Laboratory Speciation in Helianthus Evolves a Native Species

furball4paws

[furball4paws]

Laboratory Speciation in Helianthus Evolves a Native Species

DNA examination of five species of Helianthus (H. annuus, H. petiolarus fallax, H. anomalus, H. paradoxus, and H. deserticola) suggested that H. annuus and H. petiolarus fallax are the evolutionary parents of the other three species (Rieseberg 1993, 1995, 1993). All five species are self-incompatible and fertile. Typically, H. annuus (the ancestor of the commercial sunflower) and H. petiolarus fallax form hybrids that are almost fully sterile. However, the few fertile hybrids, when subjected to sib-matings and back crossing regimes yield a new species that is fully fertile and cannot cross with either of the parental species. This new species is virtually identical to H. anomalus. The produced species is genetically isolated from the parents by chromosomal barriers. "Under laboratory conditions these changes are repeatable across independent experiments" (Niklas, p.64). The laboratory derived H. anomalus readily crosses with the native H. anomalus. Results indicate that H. deserticola and H. paradoxus may also have arisen via hybridization of H. annuus and H. petiolarus fallax. These two species have different synthetic capabilities from the parents and live in sandier and drier soils. Hybrid speciation may be common in plants where hybrids often form (see Gilia sp., Grant, 1966, Stebbins, 1959, Arnold, 1995), but is presumed rare in animals where hybrids are less common (however, see the minnow Gila seminuda, Bellini, 1994). Experiments to confirm the evolutionary parents of H. deserticola and H. paradoxus have not been performed. 1. Based on nuclear and chloroplast DNA analysis results, the Theory of Evolution predicts that H. annuus and H. pertiolarus fallax are evolutionary ancestors of H. anomalus, H. deserticola and H. paradoxus. 2. Hybrids of H. annuus and H. petiolarus fallax subjected to different regimes (at least 3) of back crossing and sib-matings, all converged into a new plant species with "nearly identical gene combinations" (Rieseberg) as the native species H. anomalus. This confirms the natural evolutionary parents of H. anomalus as predicted.

References 1. Arnold, J and S.A. Hodges. 1995. Are Natural Hybrids Fit or Unfit Relative to Their Parents? Trends Ecol. Evol. 10:67-71. 2. Bullini, L. 1994. Origin and Evolution of Animals by Hybrid Animal Species. Trends Ecol. Evol. 9:422-6. 3. Futuyma, D.J. 1998. Evolutionary Biology. 3rd. Edition, Sinauer Associates Inc., Sunderland, MA. 4. Grant, V. 1966. The Origin of a New Species of Gilia in a Hybridization Experiment. Genetics 54:1189-99. 5. Niklas, K.J. 1997. The Evolutionary Biology of Plants. Univ. Chicago Press, Chicago, IL. 6. Rieseberg, L.H. 1995. The Role of Hybridization in Evolution: Old Wine in New Skins. Amer. J. Bot. 82:944-53. 7. Rieseberg, L.H., and N.C. Ellstrand. 1993. What Can Molecular and Morphological Markers Tell Us About Plant Hybridization? Crit. Rev. Plant Sci. 12:213-41. 8. Rieseberg, L.H., B. Sinervo, C.R. Linden, M. Ungerer and D.M. Arias. 1996. Role of Gene Interactions in Hybrid Speciation: Evidence from Ancient and Experimental Hybrids. Science 272:741-44.A

Nice, neat, repeatable and meets all scientific criteria for a definitive experiment.

[b_sharp]

You've made a particularily stressful day a lot easier to recover from. Thanks.

[Right Wing Professor]

There's probably more to it than simply determining the ancestral DNA sequences & engineering them into the rats' genomes. But maybe not.

I had a more mundane idea. You can often figure out an organism's environment from the properties of some of its proteins. For example, animals that live at low oxygen levels have hemoglobins with very low binding constants for oxygen. So, if you figured out the sequence of several proteins from the Murinae common ancestor, you might be able to figure out quite a bit about how it lived, even though you had no idea what it looked like.

