Evolution and Coral

[MCsaxmaster]

<a href=showthread.php?s=&postid=12232980#post12232980 target=_blank>Originally posted</a> by miwoodar
:beer:
Man - I wish my college had classes about marine environments and the ecology thereof. The closest I got were a few generalized classes that could be 'applied' for lack of a better term...ecology, genetics, biological statistics, cell bio, fisheries/wildlife management, and a limnology course. One last one - wastewater treatment and drinking water supply (it might as well have been called 'how to keep a really large fish tank').

Ha, that's mostly self-taught. You won't learn everything in school

You dont believe a new species is formed from branch fusing,or is an observable genetic mutation increasing genetic information off topic?I kind of like the branch fusing myself it is very interesting.

If branch fusion in corals results in a new species/subspecies/hybrid, then every time you have a cut that heals you are creating a new species/subspecies/hybrid of human

Suffice it to say, that is toooootally inaccurate.

 

[miwoodar]

You dont believe a new species is formed from branch fusing,or is an observable genetic mutation increasing genetic information off topic?I kind of like the branch fusing myself it is very interesting.

I can answer your question with a resounding no. I skipped school from time to time, but I definitely caught the classes that covered that.

Might I remind you that the other person in this thread, MCSaxMaster, has a masters degree in marine biology. No, I would not imply that we should *ever* listen to a person simply because they have perceived *credentials*. However, you and I have been clearly outsmarted in this thread. Keep stirring the pot a little though, I feel enlightend by MC's responses .

 

[cutegecko3]

Very funny.From your logic,if you scramble an egg it is by definition a different kind of egg.Seas of life narrarated by david attenburburgh gives the entire dna sequencing of all known acropora.I cant remember the exact number of genus,species,families or what ever it is.(sorry about that).But anyways the dna shows very few varieties despite the enourmos morphological differences.An acro. is both sexes it produces eggs and sperm in the same capsule.So when the branches fuse together the eggs get crossed as well creating a hybrid from the very same colony.Thats how several hundred varities can rapidly turn into several thousand.

 

[miwoodar]

Seas of life narrarated by david attenburburgh gives the entire dna sequencing of all known acropora.I cant remember the exact number of genus,species,families or what ever it is.(sorry about that).But anyways the dna shows very few varieties despite the enourmos morphological differences.An acro. is both sexes it produces eggs and sperm in the same capsule.So when the branches fuse together the eggs get crossed as well creating a hybrid from the very same colony.Thats how several hundred varities can rapidly turn into several thousand.

Dude....? Somebody is placing this comment on a little golf tee and is getting ready to drive it right down the center of the fairway. Whaap!

DNA sequencing of 'all known acropora'. :lol: I call BS. If you can't distinguish between the terms genus, species, and/or families, you probably aren't in a position to make such a statement no matter what show you saw.

Hybrid from the very same colony. :lol: Again

Maybe start here...http://en.wikipedia.org/wiki/Scientific_classification
I

 

[blufish]

Seas of life narrarated by david attenburburgh gives the entire dna sequencing of all known acropora.


You must be kidding, right? Please say you are kidding.

 

[MCsaxmaster]

Very funny.From your logic,if you scramble an egg it is by definition a different kind of egg.

Good lord no--that is YOUR argument. Mixing tissue of the same organism does not result in a new organism--that's they point

Seas of life narrarated by david attenburburgh gives the entire dna sequencing of all known acropora.

Considering that we have not yet sequenced the genome for even a single species of coral, much less all species of Acropora, either the film is wrong, or you misunderstood. Please watch that section of the film again as I'm almost certain they would not make such a ridiculous claim as suggesting that the genomes of all species of Acropora have been sequenced. We can amplify small sections of DNA to study relatedness, and we do that all the time in every group of organisms, not just corals. That is not remotely the same as saying that we have sequenced an organisms genome.

I cant remember the exact number of genus,species,families or what ever it is.(sorry about that).But anyways the dna shows very few varieties despite the enourmos morphological differences.

Yup, this genus shows relatively rapid evolution and speciation for corals. It's still not that fast as compared to a lot of animals, but its fast for corals. That is the point I'm sure they were trying to make in the film--there has been rapid diversification within the genus. We can tell the diversification has been rapid because variation in neutral sections of DNA is small, indicating recent divergence.

An acro. is both sexes it produces eggs and sperm in the same capsule.

Oh goodness. Most species of Acropora are hermaphroditic broadcast spawners, but not all. Some are gonochoristic and some (few) may be brooders. Of those that are hermaphroditic broadcast spawners, usually the gametes are released in egg-sperm bundles.

