Cloning
Artificial insemination, DNA, genetically engineered animals, anti-aging drugs, Genome project (human gene sequence), stem cell research.
The year 1999 through 2004

Scientist may try to clone frozen mammoth
Gene isolated that may alter life span
Genome project hits milestones
Scientists close to redefining the term 'life'

Genetic-manipulation technique could one day treat liver failure
Winners of genome race will hold keys to life, more

The Cloning Controversy - Skepticism, concern and anger greet human-cloning claim
FDA to see if laws broken; Congress may weigh ban

Journalist withdraws from Clonaid project.
First in vitro baby celebrates 25th birthday
Genes begin to reveal secret of longer life
World's first cloned horse reported by Italian scientists
Scientists report growing stem cells into sperm cells
Research links longevity, bigger cholesterol particles
Genetic bits now fit on chip the size of a dime
Scientists create sperm from mouse stem cells, fertilize eggs

Stem cells culled from cloned embryo
First human cloning to obtain stem cells sparks calls for ban
Governor to propose stem cell institute
Report finds Bush-backed stem-cell research faltering
Harvard offers new stem cell lines to scientists
Hatch: Senate has votes to change stem-cell policy
Britain opens the world's first national stem cell bank
Senators ask Bush to ease rules on stem cell research
Stem cell lines developed from defective embryos
The promise of stem cells
California voters open gold mine on stem cells
Merging man and animal


• 10/22/1999 - Scientist may try to clone frozen mammoth by Guy Gugliotta, The Washington Post.
      A French-led expedition has chopped the carcass of a 20,000-year-old woolly mammoth from the permafrost of Arctic Siberia, in the first successful salvage of an intact specimen of this ancient behemoth, now called the "Jarkov Mammoth."    This will allow them to analyze the fur, organs and tissue of an animal that has been extinct for 10,000 years.    The team hopes to recover DNA or even sperm from the carcass -- if it is a male -- and either attempt to clone it or artifically inseminate an elephant, since they are believed to be cousins with a 5 percent genetic difference.
• 11/18/1999 - Gene isolated that may alter life span by Nicholas Wade, New York Times News Service.
      In a finding that may yield a sharp insight into the genetic reasons for death, a team of Italian scientists reported discovery of a gene that exerts major control over the life span of mice.    The effects of the corresponding gene in humans is unknown, but experts in aging called the findings a milestone that could someday lead to drugs that postpone the effects of aging.    The new gene fits into a pattern of other findings about aging that highlight the role of oxygen damage to tissues as a major driver of the aging process.
      Oxygen may be the breath of life, but in the body it creates chemical byproducts, free radicals, that can corrode the cell's working parts and corrupt the information in its DNA data bank.    If the damage is too severe, cells are genetically programmed to self-destruct, a fail-safe mechanism to prevent damaged cells turning cancerous.
      The gene studied by the Italian team makes a protein that triggers the self-destruct process in response to oxygen damage.    Mice genetically engineered to lack the trigger protein turned out to live 30 percent longer than normal, with no apparent harm.
      The gene's effect was discovered by Dr. Pier Giuseppe Pelicci of the European Institute of Oncology in Milan, together with scientists at the Institute of Pathology in Perugia, Italy, and the Memorial Sloan-Kettering Cancer Center in New York.
• 11/25/1999 - Genome project hits milestones - Public, private researchers cite accomplishments - by Elizabeth Neus, Gannett News Service and Jeff Donn, The Associated Press.
      Washington -- When the government project began in the late 1980s -- sparked by the Department of Energy's desire to track minute genetic changes caused by radiation -- it was not universally embraced.    This began with the mapping of yeast in 1996, E. coli (bacteria) in 1997, C. elegans (worm) in 1998, fruit fly in 1999, and a rough draft of human in December 1999 leading to today.
      Two major milestones were reached in efforts to map the entire human gene sequence.    Federally funded scientists working on the $3 billion Human Genome Project announced they have mapped their 1 billionth piece of genetic code, a sign they are about one-third of the way to the working draft of the map they have promised by spring, but likely in 2003, which will be free to the public.
      Celera Genomics - a commercial venture announced also that it had decoded 2.7 billion pieces of genetic code, putting it three-quarters of the way toward sequencing the entire genome, and propose to complete it by the end of the year or 2001.
      Dr. Fransic Collins, director of the National Human Genome Research Institute, celebrated this event as historic.
      The human genetic pattern, or genome is the biological map of the genes that make up the blueprint (DNA) for a human being, which is 3 billion pairs of chemicals contained within 23 pairs of chromosomes.    Genes are arrayed along chromosomes, the rod-shaped bodies inside the nucleus of a cell.    Proteins and other compounds carry out the instructions of genes.    Inside the chromosomes, genetic material is linked along tightly coiled strands of the master molecule DNA, which twists like a spiral ladder.    Each rung is built with pairs of four chemical bases ordered in different numbers and combinations to form genes.    Of the 3 billion base pairs in the human genetic makeup, more than 33 million are on chromosome 22 -- the second-smallest of the 23 pairs.
      The advantages of this research is that doctors can test patients for genetic markers that may increase the risk of diseases from breast cancer to sickle cell anemia to heart disease.    This means treating the underlying genetic cause of a disease rather than just relieving its symptoms.    Science will still have to figure out how the genes work together with proteins they make; how to switch them off and on; what some of them actually do.    The genome is a parts list without an instruction book.
  
