Remember Stevebee?

Incl. intelligent design, belief in divine creation

Moderators: Calilasseia, DarthHelmet86, Onyx8

Re: Remember Stevebee?

#221  Postby GenesForLife » Jul 26, 2010 12:54 pm

Well, thank you for the tip.
GenesForLife
 
Posts: 2920
Age: 30
Male

United Kingdom (uk)
Print view this post

Ads by Google


Re: Remember Stevebee?

#222  Postby Shrunk » Jul 26, 2010 1:11 pm

Calilasseia wrote:Actually GfL, why not trawl through the literature on organisms such as Caenorhabditis elegans and Ciona intestinalis, whose genomes have been sequenced completely, and which possess simpler antecedent forms of the systems seen in mammals?


Pshaw, you evillusionaut! That's just genetics. Nothing to do with evolution!
"A community is infinitely more brutalised by the habitual employment of punishment than it is by the occasional occurrence of crime." -Oscar Wilde
User avatar
Shrunk
 
Posts: 26170
Age: 54
Male

Country: Canada
Canada (ca)
Print view this post

Re: Remember Stevebee?

#223  Postby GenesForLife » Jul 26, 2010 3:39 pm

haha.
GenesForLife
 
Posts: 2920
Age: 30
Male

United Kingdom (uk)
Print view this post

Re: Remember Stevebee?

#224  Postby eddie.zdi » Jul 26, 2010 5:57 pm

stevebee92653 wrote:
eddie.zdi wrote:Thank you Steve, but I hate to point out that you seem to accept that evolutionary biologists do attempt to disprove ToE, but they draw different conclusions this is in direct contradiction to what you said about no-one on this site attempt to disprove evolution. I gather that a few members do indeed engage in that type of work. I also hate to point out that if every other observer looks at something and draws one conclusion and you draw another there is a strong possibility that rather than a conspiracy, it's much more likely that you are wrong. Now seeing as the overwhelming of the educated, and non-indoctinated (i.e. those not being bullied into a worldview by fear of terrifying overlord) majority disagree with you, you have to entertain the possibilty that you are wrong. I also hold the view that I might be wrong and if some if the entire scientific community said that I was I would have to agree... hence the reason I stopped work on The Doomsday Device.


Science should never be done by majority vote and groupthink. If it was, we wouldn't have a Theory of Relativity, et al.


Sorry to dissapoint but this is not only a complete misunderstanding of my point but also a misrepresentation of the facts. SCIENCE IS A PEER REVIEWED SYSTEM OF KNOWLEDGE so when the theory of relativity was hypothesised by Einstein it was then studied by all other scientists worldwide, who then on the available evidence accepted it. Interestingly though I can't remember the exact source *grovelled apologies* I remember hearing that one Nazi document claimed that they had a problem with "The Jewish nature of relativity" (think I heard that in an episode of "The Mark Steele Lectures", if anyone can provide a source I'd be much obliged). Now also interestingly I would point out that one man working alone for twenty years came up with the Theory of Evolution, this was used to replace, the majority vote and group think. The idea that you are against groupthink is preposterous... I have no idea of you're religous leanings but I will bet a shiny penny that once a week, every week, you go stand in a room of like-minded individuals and repeat 2000 year old religous scripture in unison. I feel that maybe you misunderstand some key facts about history and the universe, it would also appear that you believe nearly all others to be either deluded, of lesser intelligence than yourself or involved in a global conspiracy. So I put it to you based on simple logic which of the four options is most likely
A. All evolutionary biologists on the face of our little speck of space dust are intellectual lightweights compared to a man who believes teeth are perfect despite the fact that his job is to fix them when they are not.
B. All evolutionary biologists are deluded and unquestioningly believe in evolution despite the fact that the urge to question the world around them is what first drove them to be scientists
C. All evolutionary biologists are part of global conspiracy (set up for no real reason that I can deduce), and not one of the millions involved in this lie has ever blown the whistle despite significant financial incentives being available
D. You are wrong.
Well lets analyse shall.
A: Some of these people hold degrees from the most prestigous universities on the globe... also the Theory of Evolution was accepted as fact by Mr Douglas Adams and is accepted as fact by Mr Stephen Fry, two of the wittiest and most intelligent individuals to ever grace the earth with there presence.
B: Well this just seems unlikely really doesn't it... that not one of them would go "Hold-on one cotton picking second"
C: Utterly impossible a conspiracy cannot be carried out on this scale, especially when there is an ongoing attempt to discredit ToE by creationists.
D: Well I don't know you personally but I would ask to questions... 1) Have you ever previously been wrong? 2) Are there any social of personal incentives that might play on your subconcious to believe in creationism/ID?
I think D is probably the most likely...
Also can everybody else stop reposting theropods terrifying teeth pictures, I will genuinely hunt down and bitchslap the next person who makes me look at that.
"Science is the lawman of ignorance" - Me 1984 - ????
User avatar
eddie.zdi
 
