The man who bottled evolution

https://msutoday.msu.edu/feature/2018/the-man-who-bottled-evolution/

by ramgorur • 8 years ago

44 20 8 years ago

msutoday.msu.edu

rrmm• 8 years ago

This is an amazing experiment which took an amusing detour through scientific denialism via Phyllis Schlafly's son.

Here's a summary I found surrounding the issue. https://arstechnica.com/features/2008/06/conservapedias-evol...

joobus3• 8 years ago

FYI, the ecoli used in the LTEE experiment reproduce asexually, so defining 'evolution' in this sense is entirely at the discretion of the scientists. For sexually reproducing organisms, speciation occurs when an organism can no longer reproduce with its predecessor, a feat which science still can't prove.

moh_maya• 8 years ago

umm, what? Darwin's finches comes to mind [1]. Also, since then, a host of other examples. All you need to do is look at the Wikipedia page [2], which has citations to the primary research.

Unless you mean, no one has seen it happen inside a lab? But that's not true either.., accelerated evolution experiments with uni-cellular species with different "sexes", leading to reproductive isolation (ergo, speciation) has been shown [3].

How about multi-cellular species where this has been demonstrated at the broad genetic & physiological / behavioral level? That's been done too. See these two for a review of some of the work [4,5].

[1] https://academic.oup.com/zoolinnean/article/3/9/45/2701607

"On the Tendency of Species to form Varieties; and on the Perpetuation of Varieties and Species by Natural Means of Selection", Darwin & Wallace

[2] https://en.wikipedia.org/wiki/Speciation#The_effect_of_sexua...

[3] http://www.pnas.org/content/112/14/4405

"Molecular coevolution of a sex pheromone and its receptor triggers reproductive isolation in Schizosaccharomyces pombe"

[4] http://www.pnas.org/content/97/23/12398

"Natural selection and speciation"

[5] http://www.pnas.org/content/102/suppl_1/6522

"The genetic basis of reproductive isolation: Insights from Drosophila"

And all this from a cursory 5 minute search (including time to type this up)..

joobus3• 8 years ago

None of your citations, including Darwin's finches, prove evolution.

Your citation #3 states "In conclusion, we have succeeded in creating an artificial reproductive group that is isolated from the WT group." They artificially castrated a species; that is not evolution.

Citation #4: "The authors suggest that reproductive isolation has evolved in situ as a result of...". Again, not proof.

Citation #5 adds no value at all: "Although the sample of genes characterized thus far by various laboratories remains small, and concentrated in the genus Drosophila, I suspect that these patterns may prove general, although likely not universal. Our recent work, along with that of several other groups, also suggests that the selection underlying the evolution of speciation genes may sometimes assume a surprising form, response to intragenomic conflicts, perhaps involving meiotic drive." Keywords: suspect, suggests, may, perhaps

You may want to believe evolution so badly, but science doesn't have the proof yet, and that is a fact.

klmr2• 8 years ago

defining 'evolution' in this sense is entirely at the discretion of the scientists

That’s utter nonsense. No general definition of evolution (whether as a general concept or whether via a specific mechanism, such as natural selection) requires sexual reproduction. Only some mechanisms do (in particular, obviously, sexual selection). Evolution by random mutation and natural selection (the core concept of the modern synthesis, which underpins all of modern biology) is completely independent of sexual reproduction.

For sexually reproducing organisms, speciation occurs when an organism can no longer reproduce with its predecessor

You’re misunderstanding something that is used for convenience, but is really a vast simplification. In reality speciation isn’t one defined point in time (hence it’s idiocy to ask what species the parents of the first human were — evolution is gradual!). To name just one specific example where your example breaks down: ring species [1].

[…] science still can't prove [speciation in sexually reproducing organisms].

Once more, that’s utter nonsense (e.g. [2]).

[1] https://en.wikipedia.org/wiki/Ring_species [2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1635482/

joobus3• 8 years ago

Evolution by random mutation and natural selection (the core concept of the modern synthesis, which underpins all of modern biology) is completely independent of sexual reproduction.

Now all you have to do is prove that a "random mutation" created a new species.

Second, you cite the Ring Species wiki, which links to an article which argues ring species don't exist. The proof is nebulous. https://whyevolutionistrue.wordpress.com/2014/07/16/there-ar...

_greim_• 8 years ago

The LTEE is special because it allows the team to “replay” evolution and thereby probe the effects of prior history on later events. After every 75 days (500 generations), the bacteria are frozen. This serves as an organic data backup of sorts, allowing scientists to thaw and revive living “fossils.”

This is just amazing. Kudos to this team of scientists.

Kattywumpus• 8 years ago

Whenever I read about this experiment, I think about Theodore Sturgeon's "Microcosmic God", and experience a moment of profound disappointment:

https://tinyurl.com/microcosmicgod

I won't spoil it for you. It's still a great bedtime read.

MaysonL• 8 years ago

Also, Greg Bear's Blood Music.

needz• 8 years ago

Link leads nowhere for me.

sillysaurus3• 8 years ago

http://1pezeshk.com/wp-content/pics/2013/01/microcosmicgodth...

Nelgraf• 8 years ago

Nice read, thanks for sharing.

ha8o8le• 8 years ago

I have a friend who is somewhat of a "evolution denier" (he's not religious and actually very intelligent). I was thinking about this from his perspective and would like someone else perspective.

"On human terms, the LTEE generations span the equivalent of well more than a million years of human evolution."

Haven't we evolved a lot more in 68,000 generations than the bacteria have? Or put another way, all the bacteria has done in this time period is go from consuming glucose to citrate, nothing else in its shape, structure, etc. So how did humans and other creatures evolve so much over 68,000 generations?

I am 100% on board with evolution, I'm just curious about this. This is only 6-7 times more generations than when humans split from chimps (quick google search said 6-7 million years ago).

Is it because we have way more interaction with our environment and these bacteria are just in a little petri dish? Sounds likely.

Has anyone ever heard of people questioning evolution? I think he was saying something about how impossible it would be to have every single thing we see in nature be pre-written in DNA - it has just been all expressed in genes over the millennia through natural selection.

whiskyant• 8 years ago

Because we and other mammals are much more complex lifeforms than bacteria, and likely have systems that help us adapt/evolve faster.

Scaevolus• 8 years ago

Sexual reproduction allows beneficial mutations to spread and recombine in a population much faster than asexual reproduction (yes, e.coli has conjugation, but it's nowhere near as powerful). A complex trait might require multiple mutations to support it-- a gene pool that's constantly mixed by sexual reproduction will have much higher chances of the combination arising than with asexual reproduction.

You can observe the same thing in genetic algorithms, where crossover ("sexual" reproduction / mixing of two candidates) is often performed because it creates more viable offspring than simple cloning with mutations.

ramgorur• 8 years ago

Harvard medical school did a similar experiment on fast evolution of bacterial resistance to antibiotics on a petri-dish. It also clearly shows the lineage of evolution. Very interesting.

https://www.youtube.com/watch?v=plVk4NVIUh8

The man who bottled evolution

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