barger@ils.nwu.edu (Jorn Barger) (09/17/90)
Maybe it's biological folklore, but I often see the similarity of human and chimp DNA cited as 99%. Given the X and Y chromosome thing, aren't men and women more dissimilar than that? Am I therefore more closely related to male chimps than to female humans??? ......................................................................... after the longest time things got clear, then we saw something burning in the walls. everything got very clear, and we, our eyes fell through them. nothing could make amends. when you give your heart to nothing, nothing comes back, in mortal patterns painted on the wall. do you hear me? immeasurably do i love you all... "Of the Hand in the Heart of the Mind" ........................................................................... .
loren@tristan.llnl.gov (Loren Petrich) (09/18/90)
In article <1803@anaxagoras.ils.nwu.edu> barger@ils.nwu.edu (Jorn Barger) writes: > >Maybe it's biological folklore, but I often see the similarity of human >and chimp DNA cited as 99%. Given the X and Y chromosome thing, aren't >men and women more dissimilar than that? Am I therefore more closely >related to male chimps than to female humans??? The similarity figure is for genes that we and the chimps have in common. Human X and Y may be different, but human X's and chimp X's must certainly be very close, as must human Y's and chimp Y's. Why not try to find out about this subject from some geneticist? $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ Loren Petrich, the Master Blaster: loren@sunlight.llnl.gov Since this nodename is not widely known, you may have to try: loren%sunlight.llnl.gov@star.stanford.edu
wcalvin@milton.u.washington.edu (William Calvin) (09/18/90)
I agree that, at first blush, you'd think that human males and females ought to differ by one part in 46, call it 2 percent. But you've got to remember all that duplication: 85% of all genes in your average person are homozygous (you have a duplicate copy on the other chromosome). Males have a Y chromosome that females lack, but it only have about two genes on it. Males lack a duplicate X chromosome (one reason why there are sex linked diseases like color blindness). So females have an extra 15% versatility in backup copies that might work better (slightly different version number, i.e., allele) on one chromosome out of 23, and they lack two Y-chromosome genes. That makes for a lot less than one percent DNA difference between males and females. The big question is: Which 1-2 percent of the genome is causing an ape embyro to develop a chimp brain versus a four-fold larger human brain? And modify the brain specializations, such as the lateralization to left brain of serial-order abilities such as show up affecting handedness and language abilities? William H. Calvin, University of Washington NJ-15, Seattle WA 98195 USA wcalvin@u.washington.edu Favorite books on brains and evolution (probably because I wrote them myself): _The Cerebral Symphony_ (Bantam 1989); _The River that Flows Uphill_ (Sierra Club Books 1987).
bonnie@welch.jhu.edu (Bonnie L. Maidak) (09/19/90)
In article <7713@milton.u.washington.edu> wcalvin@milton.u.washington.edu (William Calvin) writes: > > Males have a Y chromosome that females lack, but it >only have about two genes on it. In the interest of improving scientific knowledge, currently 16 genes have been located on the Y chromosome. Looking at _Cytogenetics and Cell Genetics_, Human Gene Mapping Workshop reports (HGM) 10 (1989) and 10.5 (Sept. 6-10, 1990, in progress) will list some of these genes.
AChamove@massey.ac.nz (A.S. Chamove) (09/21/90)
Over the past few years, there has been a lot of debate on the following question: If chimps and humans are so close genetically, then why can we not make hybrids? Of course a lot of people say that we can and could. Others say that there are incompatibilites, but no one I have encountered has been able to specify what those incompatibilites are. Can you? arnold
dmark@acsu.buffalo.edu (David Mark) (09/21/90)
In article <999@massey.ac.nz> AChamove@massey.ac.nz (A.S. Chamove) writes: >Over the past few years, there has been a lot of debate on the following >question: >If chimps and humans are so close genetically, then why can we not make >hybrids? Of course a lot of people say that we can and could. Others >say that there are incompatibilites, but no one I have encountered has >been able to specify what those incompatibilites are. Can you? >arnold I guess it depends on where the 1% difference is! 1% is still a heck of a lot of genes!! Remember, the horse and donkey are closer (in the same genus, I think), and while they can produce offspring, those offspring (mules) are infertile. David Mark dmark@acsu.buffalo.edu
gagen@bgsuvax.UUCP (kathleen gagen) (09/21/90)
From article <999@massey.ac.nz>, by AChamove@massey.ac.nz (A.S. Chamove): > Over the past few years, there has been a lot of debate on the following > question: > If chimps and humans are so close genetically, then why can we not make > hybrids? Of course a lot of people say that we can and could. Others > say that there are incompatibilites, but no one I have encountered has > been able to specify what those incompatibilites are. Can you? The chimp and man have incompatable chromosome numbers. Chimps (as well as gorillas) have 48 chromosomes in their diploid genome whereas men have 46 chromosomes. It is thought that human chromosome 2 (a metacentric chromosome having two chromosome arms) was formed through the fusion of two acrocentric (one armed) chromosomes. The evidence for this is cytogenetic. It is based on banding patterns and the identification of specific genes to the same band on homologous arms of the human, chimp, and gorilla chromosomes. References will be provided upon request. Kathi
sbishop@desire.wright.edu (09/22/90)