In fact, my advisor was the first person to successfully capture large numbers of gametes and rear large numbers of planulae from the endangered Elkhorn coral (Acropora palmata). Not to toot my own horn too loudly, but I am one of a couple dozen folks on the planet that has worked on the reproduction of this species. Our lab is one of the few that works heavily on coral reproduction. Suffice it to say, I know a thing or two about coral reproduction

So when the branches fuse together the eggs get crossed as well creating a hybrid from the very same colony.

Nope. Most corals cannot self-fertilize. Whether branches from the same colony have fused or not (this is simply a growth response) is entirely irrelevant. Even if they can self, that isn't a hybrid. A hybrid results from cross-fertilization between two species, not self-fertilization.

Thats how several hundred varities can rapidly turn into several thousand. [/B]

Nope. Asexual reproduction substantially reduces the rate of evolution, and cannot create hybrids, by definition. We have hundreds of species from perhaps a few dozen over many millions of years due to, what is for corals, rapid evolution.

And just for the record, I am finishing my master's. I haven't defended yet (though I will before too long). I shan't claim credentials I cannot yet officially claim. Having said that, just give me a few months

 

[cutegecko3]

<a href=showthread.php?s=&postid=12233291#post12233291 target=_blank>Originally posted</a> by blufish
Seas of life narrarated by david attenburburgh gives the entire dna sequencing of all known acropora.


You must be kidding, right? Please say you are kidding.

Are you implying i go and dna sequence them all myself?

 

[MCsaxmaster]

<a href=showthread.php?s=&postid=12233378#post12233378 target=_blank>Originally posted</a> by cutegecko3
Are you implying i go and dna sequence them all myself?

Nope. What we are flat-out saying is that you are just plain wrong. We have yet to sequence the genome of ANY species of coral, much less the entire genus Acropora (nearly 400 species).

 

[miwoodar]

In the spirit of April Fools...

 

[cutegecko3]

Were not talking about(at least im not)all corals.I said acropora and by your own admission you said most are hermorphodites.Fusing tissue together fuses tissue together i dont think thats an issue here.Acro. have individual polyps and each individual has its own chromosomes etc.If the sweat glands in your skin had fertilized eggs in them and the skin healed after a cut then yes speciation could happen.And i didnt say the entire genome has been sequenced(the basic dna test)Good luck on your masters anyway.

 

[MCsaxmaster]

Hehehehe, bunny

I will also note that there has been a lot of talk about sequencing a coral genome in the last few years. Likely candidates include Pocillopora damicornis, Acropora palmata, Montastraea faveolata, Acropora millepora and Porites lobata. It is an expensive endevour, but not terribly so (on the order of $1.6 million, last I heard) but the project is still somewhat up in the air. We are far, far from sequencing all species of Acropora.

 

[miwoodar]

That would be a neat nugget of information but I'm having difficulties envisioning what uses it could serve. Maybe other areas of science, or medicine, just because, or ???. MC - any ideas?

OT - my sister lives in Okemos.

 

[MCsaxmaster]

<a href=showthread.php?s=&postid=12233493#post12233493 target=_blank>Originally posted</a> by miwoodar
That would be a neat nugget of information but I'm having difficulties envisioning what uses it could serve. Maybe other areas of science, or medicine, just because, or ???. MC - any ideas?

OT - my sister lives in Okemos.

Believe me, I can appreciate how difficult it is to envision how pieces of information like this will be used. Perhaps think of it this way: everything an organism does or can do is ultimately governed by its genes. The genes are like a book. For most organisms, the most we can do is read a few sentences out of the book. We may or may not fully comprehend what the sentences mean, but we can at least read them. The rest of the book is essentially a black box. We have no idea what is written there. By sequencing a genome we are getting a full copy of the book. We still won't understand what every sentence means, but we can very rapidly start putting things together. For instance, similar sequences might be found--similar words. If we know what those sequences do in fruit flies, or round worms, or humans, or whatever, we then have a great idea of what they do in corals. We can begin to understand how the organism works when we know what the basic instructions are. We can also apply that knowledge to all sorts of other organisms. For instance, 40% of the DNA is homologous between humans and C. elegans. By studying a model species we can learn a great deal about other species we may be interested in.

Sequencing the genome of model species is a great beginning step toward understanding so, so many aspects of the biology of countless other species. As the number of species sequenced rises, the number of inferenses and connections we can make--the advances in our understanding--go up exponentially.

Chris

p.s. Good to hear! Most of my family is back in MI as well.

 

[thecichlidpleco]

Been a while since my genetics class but here is link to further someone's sequencing argument
http://cnidbase.bu.edu/

 

[greenbean36191]

Were not talking about(at least im not)all corals.I said acropora and by your own admission you said most are hermorphodites.Fusing tissue together fuses tissue together i dont think thats an issue here.Acro. have individual polyps and each individual has its own chromosomes etc.If the sweat glands in your skin had fertilized eggs in them and the skin healed after a cut then yes speciation could happen.And i didnt say the entire genome has been sequenced(the basic dna test)Good luck on your masters anyway.

