Featured Research

from universities, journals, and other organizations

Life On Earth May Have Originated As The Organic Filling In A Multilayer Sandwich Of Mica Sheets

Date:
December 5, 2007
Source:
University of California - Santa Barbara
Summary:
Life may have begun in the protected spaces inside of layers of the mineral mica, in ancient oceans, according to a new theory. The narrow, confined spaces between nonliving mica layers could have provided exactly the right conditions for the rise of the first biomolecules.

Mica has thin layers separated by narrow spaces. The mica hypothesis proposes that the narrow confined spaces between the thin layers of mica could have provided exactly the right conditions for the rise of the first biomolecules ---- effectively creating cells without membranes. The separation of the layers would have also provided the isolation needed for Darwinian evolution.
Credit: Michele Hogan

Life may have begun in the protected spaces inside of layers of the mineral mica, in ancient oceans, according to a new hypothesis.

The hypothesis was developed by Helen Hansma, a research scientist with the University of California, Santa Barbara and a program director at the National Science Foundation.

The Hansma mica hypothesis proposes that the narrow confined spaces between the thin layers of mica could have provided exactly the right conditions for the rise of the first biomolecules ---- effectively creating cells without membranes. The separation of the layers would have also provided the isolation needed for Darwinian evolution.

"Some think that the first biomolecules were simple proteins, some think they were RNA, or ribonucleic acid," said Hansma. "Both proteins and RNA could have formed in between the mica sheets."

RNA plays an important part in translating the genetic code, and is composed of nitrogenous bases, sugar, and phosphates. RNA and many proteins and lipids in our cells have negative charges like mica. RNA's phosphate groups are spaced one half nanometer apart, just like the negative charges on mica.

Mica layers are held together by potassium. The concentration of potassium inside the mica is very similar to the concentration of potassium in our cells. And the seawater that bathed the mica is rich in sodium, just like our blood.

The heating and cooling of the day to night cycle would have caused the mica sheets to move up and down, and waves would have provided a mechanical energy source as well, according to the new model. Both forms of movement would have caused the forming and breaking of chemical bonds necessary for the earliest biochemistry.

Thus the mica layers could have provided the support, shelter, and an energy source for the development of precellular life, while leaving artifacts in the structure of living things today.

Besides providing a more plausible hypothesis than the prebiotic oceanic "soup" model, Hansma said her new hypothesis also explains more than the so-called "pizza" hypothesis. That model proposes that biomolecules originated on the surfaces of minerals from the Earth's crust. The "pizza" hypothesis cannot explain how the earliest biomolecules obtained the right amount of water to form stable biopolymers.

A biophysicist, Hansma has worked with mica for decades beginning with her work in biological Atomic Force Microscopy (AFM) in the late 1980s. "We put our samples on mica, because it is so atomically flat, so flat that we can see even bare DNA molecules as little ridges on the mica surface," said Hansma. "The layered mineral is made of sheets so thin (one nanometer) that there are a million of them in a millimeter-thick sheet of mica."

Hansma came upon her idea one day last spring when she was splitting some mica under her dissecting microscope. She had collected the specimens in a mica mine in Connecticut. The mica was covered with organic material. "As I was looking at the organic crud on the mica, it occurred to me that this would be a good place for life to originate ---- between these sheets that can move up and down in response to water currents which would have provided the mechanical energy for making and breaking bonds," said Hansma.

She summed up her hypothesis of the origin of life by saying, "I picture all the molecules of early life evolving and rearranging among mica sheets in a communal fashion for eons before budding off with cell membranes and spreading out to populate the world."

Hansma presented her findings on Dec. 4, at the annual meeting of the American Society for Cell Biology in Washington, D.C.


Story Source:

The above story is based on materials provided by University of California - Santa Barbara. Note: Materials may be edited for content and length.


Cite This Page:

University of California - Santa Barbara. "Life On Earth May Have Originated As The Organic Filling In A Multilayer Sandwich Of Mica Sheets." ScienceDaily. ScienceDaily, 5 December 2007. <www.sciencedaily.com/releases/2007/12/071204102500.htm>.
University of California - Santa Barbara. (2007, December 5). Life On Earth May Have Originated As The Organic Filling In A Multilayer Sandwich Of Mica Sheets. ScienceDaily. Retrieved July 28, 2014 from www.sciencedaily.com/releases/2007/12/071204102500.htm
University of California - Santa Barbara. "Life On Earth May Have Originated As The Organic Filling In A Multilayer Sandwich Of Mica Sheets." ScienceDaily. www.sciencedaily.com/releases/2007/12/071204102500.htm (accessed July 28, 2014).

Share This




More Fossils & Ruins News

Monday, July 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Asteroid's Timing Was 'Colossal Bad Luck' For The Dinosaurs

Asteroid's Timing Was 'Colossal Bad Luck' For The Dinosaurs

Newsy (July 28, 2014) The asteroid that killed the dinosaurs struck at the worst time for them. A new study says that if it hit earlier or later, they might've survived. Video provided by Newsy
Powered by NewsLook.com
Did ISIS Destroy Jonah's Tomb?

Did ISIS Destroy Jonah's Tomb?

Newsy (July 25, 2014) Unverified footage posted to YouTube purportedly shows ISIS militants destroying a shrine widely believed to be the tomb of the prophet Jonah. Video provided by Newsy
Powered by NewsLook.com
Europe's Highest Train Turns 80 in French Pyrenees

Europe's Highest Train Turns 80 in French Pyrenees

AFP (July 25, 2014) Europe's highest train, the little train of Artouste in the French Pyrenees, celebrates its 80th birthday. Duration: 01:05 Video provided by AFP
Powered by NewsLook.com
Richard III's Car Park Burial Site Opens to Public

Richard III's Car Park Burial Site Opens to Public

AFP (July 25, 2014) Visitors will be able to look down from a glass walkway on the grave of King Richard III when a new centre opens in the English cathedral city of Leicester, where the infamous hunchback was found under a car park in 2012. Duration: 00:35 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins