Building Blocks of Life: Paradox of Drake Equation Fl Term

[madman143]

The evidence commonly presented for the formation of life (Fl term of Drake equation)
1.Life formed virtually as soon as possible on Earth (when conditions were suitable)
It implies that life is easy to form when we have the right conditions [Does the Rapid Appearance of Life on Earth
Suggest that Life is Common in the Universe?, Lineweaver and Davis, 2003]


2.But doesn't all life have same building blocks (i.e.DNA) implying that all life has common anscestor.
This implies that life is hard to form otherwise we would see atleast a bit of variety in the building blocks. the reason for which maybe-
Life formed with other building blocks has vanished in the course of the planet. Not yet proven by any fossil records
Or Life is very hard to form and can only be formed by the method for the formation of life on earth(i.e.abiogensis on earth) having DNA.

Isn't this a paradox when we think of the Fl term of the Drake equation. My question might be stupid and an underthought argument(experience i guess). By the way this is for my postgrad research project on SETI...

 

[Chronos]

I would assume life would take the path of least resistance, so life similar to life on Earth should be the most common manifestation in the universe.

 

[FlexGunship]

But doesn't all life have same building blocks (i.e.DNA) implying that all life has common anscestor.
This implies that life is hard to form otherwise we would see atleast a bit of variety in the building blocks.

Good point. However, there is actually some (controversial!) evidence that there were other mutually independent paths of life (http://www.guardian.co.uk/science/2009/feb/15/microbes-earth-tree-of-life) and a lot of interest in this idea.

At the heart of it, you're wondering how common abiogenesis is. All we know is that the probability is not zero.

 

[Theinvoker]

The evidence commonly presented for the formation of life (Fl term of Drake equation)
1.Life formed virtually as soon as possible on Earth (when conditions were suitable)
It implies that life is easy to form when we have the right conditions [Does the Rapid Appearance of Life on Earth
Suggest that Life is Common in the Universe?, Lineweaver and Davis, 2003]


2.But doesn't all life have same building blocks (i.e.DNA) implying that all life has common anscestor.
This implies that life is hard to form otherwise we would see atleast a bit of variety in the building blocks. the reason for which maybe-
Life formed with other building blocks has vanished in the course of the planet. Not yet proven by any fossil records
Or Life is very hard to form and can only be formed by the method for the formation of life on earth(i.e.abiogensis on earth) having DNA.

Isn't this a paradox when we think of the Fl term of the Drake equation. My question might be stupid and an underthought argument(experience i guess). By the way this is for my postgrad research project on SETI...

Life could be easy to form by DNA, but hard by any other method. Therefore it can form quickly by 1, but maintain invariability by 2.

 

[madman143]

At the heart of it, you're wondering how common abiogenesis is. All we know is that the probability is not zero.

there is a theory on multiple genesis. however there is no evidence to the contrary. i have followed up the article and it does not lead to a verifiable source. So absence of evidence is evidence of absence as it is very probable that we do have evidence. the best way to rectify this is to find life on another planet with DNA, solving everything.
As, it also suggests that life can only survive with DNA as building blocks.

 

[Chronos]

Carbon is so promiscuous, it is difficult to rate the prospects of other elemental bases. I give non-carbon based life forms a non-zero probability, but, little more. There may be other paths, however, to photosynthesis - the truly supreme accomplishment of life on earth. Arsenic might be an option, as well as some other elements aside from phosphorous. These would still be carbon based life forms, but, have very different mechanisms for harnessing light energy. This suggests an expanded temperature tolerance for photosynthesis. I view photosynthesis as absolutely essential to evolving anything resembling intelligent life.