In article <6284@bgsuvax.UUCP>, gagen@bgsuvax.UUCP (kathleen gagen) writes: > From article <999@massey.ac.nz>, by AChamove@massey.ac.nz (A.S. Chamove): >> Over the past few years, there has been a lot of debate on the following >> question: >> If chimps and humans are so close genetically, then why can we not make >> hybrids? Of course a lot of people say that we can and could. Others >> say that there are incompatibilites, but no one I have encountered has >> been able to specify what those incompatibilites are. Can you? > > The chimp and man have incompatable chromosome numbers. Chimps (as well as > gorillas) have 48 chromosomes in their diploid genome whereas men have 46 > chromosomes. It is thought that human chromosome 2 (a metacentric chromosome > having two chromosome arms) was formed through the fusion of two acrocentric > (one armed) chromosomes. The evidence for this is cytogenetic. It is based > on banding patterns and the identification of specific genes to the same > band on homologous arms of the human, chimp, and gorilla chromosomes. > > References will be provided upon request. > > Kathi I am fairly certain that horses and donkeys also have different chromosome numbers so that is not a specific barrier to fertilization. Of course, it's been a while since I studied genetics so I could be wrong about the chromosome count.
kja@cbnewsd.att.com (krista.j.anderson) (09/22/90)
<> <> In article <999@massey.ac.nz>, AChamove@massey.ac.nz (A.S. Chamove) writes: > Over the past few years, there has been a lot of debate on the following > question: > If chimps and humans are so close genetically, then why can we not make > hybrids? Of course a lot of people say that we can and could. Others > say that there are incompatibilites, but no one I have encountered has > been able to specify what those incompatibilites are. Can you? There's a different number of chromosomes. We have 46; I think chimps have 48, but it might be 44. In one species a chunk of one chromosome broke off and rejoined a different chromosome. Sorry I don't have details. -- Krista A. HONOR Our Neighbors' Origins and Rights!
dan@wystan.bsd.uchicago.edu (09/22/90)
In article <999@massey.ac.nz>, AChamove@massey.ac.nz (A.S. Chamove) writes: >Over the past few years, there has been a lot of debate on the following >question: >If chimps and humans are so close genetically, then why can we not make >hybrids? Of course a lot of people say that we can and could. Others >say that there are incompatibilites, but no one I have encountered has >been able to specify what those incompatibilites are. Can you? >arnold Putting aside chromosome number for a minute . . . . What about immunological differences? I know that the placenta is an "immunologically priveledged" site, but there's probably enough differnce between human and chimp histocompatability antigens to cause some sort of rejection response to the fetus. Sort of an Rh reaction from hell. -- Dan Rohwer-Nutter dan@wystan.bsd.uchicago.edu
overt@antony (Christian Overton) (09/23/90)
In article <999@massey.ac.nz>, AChamove@massey.ac.nz (A.S. Chamove) writes: >Over the past few years, there has been a lot of debate on the following >question: >If chimps and humans are so close genetically, then why can we not make >hybrids? Of course a lot of people say that we can and could. Others >say that there are incompatibilites, but no one I have encountered has >been able to specify what those incompatibilites are. Can you? >arnold I've heard unsubstantiated stories that viable human/chimp hybrids have been born. The first rumor I remember is the report of a primate being kept in a cage somewhere in Africa during the early part of this century. The primate was more human looking than either a chimp or gorilla, but clearly not human. The conjecture was that it was a human/chimp hybrid. The second rumor is that China had successfully bred human/chimp hybrids, but that these were all destroyed during the cultural revolution and the experiments abandoned. Unfortunately, at the moment I can't remember the sources of either rumor other than that the sources were reputable. Well ok, at least I'm pretty sure I didn't read them in a science fiction story. Has anybody else out there heard these or similar stories? Chris -- +-------------------------------------------------------------------------------+ | G. Christian Overton || Telephone: (215) 648-2420 | | Center for Advanced Information Technology || Internet: overt@prc.unisys.com | | Unisys || FAX: (215) 648-2288 |
sbishop@desire.wright.edu (09/23/90)
In article <0093D12D.0754D500@wystan.bsd.uchicago.edu>, dan@wystan.bsd.uchicago.edu writes: > In article <999@massey.ac.nz>, AChamove@massey.ac.nz (A.S. Chamove) writes: >>Over the past few years, there has been a lot of debate on the following >>question: >>If chimps and humans are so close genetically, then why can we not make >>hybrids? Of course a lot of people say that we can and could. Others >>say that there are incompatibilites, but no one I have encountered has >>been able to specify what those incompatibilites are. Can you? >>arnold > > Putting aside chromosome number for a minute . . . . > > What about immunological differences? I know that the placenta is an > "immunologically priveledged" site, but there's probably enough differnce > between human and chimp histocompatability antigens to cause some sort of > rejection response to the fetus. Sort of an Rh reaction from hell. > This argument makes more sense to me than the chromosome problem. I do remember reading a while back about experiments in crossing cattle and bison. Evidently the researcher found that some type of incompatibility between cattle and bison caused the cow who was carrying the hybrid calf to produce increasing amounts of amniotic fluid which ultimately killed the calf. I would think though, in the time of much research in repressing immunological responses in people who have had organ transplants that this could be overcome. Besides, supposedly someone did manage to come up with beefalos a few years ago. I can see all kinds of hostile reactions against the experiment. After all, it would be the ultimate proof against creationists wouldn't it? How could they deny our relationship to the rest of nature if chimps turned out to be our genetic brothers?