Wow, lots to address here.

First of all, the polyps aren't "individuals" in the normal sense of the word. They're clonally produced ramets, meaning they're genetically identical. Their tissues, including the nerve nets and guts are also highly interconnected. Sure, all the cells have their own set of chromosomes, but they're identical for every somatic cell in the whole colony. Every polyp has the same genes as its neighbor.

Second, being hermaphroditic doesn't mean you have the ability to self-fertilize. Quite a few hermaphrodites can't do it at all or have very poor rates of fertilization. After all, self-fertilizing kind of defeats the purpose of putting the effort into sexual reproduction. Most Acropora are in that category. You can collect the eggs and sperm from a single colony and mix them however you like and usually won't get viable larvae. That mixing would never occur during branch fusion though because the gonads are located entirely within the polyp. When branches fuse, the gametes never come any closer to each other than they would if they were within polyps on a single unfused branch.

Third, for there to be any evolution the changes that occur have to be heritable. That means they have to be represented in the DNA of the germ cells (or the parent cells giving rise to clones). Phenotypic changes due to lighting or flow don't change the DNA at all, just how it's expressed, so they can't be inherited. Even if you had a chimeric colony formed from two species whose branches have fused (observed with Montipora), there's no change to the genetic material and as a result no heritability and no evolution.

 

[greenbean36191]

And FWIW, I'm pretty sure I saw the Attenborough documentary you mentioned (which is probably 10 yrs old now if it's the one I'm thinking of). In it he says that rather than the 400 or so species we have now based on morphology, there may be as few as 12-15 extremely variable species. That's not a new idea and there's some molecular basis suggesting that a lot of the morphological taxonomy of Acropora is wrong, but there's also a lot that just doesn't make any sense at all when compared to the morphology. The idea that there's just 12-15 "superspecies" probably only made it into the documentary because of a single prominent supporter, not because it was ever a widely supported view.

 

[cutegecko3]

That wouldnt suprise me any.They said the branches on every colony are different species(referring to the polyps i assume)and every time a branch fuses it creates a new super species.But look at what their saying,The definition of a species is being able to produce viable offspring.So i thought they meant a hybrid.I watch a lot of the science channel,discovery etc. and i thought they are dicussing accurate and reliable science.

 

[MCsaxmaster]

That wouldnt suprise me any.They said the branches on every colony are different species(referring to the polyps i assume)and every time a branch fuses it creates a new super species.

There are three possibilities:

1) They put out completely incorrect information, and you correctly understood them.

2) They put out incorrect information, and you misunderstood them.

3) They put out accurate information, and you misunderstood them.


Whichever is the case, the characterization above is completely incorrect. All tissue on a colony not only belong to the same species, they belong to that single organism. Corals that produce many polyps within the same colony and maintan tissue connections (in other words, most corals) are functionally a single organism with many mouths. The individual polyps do not function as individual organisms. In addition, they are all simply more of the same tissue. If you brake off a piece of a coral, you have a clone, not a new individual, and certainly not a new species.

But look at what their saying,The definition of a species is being able to produce viable offspring.So i thought they meant a hybrid.

No, that is part of one definition of a biological species. Reproductive isolation between closely related species is the norm, but natural hybrid zones do exist for many species.

As mentioned above, most corals cannot self-fertilize, though a very few seem to have a limited capacity to do so if given no possibility for cross-fertilization (e.g., in the lab). Not only is this NOT a hybrid (hybridization happens between species), it isn't even cross-fertilization within a species. It's just a matter of reshuffling the genes of the parent animal.

I watch a lot of the science channel,discovery etc. and i thought they are dicussing accurate and reliable science.

See first set of responses above.

 

[greenbean36191]

Keep in mind that the people making these shows generally aren't experts. They're filmmakers who consult experts and expect that the consultants actually know what they're talking about and that there's a single explanation for things. In real life though, scientists tend to have a broad knowledge base but a narrow range of expertise. Outside of their expertise they may be able to give a "good enough" answer, but not the best, and within their expertise they often have pet theories that aren't widely held. Basically the story you get will depend on who you ask.

As an example I had a reef ecology class that was team taught. One guy told us that the shift towards algal dominance on Caribbean reefs was due to eutrophication and removal of grazers, which is the more popular story. The other guy told us that the density of grazers doesn't matter much and that it's more about the opening of space due to disturbances like WBD. That's a much less popular story. Both felt very strongly that the other was wrong and you could really get them going over a few beers. If you worked for Discovery though, you would get a very different story depending on which one you used as a consultant. As it turns out, the guy who subscribes to the less popular theory is interviewed for news stories and documentaries all the time because he happens to be the president of the International Society for Reef Studies.

 

[miwoodar]

greenbean, I like it when you post. Smarts, wisdom, and a hot avatar.