Life on Earth began at least
3.85 billion years ago
"This
research shows that life on Earth began
during the first approximately 700 million
years after the formation of the planet,
placing an upper limit on the time needed for
the creation of life on Earth, or on the time
period available for it to arrive here from
elsewhere"
-- Federation of American Scientists
The Beginnings of Life on Earth
"
The chemical evolution leading to cellular
life on earth almost four billion years ago
likely passed through a stage where RNA alone
performed all of the functions of the modern
macromolecules RNA, DNA and protein. However
the so-called RNA world was itself too
complex to evolve directly from organic
molecules found on the prebiotic earth. More
likely, the RNA world emerged from and was
supported by a primitive sort of metabolism
fueled by the bonds in sulfur-containing
compounds called thioesters. "
--American Scientist, 10/95
The Chemistry of Life
on Earth & How did Life Begin?
-- AST 103, George Mason University
Turning a corner in the search
for the origin of life
"These
scientists believe that the most important
questions on this subject can now be
addressed experimentally. Theory can leave
the realm of speculation to focus attention
on the interpretation of real data."
-- Santa Fe Institute
The Origins and Early Evolution
of Life
"In
recent years, the origin and early evolution
of life has seen an unprecedented
development. New theories concerning the
origins of life such as cometary sources of
organics, the possible role of marine
hydrothermal systems on the chemistry of the
primitive earth and the postulate of the RNA
world have brought many new scientists to the
field of origins of life. It is the role of
"Origins of Life and Evolution of the
Biosphere" to bring these articles
together in one journal."
-- Publicaton
Executive Summary of Workshop
Findings
Workshop
on Origins
-- NASA
Origins of life
College
lecture notes
-- Department of Ecology and Evolutionary
Biology, University of Arizona.
Origin of life
Discussion
forum
-- Tennessee Darwin
Coalition, University of Tennessee,
Knoxville
The Origin Of Life
-- Private website
How close are scientists to
knowing the origin of life on earth?
Q&A
-- Scientific American: Ask the Experts:
Biology
When did eukaryotic cells (cells
with nuclei and other internal organelles)
first evolve?
Q&A
-- Scientific American: Ask the Experts:
Biology
Origin of Life on Earth by
Leslie E. Orgel
"When
the earth formed some 4.6 billion years ago,
it was a lifeless, inhospitable place. A
billion years later it was teeming with
organisms resembling blue-green algae. "
-- Private website
The evolution of life
on Earth by Stephen J. Gould
"The history of life is not necessarily
progressive; it is certainly not predictable.
The earth's creatures have evolved through a
series of contingent and fortuitous events.
"
-- Private website
Evolutionary/Geological Timeline
v.1.0
Chart
-- Talk.Origins Archine
The Development of Life on Earth
and the Search for Extraterrestrial
Intelligence
"Among
the many questions ... how did life on Earth
begin? how did life evolve to its present
state? does life exist elsewhere in the solar
system? "
-- Course notes, Department of Physics, Hong
Kong University
All You Need is RNA
"Before
proteins, before DNA, scientists imagine life
arose as simple strands of RNA , formed in a
nucleotide-rich primordial ocean."
-- ABCNews.com, 8/6/98
Let There be Life
"...most
biologists have assumed that the ancestral
life form needed a rudimentary instruction
manual-a set of primitive genes -that was
copied and passed from generation to
generation. In the past year or so, a
majority view has emerged on which molecules
first acquired these abilities and so sparked
life on the planet Earth. Buoyed by some
spectacular breakthroughs, most biologists
are now convinced that life began when
molecules called RNA took on the tasks that
genes and proteins perform in today's
sophisticated cells."
Reprint, New Scientist, 7/6/96
The Origin of Life
Overview,
see section on Guenther's rebellion
-- University of Manitoba, Department of
Microbiology
Chirality
"...chirality,
a central concept in chemistry, may also
prove crucial to important questions of both
fundamental physics and the origin of life on
Earth, and may turn out to be the means by
which we first identify life outside Earth.
"
-- New Scientist, 8/28/97
The Phylogeny of Life
"The
context of evolutionary biology is phylogeny,
the relationships between groups of organisms
as expressed as ancestor/descendant
relationships. We express these relationships
in diagrams called cladograms, which are like
genealogies of species. "
--Museum of Paleontology, University of
California at Berkeley
Life, Life Everywhere
"These
have been exciting times for scientists
striving to learn about the origin of life.
