The crackpots who are trying to stop windpower because it might kill birds should concentrate on the things that actually are killing birds: cars, cats, buildings, and loss of habitat.
As often as not, the people protesting the construction of wind farms aren't actually concerned about the wildlife. They are often local landowners who are concerned about the effect that wind farms may have on their view, on noise, or on their property value.
Such a callous disregard for human life underscores the objection many people have to things such as embryonic stem cell research and abortion. This person obviously believes the unborn child is "alive"- otherwise it could not logically die. However, she does not care that it dies because of her irresponsible actions.
It depends on what you mean be 'alive' or 'die'. The dermal layer of my skin is alive, but the top edge of it is continuously dying to form a protective--and dead--epidermis. It's not callous to not care about that. Even though my dermis is "alive", I don't consider it an independent organism, or mourn its passing.
Even in humans, a significant number (one half to two thirds, approximately) of successfully fertilized eggs die in their first few days post-fertilization. They fail to implant properly, or they have a genetic defect, or they're just unlucky. In many cases, the prospective mother doesn't even realize that she was 'pregnant'; she might notice that her period was a day or three late, but think nothing of it. The body disposes of the embryo, and prepares to try again next month. In a mating between chimeric mice, it would be a similar process--if a successfully fertilized human embryo formed, the biological machinery present would reject it almost immediately, and there would be no pregnancy.
Simple as that. Humans are not some special exemption - they are animals, and so to say "when do you draw the line between humans and animals" is just plain wrong. Go take a basic high school Biology course.
Congratulations. You've successfully interpreted the question in the narrowest possible sense, using one possible definition of 'animal'. You're embarrassing real scientists--including biologists--by sticking your head in the intellectual sand that way.
There will be debate--some hysterical, some worthwhile--over the philosophical and legal distinction between humans and 'animals', and where various types of chimera fall on that continuum. Sure we're all animals--but only humans can get a driver's license.
One of the things they point out is that alchohol is listed as a contributing factor if anyone related to the accident has had *anything* to drink. So for example, a passenger who was not driving who blows 0.08 on a BAC causes the accident to be listed as part of your 40%.
Actually, that's incorrect. The National Highway Traffic Safety Administration (NHTSA) figures look at the highest blood alcohol content (BAC) of all the drivers involved in the accident, only. Granted, in some cases those drivers may not be at fault in an accident, but that's a far cry from suggesting that they count drunk passengers in the statistics. (Some of the articles on the linked web site also assert that someone who commits suicide with a firearm while drunk in their car is counted--this is also false.) The NHTSA figures are for crashes only. Here's their raw data in PDF, and the same tables in Google's HTMLized format. (You want the last page; there's data going back to 1982.)
Looking at the 2001 numbers (I can't be bothered to find the most recent 2003 figures, but I would expect them to be comparable), in 32% of fatalities, at least one of the involved drivers had a BAC of 0.08 or above. (29% for greater than 0.10)
You're right that the 40% figure is inflated, though. You only get that (actually, just 37%) if you include every driver with a perceptible level of alcohol in his blood. Consider my remarks suitably amended, but I still think that 30% is too high a fraction of accidents involving alcohol.
I'd say "geography" and "geology" except some pendant would insist that the correct term is "areology" or "gnu/areology" or something.
On behalf of the pedants, I must make two observations. First, it's GNU/areology--the capitals are important.
Second, it's only appropriate to use the GNU prefix if the Magratheans have provided full blueprints for Mars along with the distributed, completed planet. Said plans must be under the GNU GPL (General Planet License).
Yeah, but that's Sturgeon's Law: 90% of everything is crud.
This includes movies. Look at what we have in the theatres right now. The Incredibles is clever, witty, good fun. Then there's the new Bridget Jones flick, which I understand is significantly less plausible. I won't talk about Christmas With The Kranks, beyond mentioning that their rating of 96% rotten on Rotten Tomatoes is singularly impressive.
It's usually not the external impact that kills you. It's your organs getting bashed around inside your body.
And that, in turn, is more often due to people not wearing their damn seat belts than anything else. About sixty percent of traffic fatalities occur among individuals who aren't wearing their seatbelts. The human body can actually tolerate very high accelerations for short periods of time providing it's well-secured and not rattling around inside the car.
Twenty-five percent of fatalities occur among vehicle occupants who are ejected in a collision--it doesn't matter how good your roll cage and crumple zones are if you're outside the vehicle.
