I would like to explain the reasoning and sound deduction used by me for my argument, firstly.
A conditional implication is sound if the consequent 100% always follows the antecedent, and as long as the conditional chain is, so to speak, as long as each link follows from the previous one then the modus ponen rule is obeyed correctly.
So, "if you have a human, then you have a mammal", because ALL humans are mammals, therefore 100% of the time the consequent "mammal" will follow, as long as you have the antecedent "human", at least in the regard of this implication.
Note I speak unequivocally so you can't use equivocation to complain such as, "well it could appear to be a human and in fact be a waxwork."
No, that is extraneous to what I am expounding. We assume it certainly is as we assume everything I say is correct. We are obviously agreeing that you certainly do have a human being and therefore you have a mammal. So then we can now use the modus tollens to deduce a falsification which cannot be denied;
If you have a human then you have a mammal. (ponen)
If you do not have a mammal, then you do not have a human. (tollens) = CORRECT deduction.
With me so far? (Because if you agree so far, and then you agree with the following steps, then there can be no disagreement as there is no longer room for it, yes?)
If you don't agree so far, you can't be helped.
So then as long as the lengthened conditional continues, you can still use the tollens by inferring the negative by denying the extreme consequent. Which sounds double dutch but is quite simple by demonstration;
If you have a human, then you have a mammal, and if you have a mammal then you have vertebrate.
You do not have a vertebrate, therefore you do not have a human.
Or more long winded, I can show the deduction correct by saying; "well if you don't have a vertebrate, since all mammals are vertebrates then you don't have a mammal, and since all humans are mammals, then you don't have a human."
Agree so far? (you're in deep trouble if you don't agree so far, because you would be disagreeing with logical notation which doesn't mean there is much hope that you are capable of objectivity.) What might help you is picturing a Russian doll.
Here is the part you won't be able to agree with, but I am afraid that doesn't tell us anything about logical notation;
If macro evolution is true, then obviously there was an evolution of mammals, and if there was then there was an evolution of reptiles, then amphibians as we go down, then an evolution of vertebrates, then as we go further down an evolution of eukaryotes, then ultimately an evolution of a common ancestor/s into something. Then, scientifically speaking (if this is all a matter of science) there must have been some type of abiogenesis of that ancestor. (some scientific cause)
There wasn't an abiogenesis of any type of any such ancestor, therefore evolution is false.
(hypothetically I am stating abiogenesis is certainly false. If it is, then so is evolution.)
Conclusion: Sorry guys, there just isn't any mistake in my reasoning. You can whine all day, object, use propaganda, ASSERT I'm wrong. Sort of like a child having a tantrum, but at the end of the day I am simply correct which is the true cause of the tantrum.
And the problem is a big one, because for evolution theory to remain scientific, it's ancestor must have a scientific cause. If it is only INFERRED that such an ancestor existed, though there is no physical cause for such an ancestor, obviously it follows evolution is false, because if there is no cause for the ancestor for evolution, how can something evolve from it?
This is called a disjunctive syllogism.
I shall give examples;
Three people on an island at all times and no possibility of anyone else, and one person is certainly murdered, meaning Bob and Jane remain and there is no possibility of suicide.
Bob is innocent.
Therefore Jane is the murderer.
(and it doesn't matter how improbable it is, as all other options are impossible) (to say "it was a wild animal", doesn't count, we are assuming nothing like that is possible, only murder by a person.)
You're either 50 years of age or under, or over 50, if alive.
Bob is not over 50
Therefore Bob is 50 or under 50.
(objection: but he looks 65, therefore he can't be under 50. Answer; doesn't matter how improbable it seems)
You have a compelling case for evolution but it could be false which you seem to acknowledge, and if evolution is true then it's ancestor certainly is.
An ancestor is impossible.
Therefore evolution is false.
(as that is the only remaining "possible" for if evolution was true, it's ancestor must also be true which is impossible as stated)
(your predicted complaint, "explaining the ancestor isn't evolution's job, that's for abiogenesis to do." Yes, that is true however the ancestor is still only a figment of evolution for what is a primordial ancestor anyway? It is something invented by evolution theory, for one has never been found. It only pertains to evolution. For example a giraffe can't be a primordial ancestor. So then if there is no basis for the ancestor scientifically then there is no basis for evolution, EVEN IF it is not evolution's job to explain the cause of the ancestor! )
So then it's circular reasoning to merely conclude the ancestor existed without any possible cause, if you only re-iterate what evolution says. EXAMPLE;
"evolution theory says there would be an ancestor/s in the past from which all life diversified ultimately. And evolution points to an ancestor in the past from which all life diversified ultimately."
So basically even if it isn't evolution's job to prove abiogenesis, nevertheless scientifically speaking since God cannot be invoked in science then there must still be a cause, a physical cause of an abiogenesis. So then don't argue from both sides of your mouth by on the one hand saying that evolution doesn't answer for the ancestor, but in the same breath saying that evolution supports the ancestor for either evolution's job is to support the ancestor, or it isn't. You can't have both. If evolution's job is only to explain life's diversification from an ancestor then you can't say that evolution supports the ancestor, for it can only support that which came after it. It cannot support the ancestor or say anything about it, if it does not act to support it, scientifically. So the term, "that which came after it" reveals the circularity. (think about it.) If evolution only describes that which came after it, you have assumed, "it".
Think about it. If abiogenesis certainly is false, then so is evolution. I would say reasonably, there is no reason to believe an abiogenesis is possible.)
Therefore for logical reasons even though Abio and evo explain different aspects it would seem more logical to say that both are joined so tightly to each other and abiogenesis's sole relevance is to create evolution's ancestor, that you have to see the case as a claim, as both things. And so evolution is not supported scientifically, IN PART, in that it has no scientific support for the first ancestor/s. So if such an ancestor cannot scientifically be a possibility, evolution cannot act upon a non-existent entity, meaning evolution theory cannot be scientifically tenable without abiogenesis, at least not in the macro sense.
Answering thus is also insufficient; "but evolution POINTS to the ancestor, we only have to prove macro, for evolution to be true the tree points to it. Mammal evolution is still true, reptile evolution is still true"
BUT THINK BACK to the conditional. What did those evolutions all depend on as a first step? You can't actually have a mammal evolution unless you have an ancestor which evolved into a eukaryote which evolved into an invertebrate which evolved into a vertebrate which evolved into your reptile eventually which led to your mammal evolution.
If you have a roof fixed to a wall then you have a floor and if you have a floor you have to have some sort of ground or solid something for the house to sit on.
So then to say "the evidence for mammal evolution stands on it's own" would be no different to saying a roof stands on thin air.
So you may be able to define abio and evo separately, BUT LOGICALLY THEY STILL DEPEND ON EACH OTHER because the common denominator is the ancestor.
I think I've made my case, others can discuss it I suppose. But I don't have much else to say, I believe personally you either accept what deductive reason clearly shows or you don't.