The possible discovery of fossil microbes in
a Martian meteorite has already grabbed the
public's attention; another provocative
recent study suggests that life may have
arisen on the earth far earlier than
previously thought. Such work has sharpened
one of the most fascinating and least
tractable debates in modern science: Is life
a remarkable aberration, or is it a likely,
perhaps even certain, outcome of the laws of
nature? "
-- Scientific American, 11/25/96
Earliest evidence for
life on Earth
"Life
evolved on Earth just as soon as it was able,
according to a startling report in the 7
November issue of Nature. Dr Gustaf Arrhenius
of the Scripps Institution of Oceanography in
La Jolla, California and colleagues reveal
evidence for life in rocks more than 3,800
million years old. "
-- Nature, 96
Climbing Mount
Improbable
"The
human eye is so complex and works so
precisely that surely, one might believe, its
current shape and function must be the
product of design. How could such an
intricate object have come about by chance?
Yet this is exactly what Richard Dawkins
argues in his provocative and passionate new
book--that life evolves through the accident
of mutation, and that perfection in the
natural world is the result of supreme, and
fascinating, improbability. "
-- Spacelab.net
Origin of Life: the Early
Atmosphere
"Our current atmosphere consists
primarily of oxygen (21%) and nitrogen (78%)
and is called oxidizing because of chemical
reactions produced by oxygen. For example,
iron is oxidized to form iron oxide or rust.
The presence of oxygen in a hypothetical
primordial atmosphere poses a difficult
problem for notions of self-assembling
molecules. If oxygen is present, there would
be no amino acids, sugars, purines, etc.
Amino acids and sugars react with oxygen to
form carbon dioxide (CO2) and water"
-- Creation Science.
Cells: Origins
Origin
of the Earth and Life - s there life on Mars,
Venus, anywhere else?? - Terms applied to
cells - Components of Cells - The Origins of
Multicellularity -
Links
-- Estrella Mountain Community College,
Biology 181
The Evolution of
Complexity, by Means of Natural Selection
Book
Review
--Physics Dep't, University Wisconsin-Madison
Evolution Image Index
Collection
of images that have been selected to support
course on evolution.
-- Multidisciplinary Activities, University
of Southern California
Paleontology Without Walls
Phylogeny, the "family tree" of
life - Geological Time, the temporal
existence of groups of organisms -
Evolutionary Thought, evolutionary topics and
scientists in their historical context.
--Museum of Paleontology, University of
California at Berkeley
A Hellish Start for Life
"Although Charles Darwin speculated that
life originated in a warm, nourishing broth,
new evidence suggests that the cradle of life
could have been ... a sulfurous swirl of
superheated water and oozing lava."
-- The American Association for the
Advancement of Science, Science News Service,
7/31/98
Origin and History of Life
Outline, with links
--Structure and Function of Organisms,
Biology 303,University of Texas at Austin
Molecular "Fossils" Of
Early Life
"Yale scientists report they have
synthesized molecules like those that
probably gave rise to the earliest life forms
on Earth nearly 4 billion years ago."
-- exoScience, 6/6/98
Early Life Lasted a Little
Longer
"The
first multicellular organisms on Earth,
called Ediacarans, were a strange menagerie
of leaf-shaped fronds and blobs. These
creatures seemed to disappear at the end of
the Precambrian some 544 million years ago,
perhaps driven to extinction as more modern
organisms began to evolve. In today's issue
of Nature, however, paleontologists report
that two species of Ediacarans, at least,
appear to have survived into Cambrian
times."
-- American Association for the Advancement
of Science News Service, 6/11/98
Cambrian Explosion Website
"The
Cambrian Explosion Website describes, via 3-D
computer graphics, the evolutionary history
of modern animals."
-- Private website
Origin of Life Research
(technical)
"We suggest that life emerged on Earth
about 4.2 billion years ago from a redox and
pH front focused at the interface between
reduced, alkaline, off-ridge, hot submarine
spring waters and the somewhat acid and
mildly oxidised Hadean ocean."
-- University of Glasgow, Scotland
Early DNA
"Simulating evolution in a test-tube,
Yale researchers have synthesized a DNA
enzyme considered to be key to understanding
the origins of life on Earth some four
billion years ago."
