Vampires?

[lorb]

Can they work somehow? I do really want to give a shot at creating scientifically sound vampires. I think the main requirements are:
1.) they don't die of old age
2.) they feed on blood
3.) sunlight somehow damages them
4.) vampire-teeth

As for number 1 and 2 i am going for the theory that telomeres are what makes us age and vampires are somehow able to extract fresh telomeres from blood to replace their own ones. I think this can also explain why they prefer human blood. The biochemical processing of the cells could leave the vampires with some kind of HIV-like ailment that makes them hypersinsitive to sunlight. (See: http://en.wikipedia.org/wiki/Photosensi ... _infection) Number 4 seems easy ... they just evolved those teeth.

[letterX]

somehow able to extract fresh telomeres from blood to replace their own ones

That's... not how telomeres work... And even if they did, red blood cells don't even have a nucleus to begin with!

But since we're in the fictional science forum here, I'll give that a pass.

Anyways, for 2-4, you may want to look at possible connections with the disease porphyria and the origins of vampire legends.

[Copper Bezel]

Isn't one of the main requirements for the mythos that ordinary human beings can be converted into vampires? I don't think the physiological elements like fangs and light sensitivity are as important as that. I think "vampire" just requires that they drink blood to stay alive, and so long as they do so, they can stay alive longer than people who aren't vampires. Various other superhuman abilities optional.

I'd go with an endosymbiont, I think, that leeches iron for some reason but also benefits the immune system and regeneration at a cellular level. Just my thought. You could also work in some photosensitivity that way - perhaps the symbiont breaks down under UV, and it's developed the ability to somehow affect the host's psychology to protect itself.

[ikrase]

My suggestion is that they might be artificial transhuman creations meant to spread their transhuman kind through the world.

-Sunlight would cause blindness as a consequence of them being meant to live indoors in civilization, and having sensitive, broad-spectrum eyes.

-There is an infectious symbiotic bacterium or virus that is in their saliva so vampire bites infect the victim with the modifying substance. This would cause illness. If a healthy human is bitten, there is a good chance that they will survive the physiological modifications and re-writing of their DNA and will become vampires. They have a primal drive to bite and infect humans.

-The vampires can revert any part of their body to an infantile, unlimited growth stage allowing them to repair all damage in time. Therefore, they do not age. However, there is the problem of mutation over long periods. They must consume a wide spectrum of human blood to provide a broad average of human DNA. This provides a canonical human base genome. Meanwhile, sexual intercourse between vampires is not reproductive, but provides redundant synchronization of the human genome as well as a canonical vampiric extension genome and vampiric symbiote genome. They will have a primal urge to consume human blood and in particular to consume human blood from healthy humans. This both propagates the transhuman vampiric kind and maintains the vampire genome even in the absence of mates.

[gmalivuk]

it's developed the ability to somehow affect the host's psychology to protect itself.

This doesn't need to be some specialized development if it's big enough. The sheer amount of foreign proteins released into every part of the host's body upon the symbiont's death would cause plenty of problems, though I suppose they wouldn't typically manifest especially quickly.

[KrO2]

I'm kind of surprised nobody has linked this yet.
Kind of like ikrase said, there's no way this is happening naturally.

[idobox]

I would go for an infectious agent, a bacteria or a bigger parasit, that increases agressivity and metabolism, but at the same time depletes (consumes) some hormone or protein commonly found in blood.
That way, you get strong and fast people with a craving for bllod.

Theyy don't really need light to cause them physical harm. They can just be highly sensitive to strong light, which is an existing conditions, and to other stimuli, like the smell of garlic.
If you really want light to cause them harm, you could have the parasit screw up with pigmentation or repair mechanisms of the skin, making them extremely prone to sunburns.

[Tass]

I would go for an infectious agent, a bacteria or a bigger parasit, that increases agressivity and metabolism, but at the same time depletes (consumes) some hormone or protein commonly found in blood.
That way, you get strong and fast people with a craving for bllod.

Theyy don't really need light to cause them physical harm. They can just be highly sensitive to strong light, which is an existing conditions, and to other stimuli, like the smell of garlic.
If you really want light to cause them harm, you could have the parasit screw up with pigmentation or repair mechanisms of the skin, making them extremely prone to sunburns.

Or even make it excrete a substance which has a photochemical reaction when exposed to UV which turns it poisonous. Any skin exposed to too much UV would become severely damaged and in the end could kill the vampire.