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J-Dog



Posts: 4362
Joined: Dec. 2006

(Permalink) Posted: April 06 2009,11:55   

Quote (Richardthughes @ April 06 2009,10:22)
Privileged Planet? - notsomuch:


http://www.technologyreview.com/blog/arxiv/23309/

Poor , poor ID :(

After all this time, they get expelled by an old friend - thermodynamics.

RIP Dr. Gonzales... Baya con Dios.

--------------
Come on Tough Guy, do the little dance of ID impotence you do so well. - Louis to Joe G 2/10

Gullibility is not a virtue - Quidam on Dembski's belief in the Bible Code Faith Healers & ID 7/08

UD is an Unnatural Douchemagnet. - richardthughes 7/11

  
Richardthughes



Posts: 10116
Joined: Jan. 2006

(Permalink) Posted: April 08 2009,09:34   

I'm sure this is ID research, somehow:

http://www.sciencedaily.com/releases/2009/04/090402143457.htm

--------------
"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

  
ppb



Posts: 325
Joined: Dec. 2006

(Permalink) Posted: April 08 2009,10:57   

Quote (Richardthughes @ April 08 2009,10:34)
I'm sure this is ID research, somehow:

http://www.sciencedaily.com/releases/2009/04/090402143457.htm

If it spits out 42 for an answer we could be certain that Slarty Bartfast is the Designer.

--------------
"[A scientific theory] describes Nature as absurd from the point of view of common sense. And it agrees fully with experiment. So I hope you can accept Nature as She is - absurd."
- Richard P. Feynman

  
midwifetoad



Posts: 3558
Joined: Mar. 2008

(Permalink) Posted: April 08 2009,12:42   

http://www.sciencealert.com.au/news/20090604-18994.html

Quote
Murdoch University scientists have developed an improved theory of evolution – a groundbreaking hypothesis which finally reconciles evolutionary theory with the fossil record.


And the author isn't I. Lirpa, although he may be related to Mi Tu.

--------------
”let’s not make a joke of ourselves.”

Pat Robertson

  
dvunkannon



Posts: 1377
Joined: June 2008

(Permalink) Posted: April 08 2009,14:47   

Quote (J-Dog @ April 06 2009,12:55)
Quote (Richardthughes @ April 06 2009,10:22)
Privileged Planet? - notsomuch:


http://www.technologyreview.com/blog/arxiv/23309/

Poor , poor ID :(

After all this time, they get expelled by an old friend - thermodynamics.

RIP Dr. Gonzales... Baya con Dios.

I thought they had gone back and done more sensitive analysis of Miller's results and found all 20 amino acids. This paper still says only 10.

--------------
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: 3558
Joined: Mar. 2008

(Permalink) Posted: April 08 2009,15:18   

I think the others drop off a cliff in quantity.

--------------
”let’s not make a joke of ourselves.”

Pat Robertson

  
Schroedinger's Dog



Posts: 1691
Joined: Jan. 2009

(Permalink) Posted: April 15 2009,03:56   

He's done it!!!

NASA to name ISS treadmill after Colbert

--------------
"Hail is made out of water? Are you really that stupid?" Joe G

"I have a better suggestion, Kris. How about a game of hide and go fuck yourself instead." Louis

"The reason people use a crucifix against vampires is that vampires are allergic to bullshit" Richard Pryor

   
Richardthughes



Posts: 10116
Joined: Jan. 2006

(Permalink) Posted: April 16 2009,09:39   

Brace for ID spin:

http://seedmagazine.com/content/print/the_body_politic/

--------------
"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

  
Erasmus, FCD



Posts: 6349
Joined: June 2007

(Permalink) Posted: April 16 2009,11:07   

Quote
The deep symbiosis between bacteria and their human hosts is forcing scientists to ask: Are we organisms or living ecosystems?


as opposed to dead ecosystems?

yeah they're forced to ask that.

