Waterside Hypotheses of Human Evolution (Part 7)

[AlgisKuliukas]

Ouch. Complexity is not a goal of evolution. It's not even a particularly strong trend. Most of the biomass on the planet remains relatively uncomplex.

Done any biochemistry? Tell me how even the simplest bacterial metabolism can be described as anything but complex? The amazing biochemical complexity - e.g. of DNA packaging/replication/transcription - must have evolved long before even the most basic eukaryotes arrived on the scene. So much for that idea.

OTOH, as far as the existing complexities of lifeforms goes, it is probably safe to assume that most of the complexity that does exist did result from selection,

Well that's good, eversbane. Something we can agree on at last.

but that does not address the issue that your experiments demonstrate that hominids in water experience no selection on gait phenotype. This whole drift discussion arose from your failure to address this issue and your latest work only reinforces the issue. What you described just a post or two above about the results of your experiment is a setting of drift on gait phenotype. I have no problem with that, but you seem to have a huge problem with that: especially since you seem to fail to recognize the fact.

Note "no selection" - a complete distortion of my results. Only at chest deep water was there no differential in the cost of locomotion between two gaits - but even this still ignores completely all the other aspects of potential selection that would be working on hominins that moves chest deep in water.

I would also remind people - for what it's worth - that no-one else, none of the co-authors of the paper, none of the lecturers at UWA who read the paper, none of the biologists elsewhere I asked to proof read the paper, none of the editors of the six journals I sumbmitted it to, none of the referees who rejected the paper or the ones that thought it should be published, voiced this concern.

What does that tell you? It tells me (a) eversbane knows almost nothing about evolutionary biology and (b) his motives for repeatedly dragging this up are more to do with trolling - trying to annoy me into writing something I shouldn't - than anything vaguely scientific or rational.

Algis Kuliukas

[AlgisKuliukas]

In some contexts fossils of the hominid species in question were found with fossils of recognized terrestrial taxa and with fossils of recognized aquatic taxa.
In other contexts fossils of the hominid species in question were found with fossils of recognized terrestrial taxa and no fossils of recognized aquatic taxa.
In no context has a fossil of a hominid species been found with fossils of recognized aquatic taxa and no fossils of recognized terrestrial taxa.

From these finding, what can one say about the hominid species in question?

One can say that human ancestors were never aquatic. But who ever said they were?

Haven't you been listening to ANYTHING? Here we are 6.5k posts on and you still think I'm proposing an aquatic ape? What a complete waste of time!!

Algis Kuliukas

[AlgisKuliukas]

I accept the apology for the personal insults,

Thank you.

When on-topic posts critiquing the style and substance of the arguments on behalf of the OP -- posts that have not been shown to be violative of any forum rule -- are deleted from a thread merely due to the overwrought whinging of the OP author, the spirit of free and fair debate on this forum suffers.

What's "OP"?

I should point out that when I complained about the posts I got a response from one MOD telling me that it was ok to call ideas crap and that I never hoped for or expected the posts to be removed, just that some restraining comment would be made. I am very grateful for Russell's comment but not for his removal of the posts. I actually would have preferred the posts to have been kept in so that anyone reading this thread could see the level of childish sneering that it descended to. Now, no-one will ever know.

But anyway... the topic? can we, you know, stick to the topic now? Please?

Algis Kuliukas

[AlgisKuliukas]

... some scientific critique that. I wonder if PZ Myers has even read it. It slags of [sic] the aquatic ape so who cares, right?

Are you banned at Pharyngula ? Why not just hop over there and ask him, instead of using of voicing that underhanded speculation ?

I am not banned anywhere, hotshoe - much as you'd apparently like to change that.

I did go there and post a direct question to him and replies to others.

http://scienceblogs.com/pharyngula/2009 ... e_hypo.php

He didn't reply so I sent him a direct e-mail asking him personally... no reply.

What a surprise.

I see your argument is being trashed there too Algis. Funny that.

You call steviepinhead's "take the kids to a beach" posting a trashing? Blimey... you got it b-a-a-a-a-d!

Algis Kuliukas

[AlgisKuliukas]

Algis:

[Why can't we just stick to the topic and cut out all the personal stuff?

Because you continue to display, over and over, the greatest difficulty in distinguishing legitimate debate over your conjectures from sneers and insults directed at you personally.

We all appreciate that it is difficult to dispassionately observe the virtual dismemberment of our brain-children.

But please try to remember, however great your investment of time and energy into this particular brain-child, it is not your real child, nor is it you, the person, who is being attacked.

Your achieving that appreciation would do more to swerve this ongoing train-wreck back on the rails than any other single thing, and much more than any number of whinges to moderators.

I can discriminate between criticisms of the idea and a babble of newsgroup bullies queueing up to take turns at thinking of clever new alternative meanings for a wittily rearranged acronym of my model.

I do not take offence at the former. I do take offence at the latter.

It might help for a better debate if you tried to see a distinction between these too.

Algis Kuliukas

[Steviepinhead]

If you seriously think you can be "bullied" on an internet forum, Algis, then you had a far luckier childhood than did most of us.

