Spearthrower wrote:I'll reply to you Zoon as JJ's just repeating the same errors yet again.

zoon wrote:
You are saying that mutations are the only real causes in evolution, while selection pressures are so negligibly weak that they do not qualify as causes, they are mere hypothetical models to be sharply distinguished from hard facts?

How, in your view, does science explain the extreme functionality of the lens in a human eye? Since mutations, which are biologically random, are the only causes in evolution, and selection pressures are so weak as to be insignificant, how did it come about that the lens of an eye focuses light on to the retina?

So I think you need to reconsider the first paragraph as it doesn't actually render what I said accurately, and consequently your 2nd paragraph leverages an erroneous idea which is definitely not relevant to what I wrote.

So let's break it down:

You are saying that mutations are the only real causes in evolution, while selection pressures are so negligibly weak that they do not qualify as causes...

No, not quite.

First I think it's important to recognize that we're doing ornithology for birds here. We're talking about philosophy and discussing evolution, but the 2 don't necessarily employ the same language, or at least not consistently - one needs to be cautious about applying the language from one to the other.

Philosophically, we're talking about causes. A cause is something which produces an effect; effects don't precede causes. From that perspective, natural selection cannot be a cause as it comes after the mutation - what is being selected naturally is, in essence, that mutation with respect to a particular fitness landscape. The cause (mutation) precedes the evolutionary effect (natural selection).

But of course this isn't a single iteration: there is a history of causes and effects - the body of the organism in question is in essence a massive collection of effects. These actually constrain the possible mutations: for example, a given gene may have a million different ways it could mutate, but those possibilities are finite and constrained by the gene preceding the mutation. Still, when stuff changes, we must needs be able to call something causal, and if the mutation didn't arise, then no change would have occurred (not exactly true as most evolution is just statistical reshuffling, but let's keep it simple).

So a gene that is responsible for a given trait may be constrained in how it can mutate based on the DNA of the gene and its position in the sequence as any mutation outside of that scope may produce something instantly deleterious which never results in any effect on the population; basically, it's self-aborting. But there are other ways that mutation can be constrained. For example, the environment in which the organism lives may produce constraints on what mutations can occur; an organism living in a typical air environment might somehow (beyond my actual knowledge) gain a mutation that lets its cellular machinery use methane instead of oxygen, but as there is no available methane to breathe, it once again results in no evolution occurring as the organism doesn't survive. There are plenty of notional ways in which mutations can be constrained by their history and their environment, but neither their history nor their environment are actually producing the change causally, just constraining the possible changes.

Natural selection (and correspondingly selection pressures) is not "weak" in terms of evolution; what I meant is that it is weak in terms of considering causes because it can only constrain not produce particular effects (for the most part). If the latter were the case, then we'd all consider it Lamarckian Evolution, not Darwinian.

Onto your 2nd paragraph then:

Science explains the functionality (not particularly extreme in that regard at all) of the lens of the human eye in terms of gradual evolution, wherein small benefits accrued iteratively.

Mutations, as I've pointed out above, aren't strictly 'random' in the most wide meaning sense of the word - they are constrained by many things, not least the nature of DNA itself being comprised of 4 - and only 4 – nucleobases.

So there may well be many paths to improving sight (read "offering preferential fitness*) - and we have quite a selection of those on the planet. The ancestors of humans went down one particular path gaining gradual improvements iteratively over time. I am sure you've seen the sequences discussed here before:

Photoreceptor cell - offers some basic sense of direction & movement
Multiple cells congregated together - better sense of movement
Small depression focusing light onto the photoreceptive cells - directionality of light and movement
Deepening 'cup' - acuity in sensing light direction
Invagination - closing back up the exterior to limit photons - increases resolution and the production of an actual image
Overgrowth of transparent cells - protect the structure
Interior filled with clear liquid acting as a lens to aid in colour filtering, refraction, and formation of a clear image.

So in terms of causality, it's all just mutations, but those mutations of course must either be neutral in terms of fitness, or be beneficial in terms of fitness else the organism possessing those mutations cannot compete statistically; ratcheted iteratively through multiple generations, we end up with the hodgepodge of biological engineering known as the human eye... and it's really not that effective or efficient at all!

Finally, I should get onto talking about the Mullerian 2-step i.e.
Add a part.
Make it necessary.

But I have daddy duties to attend to. Basically, though... a structure can evolve from and be dependent on parts that existed at the time, but those parts may eventually be coopted or even removed without consequent loss of function in the contemporary structure. Regardless though, we are wandering further and further away from my area of expertise and many other people here are at least as well versed to explain such things as I am.

