Looking for Aliens in all the Wrong Places - io9 Comments

Looking for Aliens in all the Wrong Places

liash — Sun, 20 Apr 2008 00:47:27 PDT

It's interesting that we have such a difficult time conceiving of life without DNA. We tend to limit our speculation about possibilities to existing molecule types like nucleic acids. Surely in a non-water solvent another category of large, "organic" information-containing molecule could develop!

liash

Looking for Aliens in all the Wrong Places

Qev — Sat, 19 Apr 2008 17:16:05 PDT

@garygibson: Prions don't actually reproduce themselves, however. From what I understand, they're deformed proteins which have the odd property of, when encountering their undeformed counterparts, pass along their deformation.

Qev

Looking for Aliens in all the Wrong Places

Silver_Back — Sat, 19 Apr 2008 16:43:03 PDT

One just has look at our own planet at how life can exist and grow in elements like acids, bases, and neutral substances. I think we're looking for life connected with water because it's the closest thing we know that can support life on a grand scale.

Silver_Back

Looking for Aliens in all the Wrong Places

Gudmundsson — Sat, 19 Apr 2008 16:33:03 PDT

Hey, who doesn't like chemical minutia! It's usually just actual chemistry , which for some reason is considered "not-understandeble" by non-chemist, but I digress.

But anything that has to do with "alien"-biochemistry is instantly very cool. There are groups of biologist hunting for earth-aliens, but I imagine that it's hard work as most of our molecular-biology/biochemistry techniques are based on our kond of chemistry and wont work at all with alien"DNA". Which makes the potential discoveries of such ridiculously interesting and exciting.

But as of how dna equivalent molecules might look like in an formamide or methane world is anybodys guess. Especially since we only have one kind of life to base our guesses on.

So come on and find aliens already!

Gudmundsson

Looking for Aliens in all the Wrong Places

GuidoDavid — Sat, 19 Apr 2008 11:10:31 PDT

"Before these experiments, people wondered why the phosphates were there - whether they were simply a redundant evolutionary artefact, rather like a male nipple. It's now clear that they serve a vital function. The charges keep DNA stiff by organising a cradle of water molecules along its chain; without them, DNA easily wads into a ball - another demonstration of how water is integral to life as we know it."

As far as I remember, Watson and Crick suggested this and you get that explanation about the role of phosphates in basic lessons of Biochemistry.

GuidoDavid

Looking for Aliens in all the Wrong Places

garygibson — Fri, 18 Apr 2008 21:33:52 PDT

The speculations are assuming an alien would actually carry some form of DNA-analogue in its body, of course - 'prions' are the hypothetical transmissible agents that may be responsible for diseases like scrapie. They don't carry any DNA, yet reproduce. The problem is whether or not when we encounter alien life, that we recognise it as 'life'. It might so offend our anthropocentric (earth-centric?) ideas of life we might refuse to recognise it as such.

Anyone interested in this subject really, really needs to read 'What Does A Martian Look Like? The Science of Extraterrestrial Life' by Ian Stewart and Jack Cohen, respectively a mathematician and a reproductive biologist.

garygibson

Looking for Aliens in all the Wrong Places

aspiringexpatriate — Fri, 18 Apr 2008 18:04:02 PDT

@smcallah: Yes, but in order to become more complex organisms, doesn't it make sense that tide pools would help?

aspiringexpatriate

Looking for Aliens in all the Wrong Places

smcallah — Fri, 18 Apr 2008 17:18:49 PDT

@aspiringexpatriate:

But wouldn't the bottom of the ocean generally be stable?

And is stability that important for forming life? Just look to the organisms that live in the hot chemical geysers in the ocean. I would doubt they started life in a tide pool and found their way to a hot chemical bath and survived to evolve.

smcallah

Looking for Aliens in all the Wrong Places

aspiringexpatriate — Fri, 18 Apr 2008 15:52:57 PDT

One thing that a friend of mine pointed out, the key to life isn't simply the right chemicals, but the moon was astoundingly beneficial in that it provided a tide, and tide pools. Little pockets that were both water and land and a tiny, stable environment for some form of life to develop.

Without those, I'm not sure how any environment would be stable enough for long enough for the right type of goo to get together and create life.

aspiringexpatriate

Looking for Aliens in all the Wrong Places

Grey_Area — Fri, 18 Apr 2008 14:53:59 PDT

Okay, mind officially blown.
ThankyouThankyouThankyouThankyou.
I'm gonna study up on this. I like the idea of aliens coming from a wide range of physical and mental possibilities.

Grey_Area