A short time ago, the idea of hybrid animals and designer babies were just myths and dreams. Today, it’s the emerging reality. Monkeys have been given human genes to see if we can make them more closely resemble us, and human babies have been genetically altered to make them “better.” China is the first country to attempt genetic experimentation because it has not imposed the types of restrictions on researchers and scientists that exist elsewhere. Researchers there have applied gene-editing techniques to push the envelope of what is possible and acceptable. Two recent scientific announcements have given rise to a very heated debate among scientists, bioethicists, and policy makers.
First, a group at the Southern University of Science and Technology, in Shenzhen, selected couples in an attempt to create the first gene-edited human babies. Dr. He Jiankui, the lead scientist, said he altered embryos for seven couples during fertility treatments, with one pregnancy resulting so far. Dr. Jiankui said that he intended to eradicate a gene called CCR5 in the hope of making the genetically altered humans resistant to HIV, smallpox, and cholera. To accomplish his experiment, Jiankui used CRISPR technology, which is faster, cheaper, more accurate, and more efficient than other existing genome editing methods. It uses a protein called Cas9 to locate specific strands of DNA and cut them out. This enables editing of DNA sequences. Researchers used this CRISPR tech to customize human embryos before they were transferred into women’s uteruses.
According to Technology Review, the attempt to create children protected from HIV, “falls into an ethical grey area between treatment and enhancement.” That is because no disease or disorder seemed to be cured in the embryo. Instead, the genetic manipulation was done to confer a health advantage on the developing human, much like a vaccine. However, most scientists decry “designer babies” and agree that this procedure should not be used to “upgrade” a baby to have different physical or mental features. This type of technology would be expensive and may only be available to the wealthiest families.
The second recent experiment to sidestep these serious ethical questions involved the transplant of human genes into monkeys. In another Chinese research program, macaque monkeys were genetically modified with a human gene thought to play a role in brain development. Many scientists felt this experiment crossed an ethical boundary.
On the CBC podcast, “Quirks and Quarks,” Dr. Jim Tabery, a professor of bioethics at the University of Utah, explained the process the scientists went through, as well as his opinion on it. Human brain development, Tabery says is a “popular topic among researchers interested in what role genes play.” Human brain sizes began to get much larger for our size compared to other animals two to three million years ago. Scientists think this played an important role in human evolution which separates us from our ancestors, and from other similar species. The Chinese researchers focused on one of the genes and Tabery said they wanted to “learn what would happen if they put a human version of the gene in a similar non-human animal” — the macaque monkey.
The researchers inserted the human gene, microcephalin, a gene that is thought to be responsible for neural development, and which has been associated with brain size. “Non-human animals have their own version of it, and humans have more copies,” said Tabery. The scientists introduced it into monkey embryos via a virus that carried the gene.
Six of the eleven monkeys they created died, and the five remaining had to endure a series of tests, such as MRI and memory tests. Tabery claims, “the [cognitive] effects on the monkeys were not greatly significant.” The monkeys with human brain genes were not any bigger than the unaltered monkey’s brains. The modified brains developed slower, and Tabery said they, “scored slightly higher on a series of short term memory tests.” However, since the sample size was so small, it is likely that the result was due to chance.
Through this research, scientists can infer that there was an element of human-type development, regardless of brain size. This is because the brains of the monkeys with human genes developed slower than monkeys without human genes, similar to human babies.
Bioethicists like Tabery worry about this kind of research, in which scientists are trying to, “humanize non-human animals and make them even more biologically similar to humans.” Tabery said that if the scientists had caused significant humanizing effects in the monkeys, important ethical questions would have arisen: how are we to regard, and treat, animals that have partially human minds?
The CRISPR baby and macaque monkey experiments are just two early steps towards a future in which human gene editing is technically and financially feasible. Experts are certain that someday soon this provocative science will become commonplace. Perhaps we don’t have long to wait before there are superhuman children and talking human/ape hybrids among us. Would that be good, or bad?
Image: Виталий Смолыгин / Public Domain Pictures