--------------
You're obviously illiterate as hell. Peach, bro.-FtK

Finding something hard to believe based on the evidence, is science.-JoeG

the odds of getting some loathsome taint are low-- Gordon E Mullings Manjack Heights Montserrat

I work on molecular systems with pathway charts and such.-Giggles

  
ppb



Posts: 325
Joined: Dec. 2006

(Permalink) Posted: April 22 2009,13:31   

Interesting new fossil discovered that fills in some of the detail in the transition from land animals to ocean dwelling mammals like seals and walruses.  It's been named Puijila darwini.  Puijila means "young sea mammal" in the Inuktitut language spoken where the fossil was found in the far north of Canada.  You know where darwini comes from.  Read all about it here:

http://nature.ca/puijila/index_e.cfm

I just heard Neil Shubin talk about Tiktaalik roseae last week.  This is sort of Tiktallik in reverse!

ETA: I've taken a closer look at their web site, and it is really nicely done.  They have a cool interactive picture of the skull that lets you rotate it while reading about the skull's pinniped-like characteristics.

--------------
"[A scientific theory] describes Nature as absurd from the point of view of common sense. And it agrees fully with experiment. So I hope you can accept Nature as She is - absurd."
- Richard P. Feynman

  
rhmc



Posts: 340
Joined: Dec. 2007

(Permalink) Posted: April 22 2009,19:50   

molly mating mystery

Researchers have proposed an explanation for how three species of tiny fish manage to coexist despite having seemingly incompatible modes of reproduction, according to a study published in Oikos last week.

The Amazon molly (Poecilia formosa) is an asexually reproducing species in which females produce only female clones via parthenogenesis. To initiate embryogenesis, however, Amazon mollies require sperm from the males of one of two closely related, but sexually reproducing, species sharing their habitats in southern Texas and northern Mexico -- the sailfin molly (Poecilia latipinna) or the shortfin molly (Poecilia mexicana).

Ecological theory predicts that such species living as a complex in nature are doomed because population growth in the asexual species should overwhelm the metapopulation with females. That in turn would lead to a shortage of sperm and a collapse of the entire system. The ecological model proposed in the study suggests that with the right mating behavior in males, the arrangement could work.

"It's an interesting paper in terms of highlighting this problem," Laurence Loewe, a University of Edinburgh evolutionary biologist, told The Scientist. "But I'm not so sure they solved it."

While the model may not completely answer the question of how the mollies defy ecological theory and manage to coexist, it is one of the few solutions yet proposed.

Hanna Kokko, an evolutionary ecologist at Helsinki University in Finland who led the research, based her mathematical model on the idea that if male members of the two sexual species are able to discriminate between females of their own species and females of the asexual species, the complex has a better chance of persisting. Males would mate with their own females more often than providing sperm for their asexual cousins. The model additionally suggests that if males are also relatively efficient -- that is, they can continue servicing both sexual and a few asexual females as population numbers rise -- the three species should be able to get along.

And get along they do, though the system does collapse, with molly species going locally extinct on the average of once every four years, Kokko told The Scientist. Populations rebuild themselves, though, and the asexually and sexually reproducing species continue their mate sharing, an arrangement that has persisted for as long as 25,000 years. The Amazon molly, likely the result of a hybridization event between its two host species, has already existed for about as long as an asexual species is predicted to hang around, Kokko explained. Asexual species should theoretically accumulate deleterious mutations at a much faster rate than sexually reproducing species due to a lack of gene recombination.

Another important factor in keeping the species complex going may be how the fish species share their watery habitats. Spatially complex structures, such as tree limbs and rock bottoms, may provide molly species with the opportunity to divide up their local habitats and limit interaction between males and asexual females. Kokko said that although her current model does not account for this spatial partitioning, she and her colleagues did address that aspect in a paper published last year in Proceedings of the Royal Society B. That model suggested that the coexistence of asexual and sexual mollies could be explained by habitat partitioning alone.

But all three factors -- male discrimination, male efficiency, and spatial factors -- likely play a role, according to Kokko. "My gut feeling is that the spatial aspect could actually prove quite important," she said. The two sexual species also have broader home ranges, one stretching northward into the US and the other southward into Central America, where the asexual species do not occur. "That would mean there would be a reservoir of sexual species that the asexuals could not endanger," Loewe said.




http://www.the-scientist.com/blog/display/55611/

  
dvunkannon



Posts: 1377
Joined: June 2008

(Permalink) Posted: April 24 2009,13:05   

Titanium Infused Spider SIlk

Sometimes I read something like this, and I think Kurzweil is right, the Singularity is around the corner. Other times, I just giggle about living in the future.

