Evolution: Two Intriguing Lamarckian Experiments

Factual Questions
1

Experiment 1:

About 60 years ago Harry Schroeder performed an experiment on willow-moth caterpillars. At pupation these caterpillars crawl onto leaves, pull the tips over, then wrap the rest of the leaves around themselves.

Schroeder waited until the caterpillars were on the leaves before cutting the tips of the leaves off. The caterpillars responded by using the sides instead. Pupation continued normally thereafter.

When the time to pupate arrived for the subsequent generation 4 of the 19 offspring used the sides of the leaves in preference to the tips.

Experiment 2:

Some time ago Frederick Griffiths performed an experiment on rats whereby they were placed on slowly revolving turntables for periods of up to 18 months or so.

When the rats were removed from the turntables their heads continued to flick in the direction of rotation and so did their eyes. This automatic flickering then appeared in their offspring.
Comment: Imagine the experiment on the caterpillars being repeated along with a control group whose leaves were not altered: If it were found that genetic changes only occurred in the group with tipless leaves then this would begin to indicate that the change in behaviour wasn`t due to chance mutations.

Repeat the experiment often enough, and if the results were consistent, it would soon be statistically impossible for random mutations to be a factor.

The second experiment, though appalling, also had a potential: If it had been continued then grotesque structural changes similar to those found in flatfish might have occured.

The results of both experiments are of personal interest because they would be consistent with the existence of an internal evolutionary mechanism based on an extension to homeostasis.

References to these experiments are to be found in “The Great Evolution Mystery” by Gordon Rattray Taylor (Secker & Warburg, London). If any Reader knows the location of the primary sources of these, or similar, experiments it would be greatly appreciated.

Jorolat

2

What springs to mind is the work of Tracy M Sonneborn.

My knowledge of biology is limited, but more information can be found in the chapter from which I quoted.

Interestingly enough, Annals of Improbable Research (a rather funny “joke” journal) noted this as well, but prefaced that the column was “not necessarily humorous.” That can be found here.

3

Experiment #3. Will continual posts to the wrong forum change Manhatten’s behavior? :slight_smile:

4

Experiment #3 (ongoing):

  1. Take an ethnic group (say Jewish).
  2. Circumcise them just after birth.
  3. Repeat for 5000 years.

And that’s why Jews no longer have to be circumcized.

No, wait . . .

5

[angry southwestern furniture store owner]Yeah, and if a frog had wings he wouldn’t bump his ass a hoppin’![/angry southwestern furniture store owner]

Lots of badly controlled experiments produce intriguing results. There are many if’s and woulds in your commentary. Interesting as the studies you cite are, I don’t see how they support a case for Lamarkianism. Have either been replicated?

6

Hi Short,

Thank you for your reply. I am currently researching the possibility of an internal evolutionary mechanism. The two experiments referred to in the original post appear to meet the mechanism’s associated “method of testing” and hence my interest in their original sources.

Both of your links provide are interesting, however, and Sonneborn’s work on stenostomun and the paracecium may be relevant to how the proposed mechanism works in simpler critters.

Jorolat

7

I am new to “straightdope”, would the original post have been better suited to another forum?.

Jorolat

8

Suggested change to experiment #2:
Have the baby rats raised by other rats who have not been screwed up.

I imagine that when growing up if my mom and dad were constantly shaking their heads and eyes that I’d begin to do it to.

9

Inflicting physical trauma on successive generations of any organism proves nothing beyond how potentially dangerous a detached intellect can be to natural life.

I do not mean this in a personal way, just stating a fact.

To test a homeostatic mechanism it is necessary to fine tune the degree of “stress” an organism is subjected to because physical trauma, generally speaking, would tend to be outside the “recapture range”.

Jorolat

10

It is the potential of the experiments to illustrate a method of testing for a proposed internal evolutionary mechanism that I am in interested in.

Unfortunately I have only been able to find secondary sources so far and have little information beyond that given in the original post.

Jorolat

11

The second generation rats could have been born with:

a) No change in behaviour
b) Heads flickering only
c) Eyes flickering only

They were, in fact, born with both head and eyes flickering. The emphasis is on the “born”.

Jorolat

12 
I think the fact that these experiments haven't been repeated in a controlled fashion is almost a statement in itself. In fact, I think these experiments have been performed, but didn't show the changes hoped for. (Think Duesberg & AIDS, or Lamark himself, or cold fusion, or **Choosybeggar's** PhD work.:))

PosterChild

13

The fact that you haven’t been able to find primary sources in peer-reviewed journals should perhaps indicate to you that these studies were not legitimate, respected, accepted, and/or repeatable.

Granted, your summaries of said experiments were brief, but I can find several obvious flaws with the conclusions drawn from them, to wit:

Four out of 19 in an experiment run only once is hardly conclusive, and is barely even enough to justify speculation. This is especially a problem when it is not stated what numbers, if any, of the parent population displayed this behavior. My guess would be that some number of this species ALWAYS display this behavior.

While in your last post you do add that they were “born” this way, your initial post merely described that the offspring exibited this behavior. douglips was fully justified in that the offspring aquired this behavior through observation and mimicry.

These claims are further hard to accept when – although you have mentioned an unspecified mechanism several times – we are not presented with any conceivable mechanism by which these processes could be achieved. Darwinian selection has a simple and observable mechanism by which it is carried out, but I do not see how that could be the case with your examples.

Also, RealityChucks example – along with the classic example of successive generations of rats subjected to removal of the tail – seems to be clear evidence against Lamarckianism. If for 5000 years the foreskin of all males has been removed at birth, why ARE they still born with foreskin? Your refutation smacks of arbitrary dismissal. “Just stating a fact” how? Why is physical trauma inflicted in a consistant manner not stimulus enough to cause the Lamarckian effects you are claiming? Please make a logical argument for this rather than just dismissing a reasonable criticism with personal attacks.

