RSS 2.0 Feed

» Welcome Guest Log In :: Register

Pages: (59) < ... 46 47 48 49 50 [51] 52 53 54 55 56 ... >   
  Topic: Science Break, Selected Shorts< Next Oldest | Next Newest >  
Quack



Posts: 1961
Joined: May 2007

(Permalink) Posted: June 25 2013,04:02   

Quote (fnxtr @ June 23 2013,15:11)
Looks like the oceanic plate ridge is still spreading but instead of carrying continental plates apart, said oceanic plate is starting to subduct at its margins.


I did a google: here

Edited by Quack on June 25 2013,04:07

--------------
Rocks have no biology.
              Robert Byers.

  
dvunkannon



Posts: 1377
Joined: June 2008

(Permalink) Posted: June 25 2013,05:58   

http://www.sciencedaily.com/release....617.htm

Two Mutations Triggered an Evolutionary Leap 500 Million Years Ago

aka

http://www.pnas.org/content....3930110

Biophysical mechanisms for large-effect mutations in the evolution of steroid hormone receptors

Michael J. Harmsa,1, Geeta N. Eicka,1, Devrishi Goswamib, Jennifer K. Coluccic, Patrick R. Griffinb, Eric A. Ortlundc, and Joseph W. Thorntona,d,2
Author Affiliations

Edited by David Baker, University of Washington, Seattle, WA, and approved May 23, 2013 (received for review March 7, 2013)

Abstract
The genetic and biophysical mechanisms by which new protein functions evolve is a central question in evolutionary biology, biochemistry, and biophysics. Of particular interest is whether major shifts in protein function are caused by a few mutations of large effect and, if they are, the mechanisms that mediate these changes. Here we combine ancestral protein reconstruction with genetic manipulation and explicit studies of protein structure and dynamics to dissect an ancient and discrete shift in ligand specificity in the steroid receptors, a family of biologically essential hormone-controlled transcription factors. We previously found that the ancestor of the entire steroid receptor family was highly specific for estrogens, but its immediate phylogenetic descendant was sensitive only to androgens, progestogens, and corticosteroids. Here we show that this shift in function was driven primarily by two historical amino acid changes, which caused a ?70,000-fold change in the ancestral protein’s specificity. These replacements subtly changed the chemistry of two amino acids, but they dramatically reduced estrogen sensitivity by introducing an excess of interaction partners into the receptor/estrogen complex, inducing a frustrated ensemble of suboptimal hydrogen bond networks unique to estrogens. This work shows how the protein’s architecture and dynamics shaped its evolution, amplifying a few biochemically subtle mutations into major shifts in the energetics and function of the protein.

-------------------------

So, small change in genotype causes large change in phenotype function. Wherefore art thou, islands of function?

--------------
I’m referring to evolution, not changes in allele frequencies. - Cornelius Hunter
I’m not an evolutionist, I’m a change in allele frequentist! - Nakashima

  
fnxtr



Posts: 3504
Joined: June 2006

(Permalink) Posted: June 25 2013,09:57   

Quote (Quack @ June 25 2013,02:02)
Quote (fnxtr @ June 23 2013,15:11)
Looks like the oceanic plate ridge is still spreading but instead of carrying continental plates apart, said oceanic plate is starting to subduct at its margins.


I did a google: here

Science ftw again!

So yeah, looks like MAR is still spreading. Subduction in the Caribbean, according to wiki.

--------------
"[A] book said there were 5 trillion witnesses. Who am I supposed to believe, 5 trillion witnesses or you? That shit's, like, ironclad. " -- stevestory

"Wow, you must be retarded. I said that CO2 does not trap heat. If it did then it would not cool down at night."  Joe G

  
Thrinaxodon



Posts: 65
Joined: June 2013

(Permalink) Posted: June 25 2013,18:57   

Quote (fnxtr @ June 25 2013,09:57)
Quote (Quack @ June 25 2013,02:02)
Quote (fnxtr @ June 23 2013,15:11)
Looks like the oceanic plate ridge is still spreading but instead of carrying continental plates apart, said oceanic plate is starting to subduct at its margins.


I did a google: here

Science ftw again!