Please write again, as soon as you get over yourself.

[Steviepinhead]

... some scientific critique that. I wonder if PZ Myers has even read it. It slags of [sic] the aquatic ape so who cares, right?

Are you banned at Pharyngula ? Why not just hop over there and ask him, instead of using of voicing that underhanded speculation ?

I am not banned anywhere, hotshoe - much as you'd apparently like to change that.

I did go there and post a direct question to him and replies to others.

http://scienceblogs.com/pharyngula/2009 ... e_hypo.php

He didn't reply so I sent him a direct e-mail asking him personally... no reply.

What a surprise.

I see your argument is being trashed there too Algis. Funny that.

You call steviepinhead's "take the kids to a beach" posting a trashing? Blimey... you got it b-a-a-a-a-d!

Algis Kuliukas

Someday, maybe you'll even learn to read time-stamps, Algis.

[AlgisKuliukas]

I have read "Darwin's Dangerous Idea." It's a worthwhile and interesting exercise in explaining the power of Natural Selection. It says nothing which takes away from the power of genetic drift.

At this point I'll merely defer to mjpam, who knows a good deal more about the mathematics of population genetics than you have shown here (or than, apparently, Dawkins has shown in some of his popular writings, which for some reason you treat as a primary source):

Another issue is that, while Dawkins is correct that natural selection would not occur if there were no bias in the probabilities with respect to phenotype, he has also claimed that evolution would not occur if there were no bias in the probabilities of reproduction with respect to phenotype, which is flat out wrong. Evolution would occur through fixation of alleles through drift, which itself occurs with a probability equal to the initial frequency of the allele in the population. Since, in all but the smallest populations (N=1 for diploids and N=2 for haploids), the initial frequency of a novel mutation is less than .5, the probability of fixation is biased against the ultimate fixation of the allele. Furthermore, in the range of selection coefficients that most frequently occur in natural population, the probability of fixation is only ~.0000002 to ~.00002, which again means that the allele is 50000 to 5000000 time more likely to go extinct that be fixed. This means that it is only in fairly large populations that selection has any measurable effect, because it is only in large populations that the probability of being fixed by drift falls below the probability of being fixed by selection.

My bold. A redundnat "occur" in the next-to-last sentence deleted. What size do you hypothesize that the original population of wanna-be bipedal apes was, again, Algis?

So rather than cite from the literature, as I did, you cite from another posting on this forum. Mmm...

I don't want to criticise mjpam and have no idea how knowledgable he/she is on population genetics, although from what I've just read here, he/she seems to know more than most of the aquasceptics here.

The key statement, I think, is in saying that "it is only in large populations that the probability of being fixed by drift falls below the probability of being fixed by selection". This is essentially what I posted here weeks ago, with a formula... 1/2n (where n is the effective population size) This is the amount of selection needed to overcome drift.

Here's another citation (from the literature) which specifically makes that point...

“For the behaviour of mutant alleles to be mainly controlled by random drift, it is not necessary that be strictly neutral, that is, completely equivalent with respect to fitness. What is required is that the magnitude of their selective advantage or disadvantage, as measured by the selection coefficient, s, does not exceed, roughly speaking, the reciprocal of twice the effective population size: [s] < 1/2Ne.” Kimura (1983:43-44)

Kimura, M. (1983). The Neutral Theory of Molecular Evolution. Cambridge University Press (London)

I would contest what he/she means by "fairly large" though.

If the population was only 500, this means that the degree of selection needed for drift to be overcome was only 1/1000, or 0.1%.

I have no idea how big the population of early hominins was but, even assuming it was only similar to that of modern chimps/gorillas, you're talking about at least 100,000 or so. Even that minimum would suggest that the degree of selection required to overcome drift would be around 0.0005%.

Now I don't want to use emotive terms to describe numbers but, to me, that's tincy weensy!!

Now, what was your point again?

Algis Kuliukas

[Steviepinhead]

Point 1: in small populations, drift outperforms selection.

Point 2: the chimp genome contains much more variation than the human, thus (until the comparatively recent past) the human effective population size appears to have been smaller than that of the chimps. So if you take the past population of chimps to be 100,000, then the human population size is likely to have been much smaller, "bottle-necked," by comparison.

Point 3: but that's okay -- let's plug 100,000 into your simulator and see if you get the same numbers as mjpam did, eh?

Point 4: until you can explain why a presumptively-small population of African apes was much larger than anyone supposes, drift is likely to have been the more effective force compared with NS.

This raises any number of problems for even one of your claimed water-affected features, much less a dozen or thirty of them.

I'll post some wise words from Joe Thornton in a day or two.

Come up with any unique predictions to falsify your conjecture yet?

[AlgisKuliukas]

Algis:

The hymen argument and salt tears arguments were never more than tiny little side issues

How convenient!

It's a real advantage when a hypothesis makes no singular unique predictions, but instead makes a scatter-shot of thirty-plus claims. Whenever one of them doesn't work out, it can simply be tossed overboard without any admitted damage to the rest of the claims!