-b

14

These experiments were performed some time ago and I feel the reason they surface from time to time (on newsgroups etc.) is because some people intuitively recognize they have a potential significance but do not know what it is.

From my perspective they appear to relevant to the evolutionary mechanism I am interested in but finding the primary sources may prove that this is not so.

If I had the resources I would be tempted to repeat the experiment with the caterpillars but on the other hand I could constuct experiments for any number of different organisms.

My area of interest is still developing and at this point in time it would simply be nice to be able to say “these experiments inadvertently met the criteria for the proposed method of testing” with more certainty.

I feel many people believe in the theory of evolution in the same way that they once believed the earth revolved around the sun: It is what they have been conditioned with and to such an extent that the capability for original thought is impaired.

This results in any new proposal being met with a negative knee-jerk reaction as dogma (which they can never know for themselves anyway) is regurgitated.

I believe that evolution has occured (and is occuring) but that it is natural rather than theoretical.
This means it must be entirely testable.

Jorolat

15

Interesting thread. Does anybody know if the experiments of Paul Kammerer (Austrian biologist) have evr been repeated? Supposedly, Kammerer was able to see changes in newts, which tended to support lamarkism.
I don’t know any more about this-Kammerer commited suicide, due to the discovery that some of his research had been faked!

16

Sure, the possibilities are intriguing, but one has to wonder why, if the experiments have merit, they haven’t been repeated extensively. I mean it’s not like were talking huge, multi-million dollar investments here: get some caterpillars, a few leaves, and some graph paper and you’re set! Or a few lab rats and a lazy susan.

Try going onto Science or Nature’s web site and entering “Lamarckianism” into the search engine.

And so many people believe in evolution because there is an entire mountain of observational evidence, lucid arguments, confirming experiments, and a reasonable mechanism behind it.

And which part of evolution, exactly, isn’t “entirely testable?”

-b

17

Rats are born in a very underdevolped state. Their eyes are neither open nor functional and they are inacapable of rapid movements of any part of the body. Whenever these animals began displaying these traits and for whatever reason they were definitely not born with them.

http://corbis.altavista.com/referrals/av_image_details.asp?linkid=2623&imageid=10929836

18

I am interested in what is real and would like to quote from an earlier reply:

"I feel many people believe in the theory of evolution in the same way that they once believed the earth revolved around the sun: It is what they have been conditioned with and to such an extent that the capability for original thought is impaired.

This results in any new proposal being met with a negative knee-jerk reaction as dogma (which they can never know for themselves anyway) is regurgitated."

"Four out of 19 in an experiment run only once is hardly conclusive, and is barely even enough to justify speculation."

Twenty percent is, I feel, enough to speculate upon particularly as reflected within the figure is the fact that life is individual. I do not know how many times the experiment was run.

"This is especially a problem when it is not stated what numbers, if any, of the parent population displayed this behavior."

This is one reason why I am looking for the primary sources.

"While in your last post you do add that they were “born” this way, your initial post merely described that the offspring exibited this behavior. douglips was fully justified in that the offspring aquired this behavior through observation and mimicry."

Of course he was and I corrected my omission.

"These claims are further hard to accept when – although you have mentioned an unspecified mechanism several times – we are not presented with any conceivable mechanism by which these processes could be achieved."

The appended url (Model of an Internal Evolutionary Mechanism) describes such a mechanism.

"Darwinian selection has a simple and observable mechanism by which it is carried out, but I do not see how that could be the case with your examples."

This is a quote from “Is Evolution A God?” (New York Times Abuzz Forum http://www.abuzz.com/interaction/s.156078/discussion/):

*When reading books or articles on evolution phrases such as “Evolution does this” and “Natural Selection does that” often occur usually giving no cause for comment.

Sometimes, however, the distinct impression is gained that the author is using the words “Evolution” and “Natural Selection” in the sense of their being Entities that act on natural life without being part of it.

The apparent conclusion is that these individuals are unconsciously using the terms as psychological alternatives to God - is this why arguments rage between(some) “Evolutionists” and (some) “Creationists”?.*

“Natural Selection” does not exist outside of the human intellect.

"Also, RealityChucks example – along with the classic example of successive generations of rats subjected to removal of the tail – seems to be clear evidence against Lamarckianism. If for 5000 years the foreskin of all males has been removed at birth, why ARE they still born with foreskin?."

A homeostatic mechanism “works” by integrating transient disruptions to the existing equilibrium over time. Once existing thresholds are exceeded evolutionary changes are then triggered in a direction that restores equilibrium. This brief description presumes that the disruptions are within the recapture range of the organism.

The barbarity of mutilation is largely “nonsensical” from this perspective - too “hit or miss”.

"just dismissing a reasonable criticism with personal attacks."

Um, I’m aware of saying things that people may not like but not of making personal attacks.

Jorolat

19

I still believe the earth revolves around the sun.

20

I do have a recollection of reading about Kammerer but whatever book it was in is not, unfortunately, immediately to hand. Thanks for reminding me of him though!.

A general impression I have of scientists such as Schroeder, Griffiths, Kammerer, and Cairns (“Directed Mutation”) etc., is that they intuitively constuct experiments that go beyond the expectations of theory.

Results are then obtained that within the current cultism can only be described as “Lamarckian”.

A personal perception of “Lamarckism” is it reflects the reality that life is individual while “Darwinism” (with it’s “Populations evolve, not individuals”) does not.

The next step from recognizing that life is individual is to look for an internal evolutionary mechanism that is testable.

If an internal evolutionary mechanism didn’t exist then the mechanism would have to be external making it supernatural and probably a God. Personally I think this is highly unlikely.

Jorolat