Xenomorph evolutionary pressures

[Ender]

What could cause the xenomorphs to evolve acidic blood? Bio is NOT my forte, so I'm at a loss, but could it be a result of different base chemicals instead of the usual carbon based organism? e.g. blood is chemical X that recombines with O2 to be acidic but isn't inside the creature.

Thoughts?

[Aaron]

Weren't they engineered by the Predators or is that fanon?

[Junghalli]

Defense against predators. It has a chemical in the blood that reacts with oxygen to make a nasty acid. The chemical is harmless inside the creature as it's in the blood plasma which is kept deoxygenated, but if the blood is exposed to air it reacts. Anything that tries to eat it gets its jaw melted.

[Hawkwings]

kind of a sucky defense if it involves you bleeding before the predator is told off.

[Stark]

kind of a sucky defense if it involves you bleeding before the predator is told off.

It's not like the AvP crossover thing is a bastion of common sense, is it?

[Darth Ruinus]

Weren't they engineered by the Predators or is that fanon?

Actually, werent they made by the Space Jockeys?

[Junghalli]

kind of a sucky defense if it involves you bleeding before the predator is told off.

Doesn't a bee die after it stings someone? It could be an "altruistic" defense mechanism for the hive, or a deterrent (predators realize they're inedible and don't attack them).

[PREDATOR490]

I seem to recall Aliens 2 stating the Acid blood had some sort of effect on people like a sedative. I got the impression this was what happened to the guy in Alien 4 when he got blasted in the face since he looked like he was going limp...

At the very least I am curious to know if Xenos have the ability to sedate their victims for transport because the Drones obviously need to bring back some for the facehuggers which is going to be a real chore if your trying to bring back a fully grown adult.
At the very least, the Xeno in Aliens 2 somehow managed to move Newt out of an area filled with water in seconds and silence her while she was screaming in terror. Since Newt wasnt dead, impaled or drowned the Xeno managed to shut her up and unless you want to forward the idea the Xeno mentally controlled her or knocked her out then some sort of medium must have been used. The most sensible would be a venom and since no venom has ever been mentioned or witnessed then their blood or a biological process based off of it seems the most logical assumption.

That said, the exact nature of the Xenos has been left completely fucked up well beyond the AVP movies which for all their faults at least have a semi-sensible reason for the Xenomorphs to exist as they do.
The Predators made them for sport and the nature of the Xenomorphs biology is made to facilitate the hunt. In which case, acidic blood forces the hunters to be cautious in taking a Xenomorph on in close combat and a paralysing agent in the blood will make their mask even more important.

Beyond that, I dont see any reasonable explanation for the Xenomorphs to exist at all in nature or as an artifical creation designed for any purpose other than a Predator hunt. They are not sensible weapons in any conventional sense and their general attitude makes me highly skeptical they could ever be deployed as some sort of guard-dog or controlled beast of burden.

[Stark]

If you think the AvP rationale is better than 'who knows', you're crazy. I'd rather speculate than have some fanfiction comicbook shit.

The whole idea of using them as a weapon was always stupid; even W-Y only wanted specimens to study for military applications, not the retarded comicbook 'train them' or 'use implants to control them' shit. Superblood and ultragestation and mass-from-nowhere growth rates sound like profitable tech to me.

[Darth Raptor]

Given sufficiently advanced technology, the whole species could have been engineered by a single mad scientist for the lulz. Just because they're artificial doesn't mean they need a purpose.

[Stark]

Given sufficiently advanced technology, the whole species could have been engineered by a single mad scientist for the lulz. Just because they're artificial doesn't mean they need a purpose.

Ender was asking about evolution specifically, though. I believe somewhere there was some discussion about different biological bases and how practical a biology built around acid is, but I can't remember where.

[Junghalli]

I actually kind of lean toward the theory that they were created by (or for, at any rate) the Predators to be hunted for sport, because honestly a gladiatoral combatant of some sort is the only thing a xenomorph would make sense as.

[Darth Ruinus]

I seem to recall Aliens 2 stating the Acid blood had some sort of effect on people like a sedative. I got the impression this was what happened to the guy in Alien 4 when he got blasted in the face since he looked like he was going limp...

Or you know, he was going limp because he got acid blasted in his face.

unless you want to forward the idea the Xeno mentally controlled her or knocked her out then some sort of medium must have been used.

Why is the xeno simply knocking out Newt not a reasonable idea? Or hell, maybe it dragged her into the WATER and she simply shut up because otherwise, she would have drowned.

The most sensible would be a venom and since no venom has ever been mentioned or witnessed then their blood or a biological process based off of it seems the most logical assumption.

Or it simply knocked her out with a swift hit. The venom thing you are suggesting sounds pretty contrived, especially since easier solutions are availabe.

a paralysing agent in the blood will make their mask even more important.

Or the fact that the blood is acid and will eat through their skin and armor is what makes them be more cautious.

[Galvatron]

What could cause the xenomorphs to evolve acidic blood? Bio is NOT my forte, so I'm at a loss, but could it be a result of different base chemicals instead of the usual carbon based organism? e.g. blood is chemical X that recombines with O2 to be acidic but isn't inside the creature.

Thoughts?

http://anchorpointessays.com/blood.html

[Venator]

kind of a sucky defense if it involves you bleeding before the predator is told off.

There's a whole host of creatures on Earth who's defense centers around "I taste bad" - poison dart frogs are among the more deadly examples.

Of course, Aliens have none of the associated bright-coloured "warning" skin tones, but perhaps that trait became undesirable when the Xenomorphs evolved to become predatory themselves, while the acidic blood stayed.

Or they're just a bizarre and unrealistic species, as above posters have mentioned.