So yeah, looks like MAR is still spreading. Subduction in the Caribbean, according to wiki.

Proof that the Atlantic is shortening.

:)

--------------
Velikovsky is right.

Humans originated in the Devonian.

talk.origins is a place for people to p*ss on others.

  
fnxtr



Posts: 3504
Joined: June 2006

(Permalink) Posted: June 26 2013,15:48   

Quote (Thrinaxodon @ June 25 2013,16:57)
Quote (fnxtr @ June 25 2013,09:57)
Quote (Quack @ June 25 2013,02:02)
 
Quote (fnxtr @ June 23 2013,15:11)
Looks like the oceanic plate ridge is still spreading but instead of carrying continental plates apart, said oceanic plate is starting to subduct at its margins.


I did a google: here

Science ftw again!

So yeah, looks like MAR is still spreading. Subduction in the Caribbean, according to wiki.

Proof that the Atlantic is shortening.

:)

You probably mean "narrowing". Shortening to most minds means in the north-south direction. And... maybe.

--------------
"[A] book said there were 5 trillion witnesses. Who am I supposed to believe, 5 trillion witnesses or you? That shit's, like, ironclad. " -- stevestory

"Wow, you must be retarded. I said that CO2 does not trap heat. If it did then it would not cool down at night."  Joe G

  
Quack



Posts: 1961
Joined: May 2007

(Permalink) Posted: June 27 2013,15:05   

Don't know how much of a news item this may be but it was recently announced here that thorium is being 'burned' in Halden, home of the HBWR. IIRC, it said that thorium with 20% plutonium added is used in a conventional reactor. The experiment will run for several years but results already looks better than predicted.

--------------
Rocks have no biology.
              Robert Byers.

  
midwifetoad



Posts: 4003
Joined: Mar. 2008

(Permalink) Posted: July 11 2013,12:46   

Blue planet found. Not privileged.

http://www.universetoday.com/103440....l3GGuEP

--------------
Any version of ID consistent with all the evidence is indistinguishable from evolution.

  
REC



Posts: 638
Joined: Sep. 2006

(Permalink) Posted: July 18 2013,00:29   

The red queen in the corn: agricultural weeds as models of rapid adaptive evolution.
http://www.ncbi.nlm.nih.gov/pubmed....3188175

Abstract:
Quote
Weeds are among the greatest pests of agriculture, causing billions of dollars in crop losses each year. As crop field management practices have changed over the past 12?000 years, weeds have adapted in turn to evade human removal. This evolutionary change can be startlingly rapid, making weeds an appealing system to study evolutionary processes that occur over short periods of time. An understanding of how weeds originate and adapt is needed for successful management; however, relatively little emphasis has been placed on genetically characterizing these systems. Here, we review the current literature on agricultural weed origins and their mechanisms of adaptation. Where possible, we have included examples that have been genetically well characterized. Evidence for three possible, non-mutually exclusive weed origins (from wild species, crop-wild hybrids or directly from crops) is discussed with respect to what is known about the microevolutionary signatures that result from these processes. We also discuss what is known about the genetic basis of adaptive traits in weeds and the range of genetic mechanisms that are responsible. With a better understanding of genetic mechanisms underlying adaptation in weedy species, we can address the more general process of adaptive evolution and what can be expected as we continue to apply selective pressures in agroecosystems around the world.

  
dvunkannon



Posts: 1377
Joined: June 2008

(Permalink) Posted: July 30 2013,19:58   

http://www.pnas.org/content....bstract

Should twist a few knickers at the DI.

Basically, RNA bases and ribose do a better job at preserving amphiphile bubbles made of (prebioticlly produced) decanoic acid. Yet another reason that the building block used by life are what they are.

You'll see David Deamer's name in the author list. He is one of the leaders in discovering the importance of self assembling bubbles as proto-cell membranes.

--------------
I’m referring to evolution, not changes in allele frequencies. - Cornelius Hunter
I’m not an evolutionist, I’m a change in allele frequentist! - Nakashima

  
dvunkannon



Posts: 1377
Joined: June 2008

(Permalink) Posted: Aug. 02 2013,20:29   

https://wiki.engr.illinois.edu/display....0111207

http://www.nasa.gov/content....-easier

Sounds like a candidate for a Humie award - using evolutionary computing (in this case integer genetic algorithms and differential evolution) to do something previously done by human experts.

