Vital Dust: Life as a Cosmic Imperative

By Christian De Duve | Go to book overview

Chapter 6
The Code

WE HAVE REACHED a point in our hypothetical reconstruction of the age of information where the first peptides began to be assembled by an RNA machinery. We know what came next: translation and the genetic code. Two questions challenge the historian. First, by what succession of steps did translation and the genetic code arise? Second, what was the driving force that propelled such an extraordinary development? The two questions are intimately related, since no pathway can be considered that does not entail an explanation of its spontaneous emergence. Before we try to answer these questions, a new element needs to be introduced, namely, the concept of a primeval cell.


DARWIN NEEDS CELLS

The cell is the unit of life and figures at some stage in all attempted reconstructions of the origin of life. Some scenarios bring in cells early or, even, right at the start. Others begin with an unstructured soup and introduce cellularization later, sometimes postponing it to the last moment before it became indispensable for further progress. For reasons that will be explained in chapter 9, I have adopted the latter course. But a limit has been reached.

With the initiation of RNA-dependent peptide synthesis, if not before, emerging life had virtually exhausted the potential of molecular evolution. For further evolution to take place, less selfish criteria for selection--or, better said, less crudely selfish criteria--had to come into play. RNA molecules no longer had to be assessed solely on the strength of their intrinsic ability to survive and be replicated, but on the basis of their ability to do something that favored their survival and replication indirectly. But for this kind of selection to operate, the biogenic system needed to be parceled out into a number of discrete, semiautonomous, self-reproducing units--let us call them protocells--each containing its individual genome. Then, any useful

-65-

Notes for this page

Add a new note
If you are trying to select text to create highlights or citations, remember that you must now click or tap on the first word, and then click or tap on the last word.
One moment ...
Default project is now your active project.
Project items

Items saved from this book

This book has been saved
Highlights (0)
Some of your highlights are legacy items.

Highlights saved before July 30, 2012 will not be displayed on their respective source pages.

You can easily re-create the highlights by opening the book page or article, selecting the text, and clicking “Highlight.”

Citations (0)
Some of your citations are legacy items.

Any citation created before July 30, 2012 will labeled as a “Cited page.” New citations will be saved as cited passages, pages or articles.

We also added the ability to view new citations from your projects or the book or article where you created them.

Notes (0)
Bookmarks (0)

You have no saved items from this book

Project items include:
  • Saved book/article
  • Highlights
  • Quotes/citations
  • Notes
  • Bookmarks
Notes
Cite this page

Cited page

Style
Citations are available only to our active members.
Sign up now to cite pages or passages in MLA, APA and Chicago citation styles.

(Einhorn, 1992, p. 25)

(Einhorn 25)

1

1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

Cited page

Bookmark this page
Vital Dust: Life as a Cosmic Imperative
Table of contents

Table of contents

Settings

Settings

Typeface
Text size Smaller Larger Reset View mode
Search within

Search within this book

Look up

Look up a word

  • Dictionary
  • Thesaurus
Please submit a word or phrase above.
Print this page

Print this page

Why can't I print more than one page at a time?

Full screen
/ 362

matching results for page

Cited passage

Style
Citations are available only to our active members.
Sign up now to cite pages or passages in MLA, APA and Chicago citation styles.

"Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn, 1992, p. 25).

"Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn 25)

"Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences."1

1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

Cited passage

Welcome to the new Questia Reader

The Questia Reader has been updated to provide you with an even better online reading experience.  It is now 100% Responsive, which means you can read our books and articles on any sized device you wish.  All of your favorite tools like notes, highlights, and citations are still here, but the way you select text has been updated to be easier to use, especially on touchscreen devices.  Here's how:

1. Click or tap the first word you want to select.
2. Click or tap the last word you want to select.

OK, got it!

Thanks for trying Questia!

Please continue trying out our research tools, but please note, full functionality is available only to our active members.

Your work will be lost once you leave this Web page.

For full access in an ad-free environment, sign up now for a FREE, 1-day trial.

Already a member? Log in now.