has a blowhole and lives in water. We can't breed a dog that can graze on grass like a cow. We can't breed a dog that can purr like a cat. Etc.
Of course, evolutionists can explain why this limit exists for us but not for natural evolution, but that brings us too...
Explanations Are Unlimited:
Even young-earth creationism can explain all evidence that the earth is old. Those explanations, if pressed, become almost as contrived as the explanations I just gave for the sky being blue, but nonetheless they are possible. This is to say that searching for truth requires more than simply explaining evidence.
When discerning which model is true, you must look at what fits the bulk of the evidence best. Who has the explanation that is simplest, least contrived, most natural.
I find that an old-earth creationism model and an evolutionary model both explain a great deal of evidence equally well. But that in the cases where one can be preferred over another, old-earth creationism comes out ahead of evolutionism. But that is not to say evolutionism is entirely weak. There is *some* evidence that fits the evolutionary scenario better in my opinion. But the bulk leans toward a supernatural creation of lifeforms I think.
Here are some examples of evidence I think is better explained by creationism than evolution:
1. Explosions of life in the fossil record. The Cambrian explosion is likely the greatest example of this, with representatives of nearly all animal phyla showing up out of nowhere in a geological instant. Other explosions exist as well, for instance, following the K-PG Mass Extinction event, bird and mammal species exploded onto the scene in a geological instant.
2. Convergence. The phenomenon where species that are only distantly related from an evolutionary standpoint independantly "evolved" the exact same characteristic. The odds of random mutations causing the same feature to emerge twice are astounding. This makes little sense from an evolutionary perspective, but God can reuse the same design over and over again if he so chooses, he is not bounded by the imaginary evolutionary tree of life.
3. "Out Of Order" fossils. This I believe is a serious problem not only for the third statement listed earlier, but also for the first (that all life descends from a common ancestor). A famous example of this is the temporal paradox of the reptile-archosaur-dinosaur-bird transition. A vast enough number of reptile, bird, and "mixed-characteristic" species exist in the fossil record to create a nice, clean transition from a lizard-like reptile, all the way to a modern bird. The problem? The fossils are well-dated along with their respective geological layers, and they simply do not appear in the right order. The most bird-like dinosaurs show up only after the oldest true-birds. The oldest proto-dinosaur archosaurs show up around the same time as the first true dinosaurs.
All these things (and there are many more I didn't list) *can* easily be explained by an evolutionary model, but are better explained by creationism in my opinion. And remember this, even if I were to accept that all life descends from a common ancestor. That does not prove that the diversity of life emerged naturalistically.
God could take a species and supernaturally alter it to change it into a new species. I do not know exactly by what mechanism God creates. But I do believe, based on my "reading" of the evidence, that God supernaturally intervenes to create new species, rather than allowing natural selection and mutation to gradually "form" new species.
And I do not find the evidence for universal common descent compelling enough to rule out creation of each species from the raw elements of the earth, rather than previous lifeforms.
The "Scientific Consensus":
It simply is poor thinking to reject a seemingly solid argument simply because of the nature of it's source (it could be a crazy homeless drug-addict for all I care). Or to accept a seemingly bad argument simply because it comes from Stephen Hawking. Do *not* be a slave to authority. Ever.
Thanks for reading!