--------------
I’m referring to evolution, not changes in allele frequencies. - Cornelius Hunter
I’m not an evolutionist, I’m a change in allele frequentist! - Nakashima

  
keiths



Posts: 2195
Joined: Jan. 2006

(Permalink) Posted: Aug. 05 2013,19:25   

Some very cool gifs of n-body orbits.

--------------
And the set of natural numbers is also the set that starts at 0 and goes to the largest number. -- Joe G

Please stop putting words into my mouth that don't belong there and thoughts into my mind that don't belong there. -- KF

  
midwifetoad



Posts: 4003
Joined: Mar. 2008

(Permalink) Posted: Aug. 11 2013,14:15   

Holy shit. Actual intelligent design.

http://www.policymic.com/article....covered

--------------
Any version of ID consistent with all the evidence is indistinguishable from evolution.

  
dvunkannon



Posts: 1377
Joined: June 2008

(Permalink) Posted: Aug. 28 2013,12:32   

Structural Phylogenomics Retrodicts the Origin of the Genetic Code and Uncovers the Evolutionary Impact of Protein Flexibility

The genetic code shapes the genetic repository. Its origin has puzzled molecular scientists for over half a century and remains a long-standing mystery. Here we show that the origin of the genetic code is tightly coupled to the history of aminoacyl-tRNA synthetase enzymes and their interactions with tRNA. A timeline of evolutionary appearance of protein domain families derived from a structural census in hundreds of genomes reveals the early emergence of the ‘operational’ RNA code and the late implementation of the standard genetic code. The emergence of codon specificities and amino acid charging involved tight coevolution of aminoacyl-tRNA synthetases and tRNA structures as well as episodes of structural recruitment. Remarkably, amino acid and dipeptide compositions of single-domain proteins appearing before the standard code suggest archaic synthetases with structures homologous to catalytic domains of tyrosyl-tRNA and seryl-tRNA synthetases were capable of peptide bond formation and aminoacylation. Results reveal that genetics arose through coevolutionary interactions between polypeptides and nucleic acid cofactors as an exacting mechanism that favored flexibility and folding of the emergent proteins. These enhancements of phenotypic robustness were likely internalized into the emerging genetic system with the early rise of modern protein structure.

http://www.plosone.org/article....0072225

My take - this is great work showing how the co-evolution of proteins and amino acid sequences led to the modern genetic code.

--------------
I’m referring to evolution, not changes in allele frequencies. - Cornelius Hunter
I’m not an evolutionist, I’m a change in allele frequentist! - Nakashima

  
midwifetoad



Posts: 4003
Joined: Mar. 2008

(Permalink) Posted: Aug. 28 2013,13:08   

Gpuccio and EricB are no doubt back in their laboratories, working out the flaws in this study.

--------------
Any version of ID consistent with all the evidence is indistinguishable from evolution.

  
timothya



Posts: 280
Joined: April 2013

(Permalink) Posted: Aug. 29 2013,05:57   

If there is a particle physicist in the house, could you answer a simple-minded question about quantum entanglement.

How much energy is required to separate two entangled particles by a macroscopic distance? I think I mean the total energy required for the system as a whole, not the energy trapped inside the particles.

--------------
"In its majestic equality, the law forbids rich and poor alike to sleep under bridges, beg in the streets and steal loaves of bread." Anatole France

  
Henry J



Posts: 5786
Joined: Mar. 2005

(Permalink) Posted: Aug. 29 2013,09:57   

Quote (timothya @ Aug. 29 2013,04:57)
If there is a particle physicist in the house, could you answer a simple-minded question about quantum entanglement.

How much energy is required to separate two entangled particles by a macroscopic distance? I think I mean the total energy required for the system as a whole, not the energy trapped inside the particles.

I'd guess about the same amount as needed for separating particles that aren't entangled. Entanglement doesn't necessarily imply limits on movement.

