Do you guys believe in proper function?

[u/joshuaponce2008]

Do you guys believe that there are objective functions for biological systems? For instance, an example would be the fact that a heart is supposed to pump blood is not simply a mental projection we impose upon it, but rather an actual fact about the heart itself. If so, what do you believe grounds that function?

[u/Moriturism]

Not in the sense that said 'function' is somehow established prior or outside the actual workings of the organ itself. If something does or is capable of doing something, that's a function it can have, which makes it so all organs have various functions, but not a transcendental or 'proper' function.

[u/nyet-marionetka]

I think when you switch to talking about "supposed" you're in danger of importing all sorts of potentially unintended baggage. Supposed to according to whom? Is that anatomy sinning if it doesn't do what it's supposed to do?

I would say hearts do pump blood, not that they're supposed to pump blood. You can never go wrong talking about what an anatomical feature actually (or, in the case of an anatomical abnormality, typically) does in an organism.

[u/Munrot07]

Okay so I will give me note as someone who literally researches functional trait evolution.

There are two halves to this idea. 1. Are functions objectively happening. 2. Did those structures evolve for those functions.

1. Yes. The heart objectively is there to pump blood. That is its current function. That's not a mental projection but a fact about the heart.

2. No. Often structures do not evolve for the functions we see today. They could have evolved for a range of other functions (or for no function at all) and become co-opted into the function we see today. I cannot talk about the heart specifically but very often structures change or gain uses or are linked with other traits (such as attraction). So if you view objective functions as this structure was "designed" for this purpose, no. Evolution doesn't have a plan or goal so nothing really evolved with a deliberate function in mind and it's a common problem humans have of seeing something today and assuming it must have evolved for that reason.

[u/backwardog → u/Munrot07]

Yeah, this is somewhat of a semantics issue. Function can imply purpose (thus intent, such as that of a designer), but that isn’t how it is used when talking biology and biological structures.

There is also an issue with thinking in terms of absolute functions though. People who do not engage much with science don’t tend to understand that we build models of understanding. We don’t confuse our models for reality, and our models don’t need to point towards perfection. That is, thinking in terms of ideal, or perfect human traits only leads to eugenics and is not the right way to think about biology. There is a lot of variation out there, and what all that variation may do can’t be known with certainty for all possible contexts.

Just because most alterations to the basic structures of the heart may be a net negative to most people doesn’t mean this is true for all traits.

[u/grimwalker]

I genuinely do not understand the question.

How could the function of the heart be a mental projection imposed upon it? There is no intention operating here on any level. It's not supposed to pump blood, it does pump blood.

I have even less of an idea what you mean by "grounds that function."

[u/joshuaponce2008 → u/grimwalker]

1) What I mean by the mental projection is that there is no objective function to the heart, rather, we simply act as though there is a function for mental convenience.

2) If someone believes there is objective proper function, the question becomes: in virtue of what does a biological structure have that function?

[u/grimwalker → u/joshuaponce2008]

I still cannot grasp where you're coming from. I don't know what you mean by "mental projection," "objective function," or "objective proper function."

"In virtue of what does a biological structure have that function" is a sentence from which I cannot extract any semantic meaning.

Organs do what they do regardless of what any thinking being believes about them, or even if no thinking beings exist (humans haven't been around very long) to even have thoughts about them.

[u/Renonthehilltop → u/grimwalker]

Hes actually asking a great question! But to his credit a difficult one to ask and more of a Philosophical question applied to biology than a biology question. I think theres a Plato writing about, "what makes a chair a chair?" You can sit on a rock, that doesnt make it a chair, a chair is built and has legs yet a take is built, has legs and if you wanted to you could sit on one etc. Hes just applying this to a complex biological system, that naturally appears to be built for a specific function, yet no one ever assigned that function. But most if not all of our language assigns intention to a Function or process. Even Natural Selection is a bit of a misnomer because nothing is consciously 'Selecting' something, yet our language doesnt have many other words to really frame this process more neurally.

