J. CRAIG VENTER is founder and president of the J. Craig Venter Institute and the J. Craig Venter Science Foundation, former president of Celera Genomics, and decoder of the human genome.
With our initial analysis of the sequence of the human genome, particularly with the much smaller than expected number of human genes, the genetic determinists seemed to have clearly suffered a setback. After all, those looking for one gene for each human trait and disease won’t be happy with as few as twenty thousand or so genes, when hundreds of thousands were anticipated. Deciphering the genetic basis of human behavior has been a complex and largely unsatisfying endeavor because of the limitations of the existing tools of genetic-trait analysis, particularly complex traits involving multiple genes.
All this will soon undergo a revolutionary transformation. The rate of change of DNA-sequencing technology continues at an exponential pace. We are approaching the time when we will go from having a few human genome sequences to complex databases containing tens to hundreds of thousands of complete genomes, then millions. Within a decade, we will begin rapidly accumulating the complete genetic codes of individuals along with their phenotypic repertoires. By performing multifactorial analysis of the DNA sequence variations, along with the comprehensive phenotypic information gleaned from every branch of human investigatory discipline, we will be able to provide for the first time in history quantitative answers to those questions of what is due to genes and what is due to the environment. This is already taking place in cancer research, where we can measure the differences in genetic mutations inherited from our parents versus those resulting from environmental damage. This good news will help transform the treatment of cancer by allowing us to know which proteins need to be targeted.
However, when these powerful new computers and databases are used to help us analyze who we are as humans, will the public, largely ignorant and afraid of science, be ready for the answers we are likely to get?
For example, we know from experiments on fruit flies that there are genes that control many behaviors, including sexual activity. We sequenced the dog genome a couple of years ago and now an additional breed has had its genome decoded. The canine world offers a unique look into the genetic basis of behavior. The large number of distinct dog breeds originated from the wolf genome by selective breeding, yet each breed retains only subsets of the wolf behavioral spectrum. There is a genetic basis not only in the appearance of the breeds (a thirtyfold difference in weight and and a sixfold difference in height) but in behavior: For example, border collies use the power of their stare to herd sheep instead of freezing them in place in order to devour them.
We may attribute behaviors in other mammalian species to genes and genetics, but when it comes to humans we seem to like the notion that we’re all created equal, that each child is a “blank slate.” As we obtain the sequences of more and more mammalian genomes, including more human sequences, together with basic observations and common sense, we will be forced to turn away from these politically correct interpretations, as our new genomic tool sets allow us to sort out nature and nurture. We are at the threshold of a realistic biology of humankind.
It will inevitably be revealed that there are strong genetic components associated with most aspects of our human nature: personality subtypes, language capabilities, mechanical abilities, intelligence, sexual activities and preferences, intuitive thinking, quality of memory, willpower, temperament, athletic abilities, and so on. We will find unique manifestations of human activity linked to genetics associated with isolated and/or inbred populations.
The danger rests with what we already know—that we are not all created equal. Further danger comes with our ability to quantify and measure the genetic side of the equation before we can fully evaluate the environmental components of human nature—a much more difficult task. The genetic determinists appear to be winning, but we cannot let them forget or ignore the wide range of human potential even with our limiting genetic repertoire.