That you don't grasp why this is the "exact opposite" of parsimony (to steal a phrase of Dawkins's) is yet another reason why several of the CRAPs should not have been excised...

"scatter-shot" is only your spin on it.

The reality is there are four or five "big" claims and then ten or so others of dimninishing importance. It's interesting that Langdon's (1997) "refutation" used the same tactic you do here - to line them all up as equally important so that if a number of them can be shot down it kinda looks bad for the hypothesis. (Even Langdon admitted that 7 out of 26 were consistent with the hypothesis and this was, remember, a very exaggerated form of it - was there "an aquatic ape"? - in the true sense).

I've made predictions. I've pointed to a web page listing them...

http://www.riverapes.com/AAH/AAH_Def_Detail.htm

Now can you refer me to a similar page which lists testable predictions of any other model of human evolution? Can you even articulate in words what another model of human evolution is? I mean, I'm always being told off (by some, but not all) for referring to the savannah theory. That, Langdon would have us believe, was an invention by Elaine Morgan!

I'll repeat my promise to you guys... show me unequivocal evidence that chimpanzee infants are no less likely to survive near drowning situations than human infants and I'll drop this idea like a stone. I don't think that I can get any more clear cut than that.

I'm not sure how any idea of evolutionary biology could actually be falsified in the Popperian sense - even though that is what you seem to demand of me here - but that evidential point would falsify it for me.

Now can you offer a counter promise? I've asked this many times before but no-one, oddly, seems to want to participate. So who are the real pseudoscientists here?

Algis Kuliukas

[AlgisKuliukas]

Point 1: in small populations, drift outperforms selection.

You use vague terms like "small" and cite newsgroup postings, I quote formulae from the literature... 1/2n (where n is the effective population size). Therefore even if the population is 500 (very small) the selection coefficient need only by 0.1%. (quite small). If the population was 50,000 (moderately large) the selection coefficient need only by 0.001%. (tiny). So much for the drift idea.

Point 2: the chimp genome contains much more variation than the human, thus (until the comparatively recent past) the human effective population size appears to have been smaller than that of the chimps. So if you take the past population of chimps to be 100,000, then the human population size is likely to have been much smaller, "bottle-necked," by comparison.

Ok but how small is small? As far as i can tell no-one has ever suggested the bottleneck made the population less than 15,000 or so... do the maths... selection coefficient 0.0033% (tiny) So much for the drift idea.

Point 3: but that's okay -- let's plug 100,000 into your simulator and see if you get the same numbers as mjpam did, eh?

Of course it will. It's a standard algorithm.

Point 4: until you can explain why a presumptively-small population of African apes was much larger than anyone supposes, drift is likely to have been the more effective force compared with NS.

Nonsense. Do the maths and put the numbers in the formula rather than waffling on about vague terms like "small" and "larger."

Why are you so desperate to refute natural seelction as an explanation for the human phenotype?

Why don't you answer me this...

If random drift (and not natural selection) explains the unique human traits how come the features aren't spread evenly throughout the ape clade?

e.g. bonobos bipedal, gorillas with fat infants/mothers, naked chimps, orang utans with large brains, gibbons with voluntary breath control?

What is the probability that all of them happenned in our lineage only, and only due to drift?

So much for the drift idea.

This raises any number of problems for even one of your claimed water-affected features, much less a dozen or thirty of them.

The irony!!!

I'll post some wise words from Joe Thornton in a day or two.

Hopefully something from the literature, then, and not a newsgroup posting.

Come up with any unique predictions to falsify your conjecture yet?

Come up with any form of words that even describes an alternative idea in human evolution that two anthropologists might agree on yet?

Algis Kuliukas

[Steviepinhead]

We are not five-year-olds, Algis, playing "show me yours" in the back pantry. These are your claims which you have brought here for discussion. They stand or fall on their own merit, regardless of the strength of any competing claims.

However, none of your claims has remotely the accumulated, interlocking evidence of the claimed association between the reduced size of Homo teeth and jaw musculature (which would in turn allow for increased cranial development) with the exploitation of tools and cooking at the time of the Australopithecine to Homo transition. Actual butchering marks of tools on bones add together with the actual tools themselves with the observed reduction of tooth and jaw dimensions with the transition to a leaner, larger, longer-legged hominid with greater cranial capacity, with increased signs of innervation of the upper limbs, with adaptations for endurance running, with wrist and shoulder adaptations for tool use...

This time-and-place correlated evidence -- which OHSU went through for you exhaustively at least a couple of chapters ago -- far outweighs any comparable evidence for the "coastal people," with its vague attributions of dates, places, and refuted predictions re dentition and jaw musculature.

We'll go through your claimed list of "predictions" some other time (din-din calls my slimmed-down choppers to a munch-fest), though I seem to remember that we've covered that ground before without profit for the WHHE...

[protoart]

Here is this statement, Algis:
As the environment changes, you can only have micro-evolutionary adaptations if the period of the change is much greater than the life span of the species.
When you understand this, you will understand why you are dead wrong!
Edit: Maybe you should ask someone else in your college the ramifications of this statement.