As far as the evolution of, for example, the eye, is concerned, mutations are effectively random? Even after allowing for the constraints within the DNA molecule, a mutation which makes the lens of an eye slightly cloudier is no less probable than a mutation which makes the lens slightly clearer; it’s the subsequent selection which provides the directionality?

I think we are not in any disagreement about the facts of evolution, it’s the language around causality which is problematic? Would you perhaps agree that causality is a concept which our evolved minds find very easy to use, but which is somewhat woolly in science; science more strictly is about correlations rather than causes? A cause is merely something which our evolved minds latch on to as an explanation for practical purposes.

It seems to me that constraints can count as causes, for example, the causes of the shape of a river’s course include both gravity and the topology of the terrain. In constraining the direction of the water, the topology has an effect on the course of the river, it is one of the causes shaping the river’s geography. I would say by analogy that it’s not only the mutations, but also the fitness landscape (which was there before the selection process), which should be counted in among causes of the evolved eye or living part, if the causal story is not to give a one-sided picture?

I think what’s bothering me in this particular discussion is that an insistence that mutations are causes in evolution while selection pressures (or fitness landscapes) are not, seems to me to leave a wide-open goal for creationists to exploit? If an atheist says that the only causes in evolution are mutations, and that fitness landscapes do not have causal power, then it seems to me that a creationist could happily say: “Yes! You are acknowledging that the only scientifically discernable causes in evolution are mutations, mutations are effectively random for biological purposes, therefore science has no explanation for the functionality which is so evident, for example, in eyes, therefore God.” I would be worried if I could only answer that by trying to explain that fitness landscapes aren’t powerful causes even though, over evolutionary timescales, they have highly significant effects?

As far as the evolution of, for example, the eye, is concerned, mutations are effectively random? Even after allowing for the constraints within the DNA molecule, a mutation which makes the lens of an eye slightly cloudier is no less probable than a mutation which makes the lens slightly clearer; it’s the subsequent selection which provides the directionality?

Again, causal.

How does an effect precede its cause? That seems to be what you want to say? Or is it? I am not sure what you want to say!

Slightly less, slightly more... the mutation is random (as in not directed), the aggregate of differential fitness - the continuation of that mutation - is not. The vast majority of evolution is actually neutral in fitness terms... and the vast majority of evolution is not driven by natural selection but by reshuffling of existing genes.

To put it more strongly and to hopefully reiterate more clearly what I've said already: the consequences (effects) of any mutation have no influence at all on the probability of that mutation occurring. Mutations occur randomly with respect to whether their effects are useful - they do not supervene on the environment. That however does not mean that all mutations are equally probable - for example, some mutations may occur more readily due to the nature of the biochemistry occurring in DNA. Of course from an evolutionary perspective, mutations have to actually produce sufficiently functional proteins that don't generate such a deleterious effect that they cause the organism to die, because if that happens, then no evolution will occur although the mutation still did.

I think we are not in any disagreement about the facts of evolution, it’s the language around causality which is problematic? Would you perhaps agree that causality is a concept which our evolved minds find very easy to use, but which is somewhat woolly in science; science more strictly is about correlations rather than causes? A cause is merely something which our evolved minds latch on to as an explanation for practical purposes.

That's what I've said across each post on this topic: it's not just the language of causality, it's language itself constraining how we conceive of it - discontinuity. But if you look at what the terms mean, then causes necessarily precede effects in essentially all observable cases. So then, how can selection be causal if there's no variation, nothing to actually select? And where does that variation come from? Mutation. Sure, there may be plenty of existing variation within a population - novel effects from recombination - but all those variations originated with mutations.

It seems to me that constraints can count as causes, for example, the causes of the shape of a river’s course include both gravity and the topology of the terrain. In constraining the direction of the water, the topology has an effect on the course of the river, it is one of the causes shaping the river’s geography. Landscapes are not necessarily static, an earthquake or slow accumulation of sediment can alter the course of a river. I would say by analogy that it’s not only the mutations, but also the fitness landscape (which was there before the selection process), which should be counted in among causes of the evolved eye or living part, if the causal story is not to give a one-sided picture?

In this thread, starting a sentence with "It seems to me" is pretty much intentionally triggering!

Constraints don't cause, they constrain. Mutations don't arise because of constraints - they survive or don't survive because of constraints. Your analogy doesn't work because the reason genes mutate isn't directed by gravity or any other analogous directing force. This is a fundamental misconception. No matter how many times you drop water in that area, it's always going to end up following a particular course as gravity and topology constrain it - that is not the case with genetic mutations; they do not follow a preset course. The eye is actually a great example of this as there are at least 10 different types of eye recorded in the natural world.