• 12/10/1999 - Scientists close to redefining the term 'life' by Rick Weiss, The Washington Post.
      Washington - A team of geneticists has come close to determininig the minimum number of genes required for life to arise, an advance that ultimately could allow scientist to design and create living organisms from scratch.    But of greater interest to ethicists, who have been tacking the so-called Minimal Genome Project since its inception two years ago, the new research may enable researchers to engineer life in the laboratory for the first time from essential chemical ingredients - not by altering existing organisms, as genetic engineers do today.
      That ability could be liberating or could sow seeds of destruction, siad J. Craig Venter of Celera Genomics in Rockville, Md., the senior scientist on the new report.    Novel cells could be designed to clean up toxic wastes with unprecedented efficiency, he said.    Or they could be programmed to serve as biological weapons.
      For people who already fear that gene researchers are "playing God," the prospect of scientists actually becoming creators may seen downright blasphemous, Venter acknowledged.    Venter and colleagues at The Institue for Genomic Research, a non-profit research center he founded -- have agreed not to attempt a replay of Genesis until more public discussion takes place.
      Although on the creation of new, free-living life forms "does not violate any fundamental moral precepts or boundaries, but does raise questions that are essential to consider before technology advances further," according to the 25-member ethics panel, led by Mildred Cho of the Stanford University Center for Biomedical Ethics.    Can life be defined as having about 300 genes, with the ability to reproduce and respond to the environment?    Is there a spiritual component to being alive?    Will the creation of new life forms prove that life is reducible to nothing more than, DNA?    Is there any ecological harm from releasing novel life forms into the environment?
  
  
• 2/18/2000 - Genetic-manipulation technique could one day treat liver failure - New liver cells were grown in lab, injected into rats - by Paul Recer, The Associated Press.
      Washington -- Genetic manipulation of liver cells is pointing toward a promising therapy that one day might offer hope for the 20 million Americans who suffer from liver disease.    Laboratory experiments in which normal function was restored in rats that had lost 90 percent of their livers suggest that genetically manipulated cells, called hepatocytes, grown in test tubes could be used to rejuvenate a failing liver.    The new livers would be transplanted into the subject or could be used to delay organ failure in patients waiting for a transplant.    Uses for humans is in the future as this is still experimental, according to Dr. Philippe Leboulch of Brigham and Women's Hospital, the chief researcher on the study and an assistant professor of medicine at Harvard Medical School.
• 4/30/2000 - Winners of genome race will hold keys to life, more by Robert Cooke, News Day.
      The Rosetta stone of our time is the human genome, which is now up for grabs.    Who owns the genetic information, who gets to read it first, and how might it be exploited.    This will open a new chapter in life science research of things not yet conceived.    It will offer new medicines, hormones, growth factors, biomedical agents and even a deep understanding of our species' evolutionary history.    Clues to cancer will be found.    Patents for these will be an issue for these book of life products, which give us the key to the kingdom in understanding how complex biological systems -- such as the immune system, the cardiovascular system and the nervous system.
      The Department of Energy branch of the genome project announced recently that three of the 23 human chromosomes -- numbers 5, 16 and 19 -- recently were completed in "rough draft" form, adding about 300 million links, or base pairs, to the genome map.    The publicly funded scientists at the University of California, Berkely team had done the same for chromosome 22, announced in December.
  
