yes good day.

[kaberett]

I cannot tell if it's that I'm asleep, or that I'm Not A Biologist, or just that this paragraph (from The Challenge of Pain, Melzack & Wall) is actually very, but I am... struggling to persuade it to resolve into meaning:

Embryological and anatomical studies of fish, amphibians, and reptiles reveal that, even in the lowest vertebrates, reflexes are created by internuncial cells that link the sensory input to the motor output. During embryological development in these species, behaviour becomes increasingly a function of earlier sensory inputs as a result of the memory traces they have etched into the neural connections. Behaviour, then, is not merely the expression of a response to a stimulus, but a dynamic process comprising multiple interacting factors. Coghill (1929) was the first to propound this principle, based on his brilliant neuroembryological-behavioural studies of salamanders, which has been substantially confirmed by later investigators. Given this fundamental principle -- that organisms are not passive receivers manipulated by environmental inputs but act dynamically on those inputs so that behaviour becomes variable, unique and creative -- the remainder of evolution becomes comprehensible as a gradual development of mechanisms that make each new species increasingly independent of the push-and-pull of environmental circumstances.

Other than (but also, actually, in addition to) being sufficiently puzzled by this that I should definitely Go To Bed: I have caught up (mostly) on the PD e-mail. I completed one EYB indexing project and have been happily rolling around in making a start on the next. I made pastry, and used it as a prompt to unfuck the kitchen some, and then made progress on project Cook All The Things (From This One Book). I went on a Stupid Little Walk for my Stupid Mental Health. I am very very tired, and it has been a good day.

Comments

[redbird]

It made sense until the last sentence. I can sort of parse that last sentence, enough to suspect the author is wrong. I think they're saying something like, "behavior depends not just on the immediate environment and stimulus, but on the organism's previous experience throughout its life. Therefore, behavior is variable and creative, which [something something about new species being independent of environmental circumstances.]"

I don't know what the author means by species being independent of environmental circumstances. But I can't see how they get from the bit about previous experience, to _any_ assertion about a general difference between species and their descendants.

I am also dubious of "even in the lowest vertebrates."

[davidgillon]

Oof, that feels like three things smooshed together, or two and a reference:

Thing the first: Embryological and anatomical studies of fish, amphibians, and reptiles reveal that, even in the lowest vertebrates, reflexes are created by internuncial cells that link the sensory input to the motor output. During embryological development in these species, behaviour becomes increasingly a function of earlier sensory inputs as a result of the memory traces they have etched into the neural connections. Behaviour, then, is not merely the expression of a response to a stimulus, but a dynamic process comprising multiple interacting factors.

Thing the second/ref: Coghill (1929) was the first to propound this principle, based on his brilliant neuroembryological-behavioural studies of salamanders, which has been substantially confirmed by later investigators.

Thing the third: Given this fundamental principle -- that organisms are not passive receivers manipulated by environmental inputs but act dynamically on those inputs so that behaviour becomes variable, unique and creative -- the remainder of evolution becomes comprehensible as a gradual development of mechanisms that make each new species increasingly independent of the push-and-pull of environmental circumstances.

I'm pretty certain thing the first (animals are learning machines) does not imply thing the third. And I'm not sure thing the third is strictly compliant with traditional Darwinism, in fact if it tries to draw on thing the first then I think it has to count as Lamarckianism. OTOH I think I see what it's trying to say - that evolution favours traits that maximise adaptability, but OTGH there are a whole bunch of evolutionary specialisms that don't match that.

[fyreharper]

Admittedly I am also tired and underfed at present but yeah no that is a bit Very. :squinty-frowns at it:

[chiasmata]

I am absolutely with you on thing the first does not imply thing the third.

[aldabra]

Hello! I don't know whether you know Siderea here (she is entirely excellent but I have never met her in person). She has a question about DW posting (by e-mail, to a date in the past), and I think you are a Relevant Expert who may Just Know The Answer. In case you do and are moved to do a fly-past quick fix:

https://siderea.dreamwidth.org/1883618.html

[vass]

<3