Incidentally, we could avoid a lot of accidents altogether if we could get drunk drivers off the road--about forty percent of traffic fatalities in the States have alcohol as a contributing factor. There is this obsession in the United States with vehicle factors in traffic safety, but very little regard for personal choices and responsibility issues--driving only while rested, sober, and seatbelted--that would make a much greater difference in safety on the road.
Yep, it's a good thing that we're using a nice, safe fuel.
Wait...a low flashpoint isn't dangerous is it? And worrying about exposure to benzene, toluene, and various additives would just be silly....
We only think of gasoline as 'safe' because we've been handling it for so long. Familiarity breeds contempt, I guess. If you go behind the scenes, there's actually a tremendous amount of effort expended in terms of regulation and engineering that protects us from the hazards (mostly flammability, but also ground contamination) of storing and using gasoline.
And I see in another subthread, you bring up minimum wage. I live in the inner city, and work in my spare time with the children there. One of the biggest problems is a lack of jobs in these areas, and laws that make it very difficult to get jobs if you are under 18. Minimum wage and child labor laws stopped many abuses. However, it has created a wonderful mess... if you are under 18, and you want to earn money, it will either be through illegal means, or collecting a check for becoming a parent.
It could be argued, however, that these kids shouldn't need jobs. If they're under 18, they should be in school. Minimum wage jobs should be something they can do part time to save for college, not something that they're doing to eke out a living.
Will their condition actually be improved significantly by having access to sixty-hour weeks at three bucks an hour? That's a road to perpetual poverty, living hand to mouth, until they die or can start collecting Social Security.
If they have the filter database built for each master, how hard would it be to have it Markov chain an image with that data?
I'm going to go out on a limb and say, "Damn near impossible."
The technique described in the paper generates a vector in 72-space(!) that characterizes a given painting. Paintings with similar vectors are associated with a given artist. Attempting to iteratively generate an image which results in a similar vector--while not looking like crap--is probably nearly impossible.
It's a hashing process. For any given vector, there is an infinite number of paintings which might have produced said vector, but no computationally easy way to get from the vector back to a meaningful painting.
The other point--which siblings to this point have already made--is that even if you can generate a "genuine" Rembrandt in Photoshop, you still can't sell it as a brilliant forgery even if you print it on the finest quality laser stock.
Is there anyone else here who immediately thought, "Yeah, he's right. I had tortellini for lunch, and it wouldn't have tasted as good anywhere else...."
Feess ruled that the interception of keystrokes between the keyboard and the computer's CPU did not meet the "interstate or foreign commerce" clause in the federal Wiretap Act, even if some of those keystrokes were banging out e-mail. "[T]his court finds it difficult to conclude that the acquisition of internal computer signals that constitute part of the process of preparing a message for transmission would violate the Act."
"The network connection is irrelevant to the transmissions, which could have been made on a stand-alone computer that had no link at all to the internet or any other external network," Feess wrote. "Thus, although defendant engaged in a gross invasion of privacy... his conduct did not violate the Wiretap Act. While this may be unfortunate, only Congress can cover bases untouched."
What about monitoring the cord between the handset and the phone?
Well, would the phone still function if you disconnected it from the wall? No? How about the computer? Yes? Ah....
If I write out--by hand and in advance--everything that I want to say in a telephone conversation, and someone reads that over my shoulder, is it a wiretap? If I record a message to someone on a tape recorder, with the intent to play it to someone over the phone later, and someone listens to the recording before I send it--is it a wiretap? If I draft an email but don't send it, and my computer is seized under a valid search warrant, can I claim that the police reading it is an illegal wiretap?
Same difference here. 9 times out of 10, a computer is used to communicate with another computer in the workplace, or beyond the workplace.
I might agree with you that 9 times out of 10 a given computer is sometimes used to communicate with other computers. Of course, some computers aren't networked at all. And computers are often used for other tasks--accounting, drawing up documents, games, coding, etc.--that don't have anything to do with email or web browsing.
The judge 'gets it', and puts the blame squarely where it belongs: with Congress.
Note, the USD isnt real, its been fake since 1913 when federal reserve was setup privately, its just paper only worth the trust of the govt in getting income taxes to pay for it.
This has been covered on other tangential Slashdot segues, but it looks like time to dust it off again.