  The Cloning Controversy
• 12/28/2002 - Skepticism, concern and anger greet human-cloning claim - Group says baby, mother will soon undergo DNA tests - by Joseph B. Verrengia, The Associated Press.
      Scientists offered skepticism and ethicists expressed concern at the risks to children after a company claimed yesterday that it had produced a baby girl through cloning.    "I'm still a skeptic," University of Georgia cloning expert Steve Stice during a press conference at the Hollywood, Fla., Holiday Inn.    Brigette Boisselier, a Ph.D. chemist and the CEO of a mysterious company called Clonaid, set up a sect called the Raelians, whose members believe aliens created life on Earth, stood in front of the reporters and proclaimed the birth of a 7-pound girl cloned from the skin cell of a 31-year-old American woman.    Boisselier, who holds doctorates in analytical and physical chemistry from the University of Houston and the Universsity of Dijon, France, and taught chemistry at Hamilton College in Clinton, N.Y., promised DNA tests would confirm her claim.    Also there was Mark Westhsin, a professor at Texas A&M University who has cloned cattle and was the first to clone a house pet, a cat.    The same kind of DNA tests that are used to identify bodies or tie rape suspects to crime scenes would be sufficient to determine whether the mother and child have identical genes.
      Ethicists argue that cloning people would compromise their freedom and individuality, that it is tantamount to manufacturing humans, designed as required for commodities.    Cloning in animals often produced extremely unhealthy animals, with a 1 in 50 success rate.    At 5 years old, Dolly the sheep, the first mammal ever cloned from adult DNA, is overweight, aging rapidly and suffering from arthritis.    It is too dangerous and unethical to proceed with the cloning procedure.
      "Cloning, says Rael, the Raelians movement leader, "is the key to eternal life."    The claim is that Clonaid, the company founded by the sect, will call the healthy baby girl, born on Thursday, December 26, 2002, weighning 7 lbs, will be called Eve, and evidence will be provided within 10 days.    Based in Quebec, cloning humans is at the heart of the Raelian theology of "scientific creation," which the movement of 55,000 worldwide, describes as an alternative to both Darwinian evolution and the creation dogma of some religions.    To most this sounds like an X-Files storyline, and Rael claims life on earth was created by extraterrestrials through genetic engineering.    The leader says the alien race is even given a name in the Bible -- Elohim -- a word he says has been mistranslated as the word "God."
      Bioethicists, religious and political figures and world leaders, including President Bush and U.N. Secretary-General Kofi Annan, were almost universal in condemning the announcement.    Bush called for a ban on human cloning.    This will add to the debate over human cloning, whether for reproductive purposes or to create human embryonic stem cells, which are thought to offer promise in treating a range of diseases.
      The science already exists to clone a human embryo, and its just a matter of time before someone successfully clones a human being.    Boisselier claims that four other women are pregnant with clones created by Clonaid, one is a lesbian in Europe, one is an Asian surrogate carrying the clone of another woman and two are carrying clones of dead babies that the parents want to reproduce.    Clonaid is a company in business.
• 12/28/2002 - FDA to see if laws broken; Congress may weigh ban by Lauran Neergaard, The Associated Press.
      Washington -- The Bush administration began investigating whether the sect claiming to have produced the world's first human clone illegally performed any of the work in the United States, while it also pushed Congress to ban baby-making via cloning.    The nation has no specific law against human cloning.    But the Food and Drug Administration, which regulates human experiments, contends that its regulations forbid human cloning without prior agency permission -- permission it has no intention of giving.    There is much debate on whether to ban medical research that involves the cloning of human embryonic cells.
      Lobby groups geared up for more battle.    The National Right to Life Committee decried "human embryo farms" in urging an immediate ban of all forms of cloning, and others argue to leave medical research avenues open.
  