Name: Daniel Edwards
Posts: 178

Country: UK
United Kingdom (uk)
Print view this post

Re: Remember Stevebee?

#225  Postby eddie.zdi » Jul 26, 2010 6:37 pm

stevebee92653 wrote:
theropod wrote:Steve,

At this point I am motivated to ask a simple question, which hopefully you can answer with a simple response.

What evidence would it take to convince you that the ToE explains the biodiversity found throughout the biosphere?

If there is nothing we can do to convince you that the overwhelming evidence gathered over the past 300 years fully supports a naturalistic explanation for this biodiversity what is the point of continued conversation?

Steve, do you really want to be seen as one so inflexible in your position that NOTHING, including an Everest size mountain of hard evidence, can convince you that your views are incorrect?

RS


How about for a start:
The vid on this thread has a great one, and one that has been avoided like the plague: That a bio-system that formed in a single species was capable of spreading to other speices and how that took place. Or, did thousands of species all form all the same bio-system at about the same time? Not a plausible or possible scenario, of course. CA is not an answer but will be yours.
That natural selection was capable of inventing incredible bio-systems from a uni-celled earth. I know you evos don't like the notion of invention, but bio systems were inventions far more than any invention at the US Patent Office. There was no model or design or prior art for natural selection et al to go by. So how did that take place?
How did the designing and assembling of those systems take place in the species that the inventions formed in?
Being a dentist, this one has really bothered me: That mutaions can form and transfer information to odontolbasts, and ameloblasts so they will "know" when to turn on and turn off the knitting of enamel and dentin which will leave those incredible little sculptures that are our teeth. Since there are millions of odontoblasts and ameloblasts, each one must stop at a different point in time. Are NS and RM capable and powerful enough to originate and relay this information to the cells?
There are so many question on my blog. Feel free to visit and challenge me.
I'm sure these questions will be made great light of by your amigos. That is the typical response. The difficulty for you is that five years ago I would have been arguing with you. Until this science crashed for me. Badly. So I know where you are coming from much more than you would think.


Steve just a little logical puzzle for you my good man, I wager you $1 billion dollars that I can make a basket on a regulation size court from the halfway line 100 times in a row, now to clarify the rules of the bet, you will be seated behind a large wooden screen the with a chute attached to the basket I will take anywhere between 30 seconds and 9 years for each throw. That bet may seem stupid, however when you ask how did teeth know how to form perfectly the answer is the same... by failing spectacularly on millions of occasions, the tree of life is not a straight line my friend... it kind of looks more like, erm well a tree. Common Ancestry does answer this because of a simple set of factors. 1) The odds against teeth formation are billions to one against, so with a couple of billion attempts becomes inevitable. 2) They are beneficial. So they hang around.
"Science is the lawman of ignorance" - Me 1984 - ????
User avatar
eddie.zdi
 
Name: Daniel Edwards
Posts: 178

Country: UK
United Kingdom (uk)
Print view this post

Re: Remember Stevebee?

