A guest post by Emily Graves, DO and Yoko Ichinose, PhD¹

We’re delighted to publish excerpts from our paper “Introducing Homo sapiens sanguis”.

Homo sapiens sanguis is a novel subspecies of Homo sapiens. Known in folklore and myth as vampires, this is the first scientific paper on H. s. sanguis and their culture. We have named this subspecies to reflect their diet and predatory nature.

H. s. sanguis refer to themselves in English as kindred and in Arabic as ainsiba’. Arabic is the official kindred language. H. s. sanguis diverged from H. sapiens about 98,000 BCE. They evolved in parallel with their primary prey, H. sapiens. The kindred feel that speaking Arabic helps preserve their culture and continues to connect them to their subspecies’ origins in the Fertile Crescent. […..]

A bloodborn, or naturally concieved, specimen’s lifespan averages 1,000 years. Gestation takes 90 months. Puberty occurs at 100 years of age. H. s. sanguis are considered adults upon completing the fledging ceremony. This ceremony takes place in up to four stages: ceremonial first kill after onset of puberty, ceremonial first kill after emergence of talent (if later date), fledging journey, final ceremony. Kindred are considered elderly at about 700 years old. Talents will be discussed later in this paper.

Turned specimens live a maximum of 900 years as their resurrection makes them at least the equivalent of a pubescent ainsiba’.

Most H. s. sanguis die in combat in the prime of life.

Ainsiba’ government places strict controls on the birth or creation of new kindred. The aim is to maintain a 1 death to 1 birth or creation ratio. [….]

All H. s. sanguis require blood from H. sapiens to survive.  The bloodborn meet nearly all their dietary requirements with human blood alone, but they can eat human food in order to keep up appearances. Turned kindred must supplement their blood diet with human food. All H. s. sanguis require Vitamin D supplementation because they cannot make it from sunlight due to an extreme UV-B allergy. Kindred cannot survive more than 24 hours without blood. Blood from non-human animals is not an adequate substitute. Animal blood can sustain kindred for up to a week, but has many painful and debilitating side effects. Infant bloodborn, the newly turned, or the elderly (~700+ years old) can only go a maximum of 12 hours without blood.

Figure 1 shows the minimum number of H. sapiens prey required to feed one ainsiba’ for 1 year. In this scenario the H. s. sanguis may create a menagerie of human prey upon which they feed in rotation. The standard U.S. Blood donation is 500 ml or 1 pint and contains roughly 450 calories.  Male H. sapiens provide slightly more protein, as their blood’s plasma content is 55%. Female H. sapiens’ blood is 60% plasma, making them more desirable when an H. s. sanguisrequires an immunity boost. We will not discriminate between sexes in our calculations. An average bloodborn ainsiba’ must consume 3,000 calories per day from blood to survive, while an average turned kindred must consume only 2,000 calories of blood per day and can make up the remaining third of their daily calorie requirement with food. Thus a bloodborn requires 3,333.33 ml or 6.67 pints per day while a turned requires 2,222.22 ml or 4.44 pints per day. We will use the bloodborn figures in our calculations.

The Red Cross requires that humans wait 8 weeks minimum between donations for full reccovery. However, humans generally take 4 to 6 weeks to regenerate 1 pint of blood. Let r represent the number of days a bloodborn allows a human to regenerate blood. Let 人 represent the number of pints or feedings per cycle. This gives us the formula:

7 x r = 人

Figure 1.

Figure 1 shows that an H. s. sanguis feeding from an H. Sapiens menagerie at 1 pint per human on a 28 day cycle requires a minimum of 196 humans to survive. A bloodborn feeding from their menagerie at 1 pint per human on a 56 day cycle requires a minimum of 392 humans to survive.

Maximum allowable bloodloss and minimum allowable hemoglobin are highly individual statistics. H. s. sanguis learn quickly to estimate the point at which they must stop feeding by their prey’s symptoms and the blood’s qualities. This is only partially instinctual and must be taught. This fact along with the desire not to overhunt their prey led to a prohibition on creating kindred by any means without government permission. Kindred born or turned without government permission are called orphans and are hunted and exterminated. Any ainsiba’ who create orphans are executed. The kindred goverment maintains staff whose mission is to report suspected orphans in emergency rooms worldwide.