  
• 1/7/2003 - Journalist withdraws from Clonaid project.
      The freelance journalist Michael Guillen who said he would oversee DNA testing to prove whether the first human clone has been produced said that he is suspending his efforts for now.    The testing by a team of scientists has been blocked by the parents of the baby, according to Clonaid, the company that made the claim Dec. 27.    Clonaid was founded by the Raelian religious sect, which believes space aliens created life on Earth.    So it is unknown of whether this is a hoax to bring attention to their group or not.
• 7/27/2003 - First in vitro baby celebrates 25th birthday by Robert Barr, The Associated Press.
      Bourn, England -- Louise Brown, the world's first test tube baby (combining sperm and egg outside a woman's body and then implanting the resulting embryo in her uterus), celebrated her own birthday and the anniversary of in vitro fertilization, a technique that revolutionized treatment for the infertile and has brought about conception of more than 1 million children.
• 8/3/2003 - Genes begin to reveal secret of longer life by Jeff Donn, The Associated Press.
      Boston -- David Sinclair, a biologist at Harvard Medical School, is trying to prevent aging.    Catapulted by advances in biotechnology, scores of researchers have begun to pinpoint genes that may prolong human life while delaying its late-stage diseases, frailties and maybe even gray hair and wrinkles.    Their remarkable successes in laboratory animals - like worms that live four times longer than normal - have already germinated several drug companies.    They hope to develop compounds to stretch healthy lifetimes beyond limits say even 120, 130 or possibly 350 years old, once presumed to be fixed.    Under the best circumstances, a life-prolonging drug could conceivably arise in five years, says longevity guru Cynthia Kenyon, a molecular geneticist at the University of California-San Francisco.    These brash scientists in this new field of aging genetics are already challenging the classic theories of aging and disease.
      In the 1930s, Cornwell University nutritionist Clive McCay discovered that underfed rats live a lot longer than others.    Just cut caloric intake by about 30 percent, balance their diet, and they survive 40 percent longer or more.    The technique works in fish, fleas, and other species and early data suggest it works in monkeys too.
      Researchers suspected that the effects of underfeeding point to some built-in biological switch after all: a set of master genes that can delay aging.    Could they be found?    Could their effect be mimicked by a drug that boosts or blocks the right proteins, the soldier molecules that do the work assigned by genes?
      Cynthia Kenyon, knew of a microscopic roundworm that when starved goes into a suspended animation, which is directed by a gene, daf-2, that controls growth by helping manufacture an insulin-like hormone.    Kenyon disabled variants of this gene in worms, flies and mice and they lived longer.
      Many longevity genes in animals have human counterparts.    Nerve researcher Gabrielle Boulianne, of the University of Toronto, was studying one of them in 1998, while looking at amyotrophic lateral sclerosis, the degenrative nerve condition known as Lou Gehrig's disease.    It had been linked to a gene known as SOD1, which treats metabolic waste products.    Since fruit flies carry a twin gene, she transplanted and supercharged the human gene (APOE, which regulates cholesterol) in their nerve cells, hoping to develop a research model for the disease.    The flies lived up to 40 percent longer.    Longevity genes are flagging the likely mechanisms of aging.
      Political scientist Francis Fukuyama, on the President's Council on Bioethics, says such problems beg for discussion because a proven longevity drug would be "almost impossible to stop."
      Also see Scientific American, August 2002 issue "The Serious Search for an Anti-Aging Pill" pg. 36-41, for other articles on this subject and also at http://www.sciam.com/explorations/2002/051302aging/.
• 8/7/2003 - World's first cloned horse reported by Italian scientists by Rick Weiss, The Washington Post.
      The world's first cloned horse named Prometea, created by Cesare Galli and other Italian scientists at the Laboratory of Reproductive Technology in Cremona from one skin cell taken from a toffee-brown mare and born on May 28.    This brings to eight the number of mammalian species that has been cloned from adult cells, along with sheep, mice, rabbits, goats, cats, pigs and cattle.    This horse is the first to have been gestated in the womb of the same female that donated the skin cell from which the clone was grown, thus giving birth to her identical twin sister.    This birth has put to rest suspicions that a mare's immune system would reject a fetus that was not at least a little bit genetically different from herself by having, for example, some genes from a father.    A second horse at Texas A&M University is due to be born in November.
      Horse cloning could allow the mass-reproduction of prize-winning runners, jumpers and show horses and bolster populations of rare and endangered horse breeds.
  
