Not sure what to make of this

[Andrew]

I watched " How to grow a planet " last night, fascinating stuff about grasses and tree's. Even from grasses and tree,s new life forms were brought into existence.

 

Has anyone heard of Stephen Hawkings conclusion about the big bang ? I'm sure someone has,

[Renrag39]

That's pretty much the way I see it. If we ever found any kind of extra-terrestrial life, and no I'm not talking ET, something like our Archaea living in some hot spring on one of Jupiter's or Saturn's moons will do fine for meme. If we ever find something like that and it turns out to be based on the same DNA as we have here on Earth, now that might just throw a big really cat amongst some very small pigeons.

And the Panspermia theory will begin to gain a foothold while also challenging and redefining the liklihood of life spontaneously occuring independantly, on other planets.

 

Would be quite a shock but very telling, if we were to find ET, whether sentient or not, shared a great deal of genetic material with us.

[corydoras]

And the Panspermia theory will begin to gain a foothold while also challenging and redefining the liklihood of life spontaneously occuring independantly, on other planets.

 

Would be quite a shock but very telling, if we were to find ET, whether sentient or not, shared a great deal of genetic material with us.

Panspermia never really went away. One problem with it, if it were found to be true would be that it wouldn't really explain anything about the origin of life it would just move the goalposts.

[Steve Walker]

Would be quite a shock but very telling, if we were to find ET, whether sentient or not, shared a great deal of genetic material with us.

 

Pretty conclusively independent if it looks like this, though:

 

 

(The silicon based life form, not Kirk!)

 

I suspect that any independently evolved life would also be carbon based, but would be likely to have sufficiently different biochemistry that (for example) it wouldn't be able to eat us.

[Vagabond]

I suspect that any independently evolved life would also be carbon based.

 

It would be very difficult otherwise. Because silicon appears to be chemically similar to carbon, it is a popular idea that silicon-based life forms are possible.

 

However, such a silicon creature would have great difficulty in its chemical energy exchanges (associated with feeding, respiration, etc) Carbon-based life forms exist because of the relative ease of breaking (and reforming into different compounds) the chemical bonds between carbon, hydrogen and oxygen.

 

By contrast, the chemical bond between silcon and oxygen requires enormous amounts of energy to break, but the silicon-hydrogen bond is notoriously unstable (SiH4 is used in superconductors - a field littered with

unwanted industrial explosions as the stuff self-ignites at the drop of a hat)

[chesters1]

No chesters the egg came first. There were eggs long before there were any birds.

 

don't knock it without a chicken incubating its egg its only a potential chicken ,even if the ambient temperature was just right a chicken will not come from a chicken egg without a chicken looking after it

 

"eggs" something not directly from a chicken (the question is vague to what the egg contains) are older but bird ones still need an incubator of some sort unlike crocks and perhaps some dino's? and fish

Edited February 22, 2012 by chesters1

[Steve Walker]

It would be very difficult otherwise. Because silicon appears to be chemically similar to carbon, it is a popular idea that silicon-based life forms are possible.

 

However, such a silicon creature would have great difficulty in its chemical energy exchanges (associated with feeding, respiration, etc) Carbon-based life forms exist because of the relative ease of breaking (and reforming into different compounds) the chemical bonds between carbon, hydrogen and oxygen.

 

By contrast, the chemical bond between silcon and oxygen requires enormous amounts of energy to break, but the silicon-hydrogen bond is notoriously unstable (SiH4 is used in superconductors - a field littered with

unwanted industrial explosions as the stuff self-ignites at the drop of a hat)

 

Agreed - although there may be other biochemistries possible for life in different environments. A species living in an atmosphere high in fluorine might think carbon based life improbable given that on their planet simple carbon compounds spontaneously combust, and one living with an ambient temperature and pressure at which it is not liquid might not be convinced of the viability of water as a biological solvent

 

I think independently evolved life would be likely to be biochemically analogous, because convergence appears to be a robust feature of evolution, but radically different in detail. Detail could be as close as chirality or as different as being based on different elements, but I would guess at a different set of carbon based macromolecules.

[Ken L]

Chicken and egg:

The question itself is a copout.

There is no chicken, just a series of transitional forms representing various combinations of genes.

You could literally go back through generations of pre-chicken birds, pre-chicken dinosaurs, pre-chicken reptiles, pre-chicken amphibians, all the way to the chicken's fish like ancestor and it's eggs and at no point could you say that the parents and offspring were of a different species.

This stuff isn't controversial unless you happen to live in certain states of the USA.

[Steve Walker]

This stuff isn't controversial unless you happen to live in certain states of the USA.

 

Or, returning to topic, attend certain schools in the UK.

[Renrag39]

Or, returning to topic, attend certain schools in the UK.

Post reported to admin for breach of AN protocol.

 

For further entertaiment, get 2 calculators, type in 8008 and hold over your nipples.