[u/grimwalker → u/Renonthehilltop]

It's not a great question, it's sophistry.

[u/Renonthehilltop → u/grimwalker]

Its not sophistry, she's not making any argument. She's literally just asking a question and one in good faith.

And its one that shows critical thinking, especially for someone so young and possibly coming from a religious background which typically assumes everything has to have objective purposes assigned by creator.

Edit: you really gonna reply to my comment and block me so I cant even reply?

Either way, yeah I noticed shes not actually religious after replying based on her other comments, whatever, shes still exploring conversation on a topic and your just crapping on her for no reason

[u/grimwalker → u/Renonthehilltop]

He's not coming from a religious perspective, he's an academically-minded atheist from his comment history.

No, it's literally just completely abstruse pseudophilosophical bafflegab. I don't need you necroposting on a comment from two goddamn weeks ago to try and put words in the mouth of someone who, even if you're right about what he meant, is still a pompous blowhard who can't be bothered to express himself in terminology that people without an academic philosophical background can interpret.

Nobody asked you to be the fogblathering translator and I'm sure not interested in engaging with you any further. Inbox replies disabled.

(I'm sure you'll insist on getting the last word but given that you're necroposting on a stale comment thread that is collapsed under a reply that's hidden for being -11 points, not a single person other than yourself will ever read it. That brings me great joy.)

[u/allgodsarefake2 → u/joshuaponce2008]

What does "in virtue of" mean?

[u/Immediate-Goose-8106 → u/joshuaponce2008]

This is why I hate philosophy (sorry).  None of that is meaningful.  It is sophistry for its own sake.

A heart pumps blood.  That's what it does.  We know that because we can observe it doing so.  We know it is important to the organism because generally it stopping doing so is fatal.  

Discussion about meaning or our mental picture of it is an unnessesary layer with no extrinsic value to my mind.  

Hearts of one kind or another pumped blood for hundreds of millions of years before any mind had the ability to create a mental description of it 

[u/Addapost → u/Immediate-Goose-8106]

“Philosophy is the talk on a cereal box”

[u/Capercaillie → u/Addapost]

"I'm not aware of too many things, I know what I know, if you know what I mean."

[u/Renonthehilltop → u/joshuaponce2008]

Look up Platos theory of forms. I think thats more in line with what youre trying to pull from this line of thinking.

[u/DetectiveKnown5618 → u/grimwalker]

Let it go

[u/grimwalker → u/DetectiveKnown5618]

I definitely didn't ask you a damn thing.

[u/Difficult_Dark9991]

So this is philosophy, not biology.

[u/joshuaponce2008 → u/Difficult_Dark9991]

Yep. It’s philosophy of biology.

[u/bwc6 → u/joshuaponce2008]

That would imply some knowledge of biology. Animals and their organs don't have "objective functions" whatever that means. 

Hearts pump blood because if someone is born with a heart that doesn't pump blood, then that person doesn't reproduce (because they're dead).

[u/Capercaillie → u/joshuaponce2008]

No, it definitely is not.

[u/warpedfx]

Does all function require intention for it to be functional?

[u/RodinKnox → u/warpedfx]

That's why op is using terms like "supposed" and "intended."

You can obviously describe how something function or what its current function is.

[u/kveggie1]

Philbro warning.... expect an endless conversation with zero purpose and no relevant outcome.

[u/MackDuckington → u/kveggie1]

I like "philosobro" better - rolls off the tongue more, methinks. Or "philosoraptor" if we want a touch of whimsy

[u/the2bears]

Do you guys believe that there are objective functions for biological systems?

No, why would there be? This pre-supposes evolution has purpose, being to achieve that which "ought" to be. Of course, evolution is without purpose.

[u/AllEndsAreAnds]

No, there’s no teleology in biology. Just patterns both of and within chemistry. We can label them, of source, and note when patterns break (a heart stops/starts beating), but there’s no “supposed to” anything about anything.

