In Evolution, Last Really Can Be First

In the February 25 Issue:

In evolution, last really can be first

Bacteria experiments show how underdogs can end up on top

By Tina Hesman Saey

Web edition : Thursday, March 17th, 2011

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In an evolutionary equivalent of Revenge of the Nerds, bacteria that once seemed destined for loserdom can eventually use their hidden potential to overtake the competition.

Researchers led by Richard Lenski of Michigan State University in East Lansing have been watching E. coli bacteria evolve since 1988 (over more than 50,000 generations) and are doing experiments that replay that evolution to settle a debate about whether natural selection produces the same outcome every time or if surprises can happen along the way (SN: 1/31/09, p. 26). The experiments are also aimed at understanding the genetic mechanisms that drive evolution.

In a new study published in the March 18 Science, Lenski and his colleagues address a new concept in evolutionary biology. The issue is whether some changes in DNA give organisms differing evolutionary potential, or evolvability.

The rise of the nerds seems to indicate that evolvability is a reality. A mutation that gave some bacteria an early advantage turned out to be their downfall, the researchers discovered. But the nerd bacteria carried a different mutation that interacted with later genetic changes, increasing the microbes’ evolutionary fitness.

The findings are some of the first experimental evidence for evolvability, says Massimo Pigliucci, an evolutionary biologist and philosopher of science at the City University of New York. Theorists have devised many models to show that changes in DNA ought to interact with each other to shape a species’ evolution and that some mutations allow for greater adaptability over time. But until now, there has been little hard data to support the claims. “There’s not many examples out there, but this one is a spectacular one,” Pigliucci says. “This is an elegant demonstration of evolvability and its molecular underpinnings.”

Eventual winners in this laboratory experiment didn’t start out that way. In fact, the population of nerdly bacteria that eventually evolved into top dogs was at one point in danger of extinction. Those bacteria carried a mutation in the topA gene, which makes a protein that winds up a bacterium’s circular chromosome like a twisted rubber band. Winding the DNA can change how easy it is to turn genes on and off.

Strangely enough, the eventual winners’ rivals — the eventual losers — also carried a mutation in the topA gene, but one that alters the next link down in the chain of amino acids that makes up the protein. In the first 500 generations of the experiment the eventual losers were riding high. They dominated laboratory flasks early on because their version of topA helped the bacteria make better use of limited nutrients than the competition.

But a few hundred generations later the situation was reversed. By generation 883, the eventual winners were growing 2.1 percent faster than the eventual losers, an indication of fitness. And by generation 1,500, the eventual losers had gone extinct in the flasks.

To find out how the eventual losers went from hero to zero, the researchers replayed the evolution experiment over and over using frozen samples taken from generation 500. In general, the eventual winners managed to overtake the eventual losers, but not every time. That finding indicates that chance is at play in evolution, Pigliucci says.

The researchers looked more closely at the DNA of the eventual losers and winners and found that the eventual winners’ version of topA combined with changes in other genes, such as one called spoT, to increase fitness. But although the eventual losers’ topA gave them a huge advantage early in the game, it didn’t interact as favorably with later mutations, leading the eventual losers down an evolutionary cul-de-sac, if not exactly a dead end.

“Evolution is a mindless process. It has no foresight,” says Jeffrey Barrick, an evolutionary genomicist at the University of Texas at Austin and a coauthor of the study. “So it’s not immune from making these short-term gains, but losing in the end.”

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Comments 3

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What is the relationship to HUMANITY? Will we compete orcooperate on the 2% of the only planet in the universe available to us?

Wayne Johnson

Mar. 19, 2011 at 12:44pm
Science News, I am extremely tired of seeing spam posts scattered throughout your site's comment sections. Please get on the ball and figure out how to block them!

Wayne Johnson, what it means for humanity remains to be seen. Eventually, humanity will go extinct, but we can hope, at least, that we will figure out ways to prolong our existence by cooperation, by restricting our population growth, and by learning to live in areas of the planet that are currently uninhabitable and/or by learning to live off-planet.

Robert Woodman

Mar. 21, 2011 at 4:31am
"understanding the genetic mechanisms that drive evolution"???

Apply Critical Thinking For Solving THE RIGHT USA SCIENCE PROBLEM

AAAS Through History's Lens
Imprinting Diversity?

Enough Is Enough!
It Is Not "Genomic Imprinting Affects Diversity"
It Is "Culture/Diversity Imprints Genetics".