#226  Postby hackenslash » Jul 26, 2010 6:42 pm

Why do all the lulz happen when I'm not here? That's the real burning question. :lol:

Thank you, Steeveeeeee, for once again providing us with your comic presence. :cheers:
User avatar
hackenslash
 
Name: The Other Sweary One
Posts: 21402
Age: 50
Male

Country: Republic of Mancunia
Print view this post

Re: Remember Stevebee?

#227  Postby eddie.zdi » Jul 26, 2010 6:51 pm

Oh I just read that he ducked out... man I was gonna be up a 1 billion dollars... I'm going vegas soon I really could have used that money. Anyway we are once forced to endure a creationist running in here and arguing his case with all the effectiveness of a retarded duck trying to rape a tiger. I would happily go sit on his blog and argue every single point of his but I worried that if I try to log on to a site with evillusion in the name my laptop will think badly of me.
"Science is the lawman of ignorance" - Me 1984 - ????
User avatar
eddie.zdi
 
Name: Daniel Edwards
Posts: 178

Country: UK
United Kingdom (uk)
Print view this post

Ads by Google


Re: Remember Stevebee?

#228  Postby Rumraket » Jul 26, 2010 8:49 pm

Oh for FUCKS SAKE. I just ruined my own mood. I wrote a huge post attempting to address several of your questions SteveBee, but I accidentially closed the fucking tab I was writing in. I might write it again tomorrow or but I can't be bothered now... I'm depressed. Shutfuckcuntfuckshitcrapfhuckis pgosdfhspåofksdfs....

:waah: :whine: :waah: :whine: :waah: :whine: :waah: :whine:

Rest assured there are answers for most of your shit. Have patience. I'll go punch holes in my wall somewhere... laterz.

Okay so I managed to retype more or less the post again and it may look a little weird after being typed in notepad first. Here goes, Stevebee.
SteveBee wrote:How about for a start:
The vid on this thread has a great one, and one that has been avoided like the plague: That a bio-system that formed in a single species was capable of spreading to other speices and how that took place. Or, did thousands of species all form all the same bio-system at about the same time? Not a plausible or possible scenario, of course. CA is not an answer but will be yours. That natural selection was capable of inventing incredible bio-systems from a uni-celled earth. I know you evos don't like the notion of invention, but bio systems were inventions far more than any invention at the US Patent Office. There was no model or design or prior art for natural selection et al to go by. So how did that take place? How did the designing and assembling of those systems take place in the species that the inventions formed in? Being a dentist, this one has really bothered me: That mutaions can form and transfer information to odontolbasts, and ameloblasts so they will "know" when to turn on and turn off the knitting of enamel and dentin which will leave those incredible little sculptures that are our teeth. Since there are millions of odontoblasts and ameloblasts, each one must stop at a different point in time. Are NS and RM capable and powerful enough to originate and relay this information to the cells? There are so many question on my blog. Feel free to visit and challenge me. I'm sure these questions will be made great light of by your amigos. That is the typical response. The difficulty for you is that five years ago I would have been arguing with you. Until this science crashed for me. Badly. So I know where you are coming from much more than you would think.

Regarding the many questions in this post I'm going to take them one at a time and try to explain why they are wrong in my own words, with my limted understanding of Darwinian evolutionary theory and genetics. I welcome more competent individuals to point out flaws or misunderstandings I may propably have fathered.

That a bio-system that formed in a single species was capable of spreading to other speices and how that took place.

Your kids inherit the genes for the construction of limbs, bones, a heart, lungs and all the other organs you have. This is how evolved traits spread through populations. The offspring of an organism inherit the traits of it's parent(s). This is it basically. If the organism is born with a beneficial mutation, that beneficial mutation will possibly persist over generations as long as it is beneficial to the organism. The benefit of the mutation or inherited trait is dependent on the environment of the organism. Slightly longer/thicker fur can be negative or positive, depending on weather and climate These are general descriptions, do you undestand this?