• 9/16/2003 - Scientists report growing stem cells into sperm cells.
      Embryonic stem cells from a mouse have been encouraged to grow into sperm cells for the first time, Japanese scientists headed by Toshiaki Noce of Mitsubishi Kagaku Institute of Life Science in Japan reported.    The next step would be to see if it can be repeated in live animals.
• 10/15/2003 - Research links longevity, bigger cholesterol particles by The Associated Press.
      Chicago - One reason some people live into their 90s and beyond may be a gentic variation that makes the cholesterol particles in their blood really big.    This study led by Dr. Nir Barzilai, director of the Institute for Aging Research at Albert Einstein College of Medicine.    Smaller particles, it is believed, can more easily embed themselves in the blood vessel walls, contributing to the fatty buildups that lead to heart attacks and strokes.    Exercise can enlarge the particles.
• 10/18/2003 - Genetic bits now fit on chip the size of a dime - Market leader Affymetrix joins in breakthrough - by Paul Elias, The Associated Press.
      San Francisco - The lofty goal of "personalized medicine" is one step closer to reality as two companies say they have successfully placed vital bits of humankind's estimated 35,000 genes on a small glass chip.    Rivals Affymetrix Inc. (owner of 80% of market) and Agilent Technologies produced so-called gene chips -- dime-size pieces of glass infused with genetic material, where previous they needed two chips to hold the material.
      Chips with portions of the genome are indispensable in biology laboratories around the world.    Now, Affymetrix (CEO Stephen Fodor) says researchers can buy the entire genome for between $300 and $500 each, half the old price.
      Researchers use the chips to do basic genetic research.    Scientists believe many diseases are caused by genes "turning on" when they shouldn't.    Knowing this, researches can design drugs to attack suspect genes.
• 12/11/2003 - Scientists create sperm from mouse stem cells, fertilize eggs by The Associated Press.
      Scientists say they have turned mouse embryonic stem cells into primitive sperm cells -- and then used the sperm cells to fertilize eggs.    This offers insights into male infertility and boost human stem cell research.    The team was led by Dr. George Daley of Harvard Medical School.    Embryonic stem cells can develop into virtually any kind of cell of the body, and scientists hope to use them someday to create replacement parts to treat illnesses such as Parkinson's disease and diabetes.    This research was all done from a dish.
  