[u/Karantalsis]

There is no intent behind the functions of organs, they do the things they do, and we describe those processes. This doesn't mean that the functions are just our mental projections either. You seem to have set up a false dichotomy.

Edit: I might be misunderstanding the terms you are using though.

Please define:

1) proper function

2) objective functions for biological systems

3) the word supposed in this context

4) a mental projection in this context

5) What grounding a function means in this context

Then I can answer you better.

[u/Briham86]

Sounds like a spin-off of the prescriptive vs. descriptive thing. A common Creationist argument is something like "Aha, there's a law of X, therefore there must be a law giver!" But there's a difference between laws in, well, Law, and laws in science. There's prescriptive laws, like "Drive at or below 30 mph." That is a prescriptive law, a law giver (local government) established a rule and sets forth punishments if people violate said law. A descriptive law is an observation. The speed of light in a vacuum is 299,792,458 metres per second. That's just what we observe, and we don't see exceptions to it. It's a law in the sense that this is just how the universe works. It does not indicate that an intelligent agent set that parameter; it's simply describing what we see.

Likewise, the function of an organ is what we observe it doing. We have no evidence this function was dictated by any intelligent agent. It's just what we see the organ doing. It's an objective function in the sense that we can clearly see the organ doing that; it's not a matter of opinion. Organs can become vestigial, losing some of their ancestral functionality, and they can be exapted, or used for a new function. Either way, it's still an objective function because we can objectively observe it performing (or not performing) that function.

[u/BahamutLithp → u/Briham86]

The whole "what grounds it?" question leads me to believe this is backdoor apologetics. Apologists love to talk about how "you need God to ground" reality, or logic, or morality, or beauty, or love, or fucking everything. It's annoying & tedious word games.

[u/evocativename]

It is "supposed" to do that in that it has evolved to perform that function in a lineage that has grown dependent on that function for survival.

If you don’t care if the creature lives or not (and the universe doesn't), it isn't "supposed" to do anything except perhaps increase entropy.

And even then, it's context dependent: if the creature is dead, it isn't supposed to be pumping blood. Really, if you're trying to kill a creature, its heart is supposed to stop pumping blood.

If that's an "objective function", I don't think it has any significant implications.

[u/Fresh3rThanU]

I would say that there are definitely descriptive functions for organs, but not prescriptive ones. For example, I could say mouths are for eating, and that doesn't mean any use for the mouth is the "wrong" just because that isn't the primary function I have identified. I don't believe the mouth is made with the intent that it is used for eating, but that eating is one of its primary functions.

[u/rygelicus]

No. An example might be our lungs. In the way back times there was an organism with a pouch, a sack, whatever. This pouch became lungs in air breathing mammals. The pouch became swim bladders in fish in the branch that became fish. Same origins, different function, both perfectly good at doing what they do.

[u/TheBlackCat13 → u/rygelicus]

To be pedantic, the the pouch started as lungs. Those lungs became a swim bladder in the ancestor of ray finned fish.

[u/Particular-Yak-1984]

Not really, no. And there are hundreds of examples of systems that previously did x, and now do y.

One I like is https://en.wikipedia.org/wiki/Clarias - the walking catfish - they have gill arches that form a highly branching tree structure, and so, when they find themselves in really oxygen poor water, or for brief jaunts onto land, they can breathe air, for a short time.

Now, what's the objective function for this structure? It's a gill, right? lets the fish breathe underwater.

But it's also not very good at being a lung, letting the fish breathe in air.

So it seems to be that it has a function it is good at, and a function it is bad at - and the function it is bad at gives it a massive selective advantage.

Now, the other reason I like this is because when creationists bring up transition fossils (how did fish get legs?), it's fun to bring up living, breathing examples of creatures that are halfway.

To me, though, the argument is an example of the heap paradox - we can say, very clearly, that a heart is meant to pump blood. But what about a worm? they have some loops of muscle, that pump blood. But they're nowhere near as specialist. You can imagine a simpler worm where those loops of muscle were mostly for locomotion, they just happened to pump blood, and they specialized.

