Alternate life basis - Specifically Boron based.

**Ascarona** · September 03, 2012, 12:26 PM

I don't really know how I came up with this question, it just suddenly hit me during Chemistry class today. Of the roughly 150 atom kinds we know of, why do we always think of Carbon based life when we think of life in general? Is it possible for life to be based on different kinds of atoms?

I had to think back at some article that I read a few years ago that discussed the subject, but took Sulphur as it's basis. There were even some pictures displaying a Venus-like planet covered in Trilobite looking lifeforms with sulphuric crystals protruding from the back. I must have spent half the lesson thinking about the possibilities.

(After some digging I finally found the picture

Then I thought back to the more recent example of the famous Arsenic case back in 2010 that had the whole scientific world in shock but turned out to be nothing more than a bad case of unclean research. Now I know it's not exactly the same thing, since the study still focused on Carbon based bacteria but tried to replace another crucial atom called Phosphor with Arsenic in the DNA of the organism.

But what would true non Carbon based life look like exactly? Take Boron for example, it doesn't have as much possible Covalence bonds as Carbon (the former having 3, the latter 4), and theres a bunch of other scientific differences as well. Has anyone ever even attempted to create normal organic molecules with Boron before? And if we would be able to create a simple Boron based life form (a small kind of bacteria for example), what would it's effects be on another organism? The trace amounts of Boron in our bodies or other animals' bodies wouldn't possibly be enough for it to feed on, so I guess it wouldn't be able to reproduce and would go extinct rather fast. (Also, I have no idea why I'm so focused on Boron really

, I just haven't really seen a use for it like the other atoms in that area of the periodic table.)

Note, I am talking about organic life. I know that silicon based life is possible through robotics, but that's not really what I am looking for here.

EDIT:

I only just realised that Boron is a metalloid so the circumstances wouldn't be the same, but the questions still sort of apply.

**Lord Baal** · September 03, 2012, 12:53 PM

Here is a extensive wikipedia page where you can read some hypothesis about alternative biochemistries. In the case of boron's chemistry is possibly even more variable than that of carbon, since it has the ability to form polyhedral clusters and three-center two-electron bonds. Boranes are dangerously explosive in Earth's atmosphere, but would be more stable in a reducing environment. However, boron's low cosmic abundance makes it less likely as a base for life than carbon.

**Ascarona** · September 03, 2012, 02:51 PM

Yeah I casually read the wiki page a bit on it but it still didn't give me a good idea of what other lifeforms would look like. And I came here to discuss it tbh.

What does this part mean btw:
but would be more stable in a reducing environment.?

**Vizsla** · September 04, 2012, 08:17 AM

Originally Posted by Ascarona

What does this part mean btw:
but would be more stable in a reducing environment.?

An environment without oxygen in the atmosphere.
http://en.wikipedia.org/wiki/Great_Oxygenation_Event

**Dr. Oza** · September 04, 2012, 01:16 AM

As with many things in science, we simply won't know until we find proof. Modern bio-chemistry largely presents models that explain the research, so there is always room for future discovery. As a building block of energy and tissue, Carbon's unique property is its ability to bond 4 times. Theoretically, other elements in the same group on the periodic table, such as silicon should be able to. On Earth, one must take into account the effects of gravity and weight, Silicon, for example, is double the atomic mass of Carbon, perhaps this is why evolution has not deemed it an efficient mode of life. Furthermore, the composition of biotissue must also be permeable, adaptable, make strong bonds (but not too strong!) and be able to be acted upon by a number of other elements. Versatility is the key.

There was much excitement in the possibility of arsenic-based DNA but I believe that turned out to be false. Extraterrestrial life could, however, utilize elements that show versatile properties.

Carl Sagan often spoke of how all scientists on Earth have a terra-bias. We have been molded by chemistry, physics and biology as experienced on earth. On other planets with radically different radiation or magnetic levels, things could very well be much different.

Essentially, anything that forms covalent bonds readily can take the place of Carbon.

**Ascarona** · September 04, 2012, 07:45 AM

Well that's a bummer... I sometimes look up at the stars at night wondering what other life would look like and whether they would have any effect on us humans, and thinking that scientists would know. And now I hear that even they don't know it.

Thanks anyway Doc.

**Lord Baal** · September 04, 2012, 08:20 AM

Reducing means that an element gave a electron to the other atom, it has to do with oxidation. In organic chemistry is to give another hydrogen atom to a molecule. At least that's what I remember from chemistry class.

**Nutsack** · September 06, 2012, 08:05 AM

I've heard that carbon can create more molecules than all other atoms combined, that might have something to do with it. Also, carbon is very abundant. I think carbon is simply the best building block for life, very available and great atom to form molecules with. That doesn't exclude the possibility of anything else of course but if I was an astronaut I would expect to see most life be carbon based.