Nothing is guaranteed to happen. An organism in a large population may inherit a slightly useful trait by it's parent, or simply be born with a mutation that yields some small benfit. This is still not a guarantee the organism will survive long enough to reproduce.. but there is an increased chance.

Lets make it really simple, impossibly simple : Say your entire genome consist of 18 nucleotides making 6 genes, each making a protein(which with a triplet codon system would actually just give 6 amino acids, but anyway.. bear with me). I know I know, this is impossible, but it is easier to demonstrate like this:

AAA CCC TTT GGG AAA CCC
Now you have a child, with a woman whose genes look like this:
CCC TTT GGG AAA TTT AAA
The child will have a genome with a single mutation, looking like this :
AAA TTT TTT AAA AAA AAG

Half his genes from the mother, half his genes from his father, with a single mutation in the last gene. If your child has children of his own when he grows up, there is a 50% chance that your grandchild will inherit the mutation. If the mutation is a beneficial mutation that will increase his chance of survival and passing on his genes, chances are after many generations, that mutation will be in a larger part of the population, because those who didn't have the mutation did not have as high a chance of surviving to produce children of their own.

Chances are that people without that mutation will not be as successful at finding food, avoiding predators etc. etc. and
eventually most of the population will carry that mutation. That's it. In the beginning only one individual had the mutation(or maybe only a few, a single specific mutation in an 18 nucleotide, 6-gene genome isn't very impropable), and after many generations of successful reproduction, a large portion of the population will have the mutation.
You get it? That's how genes spread through populations and ultimately through species, indeed the entire tree of life.

I can give you a simplistic account of the possible evolution of a circular-system. All mammals have hearts because, when the first primitive multicellular organism reached a size and complexity where a circulatory system started developing, this circulatory system was useful and a benefit to the organism to an extend to which those without it either found evolutionary niches where it made no difference, or died out leaving those with it behind to survive and have successfully reproducing offspring.

At some point, this organism has become so large and complex, that simply having internal pathways through which nutrients and wasteproductes can flow on their own through various mechanics of chemical/temperature gradients or osmotic pressures, is not sufficient, and internal movement generated by various means is being selected for on the basis that this movement can serve to squeeze or push nutrients around in the "veins".

Indeed, whole-organism movement is being seleced for because this allows the organism to leave areas where nutrients are low and later to escape possible predators and other environmental harms. This development of movement could be the ancestral origin of muscle-development. Having a muscle dedicated to the task of keeping the circulatory system in a state of circulation is obviously beneficial. In any case, this is just my own simplistic account of how it could have happened. Now that I have wrote this, I found an actual paper on the subject:

For an actual hypothesis on the development of muscle-based locomotion, based on testable predictions derived from real-world observations and evolutionary theory, check out this paper:

    Evolution of striated muscle: Jellyfish and the origin of triploblasty
    Katja Seipel, Volker Schmid*
Abstract
The larval and polyp stages of extant Cnidaria are bi-layered with an absence of mesoderm and its differentiation products. This anatomy originally prompted the diploblast classification of the cnidarian phylum. The medusa stage, or jellyfish, however, has a more complex anatomy characterized by a swimming bell with a well-developed striated muscle layer. Based on developmental histology of the hydrozoan medusa this muscle derives from the entocodon, a mesoderm-like third cell layer established at the onset of medusa formation. According to recent molecular studies cnidarian homologs to bilaterian mesoderm and myogenic regulators are expressed in the larval and polyp stages as well as in the entocodon and derived striated muscle. Moreover striated and smooth muscle cells may have evolved directly and independently from non-muscle cells as indicated by phylogenetic analysis of myosin heavy chain genes (MHC class II). To accommodate all evidences we propose that striated muscle-based locomotion coevolved with the nervous and digestive systems in a basic metazoan Bauplan from which the ancestors of the Ctenophora (comb jellyfish), Cnidaria (jellyfish and polyps), as well as the Bilateria are derived. We argue for a motile tri-layered cnidarian ancestor and a monophyletic descent of striated muscle in Cnidaria and Bilateria. As a consequence, diploblasty evolved secondarily in cnidarian larvae and polyps. D 2005 Elsevier Inc. All rights reserved. Keywords: Basic Bauplan; bHLH genes; Cnidaria; Entocodon; Hydrozoan jellyfish; Medusa; Mesoderm; Metazoan evolution; Monophyletic descent; Origin of triploblasty; Prebilaterian ancestor; Striated muscle; Zootype

Free, full paper

Or, did thousands of species all form all the same bio-system at about the same time?