[UnbelievingScumOnTheOtherSide]

I think the reason it showed up in the platypus thread is because of the surprise that another unlikely ear development has been found to have occurred twice, which throws doubt on the relevance of this note:

"However, the skulls of pakicetids have an ear region that is highly unusual in shape, and only resembles that of modern and fossil whales. These features are diagnostic for cetaceans, they are found in all cetaceans, and in no other animals. These features are main why pakicetids are considered whales."
http://darla.neoucom.edu/DEPTS/ANAT/Thewissen/whale_origins/

Besides, those bodies have very little of the heads on which to make a match. And that this is the next closest "relative" makes me shake my head. At least the ears are similar.



Yes, I know. Everything is a branch. Nothing is a direct line.

[VadeRetro]

Did I mention we already had better skulls for Pakicetus? There are multiple fossils for that species.

I suppose it's safe to use that picture now that creationists are posting it at ME. Some years ago, the first time I ever used it, some lawyerly dipshoot made an incredible racket over it being a replica (in the U Cal Museum of Paleontolgy of another specimen in Europe).

A good, high-resolution picture of the fossil basis for Ambulocetus is here. It's too big to post in-line.

Note that with bilateral symmetry, if you have a bone from one side of the animal, you know it had the same thing on the other side as well. We can account for a high percentage of Amby.

The whales make a series now. We didn't used to have the fossils to do that, but evolution predicted that they must have lived. We found them. Darwin, writing before 1859 predicted something found in the 1990s. You'd think that would mean something, but all that comes from the diehards whose resistance stems from religious horror are sneering, cynical grumbles.

[furball4paws]

I love these, especially the dog one. Does anyone remember Gary Larson and Far Side - he had a couple of toons about "Great Moments in Evolution"?

The one I remember is a couple of fish at the surface, one has a baseball bat and one with a cap and glove. Unfortunately their ball is about 10 fish paces onto dry land. The title; Great Moments in Evolution.

i suppose there would be copyright problems with postings from the Far Side. Hell I can think of a bunch of Calvin and Hobbes I'd like to see too.

[balrog666]

Some truth must be suppressed--to make the world safe for lies--even if your name means "only truth."

Sometimes names are taken for other than literal reasons [wink, wink, nudge, nudge]. And here are two obvious examples.

[balrog666]

You want Mr. Scum, who I am sure is not a scientist to reinforce his view of us as Dr. Mengeles, or do you just want to smack him on the head?

BWAAAAAAAAAAAAAAHAHAHAHAHA! Wouldn't number 2 accomplish number 1 anyway?

[balrog666]

No, seriously, this is fun. I don't mind reading, even looking up a few things. I have a Bachelor of Science c.l. and an AS m.c.l. in another discipline, so I am not a *complete* doofus :-)

What the hell is an AS? Did you leave off the last S?

[UnbelievingScumOnTheOtherSide]

I'm not in horror.

But here is the basic problem you have to overcome. Using these "whales" as an example, the overall appearance between them is quite different. But a similarity in the ears is seized on as "diagnostic." And then they are placed in approximate chronological order. You assume that this particular trait was inherited. Others believe they were created independently and you have simply grouped together unrelated animals based on this one characteristic. Given the radically different appearance of the rest of the animal while the ear changes little is rather suspicious and convenient.

Another issue is DNA. DNA is like a computer program for generating organisms. One expects similar structure to be generated from similar DNA. But again, you assume the similarities to be from inheritance. Others would look at it as reusable modular code placed in various animals to fit them for the ecoregion in which they are placed.

The resolution comes in finding a mechanism likely to produce such changes. Survival of the fittest, mutation, genetic drift, hybridization (!) are all proposals. But till you find one that really works, you have a very clever taxonomic classification system and nothing more.

[VadeRetro]

But here is the basic problem you have to overcome. Using these "whales" as an example, the overall appearance between them is quite different. But a similarity in the ears is seized on as "diagnostic."

And the teeth. Pakicetus's teeth are similar to those of Archaeocetes, never mind the bridging status of the skull data of Ambulocetus, Rhodocetus, etc.

They make a series. And they were expected. A sneering dumb-bleeps like you have been asking where the missing links were for most of the 140+ years they were expected. And they turned up.

Another issue is DNA.

"Issue" is not a good term. Try "independent line of evidence which was already pointing the same way."

