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← Lab yeast make evolutionary leap to multicellularity

Lab yeast make evolutionary leap to multicellularity - Comments

Polesch's Avatar Comment 1 by Polesch

Great news!

Thu, 23 Jun 2011 18:55:29 UTC | #842001

Quine's Avatar Comment 2 by Quine

Yeast have extremely complex enzyme systems that give them the tool box for quick adaptation. We are just starting to see the great potential for this kind of forced evolution to make things that are still beyond our design capability.

Thu, 23 Jun 2011 19:01:50 UTC | #842004

ZenDruid's Avatar Comment 3 by ZenDruid

How does this 'clumping' differ from the flocculation found in top-fermenting brewer's yeast?

Thu, 23 Jun 2011 19:31:50 UTC | #842011

Bipedal Primate's Avatar Comment 4 by Bipedal Primate

Just another hoax by those pesky evolutionists.

Thu, 23 Jun 2011 19:43:56 UTC | #842016

s.k.graham's Avatar Comment 5 by s.k.graham

Why on earth should this be "surprising" at all? What on earth makes anyone think it would be "difficult" for single celled organisms to evolve multicelluarity with differentiation?

Start with a successful single celled organism... it will rapidly fill up its environment with a mass of clones, identical except for occasional mutations. Within a mass of cells, conditions will be different from one point to another, depending on things such as flow of nutrients and waste products, exposure to predation, and so forth. Quite naturally the ability of the single cells to modify their behavior according to where they are within a mass of sister-cells will be favored by natural selection. And among a population of clones, cooperation and "altruistic" self-sacrifice will also be strongly favored. Finally the ability to stick together in a unified mass can be advantages in various circumstances whether the cells are closely related or not.

Multicellular life is no evolutionary "leap". It's more like an evolutionary "roll over in bed while half asleep".

Please tell me that tell me that the idea of multicellularity as a major hurdle in not an entrenched assumption among biologists.

Thu, 23 Jun 2011 20:03:02 UTC | #842023

ChuanZiZen's Avatar Comment 6 by ChuanZiZen

@s.k.graham: Perhaps the revelation is not to science or existing theories as much as it is for those not versed academically or culturally with regard to the significance of being able to demonstrate "evolution" without the need of arguing the fossil record (yet again). Perhaps?

Thu, 23 Jun 2011 20:54:24 UTC | #842037

Sines's Avatar Comment 7 by Sines

I'm no biologist, but if most biologists think this is pretty amazing, then I'm inclined to trust them. After all, you'd think evolution by means of natural selection would be a pretty obvious idea as well.

It may sound easy, but perhaps the inner workings of the cells and their DNA just don't make it that easy. Comments from people who know better?

Thu, 23 Jun 2011 20:55:00 UTC | #842038

Anonymous's Avatar Comment 8 by Anonymous

Comment Removed by Moderator

Thu, 23 Jun 2011 21:30:46 UTC | #842048

Jos Gibbons's Avatar Comment 9 by Jos Gibbons

If I recall correctly there was also a case of a unicellular algal strain becoming multicellular in an experiment in response to a predator.

Thu, 23 Jun 2011 21:31:19 UTC | #842049

ajs261's Avatar Comment 10 by ajs261

The University of Minnesota might be getting a call from Andy Schlafly sometime soon...

Thu, 23 Jun 2011 21:33:49 UTC | #842050

Robert Firth's Avatar Comment 11 by Robert Firth

In response to #5: I think the key evolutionary step is not multicellularity but heterogeneity. Yes, its easy for a bunch of identical cells to clump together. What is hard is for those cells to differentiate, and form different organs. How can two cells with identical DNA develop in two different directions?

I suspect the answer grows out of some form of symmetry breaking. Gravity provides an up/down axis, and hence a trigger by which ventral and dorsal can differentiate. And water flow perhaps provides an upstream/downstream axis, along which head and tail can organise. No clear way to distinguish left from right, so that symmetry mostly persists in the final organism.

Later in evolution, these external stimuli can be reflected in gradients for instance of chemical concentration, so making sure all the cells can locate themselves in the Bauplan.

Fri, 24 Jun 2011 01:13:23 UTC | #842081

s.k.graham's Avatar Comment 12 by s.k.graham

@#11

I don't think differentiation within a multicellular mass is hard at all. You mention symmetry breaking. My first post mentions several possibilities -- the flow an concentration of nutrients and waste products, for example. Gravity which you mention is another. Light and shadow are another symmetry breaking signal. It is inevitable that the environment will be different in different parts of a given mass of cells.

Single celled organisms alter their behavior, (up to and including gene expression, which can in turn result in significantly altered internal and external structure of the cell, different enzymes, etc.), in response to different environments obviously happens -- it is how single celled critters survive in a changing environment over the course of a single lifetime. So there is nothing special about differentiated function among a mass of genetically identical cells, since different parts of the mass will have a different local chemical environments.

