From:    William N. Brandt
To:      All                            Jan-17-94 09:38AM
Subject: Geological/Evolutionary Timeline - ASCII VERSION

Organization: California Institute of Technology, Pasadena
From: brandt@cco.caltech.edu (William N. Brandt)
Message-ID: <2heiet$d3j@gap.cco.caltech.edu>
Newsgroups: talk.origins



--------------------------------------------
Geological/Evolutionary Timeline Version 0.0
--------------------------------------------

This is an ASCII copy of a geological/evolutionary timeline
that I have been making.

I would be grateful for factual, spelling, and grammar
corrections. I would be grateful for suggestions as to how to
better word specific entries so as to make them clearer. I am
also keen to add interesting events to the timeline and would
appreciate suggestions.

Please send any comments/suggestions/corrections to me via email.

                                         Thank you,

                                         Niel Brandt
                                         brandt@sandman.caltech.edu


EVOLUTIONARY/GEOLOGICAL TIMELINE

Time (m.y.a.)   Event

4600            Formation of the approximately homogeneous solid Earth
                by planetesimal accretion
4300            Melting of the Earth due to radioactive and gravitational
                heating which leads to its differentiated interior structure
                as well as outgassing of molecules such as water, methane,
                ammonia, hydrogen, nitrogen, and carbon dioxide
4300            Atmospheric water is photodissociated by ultraviolet light
                to give oxygen atoms which are incorporated into an ozone
                layer and hydrogen molecules which escape into space
4000            Bombardment of the Earth by planetesimals stops
3800            The Earth's crust solidifies---formation of the oldest rocks
                found on Earth
3800            Condensation of atmospheric water into oceans
3500--2800      Prokaryotic cell organisms develop
3500--2800      Beginning of photosynthesis by blue-green algae which releases
                oxygen molecules into the atmosphere and steadily works to
                strengthen the ozone layer and change the Earth's chemically
                reducing atmosphere into a chemically oxidizing one
2000            The Oklo natural fission reactor in Gabon goes into operation
1500            Eukaryotic cell organisms develop
1500--600       Rise of multicellular organisms
550             Cambrian explosion of hard-bodied organisms
545             Fossilization of the Chengjiang site
530             Fossilization of the Burgess Shale
500--450        Rise of the fish---first vertebrates
430             Waxy coated algae begin to live on land
420             Millipedes have evolved---first land animals
375             The Appalachian mountains are formed via a plate tectonic
                collision between North America, Africa, and Europe
375             Appearance of primitive sharks
350--300        Rise of the amphibians
350             Primitive insects have evolved
350             Primitive ferns evolve---first plants with roots
300--200        Rise of the reptiles
300             Winged insects have evolved
280             Beetles and weevils have evolved
250             Permian period mass extinction
230             Roaches and termites have evolved
225             Modern ferns have evolved
225             Bees have evolved
200             Pangaea starts to break apart
200             Primitive crocodiles have evolved
200             Appearance of mammals
145             Archaeopteryx walks the Earth
136             Primitive kangaroos have evolved
100             Primitive cranes have evolved
90              Modern sharks have evolved
65              K-T Boundary---extinction of the dinosaurs and beginning of
                the reign of mammals
60              Rats, mice, and squirrels have evolved
60              Herons and storks have evolved
55              Rabbits and hares have evolved
50              Primitive monkeys have evolved
28              Koalas have evolved
20              Parrots and pigeons have evolved
20--12          The chimpanzee and hominid lines evolve
10--4           Ramapithecus exist
4               Development of hominid bipedalism
4--1            Australopithecus exist
3.5             The Australopithecus Lucy walks the Earth
2               Widespread use of stone tools
1.6--0.2        Homo erectus exist
1--0.5          Homo erectus tames fire
0.3             Geminga supernova explosion---roughly as bright as the moon
0.2--0.03       Homo sapiens neanderthalensis exist
0.075--0.010    Most recent ice age---an ice sheet covers much of the
                northern United States
0.05--0         Homo sapiens exist
0.04--0.012     Homo sapiens enter Australia from southeastern Asia and North
                America from northeastern Asia
0.02            Homo sapiens paint the Altamira Cave
0.012           Homo sapiens have domesticated dogs in Kirkuk, Iraq
0.01            First permanent homo sapien settlements
0.01            Homo sapiens learn to use fire to cast copper and harden
pottery
0.006           Writing is developed in Sumeria

                Paleozoic age ``Ancient life''
550--510          Cambrian period
510--438          Ordovician period
438--410          Silurian period
410--355          Devonian period
355--290          Carboniferous period
290--250          Permian period
                Mesozoic age ``Middle Life''
250--205          Triassic period
205--135          Jurassic period
135--65           Cretaceous period
                Cenozoic age ``Recent Life''
                  Tertiary period
65--55              Paleocene epoch
55--38              Eocene epoch
38--26              Oligocene epoch
26--6               Miocene epoch
6--1.8              Pliocene epoch
                  Quaternary period
1.8--0.01           Pleistocene epoch
0.01--0             Holocene epoch