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

  
Richardthughes



Posts: 10116
Joined: Jan. 2006

(Permalink) Posted: April 24 2009,13:43   

Quote (dvunkannon @ April 24 2009,13:05)
Titanium Infused Spider SIlk

Sometimes I read something like this, and I think Kurzweil is right, the Singularity is around the corner. Other times, I just giggle about living in the future.

Probably better to cite Venge?

--------------
"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

  
rhmc



Posts: 340
Joined: Dec. 2007

(Permalink) Posted: April 29 2009,18:02   

"Chemical 'caterpillar' points to electronics-free robots

A chemical gel that can walk like an inchworm, or looper caterpillar has been demonstrated in a Japanese robotics lab.

The video above shows the material in action. It was created in the Shuji Hashimoto applied physics laboratory at Waseda University, Tokyo.

Shingo Maeda and colleagues made the colour-changing, motile gel by combining polymers that change in size depending on their chemical environment. This is based on an oscillating chemical reaction called the Belousov–Zhabotinsky (BZ) reaction. The result is an autonomous material that moves without electronic stimulation.

The BZ reaction is one of a class of chemical systems in which the concentration of one or more compounds periodically increases and decreases. As well as producing stunning patterns (video), it can even be used to perform calculations using a dish containing the pulsing patterns as a chemical brain...."

http://www.newscientist.com/article....ts.html

  
ppb



Posts: 325
Joined: Dec. 2006

(Permalink) Posted: April 30 2009,08:54   

Watched the PBS Nova program called "Alien From Earth" about Homo floresiensis, the "hobbit" fossils found in Indonesia.  The debate rages on about whether they are a separate species, but further research seems to support this.  Comparison with other human ancestors raises the possibility that H. floresiensis may be descended from australopithecines (like Lucy) rather than Homo erectus as earlier speculated.  If so, this is the first evidence of migration out of Africa of anything pre H. erectus.

There is a good article on this in The New York Times.

--------------
"[A scientific theory] describes Nature as absurd from the point of view of common sense. And it agrees fully with experiment. So I hope you can accept Nature as She is - absurd."
- Richard P. Feynman

  
mitschlag



Posts: 235
Joined: Sep. 2006

(Permalink) Posted: April 30 2009,15:46   

Intelligent machines!

Two papers in Sciencemag.org, April 3, 2009:

Page 81 describes an algorithm that derives fundamental equations of motion from raw data (e.g., Hamiltonian and Lagrange equations)

Page 85 describes a robot that conducted experiments on yeast metabolism with little human intervention, then  reasoned about its results and planned appropriate next experiments. The robot, Adam, identified orphan enzymes that were confirmed (by humans) to function in yeast metabolism, solving problems that have baffled humans for the past 50 years.

The Perspective on p 43 is also worth reading, if you have access.

--------------
"You can establish any “rule” you like if you start with the rule and then interpret the evidence accordingly." - George Gaylord Simpson (1902-1984)

  
dvunkannon



Posts: 1377
Joined: June 2008

(Permalink) Posted: April 30 2009,15:46   

Quote (Richardthughes @ April 24 2009,14:43)
Quote (dvunkannon @ April 24 2009,13:05)
Titanium Infused Spider SIlk

Sometimes I read something like this, and I think Kurzweil is right, the Singularity is around the corner. Other times, I just giggle about living in the future.

Probably better to cite Venge?

I love Marooned In Real Time! I have a friend who owns the oil painting used for the original hardcover cover art. Is there an SF thread on this board?

I think more people associate the Singularity with Kurzweil than Vinge.

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

  
Reed



Posts: 274
Joined: Feb. 2008

(Permalink) Posted: May 02 2009,23:43   

Interesting bit on the evolution design of capsaicin in chili peppers http://www.smithsonianmag.com/science....rs.html

  
jeannot



Posts: 1200
Joined: Jan. 2006

(Permalink) Posted: May 09 2009,17:49   

This is hardly a breakthrough but we've got a paper published in PNAS this week about speciation, more specifically the blurry frontier between what we may call subspecies and species. Of course, there's no strict boundary, as well as there is no qualitative difference between micro- and macroevolution, if this is relevant to the anti-evolution debate.

