Origins of Energy, Matter, Space, Time, and Life (2 of 2)
(Top Posts - Science - 073102)

Life's sweet start
Thursday, December 20, 2001
http://news.bbc.co.uk/2/hi/sci/tech/1719236.stm
Excerpt: Life on Earth may have got off to a sweet start
nourished by sugar from space. The suggestion is based
on the discovery of sugar in two meteorites that are billions
of years old.

... It is known that meteorites contain many carbon-based
compounds - such as amino acids - that could become the
building blocks of primitive life. Analysis of the Murchison
meteorite found over 90 types of amino acids.

... "Sugars are important biologically because they provide
the carbon skeletons for many other molecules." Perhaps
the most famous example here is DNA - sugars provide
part of the backbone for "molecule of life".

The presence of amino acids implies that life on Earth might
have been "seeded" by organic compounds falling on to the
planet. The discovery of sugar molecules in the meteorites
suggests that another essential building block of life may
have come from space as well.

The sugars may have been formed before the Solar System
itself was formed, by the action of starlight on molecules
resting on cold grains of dust drifting in between the stars.
When our Solar System was created, the sugar could have
become incorporated into small bodies, like asteroids, that
formed in the system's cold outer reaches. When the asteroids
broke up, fragments would have fallen to Earth and delivered
their life-forming molecules. ...

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Scientists Find Gene Clue to Human Speech
October 3, 2001
http://news.bbc.co.uk/2/hi/sci/tech/1575471.stm
Excerpt: Scientists have discovered the first gene involved
in the development of speech and language. The discovery
of the gene could provide an understanding of how speech,
a unique human characteristic, developed by comparing the
DNA in humans to the same stretch of DNA in chimpanzees.
The gene, FOXP2, was discovered by studying three gener-
ations of a family affected by a rare language impediment. ...

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Earth story: Plants arrived early
Thursday, August 9, 2001
http://news.bbc.co.uk/2/hi/sci/tech/1482382.stm
Excerpt: Plants colonised land hundreds of millions of years
earlier than the fossil record suggests, according to scientists
in North America. Genetic evidence gleaned from living species
puts the date when land plants first evolved at about 700 million
years ago.

... If their data are correct, green plants would have been grow-
ing on land well before the sudden appearance of many new
species of animals that occurred about 530 million years ago,
an event called the Cambrian Explosion. Barren landscape

The earliest evidence of land plants and fungi appears in the
fossil record around 480 million years ago. Before that, the
Earth's landscape was believed to consist of barren rocks,
home to bacteria and possibly some algae.

But some have argued that it is quite possible for land-dwelling
plants and fungi to have been around much earlier, but their
primitive bodies were too soft to be preserved as fossils in
rock. The Penn State team carried out the largest genetic study
so far of when land plants and fungi first appeared on Earth in
an attempt to resolve this debate.

Team leader Blair Hedges said: "Our research shows that land
plants and fungi evolved much earlier than previously thought
- before the Snowball Earth and Cambrian Explosion events -
suggesting their presence could have had a profound effect on
the climate and the evolution of life on Earth.

"Both the lowering of the Earth's surface temperature and the
evolution of many new types of animals could result from a
decrease in atmospheric carbon dioxide and a rise in oxygen
caused by the presence on land of lichen fungi and plants at
this time, which our research suggests.

"An increase in land plant abundance may have occurred at
the time just before the period known as the Cambrian Explo-
sion, when the next Snowball Earth period failed to occur
because temperatures did not get cold enough," he added.
"The plants conceivably boosted oxygen levels in the atmos-
phere high enough for animals to develop skeletons, grow
larger and diversify."

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Study Offers Insights Into Evolutionary Origins Of Life
Date: Posted 5/18/2001
http://www.sciencedaily.com/releases/2001/05/010518083259.htm
Excerpt: "In some of the strongest evidence yet to support the
RNA world-an era in early evolution when life forms depended
on RNA-scientists at the Whitehead Institute for Biomedical
Research have created an RNA catalyst, or a ribozyme, that
possesses some of the key properties needed to sustain life in
such a world.

