if not Creation... Creation, not

puZZle

This is NOT a post about
religion vs religion
nor
creationist vs evolutionist
and not exactly
theist vs atheist either

I've always wondered about evolutionist(macro) believing that all species on earth are evolved from a single cell organism,
and that's how we've come into being.
Leaving this argument aside for now

How did the first single cell organism come into being?

I am just interested in what the macroevolutionist in lyk think about this issue
Evolution might be an explanation of the diversity and complexity of life as it is now
(i.e. the origin(s) or species)
but it does not seem to explain the First Cause
(i.e. the origin of life)

I don't mean to stir up religious/anti religious wars here
please refrain from using or attacking religious terms if possible

mcjohnjohn

小學既時候睇<<十萬個為什麼>>, 好似話好耐好耐之前, 地球既環境係好惡劣, 到處都有雷暴.
d 雷暴就令到空氣中既nitrogen, oxygen, carbon dioxide 同hydrogen 產生化學作用, 而形成不同既amino acid.
地球當年就係有一個amino acid 既海洋.

唔知係唔係又因為d 雷暴, d amino acid 慢慢就融合成一d 結構好簡單既結構 - 粒線體. 跟住仲有好多, 不過已經唔係好記得了.

notgoddy

I remember a Star Trek episode saying that single life began when some chemicals were mixed together. like amino acid mix with protein. http://wiesium.wrzuta.pl/film/9KBoXo4aGr/

Wiki
http://en.wikipedia.org/wiki/Origin_of_life

I think this is plausible because simple condition can give rise to complex systems.  Like Chess or Go, there is many moves you can make with those simple rules, but some moves are better than other and those moves usually prevails.
Now if certain chemical reactions are favorable than those reactions will thrive, and those reaction that are better will continue to react. Like those equilibrium reaction seems to be alive as they try so hard to stay at equilibrium.

Evolution proponents will say that the processes of life is not random, and this is true, but the beginning of life is certainly by chance. If those chemicals did not come together and react I would not get to pretend to be smart ass right now.

puZZle

But the problem is
The first single cell organism (that is, if that's how we came into being) must have complex and functioning genetic material, which can "self-reproduce"
This would require billions of atoms, somehow, by chance,  getting together forming this long strand of genetic material (is that RNA in simple organisms like this? correct me if i am wrong)
This strand would have to give instruction to how the organism would
function (e.g. to produce and release certain chemicals)
be formed (the cellular level structures)
and reproduce (telling it how to copy the genetic material correctly and splitting the cell at least)

if i am not wrong, unzipping RNA/DNA would require a special enzyme to do the work

can this complexity (irreducible complexity) be formed JUST by chance?

that is the question

notgoddy

The wiki article said something about that it was random bits of RNA first so it didn't need billions of atom to come together.

http://en.wikipedia.org/wiki/RNA_world_hypothesis
whooo this article have pictures showing what the "Letters" is in chemical structure.

puZZle

notgoddy can you please point out where exactly in the article gives the exact notion you've given?

also, in the same article gives a cruicial point:

Difficulties

Since there are no known chemical pathways for the abiogenic synthesis of nucleotides from pyrimidine nucleobases cytosine and uracil under prebiotic conditions, it may be the case that nucleic acids did not contain the nucleobases seen in life's nucleic acids.[14]
Tellingly, the nucleoside cytosine has a half-life in isolation of 19 days at 100°C and 17,000 years in freezing water, which is still very short on the geologic time scale.[15]
Others have questioned whether ribose and other backbone sugars could be stable enough to be found in the original genetic material.[16]
For example, the ester linkage of ribose and phosphoric acid in RNA is known to be prone to hydrolysis.[17] Additionally, ribose must all be the same enantiomer, because any nucleotides of the wrong chirality act as chain terminators.[18]

For random molecules to join together (like they have a mind of their own) and forming complex genetic material which is also the Foundation of all future life's DNA/RNA (being meaningful and replicable)
isn't that a little stretched?

A cell coming from nothing also contradicts part of the cell theory: all cells from come from pre-existing cell(s)
(Both the classic and the modern)

notgoddy

http://en.wikipedia.org/wiki/Ori ... dels:_the_RNA_world

The first article said that "relatively short RNA molecules could have spontaneously formed that were capable of catalyzing their own continuing replication. It is difficult to gauge the probability of this formation." And the second article I linked is an hypothesis about how the formation might had come about.

I don't think random molecules needs a mind to joins together, it is all like chances of collision. Apparently scientist aren't sure about the origin of life as you know, but it looks like they have a lot of theories and a few experiments that supports them. That said, I don't think there is a full-filling answer for you puZZle, yet.

http://en.wikipedia.org/wiki/Cell_theory
Exceptions to the Theory

   1. Viruses are considered by some to be alive, yet they are not made up of cells.
   2. The first cell did not originate from a pre-existing cell. See: Origin of life.


lol quoting wiki is fun! I think I'll edit it so I am "right" lol

[ 本帖最後由 notgoddy 於 2008-8-18 21:16 編輯 ]

Blue

ahh.. no one will hv a perfect answer anywayz.

but considering "life" didnt show up until not too long ago comparing to how long earth existed. the chance of the elements colliding together n forming the first AA isnt too surprising. i guess.

scientist tested that long time ago the atmosphere is capable of producing AA and it is very likely to form AA under that circumstances anywayz. then AA covered by the clay bubble and RNA existed long b4 that too and if an RNA happens to join the little bubble isnt too crazy either.. but given that the atmosphere produced a lot of AA n only some or maybe just one outta so many of them had that combination is very likely. its like someone winning 649. chances r slim but it happens..

but the first RNA isnt as specialized tho. it only has the self replicating function and the rest of the evolution still had a long way to go.

notgoddy

May be we are thinking too small as well, because this possible life giving reaction could had taken place all over the Earth, so we are not talking about just one single pool of chemical. If the chance are like the 649, 1 in 14 millions, than it would be quite likely to be a common occurrence because of the condition at the time exists all over and there are trillions and trillions of atoms on the surface of the Earth. (Earth was just cooling down and water finally gets to be liquid at this point in time, so the theory goes.)

puZZle

it is true that chance might be a factor here
but we have to also note that chemical bonds are easily broken by elements such as oxygen
for billions of atoms to join together without breaking apart (and meanwhile carrying meaningful and super complex instructions for the organism) requires an environment with no oxygen, and the like