The work is done on an aphid species complex. Feel free to give you opinion on this. Full access requires subscription, but I can provide a pdf for those interested.

http://www.pnas.org/content/106/18/7495.abstract

  
Timothy McDougald



Posts: 1008
Joined: Dec. 2006

(Permalink) Posted: May 09 2009,21:45   

Quote (jeannot @ May 09 2009,17:49)
This is hardly a breakthrough but we've got a paper published in PNAS this week about speciation, more specifically the blurry frontier between what we may call subspecies and species. Of course, there's no strict boundary, as well as there is no qualitative difference between micro- and macroevolution, if this is relevant to the anti-evolution debate.

The work is done on an aphid species complex. Feel free to give you opinion on this. Full access requires subscription, but I can provide a pdf for those interested.

http://www.pnas.org/content/106/18/7495.abstract

I'd like a copy please. You can send it to afarensis1@sbcglobal.net

--------------
Church burning ebola boy

FTK: I Didn't answer your questions because it beats the hell out of me.

PaV: I suppose for me to be pried away from what I do to focus long and hard on that particular problem would take, quite honestly, hundreds of thousands of dollars to begin to pique my interest.

   
rhmc



Posts: 340
Joined: Dec. 2007

(Permalink) Posted: May 14 2009,20:34   

Chemists see first building blocks to life on Earth

http://news.yahoo.com/s....3210508

PARIS (AFP) – British scientists said on Wednesday that they had figured out key steps in the process by which life on Earth may have emerged from a seething soup of simple chemicals.

Genetic information in living organisms today is held in deoxyribonucleic acid (DNA), the famous "double helix" molecule of sugar, phosphate and a base.

But DNA is too sophisticated to have popped up in an instant, and one avenue of thought says its single-stranded cousin, ribonucleic acid, or RNA, came first.

RNA plays a key role in making proteins and, in viruses, is used to store genetic code.

It is chemically similar to DNA but is simpler and tougher in structure, and thus looks like a good candidate for Earth's first information-coding nucleic acid.

But for all its allure, the "RNA first" theory has run into practical problems.

Its three ingredients -- the base, ribose sugar and phosphate -- must have formed separately and then combined to form the molecule, according to conventional thinking.

Critics, though, say that RNA, while somewhat simpler than DNA, is still a complex molecule and could not have been assembled spontaneously.

These doubters have been comforted by the failure to find any feasible chain of chemical events to explain how the three components all came together.

But a paper published in the British journal Nature by University of Manchester chemists puts forward a different explanation.

The team, led by Professor John Sutherland, venture that an RNA-like synthesis took place through a series of chemical reactions and an important intermediate substance.

Their lab model uses starting materials and environmental conditions that are believed to have been around in early Earth and are also used in the standard "RNA first" scenario.

Their theory starts with a simple sugar called glycolaldehyde, which reacts with cyanmide (a compound of cyanide and ammonia) and phosphate to produce an intermediate compound called 2-aminooxazole.

Gentle warming from the Sun and cooling at night help purify the 2-aminooxazole, turning it into a plentiful precursor which contributes the sugar and base portions of the new ribonucleotide molecule.

The presence of phosphate and ultraviolet light from the Sun complete the synthesis.

In a commentary also published by Nature, US molecular biologist Jack Szostak hailed the research as an elegant explanation as to why the sugar and base would not have to form separately before forming the new molecule.

"It will stand for years as one of the great advances in prebiotic chemistry," the term for the study of the chemical processes that led to life on Earth, he enthused.

Opinions vary as to when the first organisms appeared on Earth.

One estimate, based on fossilised mats of bacteria found in Australia, is that this happened around 3.8 billion years ago, around 700 million years after the planet was formed.

  
Erasmus, FCD



Posts: 6349
Joined: June 2007

(Permalink) Posted: May 14 2009,21:41   

Quote (jeannot @ May 09 2009,18:49)
This is hardly a breakthrough but we've got a paper published in PNAS this week about speciation, more specifically the blurry frontier between what we may call subspecies and species. Of course, there's no strict boundary, as well as there is no qualitative difference between micro- and macroevolution, if this is relevant to the anti-evolution debate.