Again, with all caveats previously stated... I am not a philosopher, I am not a mathematician, I am not an evolutionary biologist or a molecular biologist, or a molecular geneticist (we need someone like Rumraket to help out here)... I am just a palaeoanthropologist and have no particular expertise or insight into this topic that would help me make sense of this for you, so forgive any convoluted explanations, but I think you need to look at what mutations are and how mutations occur.

Firstly, we need to be clear that we're only talking about germline cells because we're talking in terms of evolution, and aside from some very rare cases, somatic cell mutations are not heritable. Secondly, mutation most fundamentally means a change in the structure or order of nucleic acids - the building blocks of DNA.

So, there are many types of mutation: point mutations where a single base pair changes to be another base pair; nonsynonymous substitutions where a sequence of amino acids changes - essentially result in a change in proteins, either the type of protein, the existence of a protein, or the termination of a protein. Then there are synonymous mutations; this is a change in the DNA sequence coding for amino acids in a protein sequence, but it does not actually change the encoded amino acid - these are kind of a special case due to purifying selection because while these mutations are often 'silent' as in they have no effect, they can possibly result in the most dramatic changes which is most likely to be highly deleterious. Finally (ignoring transposable), there are the insertions and deletions which again can have a dramatic effect not just through the inserted or deleted base pair, but by the effect they have on the expression of other nucleotides.

The main ways by which germline mutations occur are through copying errors in recombination or DNA repair, and mutagens such as (albeit very rare) cosmic rays. They are all essentially 'mistakes', unintended, going against the 'planned' perfect reproduction of the existing genetic information. They are not directed by the environment. They are not directed by contingent history. They are not directed by anything, and thus they are 'random' in the previously stated sense of the word. Again, there's a probablistic element - some sequences may be more susceptible to mutation than others, some mutations may occur more frequently, and then because we're talking about evolution, there's a necessary consideration of whether that mutation is sufficiently deleterious to cause the organism to fail and self-abort, to be non-functional, and therefore never even become part of the species' genetic pool.

I think what’s bothering me in this particular discussion is that an insistence that mutations are causes in evolution while selection pressures (or fitness landscapes) are not, seems to me to leave a wide-open goal for creationists to exploit? If an atheist says that the only causes in evolution are mutations, and that fitness landscapes do not have causal power, then it seems to me that a creationist could happily say: “Yes! You are acknowledging that the only scientifically discernable causes in evolution are mutations, mutations are effectively random for biological purposes, therefore science has no explanation for the functionality which is so evident, for example, in eyes, therefore God.” I would be worried if I could only answer that by trying to explain that fitness landscapes aren’t powerful causes even though, over evolutionary timescales, they have highly significant effects?

I am very insistent in this regard even if I am not presenting the most cogent possible argumentation for it: mutations are the only cause it's useful to consider. Selection pressures are - by definition - selecting something that already exists, and therefore supervene on those events, and thus cannot be considered causal.

As for what Creationists may or may not exploit, I personally consider that absolutely irrelevant. The truth is the truth, regardless of who it's useful for. And look at JJ as a model Creationist - he doesn't need help in finding stuff 'useful' to him - he'll just make up whatever he fancies regardless of the truth.

I also think you've got it arse about tit, if you don't mind me saying. JJ wants the 'environment' to be causal - he wants the environment to craft the species towards a predestined outcome. He obviously means that the magical man in the sky is planning the outcome and employing the environment to sculpt that outcome. Creationists reject 'random' wholly as they perceive everything to be operating on Yahweh's direction. So I think your analysis is wrong, and I also think it's entirely pointless to be worrying about what Creationists may or may not do.

Of course, we do have an explanation for functionality - it's 'evolution'. Variation, heritability, differential survival. Those three components are all that's needed to explain functionality. You can do it with blind computer programs - functionality emerges and increases when these 3 components are allowed to 'compete'.

Finally, you are again misrepresenting what I am saying, and I'd prefer it if you didn't!

I never said that selection pressures are weak - I said they are not causal. Selection pressures are obviously a fairly significant chunk of evolution; they sculpt the morphology and behavior of species over generations and have a dramatic impact on both, they just don't generate the clay they sculpt to extend the metaphor.

But if you want to say they are causal, then please explain how they cause changes - what is the process for that? How does the environment or selection pressures actually produce novel DNA arrangements or sequences?

I would say that you need to consider what the component 'selection' means there. If there's no existing variation prior to seletion, then there can be no selection as there's nothing to 'select'. But if selection is meant to cause the variation, then why would 'selection' produce variation and still be considered selective? It seems a very murky grasp of the core of evolutionary theory.

Addressing Spearthrower: Thank you for your post, I have read it, and it has made me think and see your side of the discussion more clearly. Is there any book, article or author on this subject which you consider I would do well to read?