[Junghalli]

Or maybe they have bright-colored warning tones, but just not in a wavelength humans can see. Maybe most of the things that prey on them in their natural environment see in UV or IR so their striking colorations are in those wavelengths.

[Admiral Drason]

Or maybe they have bright-colored warning tones, but just not in a wavelength humans can see. Maybe most of the things that prey on them in their natural environment see in UV or IR so their striking colorations are in those wavelengths.

I thought that the Xenomorphs don't show up on IR as the Marines wern't picking them up in Aliens.

[Dooey Jo]

http://anchorpointessays.com/blood.html

So... Aliens are made of Teflon?

[Broomstick]

kind of a sucky defense if it involves you bleeding before the predator is told off.

There's a whole host of creatures on Earth who's defense centers around "I taste bad" - poison dart frogs are among the more deadly examples.

Poison dart frogs don't need to be eaten, though - a predator simply grasping one in the mouth could absorb enough poison to be fatal, allowing frog to hop away.

Puffer fish are very toxic - but only when eaten. As are monarch butterflies. Gee, that's an amphibian, a fish, and an insect that have all evolved that same "I have to get hurt/killed before this works" defense mechanism. It may suck for the individual, but clearly it can benefit a species.

[Vendetta]

Weren't they engineered by the Predators or is that fanon?

Actually, werent they made by the Space Jockeys?

50/50 fanon/Word of God is that they were a terror weapon designed by the Space Jockeys. Ridley Scott seemed to think so. (Their "weapon" value seems mostly to have been squick factor, they're not designed to be effective as a weapon, just as unpleasant as possible)

kind of a sucky defense if it involves you bleeding before the predator is told off.

As with other poisonous or otherwise icky tasting creatures, it's bad for one individual, but other copies of the gene for the poison secretion or acid blood or whatever are advantaged by predators becoming averse to eating the poisonous critter.

[Aaron]

I thought that the Xenomorphs don't show up on IR as the Marines wern't picking them up in Aliens.

It was very hot in the processor (several Marines commented on it) so the heat was likely masking the Xeno's. The surviving marines had lost all their IR kit, so there's no way they would have seen them other than with the MKI eyeball afterwards.

[Xon]

Or maybe they have bright-colored warning tones, but just not in a wavelength humans can see. Maybe most of the things that prey on them in their natural environment see in UV or IR so their striking colorations are in those wavelengths.

I thought that the Xenomorphs don't show up on IR as the Marines wern't picking them up in Aliens.

Aliens don't show up on IR in a fucking hot area, and area so hot the marines actually commented on it as a limiting factor for how long they could be there.

[Rye]

Beyond that, I dont see any reasonable explanation for the Xenomorphs to exist at all in nature or as an artifical creation designed for any purpose other than a Predator hunt. They are not sensible weapons in any conventional sense and their general attitude makes me highly skeptical they could ever be deployed as some sort of guard-dog or controlled beast of burden.

You wouldn't have to be a sensible weapon in a conventional sense in order to be useful. Dirty bombs aren't very useful conventional weapons, but they're good terror weapons.

Weyland Yutani supposedly initially wanted them for urban pacification and then Burke seemed to think their biology had some useful secrets. For all we know, the jockeys created them as living libraries that retain information genetically (Alien Resurrection flat out states that they have genetic memory, in fact).

As fpr a reasonable explanation for their existence from a natural origin; perhaps they fit perfectly well into their hypothetical home ecosystem? Perhaps acid blood is a common trait or they were the only ones to evolve it. If you'd given them an ecosystem like Earth at any point up to the last couple of thousand years, they'd easily be the top predators.

[FOG3]

At the very least, the Xeno in Aliens 2 somehow managed to move Newt out of an area filled with water in seconds and silence her while she was screaming in terror. Since Newt wasnt dead, impaled or drowned the Xeno managed to shut her up and unless you want to forward the idea the Xeno mentally controlled her or knocked her out then some sort of medium must have been used. The most sensible would be a venom and since no venom has ever been mentioned or witnessed then their blood or a biological process based off of it seems the most logical assumption.

The novelization of Aliens has it as a venom based in the tail that incapacitates people after they sting you. The company guy got taken out that way, but then nobody was about to save him.

[Zixinus]

For all we know, the jockeys created them as living libraries that retain information genetically (Alien Resurrection flat out states that they have genetic memory, in fact).

Alien one: Now, those are my hypothesis on the thesis of why the northern nations were able to gain more advantage over their neighbours. The key is opportunity and the given assets that encourage sea transport.

Alien two: Fascinating, my dear fellow. But tell me, have you considered the economic ramification that this hypothesis would entail to the sourthern continent? Oh, do you hear that? I believe that may be prey approaching. I am afraid we must savour this discussion for a later date.

Alien one: You certainly bring up a good point my friend. I hope we can continue this discussion later.

*a nervous woman walks in wearing a lab coat, zooming around a pistol with a flashlight attached to it and muttering to herself*

Scientist: "Oh god, oh god, oh god, oh god, please don't be here, please don't be here, please don't be here. Oh god, oh god, oh god, oh god, what am I gonna do, what am I gonna do?"

Alien one creeps up behind her.

The woman wears the discreet thumb as Alien One stands up.

She dodges to the side shooting wildly, as Alien One soaks up several shots. Alien Two lungs at the Scientist and rips her head open with its secondary jaw.

Alien One looks over his wounds, bleeding painful acid on himself and then to Alien Two.

Alien One: "A pity. I wanted to tell you about my theory regarding the migration patterns of the nomadic tribes. Oh well, I suppose, take and give. Good appetite."

Alien One's drops trough the floor and dies from bleeding.

Alien Two: "And we hardly knew thee."

Alien Two begins chewing on the Scientist's brains.