The work is done on an aphid species complex. Feel free to give you opinion on this. Full access requires subscription, but I can provide a pdf for those interested.

http://www.pnas.org/content/106/18/7495.abstract

pffft its still an aphid.  wake me up when one turns into a blue whale or summtin.  evilutionists

hey jean i noticed that at least some of those plants are tag-alongs with humans (clover, afalfa, peas, vetch)  i didn't recognize some of the others but i wouldn't.  

wondering if you had any idea of what the ancestral host preference mighta been?  i'm not swift enough to figure out if the biotypes that can switch hosts prefer hosts that have been strongly domesticated.  would make sense that selection for being tasty for people or livestock, if it reduces any defense complexes, might make you tastier for insects.

in one fell swoop you have generated more science than the entire ID movement in 2008 AND 2009.  Cheers!

--------------
You're obviously illiterate as hell. Peach, bro.-FtK

Finding something hard to believe based on the evidence, is science.-JoeG

the odds of getting some loathsome taint are low-- Gordon E Mullings Manjack Heights Montserrat

I work on molecular systems with pathway charts and such.-Giggles

  
Henry J



Posts: 4060
Joined: Mar. 2005

(Permalink) Posted: May 14 2009,22:27   

So we came from ammonia and cyanide, rather than from goo? Is that good or bad?

Henry

  
Erasmus, FCD



Posts: 6349
Joined: June 2007

(Permalink) Posted: May 14 2009,23:46   

anyone into this sort of thing...

Quote
Olivier Rieppel.  2008.  Species as a Process.  Acta Biotheoretica Sep 2008.  

Abstract  Species are generally considered to be the basic units of evolution, and hence to constitute spatio-temporally bounded entities. In addition, it has been argued that species also instantiate a natural kind. Evolution is fundamentally about change. The question then is how species can remain the same through evolutionary change. Proponents of the species qua individuals thesis individuate species through their unique evolutionary origin. Individuals, or spatio-temporally located particulars in general, can be bodies, objects, events, or processes, or a combination of these. It is here argued that species are best understood as open or closed, causally integrated processual systems that also instantiate an historically conditioned homeostatic property cluster natural kind.

Keywords  Species - Systems - Presentism - Eternalism - Endurance - Perdurance - Futuralism


here is a bit

Quote
Eternalism takes time as a fourth dimension that is on par with the three dimensions of space. Space-time forms a four-dimensional continuum, as is required by the space-time ontology of modern physics (Rea 2003). On that account, all the space-time slices of an object, past, present, and future, ‘co-exist’ in four dimensions. A perduring object then forms a space-time worm (Loux 2003, p. 223), as do species on a perdurantist–eternalist account (Hull 1989, p. 187; Brogaard 2004, p. 226). Species cannot be extinct, they can only be ‘far away’. Nor can species evolve in the Darwinian sense of the word, since they have no future that could bring about genuine change.


any physicists care to comment on this view of time?

contrast with

Quote
As was emphasized by Rea (2003, p. 274), presentism is in strong accord with intuition, whereas eternalism seeks empirical support from contemporary theories of physics (Sklar 2006). Where the presentist has a problem to identify the duration of the present, the eternalist has the problem of identifying the ‘thickness’ of the temporal parts (space—time slices) of the perduring object. For some philosophers such as Whitehead (1920), time obtains from the passing of nature. But if we cannot keep time from passing, we also cannot hold nature still: “There is no holding nature still and looking at it” (Whitehead 1920, p. 14). A perduring object, or species, thus threatens to disintegrate into a series of theoretically infinitely thin time-slices, i.e., fleeting Whiteheadian ‘occasions’ (Whitehead 1979) that are spatio-temporally located parts of processes whose moment “of becoming is also their moment of perishing” such that they themselves neither change nor move (Sherburne 1966, pp. 210, 222). If the question is how one and the same (numerically identical) species can persist through temporal change, an ontology premised on the notion that nothing exists for any substantial length of time would not solve the problem. Identity conditions for persistence through time would lose their relevance (Haslanger 2003, p. 335). Herein lies a strong motivation for four-dimensionalism that results from an eternalist account of time, as was employed by Whitehead (1979) in his process philosophy—an account that was also adopted by Hennig (1950, 1966; see Rieppel 2007b).