According to the Stanford Encyclopedia of Philosophy article on Natural Selection here, updated in Sept 2019, this subject divides both scientists and philosophers. Quoting the relevant section here:

4.1 Explanatory Scope
There exists a longstanding debate among both scientists and philosophers over exactly what natural selection can explain, one begun by Sober and Neander who were concerned with what natural selection can explain (Sober 1984, 1995; Neander 1988, 1995). In a recent expansive treatment, Razeto-Barry & Frick 2011 distinguish between the creative and non-creative views of natural selection. On the non-creative view, natural selection merely eliminates traits while doing nothing to create new ones; the latter phenomenon is the result of mutation. Proponents of the creative view see natural selection as a creative force that makes probable combinations of mutations that are necessary for the development of at least some traits. While Razeto-Barry and Frick grant that natural selection cannot explain the origin of traits that arise by a single mutation, they argue that it can explain the occurrence of sequences of phenotypic changes that would otherwise be wildly unlikely to occur without selection operating to cause the spread of the changes prior to the final one in the sequence.

Your view is on the side of the debate which argues that natural selection is not a creative force, “natural selection merely eliminates traits while doing nothing to create new ones; the latter phenomenon is the result of mutation.” I still find myself with the creative view, I “see natural selection as a creative force that makes probable combinations of mutations that are necessary for the development of at least some traits.”

This debate has evidently been going strong for more than 30 years, with scientists and philosophers on both sides, and neither side has yet succeeded in convincing the other. May we agree to differ?

zoon wrote:Addressing Spearthrower: Thank you for your post, I have read it, and it has made me think and see your side of the discussion more clearly. Is there any book, article or author on this subject which you consider I would do well to read?

There's always endless debates, but I can't really point to any singular tract - like I mentioned, when you have philosophy intersecting with an empirical science, you end up with rather diverse takes.

zoon wrote:According to the Stanford Encyclopedia of Philosophy article on Natural Selection here, updated in Sept 2019, this subject divides both scientists and philosophers. Quoting the relevant section here:

4.1 Explanatory Scope
There exists a longstanding debate among both scientists and philosophers over exactly what natural selection can explain, one begun by Sober and Neander who were concerned with what natural selection can explain (Sober 1984, 1995; Neander 1988, 1995). In a recent expansive treatment, Razeto-Barry & Frick 2011 distinguish between the creative and non-creative views of natural selection. On the non-creative view, natural selection merely eliminates traits while doing nothing to create new ones; the latter phenomenon is the result of mutation. Proponents of the creative view see natural selection as a creative force that makes probable combinations of mutations that are necessary for the development of at least some traits. While Razeto-Barry and Frick grant that natural selection cannot explain the origin of traits that arise by a single mutation, they argue that it can explain the occurrence of sequences of phenotypic changes that would otherwise be wildly unlikely to occur without selection operating to cause the spread of the changes prior to the final one in the sequence.

The other side there being something I tried to also explain with respect to how the selection side can only really be seen to be very weak causally because it's constraining what can work. But it does of course again fail to address that the mutation isn't actually caused by selection; the only way in which we can really talk about that is to go on a series of proximate causes, which necessarily eventually results in mutation at the outset. A stronger impact in that regard is biochemistry, with some reactions being much more probable to occur than others.

zoon wrote:Your view is on the side of the debate which argues that natural selection is not a creative force,...

My view is that it's not causal.

Spearthrower wrote:I never said that selection pressures are weak - I said they are not causal. Selection pressures are obviously a fairly significant chunk of evolution; they sculpt the morphology and behavior of species over generations and have a dramatic impact on both, they just don't generate the clay they sculpt to extend the metaphor.

zoon wrote: I still find myself with the creative view, I “see natural selection as a creative force that makes probable combinations of mutations that are necessary for the development of at least some traits.”

Ok, so there's a useful term in there: probable. To conceive of probability, one needs to look at data points in a comparative function: so what would be the data points here? How would we run a comparative analysis?

zoon wrote:This debate has evidently been going strong for more than 30 years, with scientists and philosophers on both sides, and neither side has yet succeeded in convincing the other. May we agree to differ?

Of course we can... I'm not obliging you to agree or to do homework or anything!

But I think that rather than reading more by other people, you can take a crack at answering the questions already posed yourself.

Here's an even simpler rendition of the central question:

Pick one of these.

...

If your answer is, as it must be, one of what? Then I think you must acknowledge that your selection is wholly dependent on the availability set out for you, whereas, the availability is not dependent on your selecting. Fed back into the relevant discussion: selection supervenes on mutation, whereas mutation doesn't supervene on selection. There cannot be a variation in Y without that variation originating in X.