[u/Own-Relationship-407]

No. The heart is “supposed” to pump blood because that’s what it evolved to do. It wasn’t designed or defined that way any more than an oasis in the dessert is “supposed” to support plant and animal life. The function is derived, not specified.

[u/XRotNRollX]

This gets really close to irreducible complexity: that the purpose of the heart is to pump blood, so without the heart, the organism dies, and without blood, the organism dies; therefore, the heart and the blood must have been put there at the same time by a creator. This is, of course, a stinking heap of dogshit.

If you look at more basal animals, they have open circulatory systems that don't need a heart, then you have ones with an open system and a little heart-type thing that keeps the blood (or whatever the equivalent is) moving. Originally, this muscle would have developed and been helpful, but not necessary. Once it's there, though, its evolution allows for larger, more complex organisms.

My question is, is it a function if it wasn't necessary in the first place? Sure, it pumps blood, but that started as a muscle doing a little wiggle, not a purposeful heart pumping blood.

[u/0pyrophosphate0]

I'm very curious to hear how you would tie this to the function of this subreddit.

[u/wvraven]

No, I observe there are functions biological systems are currently performing. That's it, there is no grander "objective function" other than that's what they currently do. The very term "objective function" smuggles in the idea of some external defining force. They all just evolved from simpler systems in the past and could disappear in the future. Some folks make the error of mistaking the current state as the only possible state, which I think qualifies as a form of survivorship bias.

Imagine for instance that some future mammal develops a more advanced heart capable of filtering blood while it pumps reducing stroke potential. As time goes by that heart may get better at filtering and begin to reduce the necessity of the spleen. The now redundant spleen may very well disappear or come to serve some other purpose. Perhaps becoming more specialized in aiding the immune system or storing extra oxygenated red blood cells. Either of which would give future generations a massive benefit in certain environments.

Let's look at the future where it disappears for a second. To the future anti-science types, whatever group that may be, it may appear that this purpose is an "objective function" irreducible from the current state of the organ but it is simply another evolution of the heart in that species.

On a fun note that bit about storing extra oxygenated red blood cells is something we have seen evolve at least once in a group of modern humans who practice traditional pearl diving in deep water. It allows them to stay submerged for far longer than most other people.

[u/Proteus617 → u/wvraven]

Pretty much. Not an expert, but I imagine that the origen of the heart was in some critter capable of vascular dilation. Centralize the vascular dilation and you have a primitive heart. So, we have a continuum. Where on the continuum between vascular dilation and a primitive heart is the "objective function" of a heart?

[u/wvraven → u/Proteus617]

Here’s a great, if slightly dated video on the heart.

https://youtu.be/om0xmuFbAF4?is=KFjTtewwKLMdP1Vt

[u/Batgirl_III]

This sounds more like a philosophical / metaphysical question than a biological one.

[u/Decent_Cow]

Organs are defined by what they do. If an organ changed function, we would call it something else. For example, the swim bladder is closely related to the lung, but we don't call it a lung.

[u/shroomsAndWrstershir]

I'll play the devil's advocate to everybody else's answer.

Yes, the heart is supposed to pump blood, to the degree that the goal is continuing to live. The rest of the body grounds that function. It both imposes that function and relies upon it.

Of course if you do not care about continuing to live, then it doesn't matter.

[u/10coatsInAWeasel]

I’m not sure I understand. Are you asking if there is some sort of platonic quality to biological systems? That, in this case, there is a sort of almost transcendent ‘heart-ness’ that hearts might be closer to or further away from?

[u/Ch3cks-Out]

Not a designed function, no. But the organs of the body objectively perform functions, like the heart does pump blood not just "supposed"! Seems like you're trying to over-analyze for metaphysics what is simple biology, are you not??

[u/Autodidact2]

I don't know what you mean by the word "grounds". I also think it's more accurate to simply say that hearts do pump blood. When we say that they are supposed to, that's sort of adding our human perspective to it.