But the period of change IS much greater than the life span of the species. Of course it is.
What did you think I thought evolution was working at the level of a single wet season?

Oh yes you did, you repeatedly used an annual flood. Don't make me call you a liar, something I have never done.

Potts has shown that there were distinct "wetter" phases followed by distinct "drieer" phases. During the wetter phases (lasting thousands of years) some gallery forests would have been permanently flooded but the general condition of those niches would have been more on the 'wet' side.

You are confusing phase with rate of change. There are many many species that are extinct because they couldn't adapt as fast as the change in their environment (all kinds).

How does this show that I'm "dead wrong" protart?

It's "protoart".
I (the concensus) have the gradual encroachment of the grasslands over millennia. You propose floods within a generation. Do you not understand my point?

Algis, let me back away from "death knell" , "dead wrong" and "devastating" for a moment. If Ar. kadabba is a BK walker, there is a teeny-tiny chance that it waded and improved its gait in water. It first had to get to the water, of course. And I still think that the split was driven by bipedality to survive between trees that it could not do through the canopy. Can we reconcile the difference for a few hundred posts, at least?

[Steviepinhead]

I haven't used vague terms like small and large, Mr. "teensy weensy"! I've taken your number of 100,000 and mjpam's rather explicit calculations. Fifteen thousand is much less than 100,000. Don't just talk about a "standard algorithm." It's your borrowed simulation. Plug in the numbers and show your work. Justify the assumptions of selection values for some given claimed phenotypic adaptation. Tell us why that selection hasn't kept operating over time. Explain why, if it ever operated, it hasn't been reversed or overwhelmed by stronger drift in small populations and stronger terrestrial selection in larger ones.

I don't have any problem with a plausible selection pressure for a plausibly-water-related advantage. You have yet to produce evidence which would back up even a good story, much less fill in the variables in a population genetics formula.

Yawn. Stomach rumble. Nighty-night.

[AlgisKuliukas]

We are not five-year-olds, Algis, playing "show me yours" in the back pantry. These are your claims which you have brought here for discussion. They stand or fall on their own merit, regardless of the strenght of any competing claims.

Yeah, yeah... so you keep telling me. Unfortunately there are only a limited number of competing hypotheses to explain human evolution. This is not maths or physics.

The fact that the best you seem to be able to come up with, as an alternative explanation, is drift - just shows the paucity of ideas in the field. How apalling is that? 150 years after Darwin and the best answer we can give to people who ask 'why are we so different from the apes' is "we don't know, it was probably just random drift."

However, none of your claims has remotely the accumulated, interlocking evidence of the claimed association between the reduced size of Homo teeth and jaw musculature (which would in turn allow for increased cranial development) with the exploitation of tools and cooking at the time of the Australopithecine to Homo transition. Actual butchering marks of tools on bones add together with the actual tools themselves with the observed reduction of tooth and jaw dimensions with the transition to a leaner, larger, longer-legged hominid with greater cranial capacity, with increased signs of innervation of the upper limbs, with adaptations for endurance running, with wrist and shoulder adaptations for tool use...

This time-and-place correlated evidence -- which OHSU went through for your exhaustively at least a couple of chapters ago -- far outweighs any comparable evidence for the "coastal people," with its vague assignations of dates, places, and refuted predictions re dentition and jaw musculature.

That is a matter of opinion. How does OHSU explain our improved swimming/diving ability? Our bipedalism? Our fat intants/mothers? Our voluntary breath control? Our olfactory reduction? Our nakedness?

You're clutching at straws by trying to sound technical. Nothing OHSU said contradicted the coastal model in the slightest. If dental reduction might be explained by a switch to eating more red meat, how much better to posit a diet that included even softer foods too?

The only real problem with the "Coastal People" model is clear unequivocal evidence showing early Homo procurement of shellfish on oceanic shores at around 2.6Ma. I will concede you that much. However, absence of evidence is, as we are often told (as long as the dreaded 'a' factor isn't involved, of course) is not evidence of absence.

However, even here, there's reasonably good evidence that early Homo, living by rift valley lakes, did procure fish.

While research into the diet and susistence of early hominids has focused primarily on medium to large mamals, modern ethnographic and dietary evidence suggests that other food sources are of equal or greater importance in hunter-gatherer diets, particularly in seasonally stressful times of year. Fish is examined in this paper as an alternative food source for early hominids. Nutritional, ecological and ethnographic evidence indicates that fish would be a seasonally available, nutritious and easy to procure alternative food source for early hominids, particularly during periods when other food sources may be of poor quality. Carnivours and non-human primates rely on fish as a seasonal resource, and archaelogical findings also document the importnace of fish for Late Pliestocene hominid groups. Fish remains associated with many early hominid sites, and five sites at Olduvai Gorge are examined here in detial. The patterns of fish exploitation seen in Late Pleistocene archeological sites are manifested in three of the Olduvai Gorge sites, making a strong, although not absolute, case for early hominid fish procurement. The implications for early hominid behaviour of fish procurement are several, and include timing of the early hominid seasonal round to exploit spawning or stranded fish, and group size larger than the family unit, with greater social interaction. Further investigation must also be conducted on the possible differences in procurement strategy between the hominid species at FLKNN (Homo habilis) and BK (presumed Homo erectus.)