sbishop@desire.wright.edu (09/23/90)
In article <15067@burdvax.PRC.Unisys.COM>, overt@antony (Christian Overton) writes: > In article <999@massey.ac.nz>, AChamove@massey.ac.nz (A.S. Chamove) writes: >>Over the past few years, there has been a lot of debate on the following >>question: >>If chimps and humans are so close genetically, then why can we not make >>hybrids? Of course a lot of people say that we can and could. Others >>say that there are incompatibilites, but no one I have encountered has >>been able to specify what those incompatibilites are. Can you? >>arnold > > I've heard unsubstantiated stories that viable human/chimp hybrids have been > born. The first rumor I remember is the report of a primate being kept in a > cage somewhere in Africa during the early part of this century. The primate was > more human looking than either a chimp or gorilla, but clearly not human. The > conjecture was that it was a human/chimp hybrid. > It is possible that the primate was a pygmy chimp, otherwise known as a Bonomo. They are much more 'human' in appearance than other chimps, have a more erect posture, often walk on two feet and are considered more intelligent. They are considered a sub-species of chimpanzee. I have seen the pair at the Cincinnati Zoo. They do look quite different from other chimps and the zoo has a drawing showing the fossil skeleton of Lucy (anthropological discovery from Africa of early human remains) and the skeleton of a chimp. The simularities are remarkable. So far, genetic research has not gotten precise enough to note the exact differences between Bonomos and regular chimpanzees. For the interested person, a visit to the Cincinnati Zoo might be worthwhile. The zoo is small but has a national reputation for breeding indangered species and has been the recipient of many breeding pairs from other zoos. > The second rumor is that China had successfully bred human/chimp hybrids, but > that these were all destroyed during the cultural revolution and the experiments > abandoned. > > Unfortunately, at the moment I can't remember the sources of either rumor other > than that the sources were reputable. Well ok, at least I'm pretty sure I > didn't read them in a science fiction story. Has anybody else out there heard > these or similar stories? > I would also be very interested in hearing of any sources.
sbishop@desire.wright.edu (10/01/90)
In article <1990Sep21.195915.1913@cbnewsd.att.com>, kja@cbnewsd.att.com (krista.j.anderson) writes: > <> > <> > In article <999@massey.ac.nz>, AChamove@massey.ac.nz (A.S. Chamove) writes: >> Over the past few years, there has been a lot of debate on the following >> question: >> If chimps and humans are so close genetically, then why can we not make >> hybrids? Of course a lot of people say that we can and could. Others >> say that there are incompatibilites, but no one I have encountered has >> been able to specify what those incompatibilites are. Can you? > > There's a different number of chromosomes. We have 46; I think > chimps have 48, but it might be 44. In one species a chunk of one > chromosome broke off and rejoined a different chromosome. Sorry I > don't have details. > -- > Krista A. > HONOR Our Neighbors' Origins and Rights! Sorry to correct you but this has been discussed earlier. The chromosome count difference is not considered a valid excuse for failure to crossbreed. Horses and donkeys have different numbers of chromosome pairs and they manage quite well to produce offspring when bred together. The offspring are called MULES.
gagen@bgsuvax.UUCP (kathleen gagen) (10/03/90)
From article <1340.27063f87@desire.wright.edu>, by sbishop@desire.wright.edu: > In article <1990Sep21.195915.1913@cbnewsd.att.com>, kja@cbnewsd.att.com (krista.j.anderson) writes: > > Sorry to correct you but this has been discussed earlier. The chromosome > count difference is not considered a valid excuse for failure to crossbreed. > Horses and donkeys have different numbers of chromosome pairs and they > manage quite well to produce offspring when bred together. The offspring > are called MULES. MULES, however, are almost always sterile. This is due to miotic problems resulting in inviable gametes. Kathleen Gagen