No. It happened pretty much as I very simplistically described above.

Not a plausible or possible scenario, of course. CA is not an answer but will be yours.

Not plausible, no(spontaneous evolution of complex biological systems in thousands of species). But not even possible? You do realise that science is not in the business of making absolutist claims?

That natural selection was capable of inventing incredible bio-systems from a uni-celled earth. I know you evos don't like the notion of invention, but bio systems were inventions far more than any invention at the US Patent Office. There was no model or design or prior art for natural selection et al to go by. So how did that take place?

That depends on the particular system. Now, I'm not an evolutionary biologist so I can't answer specifically "how did the human heart evolve?". I can say this much though : As the litterature I have read testifies, real-world observations of testable predictions have shown and which fits with evolutionary theory : The human heart was a heart before it was a human heart.
I hope you understand what I mean. Indeed I hope you will invest some mental effort in at least trying to understand.
Tracing the evolution of the heart back through time, will persist in it being a heart for many hundreds of millions of years, through thousands of different species until some time in the distant past we get to a common ancestor that no longer resembles anything like a mammal at all, and what later became the human heart was nothing more than the very most rudimentary circulatory system in some primitive primordial sponge.
I suggest you take people's advice and acquaint yourself with the extant litterature, which you have shown no sign of having done anywhere, despite your flatly dishonest claims that you have. What is interesting is that many of the predicted intermediary steps in the evolution of a heart like the human one, is also found in exactly the living organisms most closely related to those where we expect to find them. Primitive circulatory systems in sponges, complex hearts in humans and other large animals, and everything in those between them.

How did the designing and assembling of those systems take place in the species that the inventions formed in?

In so many fucking ways, the question is so broad a simple answer can't be given. I'm not saying this to duck answering the question. I will suggest you read up on the following key-words, because these concepts in combination are what give rise to the majority of evolutionary novelty :

Gene-duplications, gene-shufflings, frameshift and other types of mutations(there are many kinds), genetic recombinations of various sorts.

Another powerful generator of change is the mixing of genes between the sexes of sexually reproducing species.

Being a dentist, this one has really bothered me: That mutaions can form and transfer information to odontolbasts, and ameloblasts so they will "know" when to turn on and turn off the knitting of enamel and dentin which will leave those incredible little sculptures that are our teeth. Since there are millions of odontoblasts and ameloblasts, each one must stop at a different point in time. Are NS and RM capable and powerful enough to originate and relay this information to the cells?

Im sure this is baffling to you because your question is build on faulty assumptions. You are assuming that evolution is claiming that first there were odontoblasts and/or ameloblasts and then the signalling pathway developed to fit with it, or perhaps even the other way around. Your question can also be interpreted as you thinking that these processes slowly developed, but had no function or benefit until the "final product" was achieved.

Both are common and fundamental misrepresentations of evolution. As I hope I have already made clear, things don't suddenly pop into existence fully formed, indeed not even half-formed. There never was half-an-eye or 30% of a heart or 2% of a tooth with 9% of the signaling pathway for it's development. There was something different, something simpler, which already had a full and 100% use.
Half-Life 3 - I want to believe
User avatar
Rumraket
 
Posts: 13144
Age: 38

Print view this post

Re: Remember Stevebee?

#229  Postby Latimeria » Jul 26, 2010 11:11 pm

Good post, Rumraket. But I have a question. As far as I know there are no sponges with even the most rudimentary circulatory system. Was the phylum Porifera just chosen for purposes of illustrating the general concept (in which case I am totally with you), or is there a specific reason that leads you to speculate that it began with sponges? Just curious.

