Is it possible
to cross a chimp with a human being to create something
in between?(Wikipedia Commons/Lee Krystek)
Case of the Humanzee
In his 2006 book NEXT, the late author Michael
Crichton tells the story of a scientist who crosses his own genes
with a chimpanzee to create a human/ape hybrid: A Humanzee. Is
such a thing possible? Has it already been done?
Man has been crossbreeding animals for longer than
recorded history. Perhaps his greatest accomplishment is creating
more than one-hundred and fifty breeds of dogs. In physical appearance
dog breeds vary greatly from the tiny Chihuahua to the immense
St. Bernard. Despite their differing sizes and shapes, however,
all dogs are only one species: Canis lupus, the grey wolf.
Over the centuries man has manipulated dogs by mating them in
such a way as to give them shapes, sizes and temperaments that
were useful, or at least pleasing to people.
While dog breeding takes place inside a single species,
it is also possible to cross two closely related animals from
different species. The resulting creature is known as a hybrid.
Perhaps the most familiar of these animals is the mule. The mule
is the result of crossing a male donkey with a female horse. This
combination gives the hyrid some of the best characteristics of
both parents: A mule is more patient than a horse, stronger than
a donkey and more intelligent than either species.
Mules, like all hybrids between species, are almost
always infertile and cannot produce offspring. Donkeys have 62
chromosomes (the structures that carry the animal's DNA), while
horses have 64. This mismatch causes the infertility. Because
most mules cannot birth offspring, the mule population must be
maintained by constantly breeding donkeys and horses together.
Other hybrids between species exist, many created
through the intervention of man. The liger is the hybrid
of a male lion and a female tiger. (Breeding a male tiger with
a female lion produces a tigon - the convention is to use
the father's species name at the beginning of the hybrid name
and the mother's at the end).
are a hybrid between a male lion and a female tiger. They
have tiger stripes with a lion's tan fur.(Wikipedia
Since lions and tigers mostly exist on two different
continents, these hybrids did not appear until man brought the
animals together at zoos, animal parks or circuses. The resulting
liger is much larger than either of the parent species and is
considered the largest cat in the world. The combination of the
two species chromosomes short-circuits the animal's natural mechanisms
that limit size. Some examples of these animals weigh more than
a thousand pounds and are over ten feet in length.
If equines and the great cats can be crossbred over
different species, how about man? Is it possible to create a human
hybrid with some other species?
In order to create a hybrid between two species,
the species must be closely related as are horses to donkeys or
lions to tigers. The closest living animal to Homo sapiens
is Pan troglodytes, the common chimpanzee. According to
recent studies, 99.4% of the functional parts of human and chimpanzee
DNA is exactly the same. This is so close that some scientists
are suggesting that the common chimpanzee and another close relative,
the bonobo, should be reclassified to be in the genus Homo
along with humans, not Pongidae, with the rest of the great
While humans and chimps have very close DNA sequences,
the DNA is arranged differently with humans having 46 chromosomes
and chimps having 48. This is not necessarily a block to creating
a hybrid, however. Horses have 64 chromosomes and donkeys 62 but
can be crossed to create a mule. In fact, it is possible to cross
a horse with a zebra where the gap is even larger.
Scientists have also found evidence in our DNA that
human ancestors and chimp ancestors interbred as recently as 1.2
million years ago. It may be possible that humans are actually
the descendants of a hybrid of a chimp ancestor that crossed with
another human line that has since died out.
The idea that it might be possible to create a human/chimp
hybrid - a humanzee or a chuman - raises many legal and ethical
issues. Chimps are animals that can be owned as property. Humans,
in most modern countries that have outlawed slavery, cannot be
owned. Into what category would a humanzee fall? If we choose
to recognize a humanzee as having the same rights as a human,
would that change the status of chimps? Even if the legal status
of a humanzee could be ironed out, most people accord a special
status to human beings and might find the existence of such a
creature unnatural and repellant.
biologist Ilya Ivanovich Ivanov tried to create a Humanzee
Despite these quandaries, at least one scientist
has tried to create such a creature. The controversial Russian
biologist Ilya Ivanovich Ivanov was an early 20th century researcher
that specialized in creating and studying hybrid creatures. Ivanov
perfected the technique of using artificial insemination to create
these hybrids and was well known at the beginning the century
for his work in breeding horses.
In 1910 he presented a paper to the World Congress
of Zoologists in which he suggested the possibility of creating
a human-ape hybrid through artificial insemination. Fourteen years
later while working at Pasteur Institute in Paris, he got his
chance. He obtained permission from the Institute's directors
to use its primate research station in Kindia, French Guinea,
as the laboratory for his experiments and got $10,000 from the
Russian Academy of Sciences to pay for them. In March of 1926
Ivanov arrived at the station only to find it had no sexually-mature
chimpanzees to work with. So in November 1926, he traveled to
the botanical gardens in Conakry, French Guinea, and set up shop
there. Several adult chimpanzees from the interior of the country
were brought to Conakry and Ivanov artificially inseminated three
female chimpanzees with human sperm. None became pregnant.