The total amount of gold mined in the world--ever, in all of human history--is estimated at about 3.4 billion troy ounces. At current prices around 450 US dollars per ounce, that's about 1.7 trillion worth of gold.
The total number of U.S. dollars in circulation, as banknotes, is about seven hundred billion dollars' worth. Fully backing the U.S. dollar would require nearly half of all the extracted gold in the world today. Similar problems arise if you look at other precious metals, or commodities, or very nearly anything else.
The United States economy is so large, and so many people inside and outside the country find the U.S. dollar a convenient currency to use, that you can't fully back it--there just isn't enough free stuff available to tie up for the purpose.
You're always welcome, of course, to not use U.S. dollars.
Those who create and wish to share are the Good Guys, while the Bad Guys are vile lawyers and manipulative billionaires. This corner of reality is like living in the pages of a four-color comic book.
What about the Guy Who Wants to Make a Few Bucks Writing Useful Software So He Can Pay His Rent? He wants to create and share, but would like to earn a living wage doing it. Is he a Bad Guy, too?
Is this "smart" yarn smart enough to stop people from wearing lime green paisley sweaters?
Being carbon, all of the clothing will be black*.
The future will be very, very hip...albeit a bit warm when out in the Sun.
(*Yes, I know that not all carbon allotropes are black, and that it's likely possible to synthesize nanotubes with unusual optical properties. It's just a joke.)
In Ontario, Canada the guvmnt wants to declare bullet proof vests against the law, just like weapons.
I've been Googling various likely keywords, but I haven't been able to find anything...period.
Have you got any sources for that statement? Was it the 'Government' or just a backbench (or Opposition?) MPP who proposed the policy?
I know that some U.S. lawmakers (Senator Feinstein, D-CA, for example) have suggested banning the sale of bulletproof vests to the public, but I wasn't aware of similar moves in Canada.
If you have a medical condition, you probably aren't up for 80 hour work weeks.
I beg to differ--there are a number of medical conditions that may require regular and costly upkeep, but don't render the programmer unable to work. Diabetes, for instance, requires regular blood tests and (for Type I diabetics) insulin injections.
Re:Can we try something less controversial first?
on
Blending Mice and Men
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· Score: 1
I know there are more immediate 'benefits' to immediately going straight to human/animal but there would be plenty to learn by studying animal/animal chimera and we might just avoid making some serious mistakes in the process.
What specific serious mistakes are you concerned about? If you feel that there are ethical issues that need to be addressed, you can say so--but don't allude to nebulous 'mistakes' that might be made unless you have plausible scenarios in mind.
What's the rush all of a sudden? People have suffered from genetic disorders and trauma and disease in the past and will continue to in the future, regardless of how many discoveries we make... why do we need to find all the answers now?
I'm sure that the people with genetic disorders, traumatic disease, or need of an organ transplant will appreciate that. People have been wanting to use some of these techniques for decades; the technology has only just matured. These aren't spur-of-the-moment decisions--these are ideas that have been years in the making.
I can only imagine what a mouse with human brain cells (mentioned in the article) would feel like- it'd almost certainly feel unwell, to say the least. Worse yet, how a non-human critter with human brain cells exposed to culture would feel like (and thus being smart enough to 1. know how messed up he is and 2. feel more dimensions of pain).
Having human neuronal cells, in and of itself, doesn't confer intelligence. The mouse in question still has a brain the size of a thimble, which for all of its existence will receive mouse nerve signals, mouse biochemicals, mouse stimuli. Providing we can get human neuronal cells to locate and grow properly as a mouse brain, the mouse isn't going to feel or behave any differently than a conventional mouse.
My grandparents' ranch bought a critter that was 3/8 buffalo, 1/8 cow, and 1/2 yak. It was a very messed up animal and walked around in a constant state of confusion- I would guess due to conflicting instincts and brain chemistry.
With respect to the yak/buffalo/cow hybrid, that's entirely a different kettle of fish. All three species have 30 pairs of chromosomes. (For comparison, humans have 23 pairs, and mice have 20 pairs.) In the formation of sex cells, each gamete (sperm or egg) receives half of each pair of chromosomes; in cattle, that's 30 chromosomes. When an egg is fertilized, the matching chromosomes are reunited, giving an embryo with its full complement of 60 chromosomes again.