-- Access Excellence (Genentech, Inc., sole
sponsor), national educational program for
biology, 6/9/98
From Primordial Soup to the
Prebiotic Beach
"An interview with exobiology pioneer,
Dr. Stanley L. Miller, University of
California San Diego."
-- Access Excellence (Genentech, Inc., sole
sponsor), national educational program for
biology, 10/96
Cells: Origins
Origin of the Earth and Life. - Is there life
on Mars, Venus, anywhere else?? - Terms
applied to cells - Components of Cells - The
Origins of Multicellularity - Links
-- Estrella Mountain Community College,
online biology course
Evolution Introduction
"The great geneticist Theodosius
Dobzhansky wrote an article for the American
Biology Teacher. The title of the article was
"Nothing in Biology Makes Sense, Except
in the Light of Evolution." That is a
very strong statement. What do you suppose he
meant? "
-- Access Excellence (Genentech, Inc., sole
sponsor), national educational program for
biology, 11/97
Astrobiology and the Origins of
Life
"We are left with questions and the
understanding that there is a need for a
cosmological perspective when exploring the
origins of life. This brings us to the new
field of astrobiology. "
-- Access Excellence (Genentech, Inc., sole
sponsor), national educational program for
biology, 11/97
The Radiation of the First
Animals
"At the base of the Cambrian period
about 545 million years ago, all modern phyla
of animals and many algae and protists appear
or radiated--including phytoplankton,
forminifera, archeocyaphids, trilobites. Most
explanations for this radiation involve
properties of animals themselves (intrinsic
causes), but the coincident events in algae
and protozoans suggest perhaps a more
ubiquitous, ecologic trigger (extrinsic
causes). "
-- Access Excellence (Genentech, Inc., sole
sponsor), national educational program for
biology, 11/97
Primordial Soup
"The nature of the origin of life
remains one of the most intriguing questions
in biology. Researchers at the University of
California, San Diego's Specialized Center of
Research and Training in Exobiology are
approaching the question by simulating
environmental conditions as they are thought
to have existed in "prebiotic"
times."
-- Access Excellence (Genentech, Inc., sole
sponsor), national educational program for
biology, 3/20/95
RNA and the Origins of Life
"Hitherto unrecognized properties of RNA
add further support to the idea that RNA was
the central molecule in the origin of life,
report researchers."
-- Access Excellence (Genentech, Inc., sole
sponsor), national educational program for
biology, 4/26/95
Evolutionary Arms Race
"Molecular biological back-tracking is
begnning to provide clues to the appearance
of a possible worm-like common ancestor of
all current animal life. "
-- Access Excellence (Genentech, Inc., sole
sponsor), national educational program for
biology, 8/14/97
Model Of Cellular Furnace
Created
"Scientists for the first time have
synthesized a working model of the enzyme
cytochrome c oxidase, the "cellular
furnace" providing the key heat and
power in the chemistry of life. "
-- Access Excellence (Genentech, Inc., sole
sponsor), national educational program for
biology, 2/14/97
Did a Quick Spin Pump Up
Evolution?
"The continents suddenly spun off course
some 530 million years ago, perhaps due to a
quick shift of Earth's spin axis,
geophysicists report in today's Science. The
researchers speculate that the terrestrial
upheaval--which took just 15 million
years--may have set off a contemporaneous
evolutionary explosion..."
-- The American Association for the
Advancement of Science News Service, 7/25/97
First Creatures Not Animals?
"A new analysis of 600-million-year-old
fossils called Ediacarans suggests that these
creatures should be classified separately
from the types of animals that arose tens of
millions of years later during the burst of
evolution known as the Cambrian explosion. If
true, large and complex creatures appeared
twice during evolutionary history. "
-- The American Association for the
Advancement of Science News Service, 10/21/97
Hyperthermophiles
in the history of life (papers on
hydrothermal systems)
Summaries of technical papers
-- Symposium on Evolution of hydrothermal
ecosystems on Earth (and Mars?), held at the
Ciba Foundation, London, January
30–February 1 1996
Origin of Life Debate (site requires free
registration)
"When, where, and by what means did life
begin? On Earth? Elsewhere? Only once, or
many times? Such questions were the focus of
this moderated dialogue among researchers
from diverse disciplines - from cosmology,
paleontology, and geology to biophysics and
molecular biology."
-- Biomednet, 9/5/97
1997 Gordon Conference On
"The Origin of Life"
Program and literature citations.