EDIT: Just wanted to point out for Steve's benefit the lack of "groupthink" in this instance, and predict that Rumraket's response will be conducive to coherent and logical conversation in contrast to Steve's myriad ways of ruining productive discussion.
" [This space is for rent to "which ever version of POOF creates the largest cloud of obnoxious smoke following the POOF."[1] "- God
Works Cited:
[1] - theropod. Parsimony of the Miraculous. RatSkep Peanut Gallery Press, 2011.
User avatar
Latimeria
RS Donator
THREAD STARTER
 
Posts: 1083
Male

United States (us)
Print view this post

Re: Remember Stevebee?

#230  Postby Calilasseia » Jul 26, 2010 11:50 pm

One of the reasons that the Porifera is chosen for such discussions is that the literature on molecular phylogeny points to the Porifera as having had the most distant shared common ancestor with all the other multicellular animal phyla. Even more compellingly, genes that share homologies with genes for more advanced bauplan development in other phyla can be found in modern sponges, suggesting that those genes had a very ancient origin, and that while sponges didn't take the cellular differentiation route of other phyla, they inherited the genes from the common ancestor that permitted cellular differentiation and specialisation in those other phyla. The Cnidaria is the modern clade that contains evidence of what the first instances of cellular differentiation may have looked like in the past, and other clades that arose later exhibit additional features that arose when they diverged from their common ancestors with the Cnidaria etc.

Basically, the Animalia diverged into the Porifera, the Cnidaria and the Bilateria (this is a simplified rendition of the tree in question, but not essentially wrong for being a simplification thereof), and the Bilateria gave rise to the other major animal phyla. At the Bilatera node, you then have a basic division between Protostomes (which gave rise to most of the invertebrate phyla courtesy of a split into Lophotrichozoa and Ecdysozoa) and Deuterostomes (which gave rise to echinoderms and vertebrates). Tracing the phylogeny of various gene families, including HOX genes, Pax genes, and the various signalling genes such as bmp, wnt and the hedgehog signalling genes, more or less establishes the aforementioned clades as being the clades that arose early in the history of multicellular life.

An apposite paper that reveals why sponges are important from the standpoint of understanding the early history of multicellular life is this one:

Mitochondrial Genome Of The Homoscleromorph Oscarella carmela (Porifera, Demospongiae) Reveals Unexpected Complexity In The Common Ancestor Of Sponges And Other Animals by Xiujuan Wang and Dennis V. Lavrov, Molecular Biology and Evolution, 24(2): 363-373 (2007, with advance online publication November 7th, 2006) [Full paper downloadable from here]

Wang & Lavrov, 2007 wrote:Homoscleromorpha is a small group in the phylum Porifera (Sponges) characterized by several morphological features (basement membrane, acrosomes in spermatozoa, and cross-striated rootlets of the flagellar basal apparatus) shared with eumetazoan animals but not found in most other sponges. To clarify the phylogenetic position of this group, we determined and analyzed the complete mitochondrial DNA (mtDNA) sequence of the homoscleromorph sponge Oscarella carmela (Porifera, Demospongiae). O. carmela mtDNA is 20,327 bp and contains the largest complement of genes reported for animal mtDNA, including a putative gene for the C subunit of the twin-arginine translocase (tatC) that has never been found in animal mtDNA. The genes in O. carmela mtDNA are arranged in 2 clusters with opposite transcriptional orientations, a gene arrangement reminiscent of those in several cnidarian mtDNAs but unlike those reported in sponges. At the same time, phylogenetic analyses based on concatenated amino acid sequences from 12 mitochondrial (mt) protein genes strongly support the phylogenetic affinity between the Homoscleromorpha and other demosponges. Altogether, our data suggest that homoscleromorphs are demosponges that have retained ancestral features in both mt genome and morphological organization lost in other taxa and that the most recent common ancestor of sponges and other animals was morphologically and genetically more complex than previously thought.


