Is The "chickenosaurus" Project Actually Possible?

[Auspex]

As of yet I'm unaware of any plans to release these into the environment...

Not the creations themselves, no. Genetic manipulation in general is inherently dangerous, though, because unforeseen and unintended consequences could be far reaching, and not in a good way.

[Scylla]

Not the creations themselves, no. Genetic manipulation in general is inherently dangerous, though, because unforeseen and unintended consequences could be far reaching, and not in a good way.

The risk of genetic modification is real. However having said that I think we over estimate the real risk. Nature has probably done the experiment already and even a breeding pair (of anything) wouldn't have the genetic diversity to ceate a viable population. Most domesticated or lab animals do not fare well when let loose. The risk is probably similar to an invasive species. We release hundreds, if not thousands of invasive species each year and they do lots of damage, but not world ending damage (well, not yet anyway) I only make this point to temper the sometimes irrational fear that genetic modification can engender. We should not release these things if we create them, but the risk is not that huge if they do get out of the chicken coop.

[Auspex]

The flora and fauna that exist anywhere at any moment are the products of that ecosystem, and the introduction of something novel will cause a cascade of change within that system. While change itself is as natural and continuous as life on Earth, Man has shown a capacity (even a propensity) to cause an accelerated rate of change, which the evolved systems cannot balance.

As an ecologist, I am simply leery of tinkering, especially with something only partly understood.

[Mediospirifer]

The flora and fauna that exist anywhere at any moment are the products of that ecosystem, and the introduction of something novel will cause a cascade of change within that system. While change itself is as natural and continuous as life on Earth, Man has shown a capacity (even a propensity) to cause an accelerated rate of change, which the evolved systems cannot balance.

As an ecologist, I am simply leery of tinkering, especially with something only partly understood.

Oh, yes. Granted, some things don't succeed in their new environment without a lot of help. Introducing rainforest critters to a desert probably won't have much impact. Taking a mutualist without its symbiont won't last long. Bring a fast-breeding opportunistic critter into a similar environment? Wow, that's a population boom!

With GMO plants, I know of two possible impacts. One is the effect of the plant itself getting into the wild and breeding, the other is cross-pollination with wild plants. I really wish that the people developing new varieties would stick to drought resistance, better yield, and different shapes and flavors, and not try to introduce pesticide production into their crops!

I've heard that one possible factor in honeybee decline is the increase in agricultural crops that produce insecticides. The article claimed that these plants were producing the chemicals in their pollen as well as the leaves, and the bees were collecting poison with their food. Whether that's true or not, I don't particularly want to eat insecticide with my food! That's a large part of why I wash my vegetables...

The chickenosaurus experiment doesn't look like it would have any long-term effects, or at least none worse than letting chickens escape. I can imagine zoos wanting the have a few to exhibit, though!

[Carcharodontosaurus]

Oh, yes. Granted, some things don't succeed in their new environment without a lot of help. Introducing rainforest critters to a desert probably won't have much impact. Taking a mutualist without its symbiont won't last long. Bring a fast-breeding opportunistic critter into a similar environment? Wow, that's a population boom!

With GMO plants, I know of two possible impacts. One is the effect of the plant itself getting into the wild and breeding, the other is cross-pollination with wild plants. I really wish that the people developing new varieties would stick to drought resistance, better yield, and different shapes and flavors, and not try to introduce pesticide production into their crops!

I've heard that one possible factor in honeybee decline is the increase in agricultural crops that produce insecticides. The article claimed that these plants were producing the chemicals in their pollen as well as the leaves, and the bees were collecting poison with their food. Whether that's true or not, I don't particularly want to eat insecticide with my food! That's a large part of why I wash my vegetables...

The chickenosaurus experiment doesn't look like it would have any long-term effects, or at least none worse than letting chickens escape. I can imagine zoos wanting the have a few to exhibit, though!

I'm pretty sure the pesticides are made to be dangerous to insects and not to humans.

Having said that though, I would prefer GMOs like Golden Rice to GMOs like Roundup Ready.