According to the Stanford Encyclopedia of Philosophy article on Natural Selection...

I may have found the problem.

Spearthrower wrote:

Here's an even simpler rendition of the central question:

Pick one of these.

...

If your answer is, as it must be, one of what? Then I think you must acknowledge that your selection is wholly dependent on the availability set out for you, whereas, the availability is not dependent on your selecting. Fed back into the relevant discussion: selection supervenes on mutation, whereas mutation doesn't supervene on selection. There cannot be a variation in Y without that variation originating in X.

I don't think the analysis is advanced by using language like "originate" instead of "cause". We can focus on what preceded whatever followed, but we must clearly identify both before proceeding. We can relate A to B, and sometimes we can say B caused A. We can get philosophical and ask whether A is a necessary consequence of B, which is a logical deduction and not the result of observation. Of course, scientists don't wait until then to cite causes, but they do have a little patience before citing them. The situation is muddied, often woefully so, when 'softer' sciences stealthily start exposing their physics envy.

Non-scientist ideologues like JJ proceed by fogging over the events we are trying to identify as "causing" whatever "consequences" there are. I don't detect that zoon is trying to obfuscate anything, but she's very, very confused, and Fenrir has pointed out a hint as to how that confusion might have come about. It not the particular wording from some encyclopedia that is to blame for this; it's using the damned document at all to do anything but reassert that philosophy underpins science. The SEP expends millions of words to claim support for that simple hypothesis. Maybe the weight of verbiage will win in the end.

Spearthrower wrote:

zoon wrote:Addressing Spearthrower: Thank you for your post, I have read it, and it has made me think and see your side of the discussion more clearly. Is there any book, article or author on this subject which you consider I would do well to read?

There's always endless debates, but I can't really point to any singular tract - like I mentioned, when you have philosophy intersecting with an empirical science, you end up with rather diverse takes.

Spearthrower wrote:

zoon wrote:According to the Stanford Encyclopedia of Philosophy article on Natural Selection here, updated in Sept 2019, this subject divides both scientists and philosophers. Quoting the relevant section here:

4.1 Explanatory Scope
There exists a longstanding debate among both scientists and philosophers over exactly what natural selection can explain, one begun by Sober and Neander who were concerned with what natural selection can explain (Sober 1984, 1995; Neander 1988, 1995). In a recent expansive treatment, Razeto-Barry & Frick 2011 distinguish between the creative and non-creative views of natural selection. On the non-creative view, natural selection merely eliminates traits while doing nothing to create new ones; the latter phenomenon is the result of mutation. Proponents of the creative view see natural selection as a creative force that makes probable combinations of mutations that are necessary for the development of at least some traits. While Razeto-Barry and Frick grant that natural selection cannot explain the origin of traits that arise by a single mutation, they argue that it can explain the occurrence of sequences of phenotypic changes that would otherwise be wildly unlikely to occur without selection operating to cause the spread of the changes prior to the final one in the sequence.

The other side there being something I tried to also explain with respect to how the selection side can only really be seen to be very weak causally because it's constraining what can work. But it does of course again fail to address that the mutation isn't actually caused by selection; the only way in which we can really talk about that is to go on a series of proximate causes, which necessarily eventually results in mutation at the outset. A stronger impact in that regard is biochemistry, with some reactions being much more probable to occur than others.

zoon wrote:Your view is on the side of the debate which argues that natural selection is not a creative force,...

My view is that it's not causal.

Spearthrower wrote:I never said that selection pressures are weak - I said they are not causal. Selection pressures are obviously a fairly significant chunk of evolution; they sculpt the morphology and behavior of species over generations and have a dramatic impact on both, they just don't generate the clay they sculpt to extend the metaphor.

To extend your metaphor still further, perhaps beyond its breaking point, the production of a sculpture involves, broadly, 2 separate sets of processes:

1) The processes involved in the formation of the lump of clay (nucleosynthesis, sedimentation etc)

2) The processes involved in the sculpting (nerve impulses in the sculptor’s brain, movements of the sculptor’s hands, etc)

I (together with those professional scientists and philosophers with whom I am in agreement) find it weird to deny the causality of the sculpting processes. By contrast, you, and the professional scientists and philosophers on your side of the debate, find it equally blazingly obvious that only the production of the clay is causal, the sculpting isn’t. Evolved brains and their intuitions!

Spearthrower wrote:

zoon wrote: I still find myself with the creative view, I “see natural selection as a creative force that makes probable combinations of mutations that are necessary for the development of at least some traits.”

Ok, so there's a useful term in there: probable. To conceive of probability, one needs to look at data points in a comparative function: so what would be the data points here? How would we run a comparative analysis?

zoon wrote:This debate has evidently been going strong for more than 30 years, with scientists and philosophers on both sides, and neither side has yet succeeded in convincing the other. May we agree to differ?