  
• 2/12/2004 - Stem cells culled from cloned embryo by Lauran Neergaard, Associated Press.
      Washington - Researchers in South Korea for the first time have cloned a human embryo and then culled stem cells from it, marking an important step toward growing patients' own replacement tissue to treat diseases.    The experiment is sure to revive controversy over human cloning in the U.S. and internationally.    This is therapeutic cloning, in which embryos that are the genetic twins of a particular patient are grown in a test tube to supply master stem cells that can grow into any tissue - without being rejected by that patient's immune system.
      Scientists from Seoul National University report they succeeded - using extremely fresh eggs donated by South Korean volunteers and gently handling the genetic material inside.
• 2/13/2004 - First human cloning to obtain stem cells sparks calls for ban by Paul Recer, Associated Press.
      Seattle - The cloning of a human embryo and extraction of stem cells from it has ignited new calls for a ban on all forms of human cloning in the U.S.    Cloning human beings is wrong in that it is unethical to tinker with human life.    The Bush administration is against the action, and Bush stated "Human life is a creation, not a commodity, and should not be used as research material for reckless experiments."    Although some Democrats want a ban on the cloning of human babies but permit life saving stem cell research to proceed under strict ethical guidelines.
      Woo Suk Hwang, lead author of the study, admitted that the technique developed in his lab cannot be separated from reproductive cloning.    The medical use of stem cells derived from cloning will require at least another decade of research.
      Woo Suk Hwang and Shin Yong Moon and their team created the human embryo after collecting 242 eggs from 16 unpaid, anonymous volunteers.
      Cloned embryos are created through the union of a woman's egg and one of her body's adult cells - could develop to the blastocyst stage at which universal stem cells could be harvested.
• 2/22/2004 - Governor to propose stem cell institute by New York Times.
      Trenton, N.J. - New Jersey is poised to become the first state in the nation to finance stem cell research.    The state will provide $6.5 million for a stem cell research institute, and Rutgers University and the University of Medicine and Denistry of New Jersey will run it.    Governor James E. McGreevey wants to spend $50 million over the next five years for research on human embryonic stem cells.
• 3/3/2004 - Report finds Bush-backed stem-cell research faltering by Justin Gillis and Rick Weiss, The Washington Post.
      Washington - At least 16 of the 78 human stem cell colonies approved by President Bush for federal research money have died or failed to reproduce in their laboratory dishes - making them useless to scientists - and most of the others are unlikely ever to become available for disease research according to the National Institute of Health.    Many of the approved colonies extracted before Aug. 9, 2001 already available to researchers are beginning to show genetic abnormalities.
• 3/4/2004 - Harvard offers new stem cell lines to scientists by Stephanie Nano, Associated Press.
      Harvard scientists are offering colleagues free access to 17 new human embryonic stem cell lines developed without government money, hoping to boost research that the Bush administration has tried to restrict.    Stem cells are typically taken from days-old human embryos, then grown into lines or colonies.    The controversy is that once extracted the human embryos are destroyed.    Each of the new lines cost $5,000, and were developed from 344 excess frozen embryos from a fertility clinic.
• 4/6/2004 - Hatch: Senate has votes to change stem-cell policy by AP.
      Washington - Sen. Orrin Hatch, a Utah Republican supporter of embryonic stem cell research, said there is wide support in the Senate to ease the Bush administration's restrictive policy.   
• 5/20/2004 - Britain opens the world's first national stem cell bank by Jane Wardell, Associated Press.
      Potters Bar, England - Britain opened the world's first national stem cell bank, hoping to establish a lead in promising but controversial medical research.    Britain was the first nation to authorize the cloning of human embryos to produce stem cells for research.    The cell bank was established at the National Institute for Biological Standards and Control at Potter's Bar, 12 miles north of London.    Its mission is to store and grow cells and distribute them to researchers worldwide.    The bank will also accept stem cells from fetal and adult sources.    The European Union policy would require the agreement of member governments.
• 6/8/2004 - Senators ask Bush to ease rules on stem cell research by Erica Werner, Associated Press.
      Washington - Fifty-eight senators are asking President Bush to relax federal restrictions on stem cell research, right after the late President Reagan died of Alzheimer's disease.    President Bush is still standing by his stem cell policy in that we should not cross a fundamental moral line by funding or encouraging the destruction of human embryos.
• 6/10/2004 - Stem cell lines developed from defective embryos by Lindsey Tanner, Associated Press.
      Chicago - Scientists at a private Chicago fertility clinic say they have isolated 12 new stem cell lines from genetically flawed human embryos.    The cell colonies came from unused embryos donated by couples who underwent prenatal genetic screening at Reproductive Genetics Institute.    The embryos had gene mutations for two forms of muscular dystrophy, certain blood disease and a cause of mental retardation - seven diseases in all.    These are the first to be created from embryos with specific diseases, which will help scientists to determine how the cells with diseases affect the cells.    The ethicist say using genetically defective embryos does not erase the moral obligation, even though they would be discarded anyway.
• 9/19/2004 - The promise of stem cells by Greg Barrett, Gannett News Service.
      Washington - Democratic Sen. John Kerry claims stem cell research is the Holy Grail of medicine, while Bush the possiblities are uncertain and the science encroaches on the sanctity of life.    Embryonic stem cell research is still in exploration and no one knows what causes these cells to differentiate into specific cells.    No human tests have been conducted.    The assumption is made that this research will lead to cures of many diseases, which is still 10 to 20 years away.
• 11/10/2004 - California voters open gold mine on stem cells by Paul Elias, Associated Press.
      San Francsico - California voters approved Proposition 71 and $3 billion for human embryonic stem cell research.    Worcester, Mass.- based Advanced Technology, a biotech company said it will open a California laboratory so it can apply for grants.    The biotechnology industry contributed $28 million to get the measure approved.
• 11/29/2004 - Merging man and animal - Scientists are stretching the boundaries of stem cell research - by Rick Weiss, The Washington Post.
      Washington - In Minnesota, pigs are born with human blood in their veins.    In Nevada, there are sheep whose livers and hearts are largely human.    In California, mice peer from their cages with human brain cells in their skulls.
      These are not outcast from "The Island of Dr. Moreau," the 1896 novel by H.G. Wells in which a doctor develops creatures that are part animal and part human.    They are real creations of real scientists, stretching the boundaries of stem cell research.    Biologists call these hybrid animal chimeras, after the mythical Greek creature with a lion's head, a goat's body and serpent's tail.    They are the products of experiments in which human stem cells were added to animal fetuses.    This allowed scientists to watch how nascent human cells and organs mature and interact in the bodies of living creatures.
      So will it be unethical for a human embryo to begin its development in an animal's womb, and whether a mouse would be better or worse off with a brain made of human neurons.
      Who will establish guidelines on what should not be done?    Recepients of organ transplants are also chimeras, as are the many people whose defective heart valves have been replaced with those from pigs or cows.    For years scientists have added human genes to bacteria and even to farm animals - feats of genetic engineering that allow those critters to make human proteins such as insulin.    Scientists have added human stem cells to sheep fetuses, and now have sheep whose livers are up to 80 percent human, and function as that.
      Whats next, a human-chimpanzee endowed with speech and learning skills, which will be called a "humanzee."    It had been already proven in the past that complex behaviors could be transferred across species.
  

Last updated January 27, 2004, and March 15, 2006.