Ivanov was also interested in trying to impregnate
human females with chimp sperm, but officials in New Guinea balked
at this idea. When he returned to Russian in 1927 he designed
an experiment to try and impregnate 5 female volunteers, but was
hampered by the lack of a male chimp to provide the sperm. In
1930 Ivanov fell out of favor with the government, was arrested
and spent the rest of his life in exile in Kazakhstan where he
died in 1932 without doing any additional ape/human hybrid studies.
Ivanov's work is the only acknowledged attempt to
create a Humanzee, but rumors of other experiments persist. There
are stories that an attempt was made in the 1920's at the Yerkes
National Primate Research Center in Orange Park, Florida. University
of Albany psychologist Gordon Gallup relates a story that as a
young graduate student he had talked to a member of the research
team who had been at Yerkes. The elderly scientist told Gallup
that the experiment had resulted in a live birth, but the research
team had decided to destroy the creature after only a few days.
Another story from the 1960's has a female chimp at a laboratory
in China being successfully impregnated with human sperm, but
dying before giving birth.
Case of Oliver
shows his strange upright stance at a news event in the
Perhaps the most well-known humanzee rumor is the
case of "Oliver." In 1960 Oliver was one of several chimps imported
from Africa to the United States for trainers Frank and Janet
Berger. From early on the Bergers recognized that Oliver was different
from other chimps they had trained. He had a flatter face and
always walked in an upright position on two legs with his knees
locked. The Bergers began to wonder if Oliver was some kind of
human-chimp hybrid. Oliver didn't get along with other chimps
and as he reached sexual maturity he showed a marked disregard
for female chimps and an interest in human females.
In the late seventies the Los Angeles Times
did an article about Oliver suggesting he was a "missing link"
or a new sub-species of chimp. This eventually led to Oliver taking
a trip to Japan at the behest of Japanese TV and being genetically
tested by scientists there. If Oliver was a true human/chimp hybrid
he should have had 47 chromosomes, halfway between the 46 possessed
by humans and the 48 characteristic of chimps. Most of Oliver's
samples showed 48 chromosomes. What's more, the chromosomes showed
"banding" typical of chimps. A few of the samples showed 47 chromosomes,
but this was attributed to testing error.
Oliver passed through a series of owners and was
eventually bought in 1989 by The Buckshire Corporation,
a Pennsylvania laboratory that leased animals for scientific testing.
Oliver was never used for testing and was retired to an animal
sanctuary called Primarily Primates in 1998. The director,
interested in Oliver's genetic history, arranged for more testing
which confirmed the earlier Japanese results: Oliver, despite
his strange appearance and behavior, was 100 percent chimpanzee.
Given the ease of doing the experiment, it is likely
that creating a chimp/human hybrid has been tried unofficially
in at least a few laboratories over the past century. Yet, no
humanzee report has ever been confirmed. This might suggest that
despite the similarity of our DNA to chimps, it is just not compatible
enough to naturally produce a hybrid.
As scientists better understand how DNA works, the
reason for this seems to be slowly emerging. There appears to
be at least nine pericentric inversions in chimp chromosomes
compared to our own. An inversion is when a section of the chromosome
gets reversed end to end. If the inversion doesn't involve the
center of the chromosome where the arms are joined it is called
a paracentric inversion and seems to have little medical
effect on the individual involved. A pericentic inversion,
however, does involve the section where the arms of the chromosome
are joined and can cause medical problems. It also makes it less
likely that the individual can produce a viable offspring when
they mate with someone who does not have the inversion. The fact
that nine of these inversions separate humans from chimps virtually
eliminates the possibility of a viable offspring, especially given
the few times such an attempt has probably been made. Scientists
are now investigating pericentric inversions as one mechanism
that might enforce the separation of species during the course
By better understanding why a natural humanzee birth
is so unlikely, however, we also probably know how it could be
achieved. If the chromosome inversions in a chimpanzee ovum could
be reversed to match those in a human, a viable fetus might be
Sheep/Goat chimera. The term chimera comes from Greek mythology
and was a monster composed of parts of multiple animals.(Wikipedia
Currently cutting and splicing DNA is at the edge
of our technical abilities. As we get better at this, however,
chromosome alteration will become commonplace and widespread.
Even now scientists are inserting genes and cells into animals
to create what are called chimeras - a mixture of two or
more species in one body. These are used mostly to conduct medical
research. Scientists think that the more human-like an animal
is, the better research model it becomes for testing drugs or
growing "spare parts," such as livers, that could be transplanted
into humans. For example, scientists have already created pigs
that can produce human blood.
While most of this work only creates animals that
are a tiny percent human, the same techniques could be used to
make a full chimp/human hybrid. Will someone in some far-flung
laboratory attempt this experiment in the near future?
Perhaps a better question is, should someone
attempt this experiment?
Chimps are Human, Gene Study Implies by.Jeff Hech. New
Human Ancestors May Have Interbred With Chimpanzees,
by David Brown. Washington Post, http://www.washingtonpost.com/wp-dyn/content/article/2006/05/17/AR2006051702158.html
Chromosomal Inversions and the Reproductive Isolation of Species
by Mohamed A. F. Noor , Katherine L. Grams, Lisa A. Bertucci,
and Jane Reiland, Proceedings of the National Academy of Sciences
Da Capo by Grady Towers, The Prometheus Society,
Copyright Lee Krystek 2009.
All Rights Reserved.