Various chemicals released by the different cells in different amounts would depend on where the cells are in the mass (the local environment). These chemicals at first would be the byproducts of adaptive functions. Over an evolutionary time scale, these chemicals can be detected by the cells to know "where they are in the body" -- another signal for symmetry breaking. And over an even longer time, some of these chemicals (or modified versions of them) will inevitably be co-opted for the sole purpose of "telling cells where they are" and perform no other adaptive function withing complex, highly differentiated organisms.

I see nothing here but smooth, gradual, and fairly obvious transitions. Please note that you must not visualize this evolutionary process as occurring within a single mass of cells, but rather among a population of cells that often end up in clumps here and there an everywhere within the larger environment.

Fri, 24 Jun 2011 03:46:56 UTC | #842107

12PM's Avatar Comment 13 by 12PM

they look like Siamese twins to me. I wish I am wrong.

you see the reality is just the reality itself. beauty is our perception or judgement on reality or a value we add to the reality. the reality itself has nothing to do with beauty but reality itself. that's why beauty is simply up to the beholders - and there beauty has inconsistency. reality doesn't change that way.

when an idea sounds beautiful, it's just our perception - not necessarily being the reality.

Fri, 24 Jun 2011 07:54:38 UTC | #842152

sunbeamforjeebus's Avatar Comment 14 by sunbeamforjeebus

Some of the previous posts display an impressive degree of knowledge in this area which make inspiring reading.For my part, any and all advances in science are thrilling but anything to do with our development and evolution is particularly interesting.No doubt the fuckwits will still think goddunnit!

Fri, 24 Jun 2011 08:02:34 UTC | #842155

keddaw's Avatar Comment 15 by keddaw

@sunbeamforjeebus, I wish God would stop tinkering in my experiments, he's really messing up the results.

@s.k.graham, I think the difference here from the generalised case you are talking about is that these cells only seem to be clumping together with their relatives and the 'snowflakes' split and reproduce at a rate that would appear consistent with a single organism rather than a clump of cells. Or I might be reading too much into it.

Fri, 24 Jun 2011 08:36:02 UTC | #842167

DavidMcC's Avatar Comment 16 by DavidMcC

Comment 5 by s.k.graham :

Why on earth should this be "surprising" at all? What on earth makes anyone think it would be "difficult" for single celled organisms to evolve multicelluarity with differentiation? Start with a successful single celled organism... it will rapidly fill up its environment with a mass of clones, identical except for occasional mutations. Within a mass of cells, conditions will be different from one point to another, depending on things such as flow of nutrients and waste products, exposure to predation, and so forth. Quite naturally the ability of the single cells to modify their behavior according to where they are within a mass of sister-cells will be favored by natural selection. And among a population of clones, cooperation and "altruistic" self-sacrifice will also be strongly favored. Finally the ability to stick together in a unified mass can be advantages in various circumstances whether the cells are closely related or not.

Multicellular life is no evolutionary "leap". It's more like an evolutionary "roll over in bed while half asleep". Please tell me that tell me that the idea of multicellularity as a major hurdle in not an entrenched assumption among biologists.

Yet it didn't happen until there was a snowball Earth, at around 650MYa, even though there had been a global bacterial mat for a couple of billion years. Probably, the kind of yeast used is a relatively recent single celled species: whole genome duplication event @ 100MYa

Fri, 24 Jun 2011 09:10:33 UTC | #842173

12PM's Avatar Comment 17 by 12PM

Ethanol is very important during human evolution

does that mean the world environment has not evolved but human alone evolved? whey ethanol was as important as for now if the environment was different?

This will have economic impact on the wine and beer industries

this could be more true.

Fri, 24 Jun 2011 10:59:35 UTC | #842190

Chris Roberts's Avatar Comment 18 by Chris Roberts

This is excellent news, but not overly suprising. Any strong selection pressure is going to force evolution in a particular direction - but I am very suprised at how quick this has happened.

Keep up the good work guys!

Fri, 24 Jun 2011 11:15:35 UTC | #842197

SaganTheCat's Avatar Comment 19 by SaganTheCat

so in our lifetime we have seen a new species of e.coli evolve in a lab and now multicellular life.

are there any gaps left?

Fri, 24 Jun 2011 11:24:49 UTC | #842204

davedotcom's Avatar Comment 20 by davedotcom

Such a shame that this kind or news doesn't find it's way into the circle of evolution deniers.

One of the constant arguements is 'why don't we see it happening?'. Here is evidence. It's been seen to happen. Can that arguement not be put to bed now?

Fri, 24 Jun 2011 12:02:56 UTC | #842221

Rosbif's Avatar Comment 21 by Rosbif

Should we be looking for a YeastDuck or CrocYeast? Or will Kirk and the boys handle that bit of "science"?

Fri, 24 Jun 2011 12:04:30 UTC | #842222

Sample's Avatar Comment 22 by Sample

I'd like to order the first pizza made from this. On second thought, perhaps I should open an Evolutionary Restaurant emphasizing uncommon foodstuffs that are only made possible because of science. Hmmm.