Some authors take a four-dimensional space-time worm to be “the mereological fusions of instantaneous temporal parts or stages located at different times” (Crisp 2003, p. 216). Such a space-time worm stands in contrast to one whose segments are events or processes, which naturally extend through time. Organisms (Bertalanffy 1932, 1941; Hennig 1950, 1966; Rieppel 2007a) as well as evolving species take part in processes, indeed can be seen to be processes themselves (see further discussion below, and in Rieppel 2007b); Hennig (1950, 1966) realized with respect to his concept of the semaphoront that instantaneous temporal parts or stages are not a suitable ontology to capture developing organisms (Rieppel 2003, 2007b), and the same is true for evolving species. Such a radical, indeed Whiteheadian interpretation of the perdurantist–eternalist account contrasts with another possible interpretation of four-dimensionalism, which does not take time as another dimension on par with space, but which takes a persisting object to be identical with its history (Gallois 2005, p. 8). On that account, the species is a sequence of events that is identical with its history, i.e., a process that extends through space and time. History has not only a past and a present, but also a future, distinctions that are denied on the perdurantist–eternalist account. A species that is a four-dimensional space-time worm (Hull 1989, p. 187; Brogaard 2004, p. 226) has no past, nor any future: it just is (Hull 1989, p. 187). Accordingly, and for Hull (1989 , p. 187), “the species name Cygnus olor” refers “both to a spatio-temporally extended lineage and to a time-slice of that lineage.” This is why Løvtrup (1979, p. 390) contrasts Hull’s (1976) views with his own, where species (‘terminal taxa’ in Løvtrup’s (1977, 1979) axiomatic system) remain active players in the arena of evolution, making history.

Presentism yields a non-dimensional species concept (Mayr 1963, 1982) that fails to capture the species as an evolutionary process. Eternalism likewise cannot capture the species as an evolutionary process, as there is no past, nor any potential for future change and innovation. As will be illustrated by a brief excursion into the history of biology, a ‘third way’, a new metaphysics of change is required to capture species that are “evolution in the making” (Løvtrup 1977, p. 50).


i do not know many young biologists who are concerned with these issues.  yet they seem grave enough to warrant consideration.  these concepts form the foundation for discussing "speciation" and macroevolution, yet there are deep schisms between schools of thought that cannot be addressed by simply "following the evidence".

--------------
You're obviously illiterate as hell. Peach, bro.-FtK

Finding something hard to believe based on the evidence, is science.-JoeG

the odds of getting some loathsome taint are low-- Gordon E Mullings Manjack Heights Montserrat

I work on molecular systems with pathway charts and such.-Giggles

  
Erasmus, FCD



Posts: 6349
Joined: June 2007

(Permalink) Posted: May 14 2009,23:47   

Quote (Henry J @ May 14 2009,23:27)
So we came from ammonia and cyanide, rather than from goo? Is that good or bad?

Henry

why, goooooooood, of course!

--------------
You're obviously illiterate as hell. Peach, bro.-FtK

Finding something hard to believe based on the evidence, is science.-JoeG

the odds of getting some loathsome taint are low-- Gordon E Mullings Manjack Heights Montserrat

I work on molecular systems with pathway charts and such.-Giggles

  
jeannot



Posts: 1200
Joined: Jan. 2006

(Permalink) Posted: May 15 2009,09:43   

Quote (Erasmus, FCD @ May 14 2009,21:41)
Quote (jeannot @ May 09 2009,18:49)
This is hardly a breakthrough but we've got a paper published in PNAS this week about speciation, more specifically the blurry frontier between what we may call subspecies and species. Of course, there's no strict boundary, as well as there is no qualitative difference between micro- and macroevolution, if this is relevant to the anti-evolution debate.

The work is done on an aphid species complex. Feel free to give you opinion on this. Full access requires subscription, but I can provide a pdf for those interested.

http://www.pnas.org/content/106/18/7495.abstract

pffft its still an aphid.  wake me up when one turns into a blue whale or summtin.  evilutionists

hey jean i noticed that at least some of those plants are tag-alongs with humans (clover, afalfa, peas, vetch)  i didn't recognize some of the others but i wouldn't.  

wondering if you had any idea of what the ancestral host preference mighta been?  i'm not swift enough to figure out if the biotypes that can switch hosts prefer hosts that have been strongly domesticated.  would make sense that selection for being tasty for people or livestock, if it reduces any defense complexes, might make you tastier for insects.

in one fell swoop you have generated more science than the entire ID movement in 2008 AND 2009.  Cheers!

