The process of random gene selection by nature takes too long. For the first time in human history we have a chance to emulate the gods in principle and practice. Just like how we see with pity the fossils of our Neanderthal ancestors, the modern day Homo sapiens may just transition to become a new species possibly called the Homo Evolutis. A harder question is whether it is ever right to edit human germ-line cells, to make changes that are inherited. This is banned in 40 countries and restricted in many others. There is no reason for a ban on research or therapeutic use: some countries, rightly, allow research on human embryos, as long as they are left over from in-vitro fertilisation and are not grown beyond 14 days; and Britain has allowed a donor to supply mitochondrial DNA at conception to spare children needless suffering.
The first step in achieving this feat is to master our DNA. The genome is written in an alphabet of just four letters. Being able to read, study and compare DNA sequences for humans, and thousands of other species, has become routine. A new technology promises to make it possible to edit genetic information quickly and cheaply. This could correct terrible genetic defects that blight lives. It also heralds the distant prospect of parents building their children to order.
The technology is known as CRISPR-Cas9, or just CRISPR. It involves a piece of RNA, a chemical messenger, designed to target a section of DNA; and an enzyme, called a nuclease, that can snip unwanted genes out and paste new ones in. A dizzying range of applications has researchers turning to CRISPR to develop therapies for everything from Alzheimer’s to cancer to HIV. By allowing doctors to put just the right cancer-hunting genes into a patient’s immune system, the technology could lead to new approaches to oncology. It may also accelerate the progress of gene therapy where doctors put normal genes into the cells of people who suffer from genetic diseases such as Tay Sachs or cystic fibrosis.
It will be years, perhaps even decades, before CRISPR is being used to make designer babies. But the issues that raises are already the subject of fierce discussion. In April scientists in China revealed they had tried using CRISPR to edit the genomes of human embryos. Although these embryos could not develop to term, viable embryos could one day be engineered for therapeutic reasons or non-medical enhancement.
This is a Rubicon that could give rise to subsequent generations of super beings living many modern day lifespans. America’s National Academy of Sciences plans a conference to delve into CRISPR’s ethics. The debate is sorely needed. CRISPR is a boon, but it raises profound questions on how to manage any breakdowns.Practically it may take a generation to ensure that the technology is safe. Until then, couples with some genetic diseases can conceive using in-vitro fertilisation and select healthy embryos. Moreover awash with gene-sequence data, biology still has a tenuous grip on the origins of almost all the interesting and complex traits in humanity. Very few are likely to be easily enhanced with a quick cut-and-paste but an à la carte menu of attributes seems not so distant anymore. Hence scientists are right to be thinking now about how best to regulate CRISPR.
That means answering the philosophical questions. There are those who will oppose CRISPR because it lets humans play God. But medicine routinely intervenes in the natural order of things saving people from infections and parasites. The opportunities to treat cancer, save children from genetic disease and understand diabetes offer justification to push ahead.
However it is not too soon to draw on these principles to come up with rules. Some countries may have gaps in their legislation or poor enforcement, letting privately funded scientists or fertility clinics carry out unregulated CRISPR research. The conservative, painstaking approach taken by Britain’s Human Fertilisation and Embryology Authority in its decision on mitochondrial DNA is a model. Regulators must also monitor CRISPR’s use in non-human species. Changing animals’ genomes to spread desirable traits mosquitoes that cannot transmit malaria, for example could bring huge benefits. But the risk of unanticipated consequences means that such “gene drives” should be banned unless they can be reversed with proven countermeasures.
If CRISPR can be shown to be safe in humans, mechanisms will also be needed to grapple with consent and equality. Gene editing raises the spectre of parents making choices that are not obviously in the best interests of their children. Deaf parents may prefer their offspring to be deaf too, say; pushy parents might want to boost their children’s intelligence at all costs, even if doing so affects their personalities in other ways. And if it becomes possible to tweak genes to make children smarter, should that option really be limited to the rich?
Thinking through such issues is right. But these dilemmas should not obscure CRISPR’s benefits or obstruct its progress. The world has within its reach a tool to give people healthier, longer and better-quality lives. Overall I would argue that the science of editing humanity should be embraced and we all should welcome the idea of reinventing the future of us and the future of humans to come.
References- Scientific America, DARPA, Economist and TED