Freethought & Rationalism Archive

RufusAtticus · 03-28-2002, 07:29 PM

Due to the filters, i.e. Administrators, being busy, the evo/creation forum on BB will not be updated for three weeks.

I have a one or two discussions going on there now, which I will continue here.

Is that fine with you excreationist?

-RvFvS

Orpheous99 · 03-29-2002, 02:46 AM

Quote:

Originally posted by RufusAtticus:
Due to the filters, i.e. Administrators, being busy, the evo/creation forum on BB will not be updated for three weeks.

I have a one or two discussions going on there now, which I will continue here.

Is that fine with you excreationist?

-RvFvS

In other words they are losing and they want you to go away so the stuck their colective heads in the sand to hide from you.

[ March 29, 2002: Message edited by: Orpheous99 ]

excreationist · 03-29-2002, 03:50 AM

RufusAtticus -
yeah ok....

this was the list you had originally:

1. asexually reproducing unicellular organisms
2. unicellular organisms, that reproduce both asexually through mitosis and sexually through meiosis and isogametes
3. multicellular organisms
4. differentiated multicellular organisms with germ cells for mitosis (possible loss of asexual reproduction)
5. hermaphrodites with the gradual move from isogametes to motile sperm and rich eggs
6. dioecy: the specialization of individuals to produce either sperm or eggs

I was wanting that to be translated into layperson's English... (e.g. no jargon except for basic things like chromosomes, DNA, cell, nucleus, sexual and asexual)

My attempt at a translation for number 2 is this:

single-celled organisms, that reproduce both asexually by the cell and its nucleus dividing (mitosis) and sexually (by meiosis) where the nucleus divides into four nuclei where each contains half of the chromosomes... [I don't know what next... do some of the nuclei go off and merge into another cell of that same species?]

Then it could be turned into a story.

e.g. if you were talking about fish evolving into monkeys, basically "the fish lived in lakes or ponds that dried up sometimes, and those which could move on the land for small distances would have an advantage. Gradually some of their descendents grew longer limbs as a mutation and this was also beneficial. And the fins eventually turned into legs. Then some mutated descendents became less dependent on water and could wander more and more inland. (Amphibians) And then they weren't dependent on water at all as a source of oxygen. (And it's also for cooling?) So then there were the reptiles. And they had scales as well. (like fish did - I guess early amphibians might have had scales too) Then some had a self-regulated body temperature (they were warm-blooded). Then for some reason their scales turned into hairs. And instead of laying eggs the babies developed in their womb. (So they could be more mobile rather than having to guard a nest?, and gestation periods were much longer?) Then eventually there was a niche for monkeys which jumped between trees and were very acrobatic.

Something like that except it would be about chromosomes and sex cells and nuclei (without words like meiosis)

That's what I was looking for in the <a href="http://www.baptistboard.com/ubb/ultimatebb.php?ubb=get_topic;f=36;t=000142" target="_blank">How Did Sexual Reproduction Evolve?</a> thread. It was because a guy on the <a href="http://bbs.payableondeath.com/cgi-shell/ultimatebb.cgi?ubb=forum&f=2" target="_blank">P.O.D. forum</a> kept asking about it all the time and was saying that evolution couldn't be true.

Other people could help out too, otherwise in 3 weeks I'll just say that the topic is way to complex for me (and it is at the moment).

BTW, I emailed them a post about <a href="http://iidb.org/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=58&t=000521" target="_blank">Is our visual system flawed?</a> (like the thread I started here). So far not one creationist/ID-ist has replied on my thread here! I posted the text that I emailed the BaptistBoard at the <a href="http://bbs.payableondeath.com/ubb/ultimatebb.php?ubb=get_topic;f=2;t=004342" target="_blank">Christian Hip-hop band, P.O.D.'s forum</a>. There were quite a few replies but they were all were shot down in flames.

[ March 29, 2002: Message edited by: excreationist ]

Dave Cox · 03-29-2002, 04:46 AM

Quote:

Originally posted by RufusAtticus:
Due to the filters, i.e. Administrators, being busy, the evo/creation forum on BB will not be updated for three weeks.

-RvFvS

I think the word you are looking for is
censors

Dave

Dr.GH · 03-30-2002, 03:39 PM

I don't post a bap's B but it was slow today and I took a peek.

Why is it that all the other fora are active? Are the creationist moderators just particularly lazy? Or, do they work for H&R Block? Or, were they getting their collective ass kicked?

Sauron · 03-30-2002, 09:09 PM

Quote:

Originally posted by Dr.GH:
Or, were they getting their collective ass kicked?

Bingo. They shut down the forum for several months because the creationists were being shredded so badly.

Then they re-opened it, but not to direct posting.

You have to email the moderators with your posts. Then the moderators "screen" them for objectionable text, and if they pass muster, then the moderator posts the response. 24-48 hrs after you send it to them.

They've also shut down individual threads without warning or explanation; usually those threads have been ones where the theists were getting a severe beating.

