Oolon Colluphid

Followers of this thread may be interested in this from Nature Science Update: <a href="http://www.nature.com/nsu/021028/021028-9.html" target="_blank">Grandpa's diet hits descendants: Effects of nutrition could be carried down generations</a>

<a href="http://www.nature.com/cgi-taf/DynaPage.taf?file=/ejhg/journal/v10/n11/abs/5200859ab.html&dynoptions=doi1036490371" target="_blank">Abstract of original article</a>.

Discuss.

Oolon

Peez

I really don't understand why you have your back up over this. I did not say that you are not competant to communicate, I did not even say that your were at fault for any difficulty in communicating. I merely pointed out that you were being arrogant to (apparently) assume that others were entirely at fault for not understanding you. It seems that you are taking anything less than a glowing endorsement of your position as a personal attack on you.

Peez

pz

There has been no such assumption on my part. Perhaps you ought to stop assuming my intent?
In this thread, I have so far been compared to three different creationists, and been accused of being condescending, abrasive, and arrogant. I have never expected "glowing endorsements" (and in fact rather enjoy a good argument over these ideas), but if you cannot see that there has been a consistent pattern of personal attack here, then I can finally see one point where the communication failure has occurred.

As far as I'm concerned, the discussion is no longer productive. Any attempt to discuss the idea that there is more to evolutionary biology than genes and changes in allele frequency seems to be dismissed by pigeonholing the heretic as a nasty creationist, and wrestling with that attitude while trying to discuss a complex idea is just too much.

KC

That is a damned good point. The Grants were able to show that prezygotic reproductive isolation in finch populations is driven primarily by ethological factors(the birds tend to mate with birds that resemble their parents). If, for the sake of argument, beak size was influenced only by environmental factors (I think the Grants did cite evidence, however, that beak size is highly heritable), then reproductive isolation could result between populations that were identical genetically for beak shape, yet morphologically distinct. That would be macroevolution by most standards.

Cheers,

KC

[ November 05, 2002: Message edited by: KCdgw ]</p>

Doubting Didymus

I am very dissapointed that such an interesting discussion should grind to a halt because of unrelated disagreements. Can't we put our differences behind us?

Doubting Didymus

One other thing: I am missing the presence of rufusatticus. You promised a reply, and I have been anxiously waiting.

RufusAtticus

Sorry DD, I appoligize for not geting back to you in a timly manner. I'm not avoiding this thread. I want to spend a good chunch of time on my next post in this thread. I haven't been able to find the time. Sorry about that.

Doubting Didymus

No worries.

RufusAtticus

Without further delay:

Doubting Didymus,

I understand what you are trying to say, but I think it can be phrased better.

• For evolution to have occurred as we know it, some units--heck most units--must be able to improve their replicability.

To clarify, I was specifically referring to biological species, i.e. (nearly) separate gene pools. You should remember that this is distinct from taxonomic species, i.e. to what we assign a name. Sure many biological species are distinct taxonomic species, but that is not always the case. I tend to not care about where/when we designate taxonomic levels since I am more concerned with the fuzzy and fluctuating nature of populations.

Peez,

Again it all depends on what scale you are looking at. If you are investigating group evolution, then size and distribution of the separate groups would be a trait of your evolutionary “unit” (to borrow DD’s terminology). Of course, we also know that with any increase in population size, evolution will occur on the individual level since drift would affect gene frequencies. And gene frequencies are traits of a population.

Change in gene frequencies is evolution, but not all evolution is change in gene frequencies.

Okay, I didn’t phrase that right. Attempt #2:

• I think we are view the allele-centric definition differently. I do not see it as saying that populations evolve because of changes in some (any?) gene-pool, but rather that a population evolves by changes to its gene pool.

Yes, that is why “environment” depends on the scale you are looking at.

Really? So we can just inject wolbachia genes into a host and it will show the phenotype. Do you see now why hosts inherit the wolbachia-induced phenotypes via wolbachia and not wolbachia genes?

For the most part all traits are inherited through transmission of gametes. Most of these traits can be reduced to the nuclear DNA within the gametes, but not all.

Well, I haven’t read enough on wolbachia to know where (or if any) authors specifically state that wolbachia infection is evolution. But I also don’t know of any that say that it is not. I personally think that I can present my point to a fellow biologist without resorting to “see, Dr. Jon Smith thinks it is evolution.” Heck I brought up wolbachia as an example of Lamarckian inheritance, but I then shifted the conversation prematurely.

Oh I agree. Remember I am a population geneticist after all. I just like having a broad definition/description of evolution so that when something like cortical inheritance comes up we don’t immediately reject it as “evolution” because it is non-nucleotide. I also see placing “gene pools” in the definition as unnecessary because Darwin and his contemporaries didn’t need “gene pools” to recognize evolution.

~~RvFvS~~

[ November 05, 2002: Message edited by: RufusAtticus ]</p>

Doubting Didymus

This is strange. Rufus and I appear to agree on practically everything, yet I consider myself a gene-centrist and he clearly does not.

Responding to my comments about differential replication efficacy you said: "I understand what you are trying to say, but I think it can be phrased better."

My take on the importance of differential replication efficacy:

And Rufus's:

Pardon me if I am missing something, but aren't these two scentences exactly the same for all intents and purposes? Are you just correcting my use of the passive voice?

Correct, I was using 'species' to mean both biological and taxonomic. As a dyed in the wool cladist, it scarcely occurred to me to make the distinction. Meanwhile, you have not answered my question. If speciation, or something like it, can be considered to have happened at the moment of wolbachia infection, then can it not also be considered to have happened when I have five flies in a box? This is a notoriously grey area, of course, but I feel as though reproductive isolation due to wolbachia is a bit too far into the black to consider it 'speciation' of any kind. I would wait until more permanent changes have been wrought on the population due to the infection, before I would look at speciation.


This was to Peez:
This immediately raises the question of whether the three criteria are met.

First: is the species group a replicator? Probably.

Are its traits mutable? Certainly.

Are some units (species, in this case) able to become better at replicating? I would hesitantly say so, but I would keep in mind that not everything about a species can be truly considered a trait of that species. Rather, many things about it are more likely traits of the individuals in the population and not the population itself. In this case, something like the distribution is probably a trait of the species, while I would have more difficulty considering reproductive speed, (and by extrapolation, the species - spreading speed) a trait of the species. It smacks of being a trait of the individual.

The final question is the big one. Is the species unit capable of passing on its traits to its repicant species? That is: are the traits of the species really heritable? Common sense would tell us yes, of course they are: a new species of sheep has inherited the vast majority of traits from its parent species. However, on closer inspection I believe you find that the traits that are being passed on are not traits of the species, but of the individual. What of the traits that are undeniably those of the species, such as distribution? Are they really passed on? I find it difficult to accept that proposition, but it is complicated and I will not discount it.

What is your opinion? Does a species pass its distribution on to any child species?