Of course we can... I'm not obliging you to agree or to do homework or anything!

But I think that rather than reading more by other people, you can take a crack at answering the questions already posed yourself.

Here's an even simpler rendition of the central question:

Pick one of these.

...

If your answer is, as it must be, one of what? Then I think you must acknowledge that your selection is wholly dependent on the availability set out for you, whereas, the availability is not dependent on your selecting. Fed back into the relevant discussion: selection supervenes on mutation, whereas mutation doesn't supervene on selection. There cannot be a variation in Y without that variation originating in X.

Why do I have to pick one? What’s wrong with both? Of course I am not claiming that natural selection causes mutations, any more than I would claim that a sculptor causes the nucleosynthesis of the silicon atoms in the clay. I suspect we could continue this argument for the next 30 years.

Fenrir wrote:

According to the Stanford Encyclopedia of Philosophy article on Natural Selection...

I may have found the problem.

As you say, it’s a philosophical problem, both sides agree on the science. This doesn’t stop professional scientists, as well as philosophers, from getting into heated arguments on the question.

Why do I have to pick one? What’s wrong with both?

Both?

Who says there was only 2 to pick from?

I said:

Pick one of these.

...

What are you picking from?

Of course I am not claiming that natural selection causes mutations...

Because mutation causes the variation from which nature selects through differential survival.

Cito wrote:We can focus on what preceded whatever followed, but we must clearly identify both before proceeding.

And I think from that is a logical assumption that generally what follows cannot have caused what precedes it; at least on the scales we're discussing.

zoon wrote:I (together with those professional scientists and philosophers with whom I am in agreement) find it weird to deny the causality of the sculpting processes. By contrast, you, and the professional scientists and philosophers on your side of the debate, find it equally blazingly obvious that only the production of the clay is causal, the sculpting isn’t. Evolved brains and their intuitions!

That's because when a person does something like sculpting, we treat as something besides an accident and we use the same word to describe the results of actions that people perform. Bringing causality into it broadens the term to uselessness. As you point out, some extremely pedantic arguments go all the way to asserting that everything that happens is an accident, and that broadens another term to uselessness. We won't do that, will we? Dichotomize?

The point is that we cannot apply the term "causation" to "selection pressure" the same way we apply it to decide that an automobile accident was caused by one of the drivers, rather than by both of them or by no particular event. It is usually not a purposeful act by the responsible driver, else we'd not call it an accident. When you're talking to JJ, you're confronted by an assertion that divinity shapes our ends, and then, maybe, you can cite selection pressure as an alternative to divinity. See you in the free will thread, zoon.

zoon wrote:

Jayjay4547 wrote:

zoon wrote:
Your hands are in many ways far better for manipulating objects than the hands of Ardipithecus. Even so, your stick was not all that sharp, if a leopard charged me when I was holding it, I would be more likely to be knocked backwards than to make a hole in the leopard? Making a series of sharpened sticks to keep at ground level for use solely against leopards seems a waste of time, when fleeing through the canopy was the obvious alternative strategy? Ardipithecus ramidus would not usually have been threatened by the more numerous grassland predators, because it was a woodland creature.

The stick I cut the other say using an Oldowan-like stone, was cut by an amateur at first attempt and just to demonstrate something on this forum. I didn’t even want to make a point at one end, that emerged from the process. An australopith would have had how-to examples from others in the troop, examples of finished products and a lot stronger motivation.

Consider that there is an established culture in some universities to show students how to make more advanced stone tools; in a few decades they have developed this expertise. It is surely reasonable that IF early hominins used hand weapons for predator avoidance, they would have evolved serious attention to making and using those weapons. An image of a homin picking up a fallen branch to defend itself, may be seriously misguided.

The university students are recreating the possible stoneworking techniques of species of Homo, such as Homo erectus. If you were saying that Homo erectus spent time on the open savannah, was well adapted for manipulating objects and almost certainly used stones to shape weapons, nobody here would be disagreeing with you. You are not talking about species of Homo, you are currently claiming that Ardipithecus ramidus, a woodland creature with grasping hind feet and a small, weak thumb, was habitually sharpening sticks well enough to pierce a charging leopard without being knocked backwards by it.

The point I was making above was that whenever our ancestors used hand weapons for predator avoidance, they would have devoted great attention and time towards optimising the effectiveness of those weapons.

The point I tried to make earlier by making a stopper stick using a stone was that the stone could do that. You follow Spearthrower in arguing is that Au. afarensis (and now further back, Ardi) couldn’t have held that stone as effectively. I visualise that they would have found a way and their striking appearance of vulnerability, bipedal stance, their associated plant and animal species and the habits of their descendants, showed clearly that they had. Maybe they used two hands. I’m not arguing like Dean Swift, that a horse could thread a needle.