The moderators have a tendency to shut anything down that causes severe crises of faith for their members. But don't forget, "The truth will set you free."

RufusAtticus · 03-31-2002, 11:49 PM

I'm back. I'll try to get a comment up by the weekend.

-RvFvS

Nic Tamzek · 04-01-2002, 01:53 AM

Hi,

Some hints on the actual mechanics of *how* (rather than the selective aspect of "why") eukaryotic sex, i.e. meiosis, evolved, see some of my rambling comments, and more particularly references, on the origin of eukaryotes:

Eukaryotic cell division

<a href="http://iidb.org/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=58&t=000459" target="_blank">http://iidb.org/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=58&t=000459</a>

...the topic is not directly addressed, but the questions of the origin of mitosis and meiosis are very closely tied together.

...I recall recently reading about the relevance of cells glomming together into multinucleus supercells in times of starvation -- starvation is often what provokes sexual reproduction/spore formation in single-celled eukaryotes also.

E.g., "oh no, I'm starving, let's glom together, share cytoplasm so we don't starve, and hey while we're at it we might as well recombine some genes and maybe hit on a genotype that works better in these conditions".

Whoa, it must be late, I'm doing protozoan psychology...

Nick

S2Focus · 04-01-2002, 06:47 AM

Quote:

Originally posted by Dr.GH:
I don't post a bap's B but it was slow today and I took a peek.

Why is it that all the other fora are active? Are the creationist moderators just particularly lazy? Or, do they work for H&R Block? Or, were they getting their collective ass kicked?

Regarding your last question, didn't you really mean to ask, "Or, did they realize that they were getting their collective ass kicked?"

Nic Tamzek · 04-05-2002, 02:45 PM

Came across this on PubMed re: origins of meiosis/sex:

Quote:

<a href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=119327 71&dopt=Abstract" target="_blank">http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=119327 71&dopt= Abstract</a>

Heredity 2002 Feb;88(2):125-41 Related Articles, Books, LinkOut

Origins of the machinery of recombination and sex.

Cavalier-Smith T.

Department of Zoology, University of Oxford, South Parks Road, Oxford, OX1 3PS, UK.

Mutation plays the primary role in evolution that Weismann mistakenly attributed to sex. Homologous recombination, as in sex, is important for population genetics - shuffling of minor variants, but relatively insignificant for large-scale evolution. Major evolutionary innovations depend much more on illegitimate recombination, which makes novel genes by gene duplication and by gene chimaerisation - essentially mutational forces. The machinery of recombination and sex evolved in two distinct bouts of quantum evolution separated by nearly 3 Gy of stasis; I discuss their nature and causes. The dominant selective force in the evolution of recombination and sex has been selection for replicational fidelity and viability; without the recombination machinery, accurate reproduction, stasis, resistance to radical deleterious evolutionary change and preservation of evolutionary innovations would be impossible. Recombination proteins betray in their phylogeny and domain structure a key role for gene duplication and chimaerisation in their own origin. They arose about 3.8 Gy ago to enable faithful replication and segregation of the first circular DNA genomes in precellular ancestors of Gram-negative eubacteria. Then they were recruited and modified by selfish genetic parasites (viruses; transposons) to help them spread from host to host. Bacteria differ fundamentally from eukaryotes in that gene transfer between cells, whether incidental to their absorptive feeding on DNA and virus infection or directly by plasmids, involves only genomic fragments. This was radically changed by the neomuran revolution about 850 million years ago when a posibacterium evolved into the thermophilic cenancestor of eukaryotes and archaebacteria (jointly called neomurans), radically modifying or substituting its DNA-handling enzymes (those responsible for transcription as well as for replication, repair and recombination) as a coadaptive consequence of the origin of core histones to stabilise its chromosome. Substitution of glycoprotein for peptidoglycan walls in the neomuran ancestor and the evolution of an endoskeleton and endomembrane system in eukaryotes alone required the origin of nuclei, mitosis and novel cell cycle controls and enabled them to evolve cell fusion and thereby the combination of whole genomes from different cells. Meiosis evolved because of resulting selection for periodic ploidy reduction, with incidental consequences for intrapopulation genetic exchange. Little modification was needed to recombination enzymes or to the ancient bacterial catalysts of homology search by spontaneous base pairing to mediate chromosome pairing. The key innovation was the origin of meiotic cohesins delaying centromere splitting to allow two successive divisions before reversion to vegetative growth and replication, necessarily yielding two-step meiosis. Also significant was the evolution of synaptonemal complexes to stabilise bivalents and of monopolins to orient sister centromeres to one spindle pole. The primary significance of sex was not to promote evolutionary change but to limit it by facilitating ploidy cycles to balance the conflicting selective forces acting on rapidly growing phagotrophic protozoa and starved dormant cysts subject to radiation and other damage.