[Mediospirifer]

I'm pretty sure the pesticides are made to be dangerous to insects and not to humans.

Having said that though, I would prefer GMOs like Golden Rice to GMOs like Roundup Ready.

I know. I question how thoroughly they've really been tested. I'd rather avoid them. I also prefer to avoid food additives that I can't pronounce...given an affordable choice.

And I agree completely about Golden Rice vs. Roundup Ready!

[Scylla]

The past few posts have exactly made my point! The risk of each genetic manipulation should be understood and studied, but saying that ALL genetic modification is to be avoided is irrational.

The flora and fauna that exist anywhere at any moment are the products of that ecosystem, and the introduction of something novel will cause a cascade of change within that system. While change itself is as natural and continuous as life on Earth, Man has shown a capacity (even a propensity) to cause an accelerated rate of change, which the evolved systems cannot balance.

As an ecologist, I am simply leery of tinkering, especially with something only partly understood.

I agree, I was just equating the risk, roughly, to the risk of introduced species. Kudzu, snakeheads, earthworms, dandelions and tumbleweeds were never well enough understood by those that released them. Evolved systems can and will balance any disruption we can introduce, just not on human timescales. I really doubt there is much we can do that can't be remediated in 20,000,000 years or so. The present ecosystems will be long gone, but new, complex, interdependent and robust ones will form. I'm willing to bet anyone that disagrees with me.

[Auspex]

I'm pretty sure the pesticides are made to be dangerous to insects and not to humans...

Organophosphates were widely used with abandon, and not thought to be harmful to humans. This attitude proved to be wrong.

LINK

In a much larger sense, anything detrimental to the environment is potentially dangerous to humans. Please find a copy of Rachel Carson's "Silent Spring", and read it.

[Scylla]

And "The Sixth Extinction" by Elizabeth Kolbert

[PA Fossil Finder]

. . . I don't particularly want to eat insecticide with my food! That's a large part of why I wash my vegetables...

As far as I know, some pesticides enter the plant and spread to every part, so washing doesn't always help with getting rid of chemicals. I found this video interesting: My Potato Project

[jpc]

To answer the first question: is it possible? Yes it is. Put enough money and brains into it and it would be rather easy I expect. I'd even bet you could get one in less than a century with good old fashioned inbreeding and selection. Might be easier to convert a mouse into a reptilian looking creature just because the whole knockout/transgenic toolkit is built for mice. If it was up to me though I would do it with ostriches as a starting point.

I said this once before... I'll say it again. This chickenosaurus has NOTHING to do with good old fashioned inbreeding and selection. They are manipulating gene expression not cross breeding. VERY different projects. yes, scylla, it will never happen with inbreeding and selection, but it could be done with controlling gene expression. The theory is that the gene for teeth is still in the chicken somewhere, but it has been turned off by its birdness. With genetic manipulation, they hope to turn it back on...and a tail, and whatever.

As for letting these things so in the wilds... these guys are fully aware of the consequences you guys are talking about, and they plan not to allow their frankensaurs to even reach a viable state.

Edited March 7, 2014 by jpc

[Carcharodontosaurus]

I said this once before... I'll say it again. This chickenosaurus has NOTHING to do with good old fashioned inbreeding and selection. They are manipulating gene expression not cross breeding. VERY different projects. yes, scylla, it will never happen with inbreeding and selection, but it could be done with controlling gene expression. The theory is that the gene for teeth is still in the chicken somewhere, but it has been turned off by its birdness. With genetic manipulation, they hope to turn it back on...and a tail, and whatever.

As for letting these things so in the wilds... these guys are fully aware of the consequences you guys are talking about, and they plan not to allow their frankensaurs to even reach a viable state.

So they aren't planning on creating an actual living creature, just an embryo?