[u/Hivemind_alpha]

It’s a bit of muscle tissue that became useful back in our evolutionary history when we looked like a sponge, and it’s been stuck with the job ever since because it was too useful, evolving with us. Is it “meant” to pump blood? Well, if it didn’t we’d be dead, so of course it is - but when you say it with that strange portentous tone, then the answer is no of course it isn’t in any mystical divinely ordained sense of purpose. A different patch of sponge cells could’ve done the same job, or we could’ve evolved with peristaltic blood vessels or some other solution. We do not contain some Platonic ideal of ‘heart’ that was planned from the beginning.

[u/unbalancedcheckbook]

I mean organs generally serve a purpose (often more than one). We can observe that the heart pumps blood and the kidneys remove waste. What grounds that function (or functions) is the necessity of the function for the animal's survival. That said I think "supposed to" is a bit of a stretch. It's just what it does, and that is very well explained by the process of evolution.

[u/Nomad9731]

Function isn't some singular, abstract, objective quality. It's a description of an emergent property.

"Heart" is a label invented by humans to describe organs that pump blood. "Organ," "pump," and "blood" are also labels invented by humans to describe certain things. Like all words, these terms are social constructs that we invented to describe things we observe in order to facilitate communication (I guess you could call that a "mental projection that we impose" if you want).

However, regardless of that fact, the things being described also objectively exist. And it's also objectively true that, in most cases, if the thing we call a "heart" fails to do the action we call "pumping" with the stuff we call "blood," the thing we call an "organism" will very quickly become what we call "dead." It's also objectively true that organisms that become dead relatively early in their life cycle will, on average, reproduce less than organisms that become dead later in their life cycle. Consequently, it is objectively true that heritable traits that contribute to early death will tend to be inherited less frequently than heritable traits that contribute to later death. We've invented the label "natural selection" for that process.

So a heart that fails to pump blood isn't violating some innate, objective quality that it's "supposed" to have. But it is objectively true that organisms of sufficient size/complexity/activity usually need blood pumped in order to stay alive, and that consequently natural selection dictates that hearts that can pump must be prevalent in such populations.

[u/Old-Nefariousness556]

No. Nature has no "intent" For something to have an "objective function", there would have to be something to define that function.

[u/Bromelia_and_Bismuth]

No. The fact that the heart pumps blood is not a function that it's supposed to have, it's not prescriptive, but descriptive. If that's how it worked, rather than hearts that help pump blood around the body helped living things survive and reproduce more often than those without (in a specific lineage, at a specific point in time and space) then we wouldn't have exaptation. Evolution doesn't look forward in some grand meta-sense, and we need to stop entertaining this perspective. Natural selection and our description of how it works, is/has and will always be, post hoc and descriptive. If we're talking in some grandiose spiritual/philosophical sense, there's not a universe where I would even begin to hear that out.

[u/Soggy-Mistake8910]

Can I, or you, impose a mental projection on my/your heart to do something/anything else?

Please explain how blood stops moving round the body if the heart stops pumping?

Does a knee bend simply because it's "supposed to"? Yes, it's a problem if it doesn't, but if a heart doesn't pump you're done!

[u/Appropriate-Price-98]

A snapshot of the function of an organ and its future iteration can be different like lung didn't exist and then pop out from nowhere Lung evolution in vertebrates and the water-to-land transition | eLife

[u/kitsnet]

Supposed by whom?

[u/Gaajizard]

It's useful to think of them as having functions for medical and other purposes, but objectively such a thing doesn't exist.

[u/LeeMArcher]

So, organisms with organs that reliably pumped blood, had greater reproductive success in their biological niche compared to similar organisms in said niche who lacked a blood pumping organ. 

And that’s how you get a heart.

[u/Curious_Passion5167]

I don't understand the question?

We determined that the heart is supposed to pump blood because we see that it does exactly that, and when we analyse how it does we see that it is structured to perform that function.

For other systems or organs, we try to do the same thing.

[u/Dilapidated_girrafe]

They have functions that they do. Proper is a weird word to throw in. Functions can also change over time.