... These results, described in the May 18 issue of Science, sug-
gest that RNA could have had the ability to replicate itself and
sustain life in early evolution, before the advent of DNA and
proteins.

The findings will ultimately help evolutionary biologists address
questions about how life began on earth more than three billion
years ago.

... Theories about the origins of life have long intrigued scientists
and lay people alike. "A fundamental question about the origin of
life is what class of molecules gave rise to some of the earliest life
forms?" says Bartel.

... "We will never be able to prove the existence of the RNA
world because we can't go back in time-but we can examine
the basic properties of RNA and see if these are compatible
within the RNA world scenario," says Bartel."

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Hitchhiking Molecules Could Have Survived Fiery Comet
Collisions With Earth, UC Berkeley Experiment Shows
Date: Posted 4/6/2001
http://www.sciencedaily.com/releases/2001/04/010406073728.htm
"Simulating a high-velocity comet collision with Earth,
a team of scientists has shown that organic molecules
hitchhiking aboard a comet could have survived such
an impact and seeded life on this planet. The results
give credence to the theory that the raw materials for
life came from space and were assembled on Earth
into the ancestors of proteins and DNA. ..."

---

Scientists Probing The Origins Of Life Develop Method
of Making Novel Proteins Using a 21st Amino Acid
Date: Posted 4/3/2001
http://www.sciencedaily.com/releases/2001/04/010402073308.htm
"Investigations into the origins of life and the genetic code
have resulted in a method of developing novel proteins that
has enormous potential for the biotechnology industry while
providing some important clues to answering the question:
'How did life begin?' The research provides significant evi-
dence for the existence of the so-called RNA world, believed
to be the evolutionary stage that predates present biological
systems. ..."

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'Conclusive evidence' for Martian life
Monday, February 26, 2001
http://news.bbc.co.uk/2/hi/sci/tech/1190948.stm
Excerpt: Scientists have published what they claim is "conclu-
sive evidence" that bacteria once lived on Mars. The study is
a follow-up to the famous 1996 research that purported to show
ancient bacterial forms in a meteorite from Mars. Critics at the
time said the evidence was too thin to prove anything.

Now, a Nasa-backed team from the US, Spain and Germany has
published further work which it says strengthens the earlier claims.
But some British experts, at least, are still sceptical, arguing the
latest study falls short of absolute proof. ...

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DRAMATIC Discoveries About
What Humans Really Are (021801)
http://prohuman.net/science/what_humans_are.htm
"One comment - This post includes details
on one of the most exciting and dramatic
advances in human understanding of our
true place in the grand scheme of life and
matter ..."

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Are We Alien Life?
January 30, 2001
http://www.sciam.com/article.cfm?articleID=00028F2D-968B-1C5A-B882809EC588ED9F
Excerpt: Act one in the most common story about life's
origins opens in a warm puddle of "primordial soup" some-
where on Earth.

But what if that first scene took place in the cold of deep
space instead?

New findings ... suggest just that. Louis Allamandola and
his colleagues at the NASA Ames Research Center have
created primitive cells of a sort -empty, two-layer mem-
branes- from elementary chemicals, exposed to conditions
like those in interstellar clouds.

"Scientists believe the molecules needed to make a cell's
membrane, and thus for the origin of life, are all over space,"
Allamandola says. "This discovery implies that life could
be everywhere in the universe." ...

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Discovery Implies Life Could Be
Everywhere In the Universe (013001)
http://prohuman.net/science/life_everywhere.htm
"... Scientists have managed to create
'primitive cells' in an experiment which
may indicate that life began in space
and was delivered to Earth. ..."