Stewart, Kathlyn M (1994). Early hominid utilisation of fish resources and implications for seasonality and behaviour.. Journal of Human Evolution Vol:27 Pages:229-245

Algis Kuliukas

[AlgisKuliukas]

Here is this statement, Algis:
As the environment changes, you can only have micro-evolutionary adaptations if the period of the change is much greater than the life span of the species.
When you understand this, you will understand why you are dead wrong!
Edit: Maybe you should ask someone else in your college the ramifications of this statement.

But the period of change IS much greater than the life span of the species. Of course it is.
What did you think I thought evolution was working at the level of a single wet season?

Oh yes you did, you repeatedly used an annual flood. Don't make me call you a liar, something I have never done.

Then you completely misunderstood my point. I'll assume that you didn't do this deliberately and that it was me who didn't explain it clear enough.

Let me try to be more expicit: I'm not suggesting that sufficient "death by drowning" occurred to a sufficient degree to have cause enough selection to encourage bipedalissm in a single rainy season. I'm assuming that in a typical life span of an early hominin - say 20 years - it would experience several such wet seasons, say twice a year. Each one would provide it with a compelling reason to move through shallow water, each one would provide a small additional risk of death, (e.g. from drowning, croc predation etc). This is the raw material on which Darwinian natural selection would work. Throughout their lives some would not make it through to adulhood to pass on their genes because of this additional component in their lives of movingg through water (a component that I assume chimps ancestors lacked or at least had significiantly less of). Even if the amount of selection was tiny (let's say 0.05% pressure for a set of alleles that made wading better) as long as the population was at least 1,000 this would be more thana enough for traits conducive for bipedalism to have been encouraged.

What's your problem with that?

Potts has shown that there were distinct "wetter" phases followed by distinct "drieer" phases. During the wetter phases (lasting thousands of years) some gallery forests would have been permanently flooded but the general condition of those niches would have been more on the 'wet' side.

You are confusing phase with rate of change. There are many many species that are extinct because they couldn't adapt as fast as the change in their environment (all kinds).

How does this show that I'm "dead wrong" protart?

It's "protoart".
I (the concensus) have the gradual encroachment of the grasslands over millennia. You propose floods within a generation. Do you not understand my point?

I understand how you have missed my point. See above.

Algis, let me back away from "death knell" , "dead wrong" and "devastating" for a moment. If Ar. kadabba is a BK walker, there is a teeny-tiny chance that it waded and improved its gait in water. It first had to get to the water, of course. And I still think that the split was driven by bipedality to survive between trees that it could not do through the canopy. Can we reconcile the difference for a few hundred posts, at least?

Well that's good. All I'm really suggesting is that, at the very least, adding a wading component can only help explain bipedal origins. I'm not arguing that other factors (e.g. carrying, throwing, energy efficiency etc ) weren't involved too, just that wading is the most clear cut scenario to indice bipedalism in the first place and to cushion against the prohibitive costs in its early evolution.

Algis Kuliukas

[eversbane]

I think this all started when I pointed out to Algis that his wading experiment demonstrated that he was putting his hominid ancestors into a context where drift was his only option, as far as selection for gait while wading. His vigorous defense of selection, beginning with the infamous "drift is just above creationism" sparked the on-going issue concerning drift vs. selection. Looking at his latest paper, he seems to have reinforced the neutralization of selection on gait while wading. We're right back where we started with Algis claiming selection but demonstrating drift. I'm not sure where to go from there.

Still flogging that dead horse I see.

How on earth do you imagine reducing the cost differential between non-optimal and optimal gaits (in water) is indicative that drift was the only option? This is just trolling. It's just repeatedly writing stuff that I've retorted before that is provocative because you know doing so gets me irritated.

There are two big unanswered questions about hominin bipedalism:

1) What compelled the apes to start moving bipedally in the first place? and
2) In what scenario could bipedalism have been adapative even before the antomical traits evolved to make it efficient?

Wading answers both easily. My studies provide new empircle data in support of them.

I must have answered your facile point a dozen times but let me do so here again.

If I were suggesting that hominins only ever moved through chest deep water (the depth at which the cost differential is removed) and no other depth at all, eversbane might start to have a point - until, of course one remembers that moving through water up to the chest is likely to place a heap of other selection pressures (i.e. having longer legs, more vertically orientated lower back, more plantigrade foot etc. - to avoid drowning) onto the individual.

At shallower depths, the cost differential is not eliminated but reduced. It therefore provides a rather elegant evolutionary gradient towards fully upright bipedalism on dry land - the shallower the water, the more like dry land it is. This is usually the sort of smooth evolutionary gradient that Darwinists find satisfying. Of course, if it might hint, imply, suggest that Hardy might have been right the very notion that it might be useful must be questioned.

Arguing that only more extreme differential can offer selection is just not Darwinian. So, presumably, you'd argue that for flight to have evolved the very first flying therapods couldn't have done anything intermediate, or if they did it would eliminate natrural selection as a possible explanation for it.

Where we go from here, I suspect, is that the nay sayers will continue to ignore the evidence like creationists but, maybe, a few people who are little more open minded will start to see that WHHE are actually really helpful in explaning the human condition. You never know, if they really get enlightened they might start to agree that it's the best idea specifically about human evolution sincce Darwin.

On that topic, by the way, have even thought of a single other idea that you think's "ok" yet?

Wow! That demon has really got you blinded Algis! You have twice now demonstrated the inverse gradient of efficiency by gait with respect to water depth. Congratulations! But the final finding relates that gradient to a risk of drowning. What is the gradient of risk of drowning with respect to water depth, and how does that relate to the inverse gradient of gait efficiency? Lets go through this step by step.

The basic premise revolves around the efficiency differential between gait phenotypes. It is proposed that on land this efficiency differential is effectively a road block to fixation of intermediate gait phenotypes due to a greater cost in efficiency. But the selection that Algis proposes is related to drowning. So, with respect to drowning, what is the gradient on risk of drowning with respect to water depth?

Land:
On land, obviously, the risk of drowning is zero. Thus there is no selection on gait phenotype with respect to risk of drowning on land. The presumed cost differential is maximal on land.

Shallow Water:
The risk of drowning in shallow water is greater than on land (i. e. greater than zero) but not as great as say a depth equal to the level of the waist, and certainly much less than at greater depths such as at the level of the xithisternum. Meanwhile, the efficiency differential in shallow water is reduced relative to land. Thus, while there is some risk of drowning in shallow water, there is likewise reduced selective advantage between gait phenotypes.

Moderate Depth (waist):
The risk of drowning is increased over shallow water, presumably becoming critical for quadrupeds. Meanwhile, again, the efficiency differential is further reduced, thus reducing even further the selective advantage between the gait phenotypes.

Xithisternum Depth:
The risk of drowning is near maximal at this point (maximal being submersion of the airways one would presume). Alas, at precisely this point the efficiency differential goes to zero. Thus, just before drowning becomes a really serious problem the selective advantage between gait phenotypes disapears. The consequence is that risk of drowning is inversely related to selective advantage on gait phenotype. In short, no matter how many drown (and surely the majority of drownings would occur in deeper waters) there is no significant selection on gait phenotype. Drowning risk simply does not matter at the most critical water depths.

The only way to get this to work for selection on gait phenotype is to address that narrow depth range from shallow to moderate, where the risk of drowning begins to increase and before the efficiency differential becomes too small. Thus, only drownings within that narrow depth range are significant to the hypothesis. Any shallower and the efficiency differential is still too great: any deeper and there is no significant selective advantage.

It is nice to see this latest study replicate the earlier findings. That is a nice piece of science as the ability to replicate the neutralization of selection on gait phenotype with respect to wading effectively eliminates wading as a potential cause of bipedality. That is a great advancement in the field as it frees up other investigators to pursue other potential causes without having to consider wading. Good job!

[eversbane]

In some contexts fossils of the hominid species in question were found with fossils of recognized terrestrial taxa and with fossils of recognized aquatic taxa.
In other contexts fossils of the hominid species in question were found with fossils of recognized terrestrial taxa and no fossils of recognized aquatic taxa.
In no context has a fossil of a hominid species been found with fossils of recognized aquatic taxa and no fossils of recognized terrestrial taxa.

From these finding, what can one say about the hominid species in question?

One can say that human ancestors were never aquatic. But who ever said they were?

Haven't you been listening to ANYTHING? Here we are 6.5k posts on and you still think I'm proposing an aquatic ape? What a complete waste of time!!

Your posting evidences a strong perceptual demon, Algis. No where in there did I use the phrase "aquatic ape."


So... How much water related selection do you propose for those taxa recognized as terrestrial? They were found in the same context as the hominid in question. They should share some of the same water related selection. What percent aquatic are they? How would you go about confirming their aquaticness? What features do they share with the hominid in question that confirms water related selection?

[eversbane]

Ouch. Complexity is not a goal of evolution. It's not even a particularly strong trend. Most of the biomass on the planet remains relatively uncomplex.

Done any biochemistry? Tell me how even the simplest bacterial metabolism can be described as anything but complex? The amazing biochemical complexity - e.g. of DNA packaging/replication/transcription - must have evolved long before even the most basic eukaryotes arrived on the scene. So much for that idea.

What percentage of the Earth's biomass is unicellular?

OTOH, as far as the existing complexities of lifeforms goes, it is probably safe to assume that most of the complexity that does exist did result from selection,

Well that's good, eversbane. Something we can agree on at last.

This point was never disputed in this thread.

but that does not address the issue that your experiments demonstrate that hominids in water experience no selection on gait phenotype. This whole drift discussion arose from your failure to address this issue and your latest work only reinforces the issue. What you described just a post or two above about the results of your experiment is a setting of drift on gait phenotype. I have no problem with that, but you seem to have a huge problem with that: especially since you seem to fail to recognize the fact.

Note "no selection" - a complete distortion of my results. Only at chest deep water was there no differential in the cost of locomotion between two gaits - but even this still ignores completely all the other aspects of potential selection that would be working on hominins that moves chest deep in water.

Reference my previous response detailing why there is no selection on gait while wading. In summary: In shallow water, where the risk of drowning is least, the efficiency differential is still in effect, thus no selection for the intermediate gait. In deeper water, while the risk of drowning increases, the efficiency differential is reduced: eventually - at the greatest risk of drowning - to zero. Thus, no selection between gaits. Hence, the only reasonable chance for fixation of the intermediate gait while wading is through drift.

I would also remind people - for what it's worth - that no-one else, none of the co-authors of the paper, none of the lecturers at UWA who read the paper, none of the biologists elsewhere I asked to proof read the paper, none of the editors of the six journals I sumbmitted it to, none of the referees who rejected the paper or the ones that thought it should be published, voiced this concern.

What does that tell you? It tells me (a) eversbane knows almost nothing about evolutionary biology and (b) his motives for repeatedly dragging this up are more to do with trolling - trying to annoy me into writing something I shouldn't - than anything vaguely scientific or rational.

The only things we know for truth, Algis, are what is published. If you wish to discuss the comments of others you will need to publish them, first. You could publish them here. That would actually be greatly appreciated by all.

[eversbane]

I think this all started when I pointed out to Algis that his wading experiment demonstrated that he was putting his hominid ancestors into a context where drift was his only option, as far as selection for gait while wading. His vigorous defense of selection, beginning with the infamous "drift is just above creationism" sparked the on-going issue concerning drift vs. selection. Looking at his latest paper, he seems to have reinforced the neutralization of selection on gait while wading. We're right back where we started with Algis claiming selection but demonstrating drift. I'm not sure where to go from there.

Still flogging that dead horse I see.

Still missing the point, I see.

How on earth do you imagine reducing the cost differential between non-optimal and optimal gaits (in water) is indicative that drift was the only option?

That's pretty much a definition of drift. No cost differential = no selective advantage.

This is just trolling. It's just repeatedly writing stuff that I've retorted before that is provocative because you know doing so gets me irritated.

I could not care in the least how irritated you might be at any given moment. As long as you continue to misrepresent selection and drift, I will continue to point out the error of your ways.

There are two big unanswered questions about hominin bipedalism:

1) What compelled the apes to start moving bipedally in the first place?

A very dangerous adaptationist presumption.

and
2) In what scenario could bipedalism have been adapative even before the antomical traits evolved to make it efficient?

More Lamarkian Practice Effect.

Wading answers both easily. My studies provide new empircle data in support of them.

I must have answered your facile point a dozen times but let me do so here again.

If I were suggesting that hominins only ever moved through chest deep water (the depth at which the cost differential is removed) and no other depth at all, eversbane might start to have a point

Actually, at shallower depths the efficiency differential is still in effect, so the depth of the water is actually irrelevant. At shallower depths adaptation of the intermediate gait is 'blocked' by the efficiency cost: in deeper water there is no selective advantage on gait.

- until, of course one remembers that moving through water up to the chest is likely to place a heap of other selection pressures (i.e. having longer legs, more vertically orientated lower back, more plantigrade foot etc. - to avoid drowning) onto the individual.

Remember the efficiency differential. It is in effect in shallower water. And the risk of drowning in shallower water is not significant. So... none of these adaptations will be selected.

At shallower depths, the cost differential is not eliminated but reduced.

And thus, the intermediate gait will not be selected.

It therefore provides a rather elegant evolutionary gradient towards fully upright bipedalism on dry land - the shallower the water, the more like dry land it is.

You mean the greater the efficiency differential. Remember that it is the efficiency cost that is blocking the adaptation to the intermediate gait.

This is usually the sort of smooth evolutionary gradient that Darwinists find satisfying.

This is your patented Default Darwinian Assumption^TM again. In actuality there is no gradient of selection for the intermediate gait. There is selection against the intermediate gait until there is no selective advantage between gaits. I might could give you (as I indicated previously) a very narrow depth between shallow and waist deep, but really... how significant is that?

Of course, if it might hint, imply, suggest that Hardy might have been right the very notion that it might be useful must be questioned.

Hardy was never right. How is drawing congruencies between humans and seals, or otter, or whales right?

Arguing that only more extreme differential can offer selection is just not Darwinian.

Well, the strong efficiency differential on land selects against the intermediate gait. Isn't that the argument?

So, presumably, you'd argue that for flight to have evolved the very first flying therapods couldn't have done anything intermediate, or if they did it would eliminate natrural selection as a possible explanation for it.

I didn't eliminate selection!!! You did!! With your experiments! Your experiments demonstrate that drift is the only reasonable explanation for wading >>> bipedalism. That was your work. And a golly good job you did of it. Congratulations!

Where we go from here, I suspect, is that the nay sayers will continue to ignore the evidence

What evidence?

like creationists

It is the creationists who don't have evidence - much like the AAT/H/WHHE. No evidence.

but, maybe, a few people who are little more open minded will start to see that WHHE are actually really helpful in explaning the human condition. You never know, if they really get enlightened they might start to agree that it's the best idea specifically about human evolution sincce Darwin.