This matching process will also work with two closely related species with the same number of chromosomes; the markers on the two sets of chromosomes are similar enough for them to pair properly. The result is that each cell within the resulting organism contains DNA from both parents--it will be 50% buffalo and 50% cow, for instance.
These creatures are often infertile, since gamete formation tends to be very sensitive to altered DNA. Sometimes they are also sickly; each cell will produce proteins from both parents, and sometimes these chemicals don't get along well.
Further crossing a 50/50 cow/buffalo with another buffalo will produce a 25/75 cow/buffalo offspring. One more cross, this time with a yak, will give the 3:1:4 ratio of buffalo:cow:yak that is described. At that point, each cell in the resulting offspring contains genes from all three original species. No wonder it wasn't happy--you're doing a lot of new biochemistry, and there are a lot of places for things to go subtly wrong.
Now, back to our mouse/human chimera. Here, the cells in the mouse will all be 100% purebred. Each cell in the body will be pure mouse, each cell in the brain will be pure human. The only place to get screwed up there is in the chemical signalling between the two. Though that is certainly complex, it's worlds simpler than getting the machinery inside the cells to cooperate. (Besides--a mouse/human crossbreed is impossible without really heavy-duty engineering. The two species have different numbers of chromosomes.) To recap: chimeras are very different from crossbreeds.
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As often as not, the people protesting the construction of wind farms aren't actually concerned about the wildlife. They are often local landowners who are concerned about the effect that wind farms may have on their view, on noise, or on their property value.
It depends on what you mean be 'alive' or 'die'. The dermal layer of my skin is alive, but the top edge of it is continuously dying to form a protective--and dead--epidermis. It's not callous to not care about that. Even though my dermis is "alive", I don't consider it an independent organism, or mourn its passing.
Even in humans, a significant number (one half to two thirds, approximately) of successfully fertilized eggs die in their first few days post-fertilization. They fail to implant properly, or they have a genetic defect, or they're just unlucky. In many cases, the prospective mother doesn't even realize that she was 'pregnant'; she might notice that her period was a day or three late, but think nothing of it. The body disposes of the embryo, and prepares to try again next month. In a mating between chimeric mice, it would be a similar process--if a successfully fertilized human embryo formed, the biological machinery present would reject it almost immediately, and there would be no pregnancy.
Congratulations. You've successfully interpreted the question in the narrowest possible sense, using one possible definition of 'animal'. You're embarrassing real scientists--including biologists--by sticking your head in the intellectual sand that way.
There will be debate--some hysterical, some worthwhile--over the philosophical and legal distinction between humans and 'animals', and where various types of chimera fall on that continuum. Sure we're all animals--but only humans can get a driver's license.
Actually, that's incorrect. The National Highway Traffic Safety Administration (NHTSA) figures look at the highest blood alcohol content (BAC) of all the drivers involved in the accident, only. Granted, in some cases those drivers may not be at fault in an accident, but that's a far cry from suggesting that they count drunk passengers in the statistics. (Some of the articles on the linked web site also assert that someone who commits suicide with a firearm while drunk in their car is counted--this is also false.) The NHTSA figures are for crashes only. Here's their raw data in PDF, and the same tables in Google's HTMLized format. (You want the last page; there's data going back to 1982.)
Looking at the 2001 numbers (I can't be bothered to find the most recent 2003 figures, but I would expect them to be comparable), in 32% of fatalities, at least one of the involved drivers had a BAC of 0.08 or above. (29% for greater than 0.10)
You're right that the 40% figure is inflated, though. You only get that (actually, just 37%) if you include every driver with a perceptible level of alcohol in his blood. Consider my remarks suitably amended, but I still think that 30% is too high a fraction of accidents involving alcohol.
It's all right as long as he doesn't have a virus.
On behalf of the pedants, I must make two observations. First, it's GNU/areology--the capitals are important.
Second, it's only appropriate to use the GNU prefix if the Magratheans have provided full blueprints for Mars along with the distributed, completed planet. Said plans must be under the GNU GPL (General Planet License).
Glad I could help out.
Yeah, but that's Sturgeon's Law: 90% of everything is crud.
This includes movies. Look at what we have in the theatres right now. The Incredibles is clever, witty, good fun. Then there's the new Bridget Jones flick, which I understand is significantly less plausible. I won't talk about Christmas With The Kranks, beyond mentioning that their rating of 96% rotten on Rotten Tomatoes is singularly impressive.
