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The Milky Way
2011-Sep-27, 05:11 PM
Inspired by Elisabeth25īs questions bout humans, and general curiousity bout life on earth as we know it.

Have wondered about if all biologic life started out of the same "sparkle". By asking that i think of if plants is out the the same life as animals? If not, life must have started in 2 separate ways?
Do plants have a genome?

RNA/DNA - is there any theories how that was created? if life came in a "sparkle" and everything before was pure dead, how lucky is it that, that life creates something so advanced as RNA/DNA? or did the genome first appear later? or is genome equals life?

Hope someone can explain :)

Swift
2011-Sep-27, 05:49 PM
I don't know what you mean by a "sparkle". But plants do have genomes and the genomes of many plants have been sequenced. Both plants and animals on Earth evolved from the same "precursor" lifeforms.

There is considerable debate about how the genetic code developed with life. Did proteins (which form the structure of much of life and catalyze reactions) develop first, or did RNA serve both as the code and the catalyst? Read RNA World Hyothesis - wikipedia (http://en.wikipedia.org/wiki/RNA_world_hypothesis) for a start.

The Milky Way
2011-Sep-27, 05:55 PM
Thanx for the link :)

By "sparkle" i ment the moment where life became actual life.

Swift
2011-Sep-27, 07:55 PM
Thanx for the link :)

By "sparkle" i ment the moment where life became actual life.
At the moment when life became life, life was an extremely primitive one celled organism, and was neither plant nor animal (closer to bacteria).

There may also have not been a single, well-defined moment. Some hypotheses suggest that the first primitive "cells" might not have had all the functionality of what we think of as life. So there may have been a gradual increase in functionality over time - when it became "life" is probably subject to interpretation.

Cougar
2011-Sep-28, 09:21 PM
...if plants is out the the same life as animals? If not, life must have started in 2 separate ways?
Do plants have a genome?

According to this paper by researchers at UCSD (pdf) (http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.147.5075&rep=rep1&type=pdf), plants, animals, and fungi last shared a common ancestor about a billion years ago.

You should also know that single-celled life-forms persisted alone in the biosphere for perhaps 3 billion years. It took that long to happen upon multicellularism.

You should also know that in the Permian extinction, 245 million years ago, 96 percent of all species disappeared.


if life came in a "sparkle" and everything before was pure dead, how lucky is it that, that life creates something so advanced as RNA/DNA?

These proteins didn't spring forth fully formed! But early life was not a totally lucky fluke, either. You should know that order is not all accidental. Laws of complexity spontaneously generate much of the order of the natural world. It is only then that natural selection comes into play, further molding and refining. The long but satisfying answer: read Stuart Kauffman, At Home In The Universe.

Cougar
2011-Sep-28, 09:24 PM
Laws of complexity spontaneously generate much of the order of the natural world.

See Per Bak's How Nature Works.

Paul Wally
2011-Sep-28, 10:19 PM
Thanx for the link :)

By "sparkle" i ment the moment where life became actual life.

I think it depends on how exactly you want to define "life", and whatever happened at some time according to your definition, that is what you will understand as the moment life began according to your definition. "Life" is a word, a label that we impose on nature. From the point of view of nature there's no magic moment, only a gradual process of increasingly complex forms of organization.

pzkpfw
2011-Sep-29, 07:48 PM
The posts by KhashayarShatti have been moved here: http://www.bautforum.com/showthread.php/121667-KhashayarShatti-on-quot-The-Living-Matrix-quot