Part I
======

A. "Imprinting Diversity"
the-scientist.com/2011/3/1/26/1/#messing

B. On Human-Primate Diversity

"Aging rates, gender gap in mortality similar across all primates"
eurekalert.org/pub_releases/2011-03/du-arg030711.php

"Age affects us all"
eurekalert.org/pub_releases/2011-03/uonc-aau030611.php

C. Again And Again: It's Culture That Modifies Genetics

But in the case of human-primates the process takes millions of years because the original primate physiological genetics are better conserved in humans than in their original primate relatives. In humans the modifications are in the brains, in evolving capabilities to modify their environments and toolings, whereas their relative primates need to continuously adapt
physiologically to changing environments. Humans modify environs, their forefathers adapt to environs.

D. On Uniquely Human Traits

Horse And Wagon, Culture And Genetics

It's Culture That Modifies Genetics, Not Genetics That Modifies Culture!

"How DNA deletions may have produced uniquely human traits"
the-scientist.com/news/display/58044/

With such a title you don't need to read the article; it would apparently explain how a wagon pulls the horse.

See
"Seed of Human-Chimp Genomes Diversity"
pulse.yahoo.com/_2SF3CJJM5OU6T27OC4MFQSDYEU/blog/articles/53079

Dov Henis
(Comments from 22nd century)
the-scientist.com/community/user/profile/1655.page

Part II
=======

From a letter I recently e'mailed elsewhere re "Big Brains And Spineless Penises"
Or "Sex, Spines And Human Evolution":

Now, from where comes such scientific ignorance to Stanford?
Like most science ignorance (and there's plenty of it around) it flows mainly from the following "spring of creativity":

A. Genes/genomes are ORGANISMS, subject to natural selection.

Update comprehension of cosmos and life evolution.

Apply Critical Thinking For Solving THE RIGHT USA SCIENCE PROBLEM

Why Life Eats And Why Life Sleeps:
Life eats because the universe expands.
Life sleeps because when RNAs genesised there was not yet biometabolism.

US losing lead in science?

"The proportion of papers authored by US researchers, Wagner reported, dropped by 20 percent from 1996 to 2008."
News From AAAS
the-scientist.com/news/display/57994/

Just the proportion of the "papers"?
Otherwise the US "papers" have been, are, and prospected to be of scientific value?

See "Hope For Science?"
pulse.yahoo.com/_2SF3CJJM5OU6T27OC4MFQSDYEU/blog/articles/248628

And see the following two E-medium samples, thus presently taboo, nonAAASkoshered nonpeerreviewable notes:

===========================

1st sample

Genes And Genomes Are Both Organisms

Genomes Are RNA-Evolved Template ORGANISMS
EpiDNAtics Is Not Epigenetics

From "Dispel Some Figments Of 2010 Science Imagination"
pulse.yahoo.com/_2SF3CJJM5OU6T27OC4MFQSDYEU/blog/articles/245540

The "heritable or enduring changes" are epiDNAtics, not epigenetics. Alternative splicing is not epigenetics, even if/when not involving alteration of the DNA sequence. Earth life is an RNA world.

It's the RNAs that evolve proteins. AND IT'S THE RNAs THAT HAVE EVOLVED AND PRODUCE AND EMPLOY THE RNA and (stabler) DNA template genome organisms for carrying out life processes, i.e. for enhancing Earth's biosphere by proliferating RNAs, for augmenting and constraining as long as possible some energy by augmenting its, RNA's, self-propagation, constraining temporarily some of the total energy of the universe, all of which is nevertheless destined to fuel the ongoing cosmic expansion.

IT HAS ALWAYS BEEN AND IT STILL IS AN RNA EARTH LIFE.

Science should adjust its vision, comprehension and concepts.

Dov Henis
(comments from 22nd century)

==========================

2nd sample

"Suggested 2010 Updated Concepts Of Evolution, Natural Selection"
pulse.yahoo.com/_2SF3CJJM5OU6T27OC4MFQSDYEU/blog/articles/261519?listPage=index
pulse.yahoo.com/_2SF3CJJM5OU6T27OC4MFQSDYEU/blog/articles/261527?listPage=index

On The Nature And Origin Of Cosmic, Including Life, Evolution, Beyond Darwin And Einstein

The purpose of OUR life and of its promotion is ours to formulate and set. It derives solely from our cognition. The nature and origin of cosmic, including life, evolution:

Natural Selection Derives From Cosmic Expansion

"Evolution is energy temporarily constrained in a mass format to postpone reconversion of the mass to the energy fueling the cosmic expansion".

I.

