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Speciation in viruses ... but where's the sex?

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Rigil Kent
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« on: December 03, 2016, 10:35:46 AM »

This post refers to an article that was linked to in the Shoutbox.

http://phys.org/news/2016-11-biologists-speciation-laboratory-flask.html

Not to detract from the importance of the work, which is phenomenal, but it's a pity that the word "speciation" is bandied along with it. I think it premature.  Maybe my understandi​ng of "species" is outdated, but some teacher must have lead me to understand "species" to mean a group containing organisms genetically sufficiently similar to allow them to have successful sex (in the biological, not recreational, sense) and produce fertile offspring. Obviously there are exceptions. For example, many types of rotifer (and there must be other plants and animals that do the same) reproduce only asexually, and the classic definition presumably don't apply. Clearly, viruses don't mate either, but make use of host cells to do most of their reproduction for them. The computer virus has equipped most of us well enough to realise that its biological counterpart replicates without sex. The researchers now seem to hint  at a new species in the flask, but based on its novel ability to attack a different host cell. Hmmmm. I guess it could be argued that the host cell is part of reproductio​n, but still, there really is no direct sexual requirement to make this new species of virus a new species of virus. All of a sudden the concept of "species" is becoming a bit fuzzy.

Not that the researchers have done this, but I don't see how one can justifiably extrapolate speciation in virusses (with their presumably custom definition for "species") to "prove inductively" speciation in other animals (classified under a different definition). That does not mean, of course, that we cannot be excited about the possibility.

A subsequent Shoutbox remark,
Quote
(16:09:47) BoogieMonster: Now we should just figure out a way to turna crododile into a dog in a single human lifespan and it'll all be over.

holds water, because most people understand very clearly the idea of a species when it comes to these organisms. The timescale may be a problem though, which is one of the avantages that viruses offer researchers.


Rigil

ETA: In the first 10min of this funny podcast, the problem with defining species rigorously comes up. Worth a listen.
http://www.bbc.co.uk/programmes/b06ybg84

« Last Edit: December 03, 2016, 12:22:23 PM by Rigil Kent » Logged
BoogieMonster
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« Reply #1 on: December 05, 2016, 08:36:45 AM »

This post refers to an article that was linked to in the Shoutbox.

http://phys.org/news/2016-11-biologists-speciation-laboratory-flask.html

.... there really is no direct sexual requirement to make this new species of virus a new species of virus. All of a sudden the concept of "species" is becoming a bit fuzzy.


So you wanna know how I really feel: The entire concept of species and nicely delineated groups is a fuzzy conception to begin with and is a mere human attempt to assert some kind of order where there is little. Heck, I remember fun debates over whether a virus is life at all.

Fundies like to go on and on about "kinds", a specious concept they made up so they can make it mean whatever they want, whenever they want, so as to dodge the responsibility of using any kind of rational criteria to measure anything. HOWEVER, this is where my comment about crocodiles and dogs come in to the picture: Only if you could (and you can't, but if you could) do something that radical in a lifespan (or so) would it force them to concede the point. Of course, theyd 'concede' it by saying: "Blah blah interpretation we knew it all along those were those other crazy christians *PSH* surely wasn't us!"
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brianvds
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« Reply #2 on: December 05, 2016, 11:41:35 AM »

So you wanna know how I really feel: The entire concept of species and nicely delineated groups is a fuzzy conception to begin with and is a mere human attempt to assert some kind of order where there is little. Heck, I remember fun debates over whether a virus is life at all.

The species concept is very handy, but a little too good to be true. It's alternative, referring only to genomes, is a bit too true to be good. :-)

But given evolution, fuzzy borders between species are of course no surprise.

Quote
Fundies like to go on and on about "kinds", a specious concept they made up so they can make it mean whatever they want, whenever they want, so as to dodge the responsibility of using any kind of rational criteria to measure anything. HOWEVER, this is where my comment about crocodiles and dogs come in to the picture: Only if you could (and you can't, but if you could) do something that radical in a lifespan (or so) would it force them to concede the point. Of course, theyd 'concede' it by saying: "Blah blah interpretation we knew it all along those were those other crazy christians *PSH* surely wasn't us!"

If a crocodile gave birth to a dog, it would actually pretty comprehensively disprove evolution, or at least evolution as biologists understand it at the moment.
Anyway, by fundie biology, it would simply illustrate that crocs and dogs are of the same "kind", meaning even less room necessary on the ark!
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Mefiante
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« Reply #3 on: December 05, 2016, 17:02:10 PM »

Defining viral species.  There’s a more easily digestible article at Wikipedia.  Basically, viruses are “speciesfied” (to coin a term) according to their genetic closeness to their peers in combination with assorted habitat factors.  Remember that with viruses the “genetic” aspect is contained in RNA, not DNA, which makes things both a little simpler and more fuzzy.

In this view, though again DNA is the crux, Richard Lenski’s E. Coli long-term evolution experiment could be seen as throwing up at least one speciation event, namely when a strain emerged that could grow anaerobically on a citrate substrate.  This new strain opened up a new survival niche for the bacterium, and no doubt would have led to significant genetic changes over time.

The biological “kind” construct so beloved of creationists comes from the King James version of Genesis 1:24.  In any case, the only viruses they’ll be interested in are those of the mind.

'Luthon64
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