EDIT : Oh, and another apposite paper can be found here.

EDIT 2 : Found another one, though that one is behind a paywall.
Signature temporarily on hold until I can find a reliable image host ...
User avatar
Calilasseia
RS Donator
 
Posts: 22011
Age: 57
Male

Country: England
United Kingdom (uk)
Print view this post

Re: Remember Stevebee?

#231  Postby BlackRogueDreams » Jul 27, 2010 12:11 am

So what we have here is a case of willful ignorance on the part of stevebee.
BlackRogueDreams
 
Posts: 50
Age: 38
Male

Canada (ca)
Print view this post

Re: Remember Stevebee?

#232  Postby Latimeria » Jul 27, 2010 12:19 am

Calilasseia wrote:Even more compellingly, genes that share homologies with genes for more advanced bauplan development in other phyla can be found in modern sponges, suggesting that those genes had a very ancient origin, and that while sponges didn't take the cellular differentiation route of other phyla, they inherited the genes from the common ancestor that permitted cellular differentiation and specialisation in those other phyla.


I did not know that. Interesting papers, too. Thanks, Cali.
" [This space is for rent to "which ever version of POOF creates the largest cloud of obnoxious smoke following the POOF."[1] "- God
Works Cited:
[1] - theropod. Parsimony of the Miraculous. RatSkep Peanut Gallery Press, 2011.
User avatar
Latimeria
RS Donator
THREAD STARTER
 
Posts: 1083
Male

United States (us)
Print view this post

Re: Remember Stevebee?

#233  Postby Rumraket » Jul 27, 2010 5:24 am

Latimeria wrote:Good post, Rumraket. But I have a question. As far as I know there are no sponges with even the most rudimentary circulatory system. Was the phylum Porifera just chosen for purposes of illustrating the general concept (in which case I am totally with you), or is there a specific reason that leads you to speculate that it began with sponges? Just curious.

EDIT: Just wanted to point out for Steve's benefit the lack of "groupthink" in this instance, and predict that Rumraket's response will be conducive to coherent and logical conversation in contrast to Steve's myriad ways of ruining productive discussion.

You are of course right, sponges don't have circulatory systems and it seems I have picked a bad example on that basis. I knew sponges belong to one of the most distantly related phyla, courtesy of having asked that question here on this site somewhere before.
A little bit of googling would have corrected that mistake. I was also thinking jellyfish or things in that category, basically the criteria in my mind was just "early multicellular". Anyway, I like the word sponge :)
Half-Life 3 - I want to believe
User avatar
Rumraket
 
Posts: 13144
Age: 38

Print view this post

Re: Remember Stevebee?

#234  Postby GenesForLife » Jul 27, 2010 6:28 am

Blasting the protein Tbx5, mutations of which cause developmental defects in the heart, and therefore plays a role in heart development, revealed there are related proteins with the TBox domain present in sponges, I post details below.

Image
Image
GenesForLife
 
Posts: 2920
Age: 30
Male

United Kingdom (uk)
Print view this post

Re: Remember Stevebee?

#235  Postby GenesForLife » Jul 27, 2010 6:30 am

This means that the origins of this family of proteins comes from the common ancestor we share with the sponges, with the ancestor to both us and Suberites domunoula containing the closest consensus sequence for a Tbx (T-box) protein.
GenesForLife
 
Posts: 2920
Age: 30
Male

United Kingdom (uk)
Print view this post

Ads by Google


Re: Remember Stevebee?

#236  Postby Rumraket » Jul 27, 2010 7:36 am

That's interesting because this means (at least some of the) genes involved in heart development were already present and used for development of other tissues before hearts and circulatory systems started evolving. Which simply mean the later systems were diversifications of earlier systems, not new complete systems that developed by chance, mutation by mutation. That gene could have undergone duplication and the duplicate left open for mutation and co-option into circulatory development, or another related tissue.
Am I getting this right?
Half-Life 3 - I want to believe
User avatar
Rumraket
 
Posts: 13144
Age: 38

Print view this post

Re: Remember Stevebee?