[Scylla]

I said this once before... I'll say it again. This chickenosaurus has NOTHING to do with good old fashioned inbreeding and selection. They are manipulating gene expression not cross breeding. VERY different projects. yes, scylla, it will never happen with inbreeding and selection, but it could be done with controlling gene expression. The theory is that the gene for teeth is still in the chicken somewhere, but it has been turned off by its birdness. With genetic manipulation, they hope to turn it back on...and a tail, and whatever.

As for letting these things so in the wilds... these guys are fully aware of the consequences you guys are talking about, and they plan not to allow their frankensaurs to even reach a viable state.

JPC, sorry, but since it has happened at least once before with breeding that a chicken sized creature with a tail and claws and teeth has evolved, you have to admit that it is possible for it to happen again. Inbreeding tends to pull out recessive genes and make them visible in the phenotype. If some of these genetic switches are suppressed, then inbreeding may remove that suppression. It would clearly be faster and cheaper to use modern techniques in gene manipulation to get a dinosaur-looking creature, but to say it will never happen otherwise is incorrect IMHO.

[Mediospirifer]

JPC, sorry, but since it has happened at least once before with breeding that a chicken sized creature with a tail and claws and teeth has evolved, you have to admit that it is possible for it to happen again. Inbreeding tends to pull out recessive genes and make them visible in the phenotype. If some of these genetic switches are suppressed, then inbreeding may remove that suppression. It would clearly be faster and cheaper to use modern techniques in gene manipulation to get a dinosaur-looking creature, but to say it will never happen otherwise is incorrect IMHO.

It depends on whether the genes are simply turned off, or broken. A turned off gene may occasionally appear as an atavism (horses with extra toes, whales with legs, humans with tails!), but a broken gene can't be expressed. I suppose it depends on how the gene is broken; an insertion mutation that renders it nonfunctional could potentially be removed by a deletion mutation later, but the deletion would be far more likely to remove an important part of the gene and break it further. Mutations occur at random, after all, and a mutation in a gene that isn't used would not affect the organism's phenotype. Both the insertion and the deletion would be invisible to selection.

Has anyone heard of a modern bird showing teeth? I haven't, except for that one experiment I mentioned above.

[Scylla]

It depends on whether the genes are simply turned off, or broken. A turned off gene may occasionally appear as an atavism (horses with extra toes, whales with legs, humans with tails!), but a broken gene can't be expressed. I suppose it depends on how the gene is broken; an insertion mutation that renders it nonfunctional could potentially be removed by a deletion mutation later, but the deletion would be far more likely to remove an important part of the gene and break it further. Mutations occur at random, after all, and a mutation in a gene that isn't used would not affect the organism's phenotype. Both the insertion and the deletion would be invisible to selection.

Has anyone heard of a modern bird showing teeth? I haven't, except for that one experiment I mentioned above.

There are three examples listed:

http://www.nature.com/scitable/topicpage/atavism-embryology-development-and-evolution-843

[Auspex]

The latent genes for teeth in avians did re-express themselves in both the Hesperornithiformes and the Icthyornithiformes, neither of which were directly descended from the now-famous toothed Enantiornithes, so I think it can be done.

[Carcharodontosaurus]

There are three examples listed:

http://www.nature.com/scitable/topicpage/atavism-embryology-development-and-evolution-843

The teeth can't develop enamel though, unless you use tissue grafting from other species, or you use enamel genes from other species. I don't think Horner wants to use transgenesis for his project.

[Scylla]

Who cares what Horner wants? I want my pet dinosaur! And I want it NOW!

[Auspex]

Velociraptors make lousy house pets.

[xonenine]

The latent genes for teeth in avians did re-express themselves in both the Hesperornithiformes and the Icthyornithiformes, neither of which were directly descended from the now-famous toothed Enantiornithes, so I think it can be done.

you gave me something new to read Chas, thanks

Loss of teeth and enamel in tetrapods: fossil record, genetic data and morphological adaptations

[Mediospirifer]

you gave me something new to read Chas, thanks

Loss of teeth and enamel in tetrapods: fossil record, genetic data and morphological adaptations

I'm reading this article, too. Very interesting! I notice that they talk about and link to the study I mentioned above by Kollar & Fisher.