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Clues to origins of life
Friday, August 25, 2000
http://news.bbc.co.uk/2/hi/sci/tech/894481.stm
Excerpt: Scientists claim to have recreated one of the
vital steps in the origin of life on Earth. Their experi-
ments show that a chemical vital to all living creatures
can be synthesised from organic and metallic com-
pounds. Their experiments show that a chemical vital
to all living creatures can be synthesised from organic
and metallic compounds.

Researchers at the Carnegie Institution in Washington
DC "cooked" iron sulphide at very high temperatures
and pressures. Pyruvic acid was formed - a key chem-
ical which living organisms use to extract energy from
food.

The scientists believe that their experiments create
similar conditions to those in hydrothermal vents, a
type of geyser found on the ocean floor. These under-
water "chimneys" spew out a cocktail of basic chemi-
cals at scorching temperatures and under very high
pressures. Many scientists now believe that the most
important ingredients in the formation of all life on
Earth are found around these vents. ...

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Calculations Show Life's Origins
Possible In Volcanic Gases
Date: Posted 3/28/2000
http://www.sciencedaily.com/releases/2000/03/000328085015.htm
"... calculations show not only that life can arise from the
gaseous crucible of present day terrestrial volcanoes, but
that it was even more likely to develop billions of years
ago on early Earth, Mars and Jupiter's satellite, Europa.

... 'These conditions might have contributed to the produc-
tion of organic compounds required for the emergence of
life,' says Shock, who first rose to prominence in the 'Origins
of Life' debate in 1992 when he performed calculations that
showed life could have first emerged chemosynthetically
-- without sunlight -- at hot water vents on the ocean floor.

... As for the origins of life -- on Earth, at least -- there are
two basic competing views: One suggests that life was
brought here by comet or meteorite impacts or interplane-
tary dust; the other that life was generated here, either at
the ocean floor, through a lightning spark that touched off
an atmosphere that produced organic compounds in watery
environments, or in volcanic gases. All scenarios involve
organic compounds. ..."

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Life's Far-Flung Raw Materials
July, 1999

Life may owe its start to complex organic molecules manu-
factured in the icy heart of an interstellar cloud, by Max P.
Bernstein, Scott A. Sandford and Louis J. Allamandola
http://www.sciam.com/article.cfm?articleID=00067AE2-6A4B-1C72-9EB7809EC588F2D7

Illustrations/excerpts from this article:

Complex Organic Molecules
http://www.sciam.com/article.cfm?articleID=0007921C-4024-1CBC-B4A8809EC588EEDF
"... some like those found in living things--abound in dark
parts of interstellar clouds. More than four billion years ago
one such cloud collapsed into a swirling disk that spawned
the sun and planets. Some of the fragile molecules survived
the violent heat of solar system formation by sticking together
in comets at the disk's frigid fringe. Later the comets and
other cloud remnants carried the molecules to Earth."

Quinones From Space
http://www.sciam.com/article.cfm?articleID=000CEC92-406B-1CBC-B4A8809EC588EEDF
"... have structures nearly identical to those that help
chlorophyll molecules transfer light energy from one part
of a plant cell to another."

Comets and Asteroids
http://www.sciam.com/article.cfm?articleID=0000A63B-412F-1CBC-B4A8809EC588EEDF
"... heavily bombarded Earth until about four billion years ago.
Even now the planet sweeps up hundreds of tons of dust and
meteorites from these objects every day. Many of the dust
particles --most only a thousandth of a millimeter across--are
rich in organic molecules fabricated in the dark cloud that
spawned the solar system. The voids in the particle below
presumably once contained ice that evaporated when the
dust escaped its parent comet."

