Scientists Give Human Organs to Lamb

TK Interior writes "Myrtle Beach Online reports the existence of a lamb-human chimera-- a blend of two different species. Not only has a lamb been given a human liver and heart, but mice are sporting human brain cells. At what level is a chimera 'too' human? Where do you draw the line between human and animal? How will this affect evolution?"

Dupe

[Anonymous Coward]

Dupe [slashdot.org]

Goat Sheep

[CGP314]

In science, an animal is a chimera [wikipedia.org] if the cells throughout the animal are from two different animals. This is accomplished by mixing the zygotes (see the geep [wikipedia.org]). You don't get a chimera through organ transplant.


-Colin [colingregorypalmer.net]

Re:Too human?

[RichDice]

I think this is an interesting take on things, but I have to ask, does this mean that pigs and fowl -- as is -- are "too human"? Diseases from these jump over to the human populations in SE Asia, and then to the rest of the world, all the time. They're called this year's new strain of flu.

Cheers,
Richard

Re:Evolution

[Ralph Yarro]

Natural selection occurs when an individual dies before breeding or otherwise fails to breed, thus not handing on their genes.

Pretty much right, to refine it slightly more, rather than "fails to breed" you mean "fails to produce viable offspring". Might as well drop the bit about the individual dying first, it adds nothing.

Among humans pretty much everyone lives long enough to breed, and thus genetics that do not select for survival are passed on.

I'm not sure what proportion of the population fails to breed. I'm not convinced it's as insignificant as you think, especially once you factor in birth control and cuckolding. Do you have statistics? Given a hiugh survival rate, factors like ability to judge the fidelity of a spouse become major evolutionary factors. With birth control a desire to have children becomes more significant than a desire to have sex as well. Evolutionary factors still apply.

Birds do indeed feed their young but if the parents believe that the young are incapable of surviving adequately they are thrown out of the nest to die in a lot of cases. People thriving because of hospitals is not natural selection, it's artificial - a kind of eugenics.

Explain to me your theory under which the behaviour of the birds in your example arises from natural selection and the behaviour of the humans doesn't.

Re:Evolution

[Ralph Yarro]

I didn't say the behavious of birds didn't arise from evolution, only that it doesn't effect evolution.

OF COURSE it affects evolution. It's part of the environment that the chicks are born into.

Scenario as outlined so far: Birds lay eggs. Eggs hatch. Parents feed offspring. Parents eject less viable offspring, enhancing the food and other resources devoted to the more viable offspring, and thus enhancing their chances of survival.

How does can you say that this doesn't affect evolution? By your standards the parent birds are interfering in the process.

Re:You don't draw the line...

[efatapo]

Well, you may have passed your high school biology class (and I stress may) but you certainly haven't followed that through with upper level classes.

Although humans could technically breed with sheep (and living near Wales, I should know...), the offspring would be sterile...

Technically, no they couldn't. The sperm-egg recognition factors (proteins that stick out of the egg) have specific receptors on the sperm. Most animals will not recognize the receptor-ligand interaction of other animals. Additionally, the egg secretes molecules that the sperm uses to find the egg and these are also not conserved between species.

Additionally, I'll let the other posters explain to you the many many differences that separate humans from animals. Sorry bud, but you're way off on this argument. There's a lot more to life than biology when it comes to distinguising animals and humans. Not my field though...biochemistry is.

Re:Too human?

[sosegumu]

This is the problem: The Law of Unintended Consequences [wikipedia.org]. As complexity of an endeavor increases so do the amount of unintended consequences.

I'm not saying that there aren't compelling reasons for pursuing this type of thing, I'm just saying that the downside risk is just too great. Like any other great catastrophe, this potential one would come from an unforeseen unknown/error.

Re:All women are chimerae...

[myc]

moderators: please go take a genetics course. Barr bodies are formed not to make females chimeras, but to balance out X chromosome gene expression. humans are obligate diploids, and so by definition all humans, male and females are hybrids of their parents. it has nothing to do with X chromosome inactivation.

Re:Evolution

[Anonymous Coward]

What you two are arguing is the difference between micro and macro evolution. I doubt anyone would disagree with you that microevolution takes place on a daily basis. I am a biochemist and microevolution screws up my experiments all the time (I do yeast genetics on a regular basis). However, this in no way proves macroevolution. The idea that a yeast changing a single genes, sometimes a single nucleotide of DNA, is the same as a species completely reorganizing its genome and becoming a new species that is both genetically and morphologically unique from it's parent is macroevolution. I'm fairly certain that is what the original poster was calling an absurd hypothesis. Just so you two know what you're aruing.

Definition of a chimera

[PontifexPrimus]

Formation of Barr bodies is a result of inactivation of one x chromosome, thus keeping all genes on of them from being expressed, resulting in a different genotype from a cell where the other one is inactivated. Meaning there are two different possible genetic informations for each cell depending on which one forms the Barr body. A chimera is defined [websters-d...online.org] as an organism consisting of cells containing more than one genotype (usually created by combining embryonic cells at an early development stage), which human women fit. And I took a genetics course, thankyouverymuch.

Re:lamb with a human liver is no more human...

[Jim Starx]

Take a premature infant, for example, and leave them to fend for themselves. Most will not be self-sustaining either.

That point is entirely irrelevent. We're talking about whether a baby of snot as a lifeform has the capability of sustaining itself. Enviornmental concerns are of no consequence to a biological discussion, it's about capability. A child has the capability to grow into an adult and reproduce, it is a living organism. Snot is not a living organism, it cannot grow into bigger snot and make little snot babies.

That they might not integrate 'well' is a different (though related) question. That they participate and have other human qualities ascribed to them means they count.

'Human' is a biological trait that is independant of any type of social interaction or behavior that that organism may or may not engage in. Coma patients are human, people lost on a desert island are human, babies that were raised by animals are human.

Yes. And many other animals form societies, and culture too (in the sense that it is community local and passed on independently of genetics.) Perhaps we should reconsider whether being cruel to other animals is acceptable behaviour, ethically speaking?

You're dodging the point. Dogs and cats are self concious. They form bonds with their owners, participate in social interactions, have empathy toward their ownders, but they are not human. They are canines and felines. Human is not an all encompassing word that describes every organism in the universe capable of social interaction or feelings. It's a biological description of a single type of organism.

Re:Too human?

[abigor]

The U.S. gov't will stop ALL public funding, even that unrelated to stem cells, to any research group that accepts private funding for stem cell research. So yeah, that's a bit of a barrier, wouldn't you say?

It's such a strange debate, this "rights of the zygote" stuff. The rest of the western world got over this years ago, and continues to progress. The U.S., with its constant, energy-sapping moral debates fueled by religious irrationality, is so anachronistic. And the religious right has more in common with the Islamic nutbars then they'd like to think. I wish they'd stay out of the public sphere.

Re:I don't like it.

[double-oh three]

The fuller quote is:
" 1. Whatever goes on two legs is an enemy.
2. Whatever goes on four legs, or has wings, is a friend.
3. No animal shall wear clothes.
4. No animal shall sleep in a bed.
5. No animal shall drink alcohol.
6. No animal shall kill any other animal.
7. All animals are equal. "

After a few revisions it ends up as; "
1. "Four legs good, two legs better!"
2. No animal shall sleep in a bed with sheets.
3. No animal shall drink alcohol to excess.
4. No animal shall kill any other animal without cause.
5. All animals are equal, but some animals are more equal than others.

Re:Evolution

[gblues]

Wake me up when an E.coli bacteria transforms into a non-E.coli bacteria. You can create a strain that is immune to every known antibiotic, but it will still be E.coli!