#237  Postby GenesForLife » Jul 27, 2010 7:46 am

Yup.
GenesForLife
 
Posts: 2920
Age: 30
Male

United Kingdom (uk)
Print view this post

Re: Remember Stevebee?

#238  Postby GenesForLife » Jul 27, 2010 7:50 am

Basically, varied genetic expression can affect cell differentiation and development in different ways, which is how simple, small changes in expression patterns can result in disproportionately large phenotypic changes. An example would be the Bithorax mutation in Drosophila spp

The bithorax complex (BX-C) is a group of homeotic genes in Drosophila melanogaster which are believed to control the differentiation of the abdominal and posterior thoracic segments, located on chromosome III. When these genes are mutated, the third thoracic segment becomes a repeat of the second thoracic segment, creating what is essentially a second thorax. This can result in a second pair of wings, a second stomach, and duplicated thoracic features in varying degrees.[1]


http://en.wikipedia.org/wiki/Bithorax_complex

Image
GenesForLife
 
Posts: 2920
Age: 30
Male

United Kingdom (uk)
Print view this post

Re: Remember Stevebee?

#239  Postby Rumraket » Jul 27, 2010 8:59 am

Yes it seems relatively minor or benign changes can have incredible side-effects. I should propably also correct my previous statement that the supposed duplicate was left open for mutation and "co-option" into development of new tissue, it was in itself the development of a new tissue.
The duplicate, the new copy, was the new tissue's ultimate origin and I imagine that if the duplicated gene's(the one that got copied) expression was itself part of, or regulated by, another gene/expression thereof, most likely so would the new copy. So mutations on the copy would be accompanied by either additional selection on diversification(possibly also duplication) on the regulatory pathway, or simply mutations(or indeed geneshuffling) on the original regulatory pathway, so that it would also regulate the mutating duplicate.
It's all making sense to me... :cheers:
Half-Life 3 - I want to believe
User avatar
Rumraket
 
Posts: 13144
Age: 38

Print view this post

Re: Remember Stevebee?

#240  Postby Rumraket » Jul 27, 2010 9:23 am

The wikipedia article on Homeosis(although disappointingly short) wrecks another planetary-scale hole through SteveBee's assertion that there are no positive mutations :

http://en.wikipedia.org/wiki/Homeotic
Homeosis is the transformation of one body part into another, arising from mutation in or misexpression of specific developmentally critical genes. It may be caused by mutations in Hox genes, found in animals, or others such as the MADS-box family in plants. Homeosis is a characteristic that has helped insects become as successful and diverse as they are.[1]
Homeotic mutations work by changing segment identity during development. For example, the Ultrabithorax genotype gives a phenotype wherein metathoracic and first abdominal segments become mesothoracic segments.[2] Another well-known example is Antennapedia: a loss-of-function allele causes legs to develop in the place of antennae.
In botany, Rolf Sattler has revised the concept of homeosis (replacement) by his emphasis of partial homeosis in addition to complete homeosis, which is commonly accepted [3].
Homeotic mutants in angiosperms are thought to be rare in the wild: in the annual plant Clarkia, (Onagraceae), homeotic mutants are known where the petals are replaced by a second whorl of sepal like organs, originating via a mutation governed by a single recessive gene [4]. The absence of lethal or deleterous consequnces in floral mutants resuting in distinct morphological expressions has been a factor in the evolution of Clarkia, and perhaps also in many other plant groups [5].


This is very interesting since it implies that mutants in flora can have an almost endless variation of functional protein folds. Or atleast that mutations on genes involved in development can almost always find some niche where the change can be useful.
Half-Life 3 - I want to believe
User avatar
Rumraket
 
Posts: 13144
Age: 38

Print view this post

PreviousNext

Return to Creationism

Who is online

Users viewing this topic: No registered users and 1 guest

cron