One expects similar structure to be generated from similar DNA. But again, you assume the similarities to be from inheritance.

When a development is really independent, it shows in the DNA. Bat wings and bird wings, for instance. Guinea pigs have lost the ability to synthesize vitamin C. Looking at the DNA, it's recognizeably an independent mutational event from the same loss in humans. Chimpanzees and other primates also cannot synthesize DNA. Their mutations are the same as our own. That's inherited.

You don't show anything good by being this stupid. The only "evidence" for creationism is creationists pretending to be utterly, totally, clueless.

Which forces one to conclude that you are genuinely clueless. Or you're lying.

And who cares which it is?

[UnbelievingScumOnTheOtherSide]

What the hell is an AS? Did you leave off the last S?

Yes I did. Glad to see you made it anyway.

[balrog666]

Yes I did. Glad to see you made it anyway.

LOL.

Oh, hell, just bite my AS.S.

[VadeRetro]

And the teeth... They make a series.

And the nares migrate right up the head to make the blowhole of a modern whale. But the cretinists are hanging on every straw they can grasp playing "Me-No-See-Um."

This "science" has nothing to offer.

[UnbelievingScumOnTheOtherSide]

When a development is really independent, it shows in the DNA.

If you cannot see that you are assuming your conclusion, you have a serious problem.

[VadeRetro]

If you cannot see that you are assuming your conclusion, you have a serious problem.

Molecular geneticists who examine DNA sequences from an evolutionary perspective know that large gene deletions are rare, so scientists expected that non-functional mutant GLO gene copies--known as "pseudogenes"--might still be present in primates and guinea pigs as relics of the functional ancestral gene. In contrast, Creationists believe that humans and guinea pigs were each created independently of all other species and must have been "designed" to function without GLO. If this were true, these two species would not be expected to carry a defective copy of the GLO gene. In fact, GLO pseudogenes have been detected in both guinea pigs and humans (Nishikimi et al. J Biol Chem 267: 21967, 1992; Nishikimi et al. J Biol Chem 269:13685, 1994), consistent with the evolutionary view; presumably, related pseudogenes also exist in non-human primates that require dietary vitamin C. The kinds of mutations found in the human and guinea pig pseudogenes are typical of the ones seen in genetic diseases like those mentioned earlier.

Plagiarized Errors and Molecular Genetics

You are the one with the problem. It's religious horror. You are dismissing all the evidence that proves your cherished beliefs false, and it's quite an impressive pile of evidence.

Nothing you have said on this thread has borne up under any sort of examination. You have simply changed subjects or distracted in other ways and danced on. I've been watching this act for six years now. Grownups acting like fifth-graders lying to the teacher about who did what to whom on the playground.

What really bugs me about creationism isn't that it's false. What really bugs me is that it's a lie.

[UnbelievingScumOnTheOtherSide]

Creationists believe that humans and guinea pigs were each created independently of all other species and must have been "designed" to function without GLO. If this were true, these two species would not be expected to carry a defective copy of the GLO gene. In fact, GLO pseudogenes have been detected in both guinea pigs and humans...

You set up the nonsequitur and then shoot it down. Congratulations.

[furball4paws]

We've spent a lot of time fussing with Mr. Scum and every time we clear up one of his complaints, he slides away onto something else. It sounds scripted. And he has stuck around, but by his words I don't think it's because of our illustrious company. Most creationoids would have gone away a long time ago. Is there some other thread we are missing?

I love Pond Scum, Mr. Scum, but there are a lot of nasty critters lurking in it. Maybe it's time to put him to bed.

[UnbelievingScumOnTheOtherSide]

I'm not the one changing the subjects. Every time I answer something you all drop it and move on to something else. If you think the presence/absence/state of some gene follows from creation or not, I'd like to here it rather than you running out of arguments when you can't support a web page one of you brought up as soon as it's questioned. It is you who seems to need a script.

[Dimensio]

And the nares migrate right up the head to make the blowhole of a modern whale. But the cretinists are hanging on every straw they can grasp playing "Me-No-See-Um."

Actually, this one seems to be playing the game of "It could have just been designed that way, therefore it isn't evidence of evolution".

[jennyp]

The quagga is one subect of this. the Quagga Breeding Project.

Kewl!