I suppose stopper weapons were as effective as analogous antelope horns. So far as I know, African predators don’t take a horned buck from the front, but from the flank or rear. So, the horns restrict the possible styles of attack into a narrower range where the buck is good at, which is running away. Not that that is their only function.

If a predator did indeed charge at a proffered stopper, its butt could be grounded in an instant and held there with one foot so the predator would impale itself by its own momentum.

But anyway, maybe hominin stoppers weren't made of wood, maybe Dart was right about his “osteodontokeratic culture” and they used antelope horns held in the hand. I just don't see that working myself.

zoon wrote:

Jayjay4547 wrote:White says “Hominids appear to have emerged by developing a search-intensive terrestrial feeding niche, accompanied perhaps by food transport and sharing in less densely forested but still wooded areas.” Then, hominids came out from amongst the trees to find resources on the ground. Another possibility is that hominids walked from one fruiting tree to the next, because fruiting trees were far apart.

OK, yes, australopithecines, and Ardipithecus, probably lived mostly in areas which were wooded but not densely forested.

Yes, and our ancestors didn’t “come down from the trees” like chimps but walked from tree to tree to pick the fruit. (But not the fruit from the tree in the middle of the garden. That came later.)

zoon wrote:
As you say, leopards have killed many modern humans, but as far as I know most of the attacks are the typical leopard ambush or stealth hunt followed by a fast sprint to catch a non-alert individual. I was saying that I don’t know of attacks where a leopard attacked a group of modern humans who were facing the leopard, and were well aware it was there.

I found this clip of a leopard running amok amidst a crowd of men:

zoon wrote:
Even if the humans were unarmed, the leopard would be at risk of being overwhelmed by weight of numbers, and being choked or having its tongue torn out. A small group of unarmed humans would be in danger from a pride of lions or a pack of hyenas, but they are a significant threat to a solitary leopard.

The standard of African prey behaviour is set by animals like springbok and baboons, who are strikingly better equipped to avoid leopard predation. Surely, one has to look at the animal’s characteristics in a comparative context?

I found these counter examples of separate incidents in Kerala province of India, where groups of humans do kill a leopard with their bare hands. These scenes might be what Spearthrower envisages when he talks about mobbing.



Naked link: https://www.youtube.com/watch?v=TYAYtwirwDw

But those are very large groups of humans in a dense settlement area. For robust survival, ancient hominins needed to have strong predator avoidance under the greatest range of troop size and with the minimum impact of predators on their foraging abilities.

zoon wrote:

Jayjay4547 wrote:Different debunkers have widely scattershot attitudes to predators; from representing them as overwhelmingly powerful like sharks and tigers, to insignificant. Either way, the predator-prey relationship is presented as weak; distant, transient, or naïve. Quite a contrast with the detail they are prepared to go into about bones of the hand.

Relative sizes do matter. At the beginning of this thread you were arguing, I think rightly, that if australopithecines had been on the open savannah then, if they were unarmed, they would have been unable to defend themselves against the large and group-hunting predators of the grasslands. But australopithecines were not on the open savannah, they stayed near trees (as do modern chimpanzees and baboons where there are grassland predators), and they could climb up those trees; the formidable lions and hyenas (or their predecessors three or four million years ago) were not in fact an unanswerable threat to australopithecines for that reason.

This leaves the smaller, solitary tree-climbing cats such as leopards, which groups of alert chimpanzees, even female chimpanzees, can stand up to if necessary.

A group of Ardipithecus would have been no less dangerous than a group of female chimpanzees, which are capable of driving off a leopard, according to here (an article which has been repeatedly linked in this thread). Quoting from the article (my bolding):

If 4 female chimps can drive off a leopard, why should this be beyond a dozen Ardipithecus ramidus?

...The three females had no hesitation about heading towards the leopard and making mobbing calls, they did not wait for the males to arrive. A group of enraged female chimpanzees, each roughly the size of a large baboon and with non-negligible teeth, seem to be ready to mob a leopard.

Boesch himself regarded all-male and mixed chimp groups as “predator safe”. I agree that several primate species females defend themselves, their children and join in mobbing, but that doesn’t mean they could do without the males. Without males they would be more vulnerable to predation.

zoon wrote:
It remains the case that the three female chimps immediately rushed to the defence of their group-mate, they did not hesitate or show any signs of waiting for the males; it was also the case that the leopard had left before the males (and the researcher) arrived. With all due respect to the canine teeth of male chimpanzees, the teeth, hands and general strength of a female chimpanzee are also to be reckoned with; would you be in any hurry to try to take a baby chimpanzee from its mother?