:-j

Mike

Fri, 24 Jun 2011 12:33:15 UTC | #842231

DavidMcC's Avatar Comment 23 by DavidMcC

I wonder how much further this experiment could go, in terms of the multicellularity. Will this new form of yeast walk out of the test-tube (presumably feeling a bit giddy!) one day? It is surely already a new species.

EDIT: I imagine it was genes left over from the genome duplication event 100MY ago that made it relatively quick to speciate in a way that increases the complexity of the organism. It reminds me of the likely evolution of sponges from single-celled choanoflagellates.

Fri, 24 Jun 2011 14:27:43 UTC | #842270

littletrotsky13's Avatar Comment 24 by littletrotsky13

@DavidMcC I presume that as the organism becomes more complex its reproductive speed will slow somewhat, but I would think that if they were to continue for a bit they would find cells starting to specialise to their tasks and apoptosis (programmed cell death, essentially a "for the greater good" event in an organism) appearing. Having said that I would need to see it in an organism without multicellular ancestors, such as amoeba (also making sure that they have functional mitochondria, let's not stack the odds too far against them or we'll never get anything hapenning). @S.K. Grahame there's a fair amount of adjustments a unicelluelar organism needs to make in order for multicellularity to become viable or a beneficial route, it needs to be more cooperative to it's "siblings" than most unicellular organisms are, it needs to gain some form of adhesion (rather than merely developing into a colony) and the cells then need to develop a way of growing in tandem in a relatively coordinated fashion, and fairly soon after that apoptosis almost has to develop or cooperation breaks down and it stops being a multicellular organism. What's excited those of us who are excited is bsically that we got to see it in a lab with just 350 generations (for those who do not know it often takes that long to force quite minor changes, and despite the fact that a lot of the potential multicellularity factors are merely inactivated it's still extremely fast even for a labratory selection experiment)

Fri, 24 Jun 2011 15:07:45 UTC | #842281

DavidMcC's Avatar Comment 25 by DavidMcC

I've just noticed a crucial section of the linked article:

Sceptics, however, point out that many yeast strains naturally form colonies, and that their ancestors were multicellular tens or hundreds of millions of years ago. As a result, they may have retained some evolved mechanisms for cell adhesion and programmed cell death, effectively stacking the deck in favour of Ratcliff's experiment.

"I bet that yeast, having once been multicellular, never lost it completely," says Neil Blackstone, an evolutionary biologist at Northern Illinois University in DeKalb. "I don't think if you took something that had never been multicellular you would get it so quickly."

There's your apoptosis pathway, trotsky, although I suspect that a single celled organism would quickly lose it, and in 100MYa, it might well be more than just switched off!

Fri, 24 Jun 2011 15:31:11 UTC | #842288

isisdron's Avatar Comment 26 by isisdron

wonderful news for vaginas everywhere. :( They arent yeast anymore, ladies. They're parasites! Yikes.)

Fri, 24 Jun 2011 19:57:41 UTC | #842347

cerad's Avatar Comment 27 by cerad

But sadly it's still yeast. If a sex starved sea monkey from the future popped out from the vat then we would have something worthwhile to discuss.

Fri, 24 Jun 2011 21:54:41 UTC | #842373

reebus's Avatar Comment 28 by reebus

I saw this article and I didn't think it lived up to the sensationalism of the title, after the last paragraph reminded us that the capacity for multicelluarism is ancesteral in that yeast. This is at least the second time new scientist pulled this tabloid trick on me lol, from now on I'm just going to read the last paragraph of every article of theirs because I expect its going to be most representative of what's actually happenin :D

Fri, 24 Jun 2011 23:52:06 UTC | #842390

AnAtheistBastard's Avatar Comment 29 by AnAtheistBastard

If multicellular lab yeast came from single celled yeast, why is there still single celled yeast? ;)

Comment 19 by Daniel Clear :

...

are there any gaps left?

I think the asexual -> sexual reproduction transition is still an open issue.

Maybe that can be there next challenge? Just as an idea of how to do it: "Make" a virus that only attacks yeast with a specific set of genes and set it loose on the cultures. Children formed by sexual reproduction will only have half of each of their parent's genes, so they will be resistant. Or something like that, my idea requires quite a large leap for a mutation to make. Their solution to select for larger organisms was ingenious.

The best part is that any newly evolved sexual species wouldn't have yet differentiated into two (or more???) genders. Thats right, gay yeast.

I'm sure the creationists will like that.

Sat, 25 Jun 2011 12:40:13 UTC | #842483

showmeproof's Avatar Comment 30 by showmeproof

This would be a great demonstration of evolution in High School biology class. All you need is a centrifuge a eppendorf repipetter, an incubator and a microscope.

I hope the chlamydomanus experiment works out.

Sat, 25 Jun 2011 19:02:23 UTC | #842573