Laboratory Simulations
http://www.sciam.com/article.cfm?articleID=00037C68-419D-1CBC-B4A8809EC588EEDF
"... mimic what happens in the cold parts of interstellar
clouds such as the Eagle Nebula (above). Inside a shoebox-
size metal chamber (below), a special refrigerator and pump
generate the subzero vacuum of space. A mist of simple gas
molecules sprayed from a copper tube freezes onto a salt
disk, which acts as the silicate core of an ice grain in space (1).
An ultraviolet lamp bathes the newly formed ice in a potent
dose of starlike radiation (2). Infrared light, also emitted by
stars, is later projected through the ice to determine what
molecules are frozen inside (3). Comparison of infrared
absorption spectra reveals that the composition of the
laboratory ice is strikingly similar to that of ice in the clouds."

Interstellar Ice
http://www.sciam.com/article.cfm?articleID=000226D6-41FD-1CBC-B4A8809EC588EEDF
"... begins to form when molecules such as water, methanol
and hydrocarbon freeze to sandlike granules of silicate
drifting in dense interstellar clouds (1). Ultraviolet radiation
from nearby stars breaks some of the chemical bonds of the
frozen compounds as the ice grain grows to no bigger than
about one ten-thousandth of a millimeter across (2). Broken
molecules recombine into structures such as quinones, which
would never form if the fragments were free to float away (3)."

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Life's First Scalding Steps (January 9, 1999):
http://www.sciencenews.org/sn_arc99/1_9_99/bob1.htm

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Hypotheses about the possibility of life's origins in
hydrothermal vents:
http://www.resa.net/nasa/ocean_hydrothermal.htm#origins

- - -

Details on current life (300 species) which resides
near hydrothermal vents:
http://www.pbs.org/wgbh/nova/abyss/life/extremes.html

- - -

Map of currently known hydrothermal vent locations:
http://www.pbs.org/wgbh/nova/abyss/frontier/vents.html

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Theories on Origin of Life on Earth:
http://ethomas.web.wesleyan.edu/ees104/lect6b.htm

- - -

How did it all begin? The self-assembly of organic
molecules and the origin of cellular life:
http://www.ucmp.berkeley.edu/education/events/deamer1.html

- - -

How did life evolve?

Excerpt from a BBC special, Hopeful Monsters:
http://www.bbc.co.uk/horizon/hopefulmonsters.shtml
"...in a matter of weeks, they performed a series of
experiments that was to blow apart the world of genetics,
and crack open the mysteries of the developing embryo
and the secrets of how we and all other animals came to
be the way we are. Through their work it is now known
that humans share the same gene inventory as the goldfish,
the dinosaur, the sparrow and the beetle. Instead of millions
of genes doing different things in different animals, there is
a basic toolkit of genes used over and over again throughout
the animal kingdom.

The human baby in the womb is being sculpted by exactly
the same genes that shape the developing fly.

This toolkit, known as the homeobox genes, is the key to
how nature has produced the staggering diversity within
the 4 billion species that have existed on Earth since life
began, and it is leading to a new understanding of the
mechanism of evolution itself. The tiniest mutation in
the toolkit genes can result in rapid and dramatic changes
in the animal, as it triggers a cascade of inevitable
consequences."

Excerpt from a key segment in the detailed transcript
from the show:
http://www.bbc.co.uk/horizon/hopefulmonsterstran.shtml
"NARRATOR - Not knowing whether their 8 control genes
were unique to just the fly, they went critter hunting. Bill and
his wife, Nadine, fished in the streams around Basel for other
interesting creatures in which to look for Hox genes. They
even visited fishing tackle shops for worms and maggots,
eventually amassing an impressive array of creatures.

The fact that they had proved that just 8 powerful Hox control
genes shaped a creature like the fruit fly was extraordinary
enough. But this experiment was running counter to all the
accepted theories. Each type of animal was thought to have
unique genes, so looking for fruit fly control genes even in
closely related species seemed a wild goose chase. (Indeed)
they were quite cavalier in the creatures they chose. Amongst
the samples from worms and insects they had included one
from a cow - and two from human friends.

