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Predicting Evolution

SezMe

post-pre-born
SezMe
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This article discusses a study the outcome of which seems obvious to me...but not being a biologist maybe I just don't get it. I have two questions:

1) Is "strain" a proper scientific term? If so, what does it mean? Or is this usage just sloppy journalism?

2) In the next to last paragraph, the article states, "The group then conducted the experiment again, and the same mutations developed." (My emphasis).

Wouldn't this be more properly phrased as "survived"?
 
IMHO the last sentence contains what this experiment was all about:

This suggests that very few molecular pathways are available for a specific molecular response.
Click to expand...

If enough about the molecular and genetic makeup of the organism and about the responsiveness of specific genes is known, there might be a fair chance (literally - it's a purely stochastic approach) of predicting which phenotype will emerge under adaptive pressure. Not something to blow the bugles about though, I think, and as you say, rather obvious too.

AFAIK, "strain" is used in microbiology for genotype lines. But the "developing mutations" bit IS sloppy journalism.
 
I dunno, I don't see it as sloppy, imprecise, perhaps.

Because really, the mutations would have to develop before being selected, and assuming identical environments then the same mutations that provided advantage before would provide advantage the second time, and thus be selected. But, something different might have developed leading to a different way to adapt.

Just my take :)
 
Floyt said:
I guess it rubs me the wrong way because the term "development" is usually used for genetic expression (i.e. phenotypic) rather than for changes in the genotype. Let's settle on imprecise :)
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Yeah. Of course, development is a much looser term outside the scientist world, so he could have been trying to repot accurately.

Of course, he could not have a clue, as well, but it isn't necessarily a bad thing :)
 
Floyt said:
IMHO the last sentence contains what this experiment was all about:
Click to expand...
Exactly my reaction. Notice that this is from the first direct quote, down at the bottom of the piece.

There are millions of organisms over many generations, with a certain degree of copying-error. Just about every possibility is going to crop up, and assuming that only one constraint/parameter is varying those organisms that get through a bottleneck will rapidly repopulate the environment. Successive bottlenecks will narrow the options down to the few viable strategies at the extreme. Or, if there aren't any viable strategies, lead to extinction.

On the sloppy journalism issue, the title
Can we predict how animals and plants evolve in response to changes in the environment? Maybe, according to preliminary research from Rice University.
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may not be the author's fault, titles are usually down to subs (meaning sub-editors or sub-literates according to taste). All the same, it sucks. From microbes to plants and animals ... puhlease. The journalist did at least mention microbial resistance as the reason this article should interest the general public. Multi-resistant bugs are a widely-recognised problem in the general population.
 
Do bacteria have junk DNA? I'm curious because some junk DNA appears to be degraded genes which might be restored by copying-error. So knocking out the functional gene might bring the occasionally resurrected gene into the spotlight.
 
They do not have introns (sez my hazy recollection).

*check*

Nope, they don't. So there goes the major source for "junk".
Is resurrection of accidentally restored defunct genes a common occurrence in eucaryotes? Seems like an awfully long haul to contribute anything substantial to adaptation...
 
Floyt said:
They do not have introns (sez my hazy recollection).

*check*

Nope, they don't. So there goes the major source for "junk".
Click to expand...
Thanks for that.

Is resurrection of accidentally restored defunct genes a common occurrence in eucaryotes? Seems like an awfully long haul to contribute anything substantial to adaptation...
Click to expand...
Junk could contain an archive of genes that are no longer useful but might be again if circumstancs change. Just wild speculation on my part.
 
SezMe said:
This article discusses a study the outcome of which seems obvious to me...but not being a biologist maybe I just don't get it. I have two questions:

1) Is "strain" a proper scientific term? If so, what does it mean? Or is this usage just sloppy journalism?
Click to expand...
I think it is a scientific term to describe changes in DNA that do not result in new species or something like that. The word strain is used to describe subspecies groupings of bacteria which have certain notable differences for instance the bacteria Escherichia coli (e coli), there are hundreds of different strains most of which are normal digestive tract flora but then along comes the strain Escherichia coli O157:H7 which causes severe gastrointestinal disease.



2) In the next to last paragraph, the article states, "The group then conducted the experiment again, and the same mutations developed." (My emphasis).
Wouldn't this be more properly phrased as "survived"?
Click to expand...
The mutations developed and then they may or may not survive.

In general the idea that evolution is predictable might be ultimately true but only if we know all of the factors going into the process. In this situation we have a very controlled process and as we all know life outside of a laboratory is not like that and so not predictable (yet).
 
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