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Scientists Resurrect 500-Million-Year-Old Gene Inside Modern Organism
An anonymous reader writes with news that researchers at the Georgia Institute of Technology have taken a gene from 500-million-year-old bacteria and inserted it into modern E. coli bacteria. They then allowed the bacteria to evolve over the course of a thousand generations to see whether it would resemble its original 'evolutionary trajectory.' From the article:
"After achieving the difficult task of placing the ancient gene in the correct chromosomal order and position in place of the modern gene within E. coli, Kaçar produced eight identical bacterial strains and allowed 'ancient life' to re-evolve. This chimeric bacteria composed of both modern and ancient genes survived, but grew about two times slower than its counterpart composed of only modern genes. 'The altered organism wasn’t as healthy or fit as its modern-day version, at least initially,' said Gaucher, 'and this created a perfect scenario that would allow the altered organism to adapt and become more fit as it accumulated mutations with each passing day.' The growth rate eventually increased and, after the first 500 generations, the scientists sequenced the genomes of all eight lineages to determine how the bacteria adapted. Not only did the fitness levels increase to nearly modern-day levels, but also some of the altered lineages actually became healthier than their modern counterpart."
Twelve. Monkeys.
this damage they inferred as meaning they took the gene back 500 million years
then the bacteria slowly repaired the damage with successive mutations, somehow meaning 500 million years of evolution had been reacquired
"some of the altered lineages actually became healthier than their modern counterpart"
meaning the typical background noise of random mutations, within or without this experiment, leads to natural variation in fitness
it's an interesting experiment, but the write up is highly contrived about what they actually did
intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
“we want to know if an organism’s history limits its future and if evolution always leads to a single, defined point or whether evolution has multiple solutions to a given problem.”
I would wager it would almost have to be the latter. For example, I found it odd that the article made no mention of horizontal gene transfer and how, over 500 million years, the chance of that bacteria participating in HGT with a distantly related bacteria could have given it, say, a faster growth mechanism -- just like bacterial resistance to drugs is theorized to be a result of HGT. This is probably a useful experiment to look at one of the many mechanisms of evolution but not the entire picture of evolution nor could it effectively draw a final conclusion that "evolution always leads to a single, defined point."
My work here is dung.
Well, a defining characteristic of the e. coli species is the lack of an ability to transport citrate across the cell membrane. Enough so that this is often used to differentiate e. coli from salmonella in cultures. So, evolving the ability to transport (and therefore metabolize) citrate in the lab would seem to be a pretty good example of e. coli becoming something other than e. coli (lacking one of the defining characteristics of the species).
Not only in the summary here on /. horrible, but the PR ... is even worse.
Where's the link to the peer-reviewed work? Neither in the "summary", nor in the PR.
FWIW, I don't find the purported results interesting in the slightest in their current form.
For example, how were the cells grown? (please don't say in LB in a chemostat.)
I was expecting a huge explosion of growth that chases the scientist out of the lab, grabs his ankle with a tentacle, drags him back into the lab to infect him and give him Akira-like telekinetic power and a thirst for world rule
What's amazing in modern society is how so many non-scientists (mainly religious fundamentalists of different sects) think evolution is very much up for debate while problems in physics are totally solved when it's the other way around. I was confronted once by an anti-evolution person who thought exactly how gravity works was a long ago solved case but evolution was some new wacky baseless idea being forced on gullible unbelievers.
E. coli is absolutely everywhere. Some strains are dangerous, but other strains are beneficial; like the ones living in your gut.
The world's burning. Moped Jesus spotted on I50. Details at 11.
Man. It's like these scientists have never even seen a horror movie.
Arslan BK and Gaucher EA Replaying the Tape of Life Through Experimental Evolution of Ancient EF-Tu proteins Astrobiology Science Conference 2010: Evolution and Life: Surviving Catastrophes and Extremes on Earth and Beyond, held April 26-20, 2010 in League City, Texas. LPI Contribution No. 1538
Which I think was just a presentation that provides very little information given all I can find is this PDF:
Whether evolution would ‘replay the tape of life’ if given the opportunity has long fascinated biologists. Paleogenetics via laboratory resurrected ancient genes not only reveals information regarding ancestral phenotypes and environments but also provides an opportunity to ‘replay’ the molecular tape of life. Recent work has demonstrated that ancestral sequences can be computationally determined and experimentally resurrected. The ideal paleoexperimental evolution system requires an organism with a short generation time and a protein whose ancestral genotype and phenotype used to replace the modern gene and causes the modern host to be less fit. The research described here focuses on Elongation Factor Tu (EF-Tu) involved in the protein synthesis machinery of both eukaryotic and prokaryotic organisms. The optimal thermostability of EF-Tus correlates with the optimal thermostability of their host organisms and are ideal for these types of experiments. Previously we have resurrected ancient EF-Tus and showed that these ancient proteins display a range of thermostability profiles. We will replace the modern EF-Tu sequences with ancient EF-Tus and observe their adaptation through experimental evolution. Results from this work will help us identify whether evolution is repetitive for this experimental system.
I don't think that really answers your question and I think this research has only been presented at conferences, published in conference proceedings and not yet peer reviewed in a journal (if it has there is no mention of it on Kacar's CV). I also find it odd that on her site she's using the phrase "tree of life" and not "web of life" which I thought was a more modern way of looking at evolution -- especially in prokaryotes.
I will say that it is probably within line to chide the researcher for putting this little blurb on her research page:
Experimental Evolution of Ancient Proteins
To assess the role of contingency in evolution, I construct an experimental time machine in the lab by inserting previously resurrected genes into a modern bacterial genomes, then subjecting them to experimental evolution. Observing the real-time evolution of ancient genes as they adapt to the conditions of modern bacteria allows us to analyze evolution in action.
"Experimental time machine?" Please, leave the hype and sensationalism to the "science" reporters.
My work here is dung.
What?! It's evolving...
Congratulations! Your E.Coli evolved into MoreFundingForLenski.
http://en.wikipedia.org/wiki/E._coli_long-term_evolution_experiment
Hugh Hefner has been doing this for a while.
See my journal for slashdot ID's by year. Mine created in 2005. http://slashdot.org/journal/289875/slashdot-ids-by-year
Damn hypocrites, slicing ancient genes is ok but re-cloning Hitler and put his brain in a great white shark is suddenly over the top!
The world is only 6000 years old.
taken a gene from 500-million-year-old bacteria and inserted it into modern E. coli bacteria.
Well that's just rude.
These are generally people who can't conceive of really big things, really small things and really long times. They think that light speed means "instantaneous". They think the WTC towers should have fallen over on their sides. They can't understand that lighter than air isn't necessarily weightless. They simply cannot imagine the timespans necessary to understand evolution. In their minds, it's an ape giving birth to George Washington.