BILL McGINNIS - I remember running the gel and er taking
the probe that Mike gave me and hybridising this blot,
so I er, put into the film cassette, left it overnight, and
I remember it there was a lot of anticipation over that night,
you know, wanting early, you know to get up early the next
morning and see what the result was. Their sense of antici-
pation was enormous and er taking the film cassette out of
the minus 80 freezer and waiting for it to warm up a little bit,
and then developing the film to see what the result would be.

MIKE LEVENE - When Bill came out of the darkroom
showing us bands of signals from human DNA and mouse
DNA it was really just too fantastic to believe.

NARRATOR - In every one of the samples the same 8 tell
tale bands had emerged, in primitive worms, in other insects
but, most amazing, in their human samples. From insects to
ourselves they had discovered an underlying genetic unity
across the whole animal kingdom that absolutely no one had
expected. They showed the same Hox control genes to be
structuring all living things. We are all running on literally the
same genetic software."

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Excerpt from the "Discovery of the Molecular
Basis of Evolution" (November 25, 1998)
http://news.bbc.co.uk/2/hi/sci/tech/222096.stm
"They may have found out what actually happens to an
organism's genes that enables its offspring to adapt and
change - that is to evolve into new types of living creatures.
The researchers at the University of Chicago say that
although an organism's DNA is changing over time, many
of the individual, small genetic variations just accumulate
and only become noticeable when that organism is under
environmental stress. You can look at it this way: while an
animal may be perfectly adapted to its environment, behind
the scenes redundant copies of its genes are mutating."

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Yale Scientists Recreate Molecular "Fossils," Now Extinct,
That May Have Existed At The Beginning Of Life
Date: Posted 6/10/1998
http://www.sciencedaily.com/releases/1998/06/980610082901.htm

Excerpt: Yale scientists report they have synthesized mole-
cules like those that probably gave rise to the earliest life
forms on Earth nearly 4 billion years ago, thus creating a
biochemist's version of "Jurassic Park" populated by exotic
molecular "fossils" that have long since become extinct.

... The feat was accomplished using a technique known as
test-tube evolution.

Breaker's tailor-made enzyme is the first known nucleic
acid enzyme that uses an amino acid to trigger chemical
activity, and it brings scientists a step closer to finding
the precursor of all life -- a single molecule containing
both genetic code and an enzyme capable of triggering
self-replication.

Which Came First -- DNA, RNA Or Proteins?

The discovery provides important clues to the chicken-or-
egg dilemma of which came first -- DNA, RNA or proteins.

Most scientists agree life as we know it cannot exist without
DNA as the storehouse of genetic code, RNA as the genetic
messenger, and proteins to carry out the chemistry of repro-
duction.

Can any one of these three key molecules have existed as
the precursor of the other two, serving as both chicken and
egg?

Evidence is mounting that "it was an RNA World at the dawn
of life as the Earth began to cool," said Breaker. ..."

... "Our latest findings not only improve our understanding
about the origins of life, they also expand our skills in mol-
ecular evolution," he said.

"While we may not be able to resurrect fossilized creatures
like they did in 'Jurassic Park,' we very well may be able to
recreate many of the ancient enzymes that were needed at
the very beginning of life nearly 4 billion years ago."

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(end 2 of 2)

Posts in this series:

Origins of Energy, Matter, Space, Time, and Life (1 of 2)
http://prohuman.net/science/origins_1_of_2.htm

Origins of Energy, Matter, Space, Time, and Life (2 of 2)
http://prohuman.net/science/origins_2_of_2.htm

 

- - - Additional Information of Relevance - - -

Preponderance of Evidence for Naturalistic
Origins and Evolution of Life (1 of 3)
http://prohuman.net/science/evidence_for_evolution_1_of_3.htm

Preponderance of Evidence for Naturalistic
Origins and Evolution of Life (2 of 3)
http://prohuman.net/science/evidence_for_evolution_2_of_3.htm

Preponderance of Evidence for Naturalistic
Origins and Evolution of Life (3 of 3)
http://prohuman.net/science/evidence_for_evolution_3_of_3.htm

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