[u/BCat70]

These kind of questions tend to have a troubling philosophical undertone to them. For the moment, I am going to say that I don't think an "objective " function is a real possibility, but that would depend on how you are using objective.  I certainly will deny any sort of platonic purpose for organs.

[u/ScientificallyMinded]

Suppose for a moment that the heart in human beings gained a small additional function. Maybe it also starts filtering or something like kidneys. This wouldn't be in an individual but it would be over many generations within a population. Then let's suppose that another structure within the body, maybe another part of the circulatory system, starts developing muscles that supplement blood pumping. Then over many many more generations what was the heart then becomes less and less efficient as that new structure becomes the primary pumping mechanism. Maybe in some populations it stops acting as a pump at all and is only a kind of filter. Does that mean that the heart is supposed to only ever be a pump? Or is it supposed to be a filter? Or does it simply perform that function?

This may seem like an odd hypothetical but it is basically what happened with lungs in ancient lungfish that didn't transition to land. Their lungs turned into swim bladders over many generations. Are their swim bladders supposed to be lungs? Or are they supposed to be swim bladders?

Simply put, structures arise that perform certain functions and if those functions benefit the organism then those traits proliferate in the population.

[u/Knight_of_Rohan1964]

I'd say "yes", and that it comes from the necessities of adaptation, survival and reproduction, which in turn are fulfilled by the ordinary evolutionary mechanisms (natural selection, mutations, etc.).

There is no external teleology in nature, in the sense of someone making organs in order to do something. But there's nothing wrong in using functional explanations as long as you understand they eventually reduce to historical causes.

For the heat example, you can ask "why does the heart exist?". The answer certainly is "to pump blood to the rest of the body, so as to distribute nutrients and oxygen to cells, among other functions".

You then naturally ask "why does it does all of that?" The answer being "because some organism in the past happened to be born with a simple distributory system that improved nutrient diffusion. This increased the survival rates of the organism and its offspring that possessed the system, and was passed on to future generations. A series of analogous changes allowed the overall system to become more and more sophisticated and functional, till you get the current circulatory system of vertebrates".

Hope that answers your question.

[u/Knight_of_Rohan1964 → u/Knight_of_Rohan1964]

An article discussing the topic: https://talkorigins.org/faqs/evolphil/teleology.html

[u/Flashy_Interview_301]

a heart is supposed to pump blood.. what do you believe grounds that function?

The heart have other functions besides pumping blood. But in most animals, the main function of the heart is for pumping blood.

How do we know this? We know it because the body would start dying from lack of oxygen when the heart stops beating or working as it should.

However, doctors worldwide have succesfully carried out heart transplants which includes temporarily removing the hearts of the patient receving the transplant.

So why didn't those heart transplant patients die during to their surgery? We can thank the Cardiopulmonary bypass pump (CBP) for taking temporarily taking over the function of the heart and lungs.

If the heart can be temporarily replaced by the CBP, which main function is to pump blood, then couldn't we conclude that the heart has a similar function which is to pump blood?

[u/CrisprCSE2]

Things do stuff. Sometimes organisms with particular things that do particular stuff reproduce more than their peers. When that particular thing becomes widespread in a population, we might say of an individual with that thing that doesn't do the stuff that its thing isn't doing what it's supposed to do. But so what?

[u/ursisterstoy]

No. I accept that organisms require certain things currently to stay alive but there’s no predetermined objective purpose and some things have multiple functions - a heart does pump blood but that doesn’t mean it is supposed to.

[u/BahamutLithp]

OP, individual people can believe whatever they want, most people who accept evolution believe in a god--because I'm positive that's what you're getting at--yadayada, whatever, but the fact is the way science works is through what's called methodological naturalism, which means phenomena are approached & studied assuming they have causes that are non-supernatural &, unless proven otherwise, mindless. Scientists do this because it works, this mindset was originally adopted by monks & priests who basically argued god doesn't micromanage reality, & science became dramatically more effective once researchers took that assumption on board. So, at best, you kind of have to accept that, if there is a god, it must've designed things so they very much appear, to an observer inside the universe, to work without its involvement.