  
Tracy P. Hamilton



Posts: 1239
Joined: May 2006

(Permalink) Posted: Aug. 29 2013,10:15   

Quote (timothya @ Aug. 29 2013,05:57)
If there is a particle physicist in the house, could you answer a simple-minded question about quantum entanglement.

How much energy is required to separate two entangled particles by a macroscopic distance? I think I mean the total energy required for the system as a whole, not the energy trapped inside the particles.

The actual energy used is way higher than that which would be required for a single particle pair.  First, one must do a large number of pairs to get a statistical ensemble.  My understanding (OlegT can chime in here, PM him perhaps) is that the meaning of a wavefunction for a single pair is more problematic than for an ensemble.  One must run the instruments that do the detection.  One must do specific manipulations to prepare the state in the entangled state.

--------------
"Following what I just wrote about fitness, you’re taking refuge in what we see in the world."  PaV

"The simple equation F = MA leads to the concept of four-dimensional space." GilDodgen

"We have no brain, I don't, for thinking." Robert Byers

  
timothya



Posts: 280
Joined: April 2013

(Permalink) Posted: Aug. 29 2013,21:43   

Quote
The actual energy used is way higher than that which would be required for a single particle pair.  First, one must do a large number of pairs to get a statistical ensemble.  My understanding (OlegT can chime in here, PM him perhaps) is that the meaning of a wavefunction for a single pair is more problematic than for an ensemble.  One must run the instruments that do the detection.  One must do specific manipulations to prepare the state in the entangled state.

My reason for asking concerns the claims made by woo-merchants who witter on about "quantum consciousness" and suchlike. My reading is that the energy required to make any use of the phenomenon would make your brain leak out of your ears.

--------------
"In its majestic equality, the law forbids rich and poor alike to sleep under bridges, beg in the streets and steal loaves of bread." Anatole France

  
Richardthughes



Posts: 11178
Joined: Jan. 2006

(Permalink) Posted: Aug. 30 2013,03:53   

http://www.weather.com/news....0130826

strange microbial life. Designer be praised!

--------------
"Richardthughes, you magnificent bastard, I stand in awe of you..." : Arden Chatfield
"You magnificent bastard! " : Louis
"ATBC poster child", "I have to agree with Rich.." : DaveTard
"I bow to your superior skills" : deadman_932
"...it was Richardthughes making me lie in bed.." : Kristine

  
Henry J



Posts: 5786
Joined: Mar. 2005

(Permalink) Posted: Aug. 30 2013,10:12   

Quote (timothya @ Aug. 29 2013,20:43)
Quote
The actual energy used is way higher than that which would be required for a single particle pair.  First, one must do a large number of pairs to get a statistical ensemble.  My understanding (OlegT can chime in here, PM him perhaps) is that the meaning of a wavefunction for a single pair is more problematic than for an ensemble.  One must run the instruments that do the detection.  One must do specific manipulations to prepare the state in the entangled state.

My reason for asking concerns the claims made by woo-merchants who witter on about "quantum consciousness" and suchlike. My reading is that the energy required to make any use of the phenomenon would make your brain leak out of your ears.

Oh, that's only because practical application would need huge numbers of entangled particles, which would have to be carefully kept in isolation to keep them from having interactions that would cause them to lose the entanglements. (Uncontrolled interactions would distribute the entanglement to other particles.)

  
midwifetoad



Posts: 4003
Joined: Mar. 2008

(Permalink) Posted: Sep. 12 2013,21:13   

New mascot for UD.

http://www.popularmechanics.com/science....5916433

--------------
Any version of ID consistent with all the evidence is indistinguishable from evolution.

  
Henry J



Posts: 5786
Joined: Mar. 2005

(Permalink) Posted: Sep. 12 2013,22:36   

Gears? Why that shifty little bug!

  
dvunkannon



Posts: 1377
Joined: June 2008

(Permalink) Posted: Oct. 04 2013,09:56   

http://www.pnas.org/content....3473110

Naked mole rats live a long time (for rats). Now it seems that they have a unique ribosome structure that increases the fidelity of protein construction. Fewer mistranslated, poorly folding proteins == less cancer, disease, etc.

And all because of a mutation (deletion) in a key ribosome component! Functional mutation FTW!!1!