I certainly wouldn’t try to take a baby even from a much smaller female vervet, using my bare hands. That’s because the body plan I inherited from ancestors as far back as Ardipithecus leaves me hopelessly vulnerable even to small animals. When I’m not carrying a stick that is. But according to Cheney and Seyfarth, male baboons in Okavango often take baby baboons from their mothers and kill them. Those males are well equipped for that.

Cito di Pense wrote: When you're talking to JJ, you're confronted by an assertion that divinity shapes our ends, and then, maybe, you can cite selection pressure as an alternative to divinity.

Really, the opposite. What shapes our ends is what we call "divinity". We paint the ceiling with beautiful or awful designs to express our condition.

That's a lot of words to say "I got nothing".

We have the same old assertions being asserted yet again.

I certainly wouldn’t try to take a baby even from a much smaller female vervet, using my bare hands.

Let's remember how JJ responds to a video of a tiger appearing out of nowhere and leaping in one bound high enough to clear an elephant's head to attack the man - who happens to be carrying two sticks - sitting on the elephants back:

That clip of a tiger leaping onto an elephant has been used a few times before on this forum, to shock and awe the viewer into a simplistic “slam dunk” conclusion about the power of a predator.

That 'simplistic slam dunk' of being able to watch the real-world power and ferocity of a large cat hunting is just to 'shock and awe' - but when JJ expresses his apparent innate fear of monkeys appealing to others to join him in that supposedly rational and ubiquitously held fear that monkey canines (amusingly using a female as his example this time) are effective predator deterrents and thus all his claims are valid.

And it's all meant to be extrapolated from what JJ would or wouldn't do in a hypothetical scenario!

JayJay4547 wrote:

Zoon wrote: As you say, leopards have killed many modern humans, but as far as I know most of the attacks are the typical leopard ambush or stealth hunt followed by a fast sprint to catch a non-alert individual. I was saying that I don’t know of attacks where a leopard attacked a group of modern humans who were facing the leopard, and were well aware it was there.

I found this clip of a leopard running amok amidst a crowd of men:

There you go Zoon - JJ's doing it to you too!

Of course, the video isn't actually an example of a leopard hunting humans as per the context of your post - it's a video of a leopard attempting to flee a group of men who are the aggressors in this context.

But JJ thinks he's rebutted your point now and will ignore any attempts at reasoned discussion on the topic.

Bait and switch.

The point I tried to make earlier by making a stopper stick using a stone was that the stone could do that. You follow Spearthrower in arguing is that Au. afarensis (and now further back, Ardi) couldn’t have held that stone as effectively.

Couldn't have held it as effectively to do the thing you're claiming they used the stick/stone for.

Also, as Spearthrower pointed out a dozen times, if a stone in your hand is your weapon, then to use that stone you've already within range of the much more dangerous suite of killing tools the predator possesses.

You live in fantasy world JJ. You can't expect other people to join you there.

So far as I know, African predators don’t take a horned buck from the front, but from the flank or rear.

Which is because, as I have pointed out dozens of times, the prey animal gains no benefit from engaging in gladiatorial combat with a predator, and consequently the horned end is facing away from the predator as the buck is preoccupied with fleeing the fuck away.

When does the horned end actually get used as a weapon? When it's fighting other males of its own species for access to mates. Gonna try and claim that's me arguing for 'antelope self-creation'?

Jayjay4547 wrote:

Cito di Pense wrote: When you're talking to JJ, you're confronted by an assertion that divinity shapes our ends, and then, maybe, you can cite selection pressure as an alternative to divinity.

Really, the opposite. What shapes our ends is what we call "divinity". We paint the ceiling with beautiful or awful designs to express our condition.

Finish your thought, JJ. How is it important that we express our condition so as to suit your emotional needs (to call it "divine", or to see it as "beautiful" or "awful")? You don't have a good answer for this, so you keep on about divinity without saying how anyone else's world view needs to incorporate it. To be like you is not attractive, not because you go on and on about divinity, but because you can't or won't say why you do it. When you explain that, it's not going to do to simply repeat that "the truth is the truth is the truth". If I believed that, without more than your audacious stories to support it, I'd be on your side at least as far as understanding why you go on and on about divinity. But you can't or won't finish your thought. I think you know your campaign is nutty. Only a child would need to paint it as "beautiful" when a more sober view is that it's simply "interesting". There's no harm in your fashioning a beautiful fantasy to make your existence more exciting, but don't expect anyone else to ride along with you, let alone demand that anyone use language you prescribe.

Spearthrower wrote:
You live in fantasy world JJ. You can't expect other people to join you there.