-- New England College, New Hampshire, July
27 - August 1, 1997
A New Tree of Life
FOSSIL
RECORDS; MOLECULAR EVOLUTION; BACTERIA;
EVOLUTION;
MUTATION RATES; EUKARYOTES; ARCHAEA
-- Discover, June, 1996 (From Washington and
Lee University Science Library)
The Adam-and-Eve Cells
SINGLE-CELL
ORGANISMS; BACTERIA; PICOPLANKTON;
ANTARCTICA;
ALASKA; RNA/ARCHAEA; OCEAN CHEMISTRY/ARCHAEA;
ARCHAEA
-- Earth, April, 1995 (From Washington and
Lee University Science Library)
A Pressure-Filled Life
MICROORGANISM
EVOLUTION; PSYCHROPHILIC BACTERIA;
THERMOPHILIC BACTERIA; BAROTOLERANCE;
PRESSURE ADAPTATIONS; ARCHAEA;
EVOLUTION/MICROORGANISMS
-- BioScience, October, 1994 (From Washington
and Lee University Science Library)
From Proteins to
Protolife
ORIGIN OF
LIFE; PROTOCELLS; THERMAL PROTEINS;
MICROSPHERES;
AMINO ACIDS; PROTEINS; EVOLUTION/ORIGIN;
PRIMORDIAL LIFE
-- Science News ,July 23, 1994 (From
Washington and Lee University Science
Library)
Origin of the First
Cell Membrane?
EVOLUTION;
CELL MEMBRANES; BIOCHEMICAL CONSERVATION;
BIOCHEMISTRY; ORIGIN OF LIFE; TERPENOIDS;
FOSSILS
-- Nature, September 8, 1994 (From Washington
and Lee University Science Library)
Animals and Fungi
Closer Than Anyone Expected
MOLECULAR
GENETICS; EUKARYOTES; FUNGI; GENETIC TREE OF
LIFE;
EVOLUTIONARY RELATIONS/EUKARYOTES
-- New Scientist, June 12, 1993 (From
Washington and Lee University Science
Library)
Researchers Find
Organism They Can Really Relate To
EVOLUTIONARY
BIOLOGY; EOCYTES; EUKARYOTES; ARCHAEBACTERIA,
PALEONTOLOGY; MOLECULAR EVOLUTION;
RELATEDNESS
-- Science, July 3, 1992 (From Washington and
Lee University Science Library)
Score One for Punk Eek
"The fitful evolution of bacteria
supports a controversial theory - In an
ingenious experiment conducted at Michigan
State University, researchers have observed
evolutionary changes as a family of bacteria
passed through 3,000 generations. The
procedure took a mere four years; conducting
an analogous experiment with Homo sapiens
would require roughly 60,000 years..."
-- Scientific American, 7/21/96
Creation could be
left-handed
"In 1848 Louis Pasteur discovered that
some molecules can exist in two mirror-image
forms, termed right or left-handed.
Curiously, in living things the molecules
tend to be one of these types and not a
mixture of both. ... Why life on the
molecular level is like this is a mystery but
now an international team of astronomers may
have discovered why life on planet Earth is
left-handed."
-- BBC News, SciTech, 6/30/98
Links to Evolution and
Darwin related sites
Links
-- Private site
Palaeoecology and
Evolutionary Biology
"Useful WWW sites, containing material
available for research in palaeoecology,
plant evolution, techniques in these and
other disciplines, and some more general
sites to facilitate searching."
-- Department of Plant Sciences, University
of Cambridge
Structure and Functions
of Simple Peptides at Water-Membrane
Interfaces
"Even the simplest protocell must have
had the capability to catalyze the chemical
reactions needed for its survival and growth,
and to communicate with its environment.
These functions must have been accomplished
by simple molecules that could have been
present in a protobiological milieu."
-- NASA, Exobiology branch at
ARC
What are the conditions
that favour the development of Intelligent
Life?
"How did Life evolve upon the Earth?
There is certainly no simple answer except:
slowly. Very, very slowly. . . "
-- THE SEARCH FOR EXTRA-TERRESTRIAL
INTELLIGENCE
What is Astrochemistry?
"Astrochemistry
is the study of chemistry in space. More
specifically, it is the study of the chemical
interactions between the gases and dust
interspersed between the stars. "
-- University of Illinois