We don't know the ancestral host. It could be an annual vetch related to broad bean, which is suitable for all biotypes. But we don't have the data to test this.

Artificial selection for/against plant defenses is an interesting question. But pea and broad bean, which do not grow in the wild, are far from being deprived of anti-insect defenses.
In fact, host fidelity seems a bit stronger in some biotypes feeding on wild plants, like broom, restharrow and meadow vetchling. But these biotypes may have diverged more anciently.

  
Erasmus, FCD



Posts: 6349
Joined: June 2007

(Permalink) Posted: May 15 2009,10:10   

i never thought it before but how old are peas?  are there new and old world peas?

can you date those divergences in the aphids molecularly?

is domestication of wild pea lineages likely to have played a role in the extinction of the ancestral pea?  

perhaps if there were never peas would call them some other sort of aphid.  if only there were poison ivy aphids.

i just picked a gallon or so of peas in my garden and i am tickled about it

we planted some storebought 'alaska' spring peas and 'little marvel' bush peas.  i  should have picked them the first time several weeks ago but we'll probably get another good pick out of these two patches.  

peas don't do very well here but its not aphids its heat.  in fact i have never seen an aphid on them but that doesn't mean anything.  they don't seem to have much insect damage at all.

thanks for posting that very cool

--------------
You're obviously illiterate as hell. Peach, bro.-FtK

Finding something hard to believe based on the evidence, is science.-JoeG

the odds of getting some loathsome taint are low-- Gordon E Mullings Manjack Heights Montserrat

I work on molecular systems with pathway charts and such.-Giggles

  
Richard Simons



Posts: 425
Joined: Oct. 2006

(Permalink) Posted: May 15 2009,13:18   

Quote (Erasmus @ FCD,May 15 2009,10:10)
i never thought it before but how old are peas?  are there new and old world peas?

can you date those divergences in the aphids molecularly?

is domestication of wild pea lineages likely to have played a role in the extinction of the ancestral pea?  

perhaps if there were never peas would call them some other sort of aphid.  if only there were poison ivy aphids.

i just picked a gallon or so of peas in my garden and i am tickled about it

we planted some storebought 'alaska' spring peas and 'little marvel' bush peas.  i  should have picked them the first time several weeks ago but we'll probably get another good pick out of these two patches.  

peas don't do very well here but its not aphids its heat.  in fact i have never seen an aphid on them but that doesn't mean anything.  they don't seem to have much insect damage at all.

thanks for posting that very cool

Off the top of my head: Peas are amongst the oldest crops from the Fertile Crescent (the higher ground around what was Mesopotamia) together with wheat, barley and lentils. I seem to recall the suggestion that they came from Anatolia. The ancestral form quite likely became extinct because it was swamped by the crop and the hybrids could not survive in the wild. It is thought that the same thing happened to onions.

I would be pleased if I had just picked a gallon of them, too. There's nothing quite like fresh-picked peas. Unfortunately, our garden will be just about ready to sow peas in about a week.

Edit to change silly mistake.

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All sweeping statements are wrong.

  
Erasmus, FCD



Posts: 6349
Joined: June 2007

(Permalink) Posted: May 15 2009,13:33   

thanks richard that is good stuff.  i wonder how long that hybridization/backcross process lasts til extinction?  it must be a complex sequence of events, patchy in space and sensitive to human interactions with domestication.

probably different for different critters but it must not always happen...  thinking about blueberries potatoes bananas and tame blackberries but i reckon it is similar for any domesticated thing if there is gene flow between cultivars and wild types

you must be far north of that sunny state of tennessee.  i wish we could grow peas longer.  i am going to try a fall crop this year but i dunno if i can time it right

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You're obviously illiterate as hell. Peach, bro.-FtK

Finding something hard to believe based on the evidence, is science.-JoeG

the odds of getting some loathsome taint are low-- Gordon E Mullings Manjack Heights Montserrat

I work on molecular systems with pathway charts and such.-Giggles

  
jeannot



Posts: 1200
Joined: Jan. 2006

(Permalink) Posted: May 15 2009,15:41   

I am not sure that the wild ancestor of pea is extinct. I thought it was Pisum fulvum.

But the wild ancestor of broad bean, which is as old as cultivated pea, is unknown/extinct.

  
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