You still have not bridged the gap I pointed out.
I am not denying that eyes see, lungs exchange gases, claws help predators catch prey, vocal cords facilitate sound, or that organisms possess traits suited to their environments. Those are biological functions. The disagreement is over whether those functions prove that somebody intentionally designed them for an existential purpose.
Saying "the lungs have a purpose, therefore they were made on purpose" simply builds your conclusion into the word "purpose."
There are at least two different concepts here:
A function: what a structure does and why that structure was retained biologically.
An intended purpose: what some mind deliberately created the structure to accomplish.
The first does not logically entail the second.
A heart pumps blood. That establishes a function. It does not independently establish that a conscious agent designed the heart with that intention. To establish that, you need an additional argument for a designer. Repeating that the heart "serves a purpose" does not supply one.
The same issue appears in your argument about Earth. Yes, humans require particular environmental conditions. That shows that humans are adapted to a narrow range of conditions. It does not establish that Earth was intentionally prepared for humans.
You are reversing the relationship.
You say oxygen exists here and lungs use oxygen, therefore the environment and organism were deliberately matched. But organisms that could not function within their environments would not survive and reproduce there. Consequently, surviving organisms are exactly the ones we should expect to observe possessing traits compatible with their environments.
That compatibility is the observation requiring explanation. It is not by itself evidence that your preferred explanation is true.
Your language analogy makes the distinction even clearer.
English words have assigned meanings precisely because humans assigned them. The word "tree" does not contain its English meaning intrinsically. Another language can attach a completely different sound to the same object. If every English speaker disappeared, the physical sequence of letters T-R-E-E would not retain some independently existing semantic property in the universe.
That is conventional meaning, not inherent meaning.
I can inherit a convention without the convention becoming intrinsic.
Likewise, if a creator assigned humanity a purpose, that would establish an assigned purpose originating in that creator. You can call it "inherent" afterward, but you have not changed the logical origin of the purpose. It remains dependent upon the assigning mind.
Your DNA example has the same problem. If genetic traits make certain abilities easier to develop, then those abilities have a biological basis. Fine. But saying that this constitutes "inherent meaning" just substitutes the word "meaning" for "function," "capacity," or "adaptive consequence."
I am not saying the ability "means nothing" in the ordinary descriptive sense. I am saying that a biological consequence is not equivalent to objective existential significance.
Those are different propositions.
You also say that because humans are part of the universe, what humans do therefore has a "universally independent purpose." That does not follow either. Being physically contained within the universe does not make a person's preferences, intentions, or activities objective properties of the universe.
If I value another person, my valuation is itself an event occurring within the universe. That does not make the value independent of the mind producing it.
The statement:
"I value this person"
does not become:
"This person possesses a mind-independent existential purpose"
merely because both of us consist of matter originating within the universe.
And I do understand the theistic position. Understanding a position does not require accepting its premises.
Your position is approximately this:
Biological systems exhibit functional organization.
You believe that organization is too coordinated or improbable to be unguided.
Therefore you infer intelligence.
You then infer that this intelligence intentionally created organisms.
You then infer that intentional creation supplies objective purpose.
That is a coherent chain of claims, but the controversial steps are the inferences from function to intelligence and from intelligence to existential meaning.
You repeatedly point back to the function itself as though it proves those inferences.
It does not.
Calling life a "setup," saying it is "done intelligently," or saying that purpose cannot exist without a creator restates your conclusion. It does not independently demonstrate it.
The same applies to "something cannot come from nothing." I have not argued that something came from nothing. Nihilism does not require that claim, atheism does not require that claim, and modern cosmology does not simply assert "absolute nothing spontaneously produced everything."
Even if it were demonstrated tomorrow that the universe had an intelligent cause, another question would remain: why would the intentions of that cause automatically constitute objective meaning?
If a human creates a hammer to drive nails, the hammer has an assigned function relative to the creator's intention. That does not produce some metaphysically independent property called "meaning." It establishes what the creator wanted the object to do.
Scale the creator up to a god and the logical structure does not change. You have an extremely powerful assigning mind, but still an assigning mind.
So no, I am not avoiding the observation that biological structures have functions. I have explicitly accepted that observation repeatedly.
What I reject is the unstated equation:
function = intention = creator = inherent existential meaning.
Those are four different concepts.
Your argument keeps moving between them as though establishing the first automatically establishes the other three.
That is the exact step you still have not demonstrated.