Origin And Nature Of Natural Selection

Life is another mass format, a self-replicating mass format.
All mass formats are subject to natural selection.
Natural selection is the delaying conversion of mass to the energy fueling cosmic expansion.
Cosmic expansion is the reconversion of all mass to energy.

Natural Selection Updated 2010, Beyond Historical Concepts:

Natural Selection applies to ALL mass formats. Life, self-replicating format, is just one of them.
Natural Selection Defined:

Natural selection is E (energy) temporarily constrained in an m (mass) format. Period.

Natural selection is a ubiquitous property of each and every and all cosmic mass, spin array, formats. Mass strives to increase its constrained energy content in attempt to postpone its reconversion to energy and to postpone addition of its constitutional energy to the totality of the cosmic energy that fuels the cosmic expansion going on since Big Bang.

Dov Henis
(Comments From The 22nd Century)

"Cosmic Evolution Simplified"
the-scientist.com/community/posts/list/240/122.page#4427"
"Gravity Is The Monotheism Of The Cosmos"
the-scientist.com/community/posts/list/260/122.page#4887

II.

Longevity Schmongevity Genes?

It's Not The Procedure, But The Concept That Is Absurd

"Longevity Genes Search Reflects Science Decadence"
the-scientist.com/community/posts/list/320/122.page#6368

A. "For most centenarians, longevity is written in the DNA."

A study of people who live past 100 reveals many genetic paths to a long life.
sciencenews.org/view/generic/id/60772/title/For_most_centenarians%2C_longevity_is_written_in_the_DNA

B. Longevity is about survival, which is about "natural selection", which is about energy constrainment, which is about life evolution, which is about cosmic evolution. All mass is destined to reconvert to energy to fuel the ongoing cosmic expansion. This is why organisms and black holes etc., eat, digest energy in mass forms, to delay-postpone conversion to energy. This is evolution, which is natural selection, which is survival, which is longevity.

All mass formats age, degenerate back into enery. Life is a mass format. Searching for longevity genes is searching for evolution genes...

C. The search for longevity genes is a reflection of the 20th-21st centuries science decadence

Its concepts and terminology reflect the abandonment of basic science for adoption of the pretentious cancerous capitalist 20th-21st century technology culture.

Dov Henis
(Comments From The 22nd Century)

III.

Rethink Astronomy And The Universe
( even without Quantum Unique Ergodicity, but with plain commonsense )

Galactic clusters formed by dispersion, not by conglomeration. The proof of this is their behaviour, including acceleration, as Newtonian bodies.

These bodies formed at the start of inflation, when all energy was still in mass format, and the inflation was the start of reconversion of cosmic mass into energy. Cosmic expansion acceleration rate differs for galactic clusters, proceeding according to Newton's laws, proportional to the various galactic clusters' masses.

Rethink
- A Basic Physics Tenet
- The Universe In Which We Live

A. "Neutrino quick-change artist caught in the act"

"A transformation from one ‘flavor’ to another confirms the elusive elementary particles have mass and suggests a need for new physics."
sciencenews.org/view/generic/id/59825/title/Neutrino_quick-change_artist_caught_in_the_act

B. Adopt

- Each and every particle has mass.
- Dark energy and dark matter YOK. All the universe energy and mass are plainly accounted for.
- Higgs field/particle YOK. Mass forms below some value of D in E=Total[m(1 + D)] .
- Do not be afraid of embarrassingly obvious answers. Adopt space-distance in lieu of space-time.

C. And Rethink The Universe:

By the presently available data our universe is a dual-cycle array, between the mass and energy poles.

One cycle, the present, started from singularity, with all cosmic energy in mass format, and it has been proceeding to reconvert all the mass resolved at the Big Bang back to energy, by expanding the cosmos, by accelerating away the galaxy clusters.

The other cycle, the cycle leading to singularity, will re-start when expansion consumes most of the mass that fuels it. Gravity will then overcome expansion and initiate reconversion of all the energy back to mass, to singularity, again.

Dov Henis
(Comments From The 22nd Century)

"Dispel Some Figments Of 2010 Science Imagination"
pulse.yahoo.com/_2SF3CJJM5OU6T27OC4MFQSDYEU/blog/articles/245540
"03.2010 Updated Life Manifest"
the-scientist.com/community/posts/list/54.page#5065
"28Dec09 Updated "Implications Of E=Total[m(1 + D)] "
the-scientist.com/community/posts/list/180/122.page#3108
"Evolution, Natural Selection, Derive From Cosmic Expansion"
darwiniana.com/2010/09/05/the-question-reductionists-fear/

Dov Henis

Mar. 22, 2011 at 11:48am

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