And that, in turn, is more often due to people not wearing their damn seat belts than anything else. About sixty percent of traffic fatalities occur among individuals who aren't wearing their seatbelts. The human body can actually tolerate very high accelerations for short periods of time providing it's well-secured and not rattling around inside the car.
Twenty-five percent of fatalities occur among vehicle occupants who are ejected in a collision--it doesn't matter how good your roll cage and crumple zones are if you're outside the vehicle.
Incidentally, we could avoid a lot of accidents altogether if we could get drunk drivers off the road--about forty percent of traffic fatalities in the States have alcohol as a contributing factor. There is this obsession in the United States with vehicle factors in traffic safety, but very little regard for personal choices and responsibility issues--driving only while rested, sober, and seatbelted--that would make a much greater difference in safety on the road.
Wait...a low flashpoint isn't dangerous is it? And worrying about exposure to benzene, toluene, and various additives would just be silly....
We only think of gasoline as 'safe' because we've been handling it for so long. Familiarity breeds contempt, I guess. If you go behind the scenes, there's actually a tremendous amount of effort expended in terms of regulation and engineering that protects us from the hazards (mostly flammability, but also ground contamination) of storing and using gasoline.
Yes, but how do I fix "When I click on the winged monkey god, the server crashes and the little bugs come out. OH MY GOD! THE LITTLE BUGS!"?
Don't forget, your notetaking skills (and your handwriting--I've been bitten by this) get worse when you're exhausted, too.
It could be argued, however, that these kids shouldn't need jobs. If they're under 18, they should be in school. Minimum wage jobs should be something they can do part time to save for college, not something that they're doing to eke out a living.
Will their condition actually be improved significantly by having access to sixty-hour weeks at three bucks an hour? That's a road to perpetual poverty, living hand to mouth, until they die or can start collecting Social Security.
I'm going to go out on a limb and say, "Damn near impossible."
The technique described in the paper generates a vector in 72-space(!) that characterizes a given painting. Paintings with similar vectors are associated with a given artist. Attempting to iteratively generate an image which results in a similar vector--while not looking like crap--is probably nearly impossible.
It's a hashing process. For any given vector, there is an infinite number of paintings which might have produced said vector, but no computationally easy way to get from the vector back to a meaningful painting.
The other point--which siblings to this point have already made--is that even if you can generate a "genuine" Rembrandt in Photoshop, you still can't sell it as a brilliant forgery even if you print it on the finest quality laser stock.
Is there anyone else here who immediately thought, "Yeah, he's right. I had tortellini for lunch, and it wouldn't have tasted as good anywhere else...."
Well, would the phone still function if you disconnected it from the wall? No? How about the computer? Yes? Ah....
If I write out--by hand and in advance--everything that I want to say in a telephone conversation, and someone reads that over my shoulder, is it a wiretap? If I record a message to someone on a tape recorder, with the intent to play it to someone over the phone later, and someone listens to the recording before I send it--is it a wiretap? If I draft an email but don't send it, and my computer is seized under a valid search warrant, can I claim that the police reading it is an illegal wiretap?
Same difference here. 9 times out of 10, a computer is used to communicate with another computer in the workplace, or beyond the workplace.
I might agree with you that 9 times out of 10 a given computer is sometimes used to communicate with other computers. Of course, some computers aren't networked at all. And computers are often used for other tasks--accounting, drawing up documents, games, coding, etc.--that don't have anything to do with email or web browsing.
The judge 'gets it', and puts the blame squarely where it belongs: with Congress.
How do you murder someone with a printer?
"Excuse me--can you stand on the big X there? No need to be looking up. Now a little to the left? Perfect...."
This has been covered on other tangential Slashdot segues, but it looks like time to dust it off again.
The total amount of gold mined in the world--ever, in all of human history--is estimated at about 3.4 billion troy ounces. At current prices around 450 US dollars per ounce, that's about 1.7 trillion worth of gold.
The total number of U.S. dollars in circulation, as banknotes, is about seven hundred billion dollars' worth. Fully backing the U.S. dollar would require nearly half of all the extracted gold in the world today. Similar problems arise if you look at other precious metals, or commodities, or very nearly anything else.
The United States economy is so large, and so many people inside and outside the country find the U.S. dollar a convenient currency to use, that you can't fully back it--there just isn't enough free stuff available to tie up for the purpose.