TCS' dating is highly debatable, but the rest of it looks OK...

nic

[ April 05, 2002: Message edited by: Nic Tamzek ]

03-28-2002, 07:29 PM	#1
RufusAtticus Veteran Member Join Date: Nov 2001 Location: NCSU Posts: 5,853	BaptistBoard Down Due to the filters, i.e. Administrators, being busy, the evo/creation forum on BB will not be updated for three weeks. I have a one or two discussions going on there now, which I will continue here. Is that fine with you excreationist? -RvFvS

03-29-2002, 03:50 AM	#3
excreationist Veteran Member Join Date: Aug 2000 Location: Australia Posts: 4,886	RufusAtticus - yeah ok.... this was the list you had originally: 1. asexually reproducing unicellular organisms 2. unicellular organisms, that reproduce both asexually through mitosis and sexually through meiosis and isogametes 3. multicellular organisms 4. differentiated multicellular organisms with germ cells for mitosis (possible loss of asexual reproduction) 5. hermaphrodites with the gradual move from isogametes to motile sperm and rich eggs 6. dioecy: the specialization of individuals to produce either sperm or eggs I was wanting that to be translated into layperson's English... (e.g. no jargon except for basic things like chromosomes, DNA, cell, nucleus, sexual and asexual) My attempt at a translation for number 2 is this: single-celled organisms, that reproduce both asexually by the cell and its nucleus dividing (mitosis) and sexually (by meiosis) where the nucleus divides into four nuclei where each contains half of the chromosomes... [I don't know what next... do some of the nuclei go off and merge into another cell of that same species?] Then it could be turned into a story. e.g. if you were talking about fish evolving into monkeys, basically "the fish lived in lakes or ponds that dried up sometimes, and those which could move on the land for small distances would have an advantage. Gradually some of their descendents grew longer limbs as a mutation and this was also beneficial. And the fins eventually turned into legs. Then some mutated descendents became less dependent on water and could wander more and more inland. (Amphibians) And then they weren't dependent on water at all as a source of oxygen. (And it's also for cooling?) So then there were the reptiles. And they had scales as well. (like fish did - I guess early amphibians might have had scales too) Then some had a self-regulated body temperature (they were warm-blooded). Then for some reason their scales turned into hairs. And instead of laying eggs the babies developed in their womb. (So they could be more mobile rather than having to guard a nest?, and gestation periods were much longer?) Then eventually there was a niche for monkeys which jumped between trees and were very acrobatic. Something like that except it would be about chromosomes and sex cells and nuclei (without words like meiosis) That's what I was looking for in the <a href="http://www.baptistboard.com/ubb/ultimatebb.php?ubb=get_topic;f=36;t=000142" target="_blank">How Did Sexual Reproduction Evolve?</a> thread. It was because a guy on the <a href="http://bbs.payableondeath.com/cgi-shell/ultimatebb.cgi?ubb=forum&f=2" target="_blank">P.O.D. forum</a> kept asking about it all the time and was saying that evolution couldn't be true. Other people could help out too, otherwise in 3 weeks I'll just say that the topic is way to complex for me (and it is at the moment). BTW, I emailed them a post about <a href="http://iidb.org/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=58&t=000521" target="_blank">Is our visual system flawed?</a> (like the thread I started here). So far not one creationist/ID-ist has replied on my thread here! I posted the text that I emailed the BaptistBoard at the <a href="http://bbs.payableondeath.com/ubb/ultimatebb.php?ubb=get_topic;f=2;t=004342" target="_blank">Christian Hip-hop band, P.O.D.'s forum</a>. There were quite a few replies but they were all were shot down in flames. [ March 29, 2002: Message edited by: excreationist ]</p>

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03-30-2002, 03:39 PM	#5
Dr.GH Veteran Member Join Date: Jul 2001 Location: Dana Point, Ca, USA Posts: 2,115	I don't post a bap's B but it was slow today and I took a peek. Why is it that all the other fora are active? Are the creationist moderators just particularly lazy? Or, do they work for H&R Block? Or, were they getting their collective ass kicked?

03-31-2002, 11:49 PM	#7
RufusAtticus Veteran Member Join Date: Nov 2001 Location: NCSU Posts: 5,853	I'm back. I'll try to get a comment up by the weekend. -RvFvS

04-01-2002, 01:53 AM	#8
Nic Tamzek Senior Member Join Date: Jan 2002 Location: California Posts: 646	Hi, Some hints on the actual mechanics of how (rather than the selective aspect of "why") eukaryotic sex, i.e. meiosis, evolved, see some of my rambling comments, and more particularly references, on the origin of eukaryotes: Eukaryotic cell division <a href="http://iidb.org/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=58&t=000459" target="_blank">http://iidb.org/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=58&t=000459</a> ...the topic is not directly addressed, but the questions of the origin of mitosis and meiosis are very closely tied together. ...I recall recently reading about the relevance of cells glomming together into multinucleus supercells in times of starvation -- starvation is often what provokes sexual reproduction/spore formation in single-celled eukaryotes also. E.g., "oh no, I'm starving, let's glom together, share cytoplasm so we don't starve, and hey while we're at it we might as well recombine some genes and maybe hit on a genotype that works better in these conditions". Whoa, it must be late, I'm doing protozoan psychology... Nick

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