Enlightened!? Oh, dear. Is that what it takes?! And all this time I've been putting my stakes on science.

On that topic, by the way, have even thought of a single other idea that you think's "ok" yet?

The thread topic is WHHE, Algis. Stay on topic.

[eversbane]

... some scientific critique that. I wonder if PZ Myers has even read it. It slags of [sic] the aquatic ape so who cares, right?

Are you banned at Pharyngula ? Why not just hop over there and ask him, instead of using of voicing that underhanded speculation ?

I am not banned anywhere, hotshoe - much as you'd apparently like to change that.

I did go there and post a direct question to him and replies to others.

http://scienceblogs.com/pharyngula/2009 ... e_hypo.php

He didn't reply so I sent him a direct e-mail asking him personally... no reply.

What a surprise.

I see your argument is being trashed there too Algis. Funny that.

From the link:

Quick! Someone give Jim Moore an honorary degree in evolutionary biology and settle the question.

[eversbane]

Algis, let me back away from "death knell" , "dead wrong" and "devastating" for a moment. If Ar. kadabba is a BK walker, there is a teeny-tiny chance that it waded and improved its gait in water. It first had to get to the water, of course. And I still think that the split was driven by bipedality to survive between trees that it could not do through the canopy. Can we reconcile the difference for a few hundred posts, at least?

Orrorin was a fully obligate biped. Ardi is a fully obligate biped. Why would Ar. kadabba not be also?

What standard of 'optimal' are we using here? That of anotomically modern humans? Is any species' adaptations not optimal for that species? In what way was the gait of Ar. kadabba not optimal for Ar. kadabba?

This kind of talk is based on the adaptationist misconception that the primitive condition 'needs' to be adapted somehow to the 'more optimal' modern condition. This misconception of evolutionary mechanics leads to all kinds of storytelling: all without evidential support.

Also, Algis' experiments have demonstrated that wading would not select for an intermediate gait with a higher efficiency cost: so, no 'improved its gait in water'.

[DavidMcC]

This kind of talk is based on the adaptationist misconception that the primitive condition 'needs' to be adapted somehow to the 'more optimal' modern condition. This misconception of evolutionary mechanics leads to all kinds of storytelling: all without evidential support.

You apparently have a misconception of how evoutioon by RM & NS. The meaning of "need" in this context is that if an individual happens to acquire a beneficial mutation, then it as if the others (lacking it) would "need" that to compete in the long run. Of course, it is only their descendants that actually have that possibility.

[Debbygt]

Thank you to all who replied to my post. I realise I did sound very school ma'amish, an unfortunate side effect from dealing with primary school children at work, so I apologise for that. I also apologise that as a newbie I am finding it hard to pull quotes out from any but the last page of the thread. I certainly am not expecting any of you to waste valuable time on telling me how, I am sure if I look hard enough there will be a 'how to' thread somewhere on the website.

Algis thank you very much for posting all the links to relevent literature, I will really enjoy reading them. I have visited many of the web links in the past and I am lucky enough to have been given 'The Aquatic Ape: fact or fiction?" which I have just pulled out again and will reread. I would just like to point out to those who may not have had an opportunity to read this book that it contains scientific evaluations for and against the aquatic ape theory. Thank you as well for posting the main points of your argument, I realise that you have done so many times before.

Ericv00, thank you for replying as well. I have followed the posts over the last year since I found this website. I can see that at the beginning of this thread (October 2008) all participants were remarkably civil to each other, just a shame that this civility has all but disappeared. Your posts were very civil and open minded then. But from quite early on into the thread (January 2009) another poster Eversbane has regularly attached a quote on his posts to this thread which appear to be credited to you "Continuously Regurgitated Aquatic Pseudoscience.- EricV00" I don't know where this quote comes from and sincere apologies if you did not come up with phrase but if you did then I think you may have to admit to just a smattering of bias from the beginning.

I will now go back to quietly reading the posts some of which I find very interesting. I really can't offer anything to the debate as my knowledge of the subject is not up to it so I won't be posting again and probably shouldn't have posted in the first place. I was just hoping that some of the posters here who are particularly vitriolic towards Algis might be prompted to evaluate their behaviour
DG

[gib]

... some scientific critique that. I wonder if PZ Myers has even read it. It slags of [sic] the aquatic ape so who cares, right?

Are you banned at Pharyngula ? Why not just hop over there and ask him, instead of using of voicing that underhanded speculation ?

I am not banned anywhere, hotshoe - much as you'd apparently like to change that.

I did go there and post a direct question to him and replies to others.

http://scienceblogs.com/pharyngula/2009 ... e_hypo.php

He didn't reply so I sent him a direct e-mail asking him personally... no reply.

What a surprise.

I see your argument is being trashed there too Algis. Funny that.

You call steviepinhead's "take the kids to a beach" posting a trashing? Blimey... you got it b-a-a-a-a-d!

Sorry i wasn't clear. Although Stevie's post was excellent, i was actually referring to the comments thread over at Pharyngula.