You're always welcome, of course, to not use U.S. dollars.
Anyway, mad props to Bill Watterson, who coined the phrase.
What about the Guy Who Wants to Make a Few Bucks Writing Useful Software So He Can Pay His Rent? He wants to create and share, but would like to earn a living wage doing it. Is he a Bad Guy, too?
What about the vile lawyers who work for the FSF?
Why aren't there any shades of gray?*
*I know. I must be new here.
Being carbon, all of the clothing will be black*.
The future will be very, very hip...albeit a bit warm when out in the Sun.
(*Yes, I know that not all carbon allotropes are black, and that it's likely possible to synthesize nanotubes with unusual optical properties. It's just a joke.)
I've been Googling various likely keywords, but I haven't been able to find anything...period.
Have you got any sources for that statement? Was it the 'Government' or just a backbench (or Opposition?) MPP who proposed the policy?
I know that some U.S. lawmakers (Senator Feinstein, D-CA, for example) have suggested banning the sale of bulletproof vests to the public, but I wasn't aware of similar moves in Canada.
Verbing weirds language....
People without diabetes should also limit stress and exercise daily.
Working eighty hour weeks is bad for your health whether you are diabetic or not.
I beg to differ--there are a number of medical conditions that may require regular and costly upkeep, but don't render the programmer unable to work. Diabetes, for instance, requires regular blood tests and (for Type I diabetics) insulin injections.
What specific serious mistakes are you concerned about? If you feel that there are ethical issues that need to be addressed, you can say so--but don't allude to nebulous 'mistakes' that might be made unless you have plausible scenarios in mind.
What's the rush all of a sudden? People have suffered from genetic disorders and trauma and disease in the past and will continue to in the future, regardless of how many discoveries we make... why do we need to find all the answers now?
I'm sure that the people with genetic disorders, traumatic disease, or need of an organ transplant will appreciate that. People have been wanting to use some of these techniques for decades; the technology has only just matured. These aren't spur-of-the-moment decisions--these are ideas that have been years in the making.
Having human neuronal cells, in and of itself, doesn't confer intelligence. The mouse in question still has a brain the size of a thimble, which for all of its existence will receive mouse nerve signals, mouse biochemicals, mouse stimuli. Providing we can get human neuronal cells to locate and grow properly as a mouse brain, the mouse isn't going to feel or behave any differently than a conventional mouse.
My grandparents' ranch bought a critter that was 3/8 buffalo, 1/8 cow, and 1/2 yak. It was a very messed up animal and walked around in a constant state of confusion- I would guess due to conflicting instincts and brain chemistry.
With respect to the yak/buffalo/cow hybrid, that's entirely a different kettle of fish. All three species have 30 pairs of chromosomes. (For comparison, humans have 23 pairs, and mice have 20 pairs.) In the formation of sex cells, each gamete (sperm or egg) receives half of each pair of chromosomes; in cattle, that's 30 chromosomes. When an egg is fertilized, the matching chromosomes are reunited, giving an embryo with its full complement of 60 chromosomes again.
This matching process will also work with two closely related species with the same number of chromosomes; the markers on the two sets of chromosomes are similar enough for them to pair properly. The result is that each cell within the resulting organism contains DNA from both parents--it will be 50% buffalo and 50% cow, for instance.
These creatures are often infertile, since gamete formation tends to be very sensitive to altered DNA. Sometimes they are also sickly; each cell will produce proteins from both parents, and sometimes these chemicals don't get along well.
Further crossing a 50/50 cow/buffalo with another buffalo will produce a 25/75 cow/buffalo offspring. One more cross, this time with a yak, will give the 3:1:4 ratio of buffalo:cow:yak that is described. At that point, each cell in the resulting offspring contains genes from all three original species. No wonder it wasn't happy--you're doing a lot of new biochemistry, and there are a lot of places for things to go subtly wrong.
Now, back to our mouse/human chimera. Here, the cells in the mouse will all be 100% purebred. Each cell in the body will be pure mouse, each cell in the brain will be pure human. The only place to get screwed up there is in the chemical signalling between the two. Though that is certainly complex, it's worlds simpler than getting the machinery inside the cells to cooperate. (Besides--a mouse/human crossbreed is impossible without really heavy-duty engineering. The two species have different numbers of chromosomes.) To recap: chimeras are very different from crossbreeds.