An adult human male weighing 175 lbs with an intial hemoglobin of 17 g/dl and a final hemoglobin of 10 g/dl may loose 2456.6 ml or 4.91 pints before transfusion is required. Thus, if a bloodborn drinks 4 pints of blood from each human, a minimum of 49 and a maximum of 98 humans are required to feed 1 bloodborn per day.

Feeding from so many humans each day and maintaining such a large menagerie are prohibitive in practical terms. Many H. s. sanguis therefore either supplement their diet with or subsist entirely on bloodbags.

Using the above calculations, however, we can estimate the maximum population of H. s. sanguis which can exist for a given H. sapiens population. To do so we use the following formula, where p represents the human population and v represents the kindred population:

p / 392 = v

For example, the 2011 human population of San Francisco, California is about 706,856 people. Therefore a maximum of 1,803 kindred may live and hunt in this city. These calculations presume that every member of the adult human population is a feeding candidate. The actual ainsiba’ population is likely half to two-thirds this quotient. [….]

The one food  H. s. sanguis avoids is garlic. Garlic causes no ill effects, but it smells like rotting flesh to them and is unappetizing. Kindred have twice the number of olfactory receptors as humans: 12 million compared to humans’ 6 million. This assists H. s. sanguis in hunting prey. They use a combination of the chimicals in sweat, scent, and exhaled carbon dioxide to track and select prey. Kindred can discriminate potential prey’s state of health, whether they have any drugs in their system and, often, which drugs, and blood type. Bloodborn kindred tend to prefer blood type O. This may be due to the properties which make it the universal donor. The turned generally prefer blood types compatible with the blood type they had prior to resurrection. Both types of  H. s. sanguis prefer overweight and obese prey. Obese prey are less likely to escape and their blood provides more calories. [….]

H. s. sanguis adapts their internal temperature according to their fluid levels. When water reserves are full, their resting body temperature is 99.9℉, measured orally. When reserves are low, the acceptable temperature range shifts to 93-106℉. Heat accumulated during the day is offloaded as much as possible at night.

Due to the above, H. s. sanguis generally require more frequent hydration than humans, particularly when active, and are more susceptible to heat exhaustion. Depending on humidity, an apparent temperature of 80°F or above could be dangerous for a kindred. This is another reason H. s. sanguis traditionally prefer nighttime. Crypts, caves, and the like offered stable, comfortable temperatures and humidity before air conditioning.

When H. s. sanguis experiences heat exhuastion or dehydration, first they will go mad with thirst. If the kindred cannot quench it and the heat exhaustion is not ameliorated, starvation will be accelerated by continued fluid loss. As the ainsiba’ continues to dry out, a point of no return is reached when a biological self destruct signal is tripped and the immune system imitates the UV-B allergy, immolating them. The length of time this takes is highly individual, depending on many factors including individual biology, nutrition, weather, and access to aid. The longest our colleague, researcher Dane Grokelstern, PhD, has observed a subject surviving is 8 hours. The average so far appears to be 3. If you have any specimens, please direct them to Xeno Labs, care of Dr. Grokelstern.

All of the above helps explain why  H. s. sanguis has not physically taken over Earth. During times of famine prior to industrial agriculture, kindred were more vulnerable than humans.

Most have milder allergies to silver. Silver causes contact dermatitis. Lengthy exposure can result in welts, rash, hives, blisters, and lesions. If any silver is left in a wound, it will heal as slowly as the same wound on a human body.

As noted above, H. s. sanguis is also allergic to UV-B. This is an extreme allergy cumulating in immolation. The mechanism of immolation is unknown at this time. [….]

H. s. sanguis may appear pale, however this is the effect of lack of blood rather than little melanin. Contrary to popular belief, H. s. sanguis are dark-skinned. The bloodborn are born with dark complexions. Turned ainsiba’ complexions resemble their most tanned possible state as a human. This provides some protection against UV-B. The darker a kindred’s skin, the longer they can stand exposure to UV-B.

¹These are characters from my novel, House Ibsen. All facts and calculations in their paper are real except for the existence of Homo sapiens sanguis. As far as we know, anyway… 😉