--------------
I’m referring to evolution, not changes in allele frequencies. - Cornelius Hunter
I’m not an evolutionist, I’m a change in allele frequentist! - Nakashima

  
Henry J



Posts: 5786
Joined: Mar. 2005

(Permalink) Posted: Oct. 08 2013,21:34   

Nobel physics prize spotlights Higgs boson, plus Drs. Higgs and Englert

(i.e., they finally found that gosh-darn particle!)

  
dvunkannon



Posts: 1377
Joined: June 2008

(Permalink) Posted: Oct. 23 2013,12:27   

http://www.plospathogens.org/article....1003688

More functional mutation goodness. Changing even one amino acid changes the cell surface sugar targetted by a virus, allowing it to access new cell types, even new species, for infection.

--------------
I’m referring to evolution, not changes in allele frequencies. - Cornelius Hunter
I’m not an evolutionist, I’m a change in allele frequentist! - Nakashima

  
fnxtr



Posts: 3504
Joined: June 2006

(Permalink) Posted: Oct. 23 2013,13:23   

Quote (dvunkannon @ Oct. 23 2013,10:27)
http://www.plospathogens.org/article....1003688

More functional mutation goodness. Changing even one amino acid changes the cell surface sugar targetted by a virus, allowing it to access new cell types, even new species, for infection.

Viruses are bad. Therefore genetic entropy and Jesus.

--------------
"[A] book said there were 5 trillion witnesses. Who am I supposed to believe, 5 trillion witnesses or you? That shit's, like, ironclad. " -- stevestory

"Wow, you must be retarded. I said that CO2 does not trap heat. If it did then it would not cool down at night."  Joe G

  
Henry J



Posts: 5786
Joined: Mar. 2005

(Permalink) Posted: Oct. 23 2013,13:58   

Quote (fnxtr @ Oct. 23 2013,12:23)
Viruses are bad. Therefore genetic entropy and Jesus.

They're not bad; they were just drawn designed that way!

Oh wait...

  
dvunkannon



Posts: 1377
Joined: June 2008

(Permalink) Posted: Oct. 25 2013,10:29   

http://www.sciencedaily.com/release....422.htm

Grasshopper Mice Are Numb to the Pain of the Bark Scorpion Sting

"Incredibly, there is one amino acid substitution that can totally alter the behavior of the toxin and block the channel," said Zakon.

Sounds like a beneficial, functional mutation to me. The mice couldn't pursue their lifestyle of eating scorpions without it.

--------------
I’m referring to evolution, not changes in allele frequencies. - Cornelius Hunter
I’m not an evolutionist, I’m a change in allele frequentist! - Nakashima

  
stevestory



Posts: 13407
Joined: Oct. 2005

(Permalink) Posted: Oct. 25 2013,11:06   

Quote (fnxtr @ Oct. 23 2013,14:23)
Quote (dvunkannon @ Oct. 23 2013,10:27)
http://www.plospathogens.org/article....1003688

More functional mutation goodness. Changing even one amino acid changes the cell surface sugar targetted by a virus, allowing it to access new cell types, even new species, for infection.

Viruses are bad. Therefore genetic entropy and Jesus.

Are any of those numbnuts believers in both genetic entropy and Front-Loaded evolution?

   
stevestory



Posts: 13407
Joined: Oct. 2005

(Permalink) Posted: Oct. 25 2013,11:08   

Quote (dvunkannon @ Oct. 25 2013,11:29)
http://www.sciencedaily.com/release....422.htm

Grasshopper Mice Are Numb to the Pain of the Bark Scorpion Sting

"Incredibly, there is one amino acid substitution that can totally alter the behavior of the toxin and block the channel," said Zakon.

Sounds like a beneficial, functional mutation to me. The mice couldn't pursue their lifestyle of eating scorpions without it.

Article I saw yesterday suggested the mice actually got a morphine-like high from eating the things.

   
  1753 replies since July 16 2008,08:10 < Next Oldest | Next Newest >  

Pages: (59) < ... 46 47 48 49 50 [51] 52 53 54 55 56 ... >   


Track this topic Email this topic Print this topic

[ Read the Board Rules ] | [Useful Links] | [Evolving Designs]