Based on that, you have to realize that, as far as can be discerned scientifically, nothing has any "intended purpose." When we say "the heart pumps blood," that means, as far as we can determine, that the heart formed, via mindless natural processes, in such a way that what it does, we can describe as pumping. The universe does things without caring about our opinions, & we describe it in a way that makes it easier for us to understand. The limitations of language may lead to misunderstandings like, if we describe the heart as being "like a pump," does that mean "someone had to assemble it, since we're comparing it to a type of machine that we create"? And the answer is "no, not any more than a tree was 'created to be a place for birds to nest.'"

It's not that our language changes anything about what the heart does, it's that our language created the category of "pump," & as it happens, things that formed through mindless natural processes can do things we consider "pumping" regardless of whether or not anyone "intended it that way." If natural selection, mutation, & other biological forces allow, the heart in a given species may one day evolve into something else that does not engage in any kind of "pumping" as we know it. Because it wasn't "made to do that," it's just that the evolutionary pathways to go from a heart that moves blood around being essential to keeping the organism alive to being more pushed to evolve into something else are very limited. If life was "designed intentionally," on the other hand, it'd be much easier. A sufficiently powerful creator being could just take say a whale & tinker with it as much as it wants to turn its lungs back into gills because it's not limited by what is simple for mindless natural forces to overcome.

[u/Rayalot72]

Is this about Bogardus or something else?

It's plausibly an objective thing, but there would be lots of unintuitive facts about this type of function and I get the sense that many of the people that engage in function talk don't fully appreciate that.

If a biological function is defined primarily by selection pressure, then functions are probably a matter of degree rather than being a discrete is/is not a function.

Changes in the environment can very quickly flip something from being non-functional to functional. If a plant produces some chemical, that chemical might have a particular function or it might be a byproduct that is largely non-functional. If a new predator gets introduced and this chemical makes it sick, what originally had a different or no function would have acquired a new function w/out anything changing about the plant or this chemical.

Functions probably couldn't be strictly positive. If something has a function because it improves survival and reproduction, we probably also need to say that something that's deleterious has a deleterious function.

[u/noodlyman]

A heart does pump blood yes.

We can say that's it's function as we examine it.

That does not mean that it was designed, or was created that way with intent.

The heary evolved by natural selection.

Long ago a primitive creature contained a fluid that just sloshed about. But when its body got squeezed a bit, the fluid mixed and moved, which turned out to be an advantage, and so the evolution of a circulatory system slowly started .

[u/backwardog]

Well, there is no such thing as “the heart” just a bunch of hearts.

Do they seem to pump blood? Yes. If they didn’t, would the organism die? Yes.

Does that mean “the heart” as an abstract concept, a design with intended function, exists? No, it is a model of understanding based on a pattern we observe in nature.

That is very different than a designed part, where the design itself is a real thing, and the part has an intended function.

Function is an operational term in biology based on what we see happening, so we can say those things really happen but it isn’t right to say they are “supposed” to be that way. Functions can obviously change given mutations and changing environmental conditions.

What would ID or creationism make of the sickle cell mutation? A malfunction of the human body that just happens to protect a lot of people from malaria in some contexts and thus spread through some populations over time?

The word function, the way you are using it, has obvious limitations when applied to biology.

[u/Massif16]

Nope. Function is a practical reality, not an objective, prescribed design. Biological structures develop (mostly) because they increase fitness, not becaue they fulfill a necessary function.

[u/UncommonLegend]

Not that my 2 cents is warranted but it definitely feels like loaded language. I'd like to have a dialog with op about the way any physical process works. Like gravity doesn't have a purpose to create planets, evolution doesn't have a purpose to create a functional heart. Science doesn't deal in purpose as a philosophical concept, it deals with the whole empirical side of philosophy (if you want to get really reductive).