[Mediospirifer]

Very interesting article! It took me a while to take it all in, but it's truly fascinating.

Among other things, I see that the Kollar & Fisher article I mentioned had some potential problems, and later work failed to replicate the enameled teeth produced from mouse mesenchyme with chick epithelium. The follow-up experiment did produce tooth buds, but no enamel.

The postulated reason for the production of enamel in the first experiment was possible contamination with mouse epithelium; it's apparently very difficult to collect one tissue without getting traces of the other. And it's completely to be expected that mouse epithelium can produce enamel under the right conditions!

I also noticed that the three ta² mutant chick embryos that developed tooth buds didn't survive to hatch. The article mentioned that the mutation affected the development of several organ systems in the chicks, and that the oldest chick died at 16 days of embryonic development. This aroused my curiosity about the full effects of this mutation, so I looked up the research paper referenced in that section. According to that paper ("The Development of Archosaurian First-Generation Teeth in a Chicken Mutant" Current Biology 16, 371-377 (2006)), chicks with this mutation rarely survive past 12 days embryonic development, although they don't give any details of what the other effects on the chick's development are. Presumably, there are other papers available on the subject of this mutation and its effects, I just don't have time now to go digging for them. The particular question I had was answered: this particular known mutation that initiates tooth development in birds works by regulating gene expression, and it is lethal. It's not something that a breeder will be able to use to get a chicken with teeth.

In conclusion, I would say that Horner may very well be able to coax his chicken embryos to grow wing claws and long tails, but teeth will be more troublesome. With the caveat that I'm not an expert in any of these fields! I just like to read about them...

[Carcharodontosaurus]

Very interesting article! It took me a while to take it all in, but it's truly fascinating.

Among other things, I see that the Kollar & Fisher article I mentioned had some potential problems, and later work failed to replicate the enameled teeth produced from mouse mesenchyme with chick epithelium. The follow-up experiment did produce tooth buds, but no enamel.

The postulated reason for the production of enamel in the first experiment was possible contamination with mouse epithelium; it's apparently very difficult to collect one tissue without getting traces of the other. And it's completely to be expected that mouse epithelium can produce enamel under the right conditions!

I also noticed that the three ta² mutant chick embryos that developed tooth buds didn't survive to hatch. The article mentioned that the mutation affected the development of several organ systems in the chicks, and that the oldest chick died at 16 days of embryonic development. This aroused my curiosity about the full effects of this mutation, so I looked up the research paper referenced in that section. According to that paper ("The Development of Archosaurian First-Generation Teeth in a Chicken Mutant" Current Biology 16, 371-377 (2006)), chicks with this mutation rarely survive past 12 days embryonic development, although they don't give any details of what the other effects on the chick's development are. Presumably, there are other papers available on the subject of this mutation and its effects, I just don't have time now to go digging for them. The particular question I had was answered: this particular known mutation that initiates tooth development in birds works by regulating gene expression, and it is lethal. It's not something that a breeder will be able to use to get a chicken with teeth.

In conclusion, I would say that Horner may very well be able to coax his chicken embryos to grow wing claws and long tails, but teeth will be more troublesome. With the caveat that I'm not an expert in any of these fields! I just like to read about them...

So basically, an Archaeopteryx with a beak?

I wonder if Horner could get a chicken embryo to grow arms with hands instead of wings with claws.

[Mediospirifer]

So basically, an Archaeopteryx with a beak?

I wonder if Horner could get a chicken embryo to grow arms with hands instead of wings with claws.

Seems like it ought to be possible. From what (little) I do know about wing morphology, all of the bones present in a standard tetrapod forelimb start to form in early embryonic development, then fuse into the wing structure. If Horner can control how the genes get switched on and off, precisely, he might be able to grow a lizard hand and claws. Getting a hoatzin clawed wing would be much easier, of course!

[Auspex]

So many genes are linked in so many unknown ways that the only way to know what else will happen is to try it and see.