Donnie’s death was a real tragedy in terms of our research. Our post-mortem work was severely hampered by his next-of-kin, who in their grief-stricken state seemed to hold us in some way responsible for his death. Despite our best efforts they refused to release the body for further research, and our attempts at court action were hamstrung by a judicial system that tends to value motherhood issues over science. We were ultimately able to serve Donnie’s parents with an emergency injunction compelling them to relinquish the body, but by that time the remains had been cremated.
But all was not lost. Donnie was far from a unique individual. The genes responsible for his transformation are widely spread among the population; they’re just dormant in most of us. And it turns out that in certain cases, some of these genes do express spontaneously. It was looking increasingly possible that psychopathy, autism, and certain types of schizophrenia—to name but a few—might arise at least partly from the partial expression of these genes, albeit in a very broken and rudimentary form. Sociopaths and savantes show us one or two bits of this hidden subspecies; Donnie showed us many more traits manifesting together, although he was still a few bricks short of an operational prototype. But if we could awaken these traits—and if the genes were present in other people—who knew how much more we could discover with access to a large sample of human subjects under controlled conditions?
We applied for funding from a number of sources including NSERC, SSHRC, the Department of National Defense, and the Wellness Foundation of the West Edmonton Mall. Unfortunately, Canada’s federal policy is not what you would describe as "science-friendly"; everyone turned us down, generally using the excuse that our human-subject protocols violated so-called "ethical standards". We then sought funding in the US, specifically the state of Texas, which routinely incarcerates large numbers of people under conditions suitable for experimentation.
Even here, we encountered some resistance from the so-called "family values" lobby. However, we were willing to stipulate contractually that our research did not involve the use of any fetal tissue, unfertilised ova, or seminal ejaculate; and that our studies in no way promoted or contributed to the spread of information regarding contraception, STDs, or the teaching of evolutionary principles. This last item was a bit tricky, as the entire project was of course focused on issues of hominid evolution—but at the same time we were talking about proprietary information that we weren’t about to publicise anyway until the patents had been locked down. Understanding this, the state of Texas gave us unfettered access to their population of death row inmates, which of course already contained a large proportion of preselected sociopaths and developmentally-challenged individuals.
Of course, one can’t conduct a proper scientific experiment without controls; we needed a population of normal, baseline individuals against whom our experimental subjects could be compared. Discreet advertisements in local media turned up little in the way of volunteers, but once again the Texas penal system came to our aid. As it turns out, a large number of convicts showed no sociopathic pathological tendencies whatsoever; in fact, many of them were not even guilty of actual crimes. They had, however, been incarcerated under conditions identical with those of true sociopaths; this made them an ideal and ready-made control group.
From here on in our research proceeded by leaps and bounds. We encountered the inevitable setbacks that are a part of pushing back any frontier, but we were ultimately able to activate most of the genes of this long-lost and unsuspected branch of the hominid family tree. In fact, not to fine a point on it, we were actually able to resurrect—from baseline humans—something close to our long-lost cousins, and to learn a great deal about what they were, and where they came from.
We are dealing with a short-lived offshoot of the Human race that arose somewhere between four and five hundred thousand years before present, and which died out only recently. Taxonomists are divided on what exactly to call this creature—some say that it’s a whole new species, others point out that it obviously interbred with us, so there was never complete reproductive isolation. A few little old ladies say that we shouldn’t give these guys any kind of special status, that they were basically just a bunch of cannibals with a consistent set of deformities, and you don’t classify Down’s Syndrome kids as a separate species. I’m taking a middle road here, and calling it a subspecies; here are some of the suggested names currently under consideration.
External diagnostic features are actually pretty subtle, both because vampires never lasted long enough to diverge greatly from the Human baseline, and also because natural selection is going to promote superficial similarity; if you hunt people for a living, it really helps to be able to blend in with your prey. The most radical differences between them and us are neurological and digestive — soft-tissue stuff that doesn’t fossilise well. This is one of the reasons why it’s so difficult to identify these creatures in the fossil record—the other reason being that they sat at the very apex of the food pyramid, which means that they were quite rare even at peak numbers.
Nonetheless, there are some statistically significant differences between vampires and baselines. Vampires tend to be taller and longer-limbed than humans. There’s a slight but distinct extension of the mandible, and of course of the canines, the classic "fangs" of the predatory grip-and-tear feeding mode (although this wasn’t quite as pronounced as the popular mythology would have you believe).
Tapetum lucidum, as I mentioned before; enhances night-vision by increasing the reflectivity of the retina; vampires also have quadrochromatic vision; while we humans have only three types of cones in our eye vampires have four, the fourth being tuned to near-infrared.
Motor nerve axons almost twice as thick as those of conventional humans; hence, faster signal transmission, faster reflexes. A vampire could literally snatch a speck out of your eye before you had time to blink.
Here we’re getting into the central nervous system, and this is where the real differences show up. The corpus callusum is twenty percent larger in vampires than in humans, resulting in high-speed broadband communication between hemispheres. Interneuron density, cortical folding and lamination way above normal, particularly in the visual cortex; these creatures have pattern-matching skills far in excess of the human norm. You may remember the "savantes" from movies like Rain Man and Oliver Saks' books: they can play complex piano arrangements after a single listening, or predict the day of the week that your birthday will fall on, every year for the next thousand years. Any of us could perform those calculations if we had to—painstakingly referring to our calendars and correcting for leapyears and working out each year in turn—and you might think that savantes simply do that faster than we do. No: savantes don’t do those calculations at all. There is no process by which they "work out" these solutions:they simply see them, fully formed, laid out instantly. They don’t even have to think about it consciously.
You can do the same thing, in a very limited sense. If I show you one marble, you don’t have to count it to know how many there are. Two or three marbles, same thing; you don’t have to count, you see. You just know. But if I showed you ten or twenty marbles, you’d have to consciously tally them up. Savantes don’t. When they’re in their groove, they "see" everything; days of the week, ten-digit primes, you name it. Instantly.