The federal government announced plans Thursday to lift a moratorium on funding of controversial experiments that use human stem cells to create animal embryos that are partly human.

The National Institutes of Health is proposing a new policy to permit scientists to get federal money to make embryos, known as chimeras, under certain carefully monitored conditions.

The NIH imposed a moratorium on funding these experiments in September because they could raise ethical concerns.

One issue is that scientists might inadvertently create animals that have partly human brains, endowing them with some semblance of human consciousness or human thinking abilities. Another is that they could develop into animals with human sperm and eggs and breed, producing human embryos or fetuses inside animals or hybrid creatures.

But scientists have argued that they could take steps to prevent those outcomes and that the embryos provide invaluable tools for medical research.

For example, scientists hope to use the embryos to create animal models of human diseases, which could lead to new ways to prevent and treat illnesses. Researchers also hope to produce sheep, pigs and cows with human hearts, kidneys, livers, pancreases and possibly other organs that could be used for transplants.

To address the ethical concerns, the NIH's new policy imposes several restrictions.

The policy prohibits the introduction of any human cells into embryos of nonhuman primates, such as monkeys and chimps, at their early stages of development. Previously, the NIH wouldn't allow such experiments that involved human stem cells but it didn't address the use of other types of human cells that scientists have created. In addition, the old rules didn't bar adding the cells very early in embryonic development.

The extra protections are being added because these animals are so closely related to humans.

But the policy would lift the moratorium on funding experiments involving other species. Because of the ethical concerns, though, at least some of the experiments would go through an extra layer of review by a new, special committee of government officials.

That committee would, for example, consider experiments designed to create animals with human brain cells or human brain tissue. Scientists might want to create them to study neurological conditions such as Alzheimer's and Parkinson's diseases. But the experiments would undergo intensive scrutiny if there's any chance there might be a "substantial contribution" or "substantial functional modification" to an animal's brain.

In addition, the NIH would even consider experiments that could create animals with human sperm and human eggs since they may be useful for studying human development and infertility. But in that case steps would have to be taken to prevent the animals from breeding.

"I am confident that these proposed changes will enable the NIH research community to move this promising area of science forward in a responsible manner," Carrie Wolinetz, the NIH's associate director for science policy, wrote in a blog post.

"At the end of the day, we want to make sure this research progresses because its very important to our understanding of disease. It's important to our mission to improve human health," she said in an interview with NPR. "But we also want to make sure there's an extra set of eyes on these projects because they do have this ethical set of concerns associated with them."

Several scientists said they are thrilled by the new policy. "It's very, very welcome news that NIH will consider funding this type of research," says Pablo Ross, a developmental biologist at the University of California, Davis, trying to grow human organs in farm animals. "We need funding to be able to answer some very important questions."

But critics denounced the decision. "Science fiction writers might have imagined worlds like this — like The Island of Dr. Moreau, Brave New World, Frankenstein," says Stuart Newman, a biologist at New York Medical College. "They've been speculations. But now they're becoming more real. And I think that we just can't say that since it's possible then let's do it."

The public has 30 days to comment on the proposed new policy. NIH could start funding projects as early as the start of 2017.

 jmurph wrote:
Also, Manbearpig.

 jmurph wrote:
I have long though that growing human compatible replacement organs would be a huge boon to medicine. For example, a pig with human compatible heart for transplants. Such animals should not be used for consumption, for obvious reasons.

The doomsaying is overblown. (The biologist quoted obviously didn't realize only one of the works he named even involved crossing man with animals.) So long as ethical safeguards and monitoring are in place, it's far less a risk than some of the stuff that has been done with engineered food or viruses, for example.

 jmurph wrote:
The biologist quoted obviously didn't realize only one of the works he named even involved crossing man with animals.

 d-usa wrote:

 Orlanth wrote:
The sources of the embryos sperm should be made specific.

People make donations to sperm/egg banks intentionally so an unknown parents can have a child. They might be less happy if said 'child' is 'half dog'.

 d-usa wrote:

 Orlanth wrote:
The sources of the embryos sperm should be made specific.

People make donations to sperm/egg banks intentionally so an unknown parents can have a child. They might be less happy if said 'child' is 'half dog'.

A lot of places have a "unused specimens may be used for medical research" clause in their consent forms. I think there was recently a ruling/decision/something in the US that clarified that the generic "may be used for research" is all that is needed to pretty much do whatever you want with it.

 Mozzyfuzzy wrote:
Has science gone too far?

 whembly wrote:

 d-usa wrote:

 Orlanth wrote:
The sources of the embryos sperm should be made specific.

People make donations to sperm/egg banks intentionally so an unknown parents can have a child. They might be less happy if said 'child' is 'half dog'.

A lot of places have a "unused specimens may be used for medical research" clause in their consent forms. I think there was recently a ruling/decision/something in the US that clarified that the generic "may be used for research" is all that is needed to pretty much do whatever you want with it.

Woah... so an The Island of Doctor Moreau could actually be a thing?

According to proposed updates to ethics rules imposed by the US government, the answer to both questions is almost always no. Many advocate that you should be required to give explicit consent for the use of your specimens, especially as new medical developments are making it possible to link once-anonymous samples back to their donors.

However, under current rules, researchers can use human biological specimens leftover from blood drawn at the doctor’s office or leftover from previous research. But the US government is proposing an update to those rules.

“What's being proposed to be changed now is saying, ‘It doesn't matter if those specimens have been de-identified. We're still going to require researchers to get your consent before using them,’” says Holly Fernandez Lynch, the executive director of the Petrie-Flom Center for Health Law Policy, Biotechnology and Bioethics at Harvard Law School.

 Frazzled wrote:
This is awesomely terrifying. Now those heroes who brought us the IPOD, mustard gas, zyklon B, thermonuclear war, the Tuskegee Experiments, and probably had a hand in setting up the DMV are now going to be unleashed on nature itself.

 Silent Puffin? wrote:
This can only be good news for medical science.

 Frazzled wrote:
This is awesomely terrifying. Now those heroes who brought us the IPOD, mustard gas, zyklon B, thermonuclear war, the Tuskegee Experiments, and probably had a hand in setting up the DMV are now going to be unleashed on nature itself.

We have been 'playing god' for millennia, its just that now we have the tools and the skill to guide what we need with at least some degree of precision. Incidentally without a long line of heroes we would still be trying to catch deer with rocks and dying before we were 30.

 Frazzled wrote:
This is awesomely terrifying. Now those heroes who brought us the IPOD, mustard gas, zyklon B, thermonuclear war, the Tuskegee Experiments, and probably had a hand in setting up the DMV are now going to be unleashed on nature itself.

 A Town Called Malus wrote:
The hero who brought us zyklon B also brought us the process of manufacturing ammonia, allowing the production of synthetic fertilisers which in turn allows us to feed people on an enormous scale.

 d-usa wrote:

 d-usa wrote:

 cuda1179 wrote:
My biggest problem with spicing human DNA into animals is the potential for certain diseases to make the animal-human jump. Many potentially harmful diseases are locked into certain animal strains. If a hybrid gets infected the disease could potentially mutate to accept a human as the next body to infect.

 Kovnik Obama wrote:

 cuda1179 wrote:
My biggest problem with spicing human DNA into animals is the potential for certain diseases to make the animal-human jump. Many potentially harmful diseases are locked into certain animal strains. If a hybrid gets infected the disease could potentially mutate to accept a human as the next body to infect.

That's a risk I'm willing to make you take if it's going to get me my talking cats.

 LordofHats wrote:
I have to agree with Cuda on that one. We'd make for more progress making some talking mice

cuda1179 wrote:Of all the things you could make talk you choose cats???? They'd ignore you for hours before telling you to F-off