% % -------------------------------------------- % Evolutionary/Geological Timeline Version 1.1 % -------------------------------------------- % % This is a copy of an evolutionary/geological timeline that I have % been making. % % This is a plain TEX file and does not require any TEX macro % files. One should only need to edit out the usenet/email header % information and then the file should be able to be passed % through TEX. You do not need to edit out this information % and I would appreciate it if you would not so that if % later you give this file to someone else they will be % able to send me their ideas. The TEX page size variables are % currently set for American sized paper and may have to be changed % for other sizes of paper. % % 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 suggestions to me via email. % % An XMOSAIC page has been created for my timelines and scales of measurement % list. The URL is the following: % % http://www.astro.psu.edu/users/niel/scales/scales.html % % If you are not able to obtain one of my lists via the WWW or usenet, please % send me an email request and I will email you the list you want. Please % specify desired format (ASCII or TEX). % % Niel Brandt % niel@astro.psu.edu % % This document is copyright Niel Brandt 1994. You are allowed to copy, % distribute, and edit this document at will without any obligation as long % as you do not remove the above header. Reproduction and distribution for % personal profit is not permitted. %--------------------------------------------------------------------- \font\sevenrm=cmr7 \font\sevenbf=cmbx7 \font\sevenit=cmti7 \font\tenrm=cmr10 \font\tenbf=cmbx10 \font\tentt=cmtt10 % \voffset=-0.8 in % \vsize=11.0 in \hoffset=-0.5 in \hsize=7.0 in \sevenrm \baselineskip=8 pt \noindent {\bf EVOLUTIONARY/GEOLOGICAL TIMELINE} \vskip 0.1 in \halign{ \hbox{#}&\quad\hbox{#}\cr Time (Myr ago) & Event\cr & \cr 4600 & Formation of the approximately homogeneous solid Earth by planetesimal accretion\cr 4300 & Melting of the Earth due to radioactive and gravitational heating which leads to its differentiated interior structure as\cr & well as outgassing of molecules such as water, methane, ammonia, hydrogen, nitrogen, and carbon dioxide\cr 4300 & Atmospheric water is photodissociated by ultraviolet light to give oxygen atoms which are incorporated into an ozone\cr & layer and hydrogen molecules which escape into space\cr 4300 & First minerals (zircons) crystalize on the molten Earth\cr 4000 & Bombardment of the Earth by planetesimals stops\cr 3800 & The Earth's crust solidifies---formation of the oldest rocks found on Earth\cr 3800 & Condensation of atmospheric water into oceans\cr 3500--2800 & Prokaryotic cell organisms develop\cr 3500--2800 & Beginning of photosynthesis by blue-green algae which releases oxygen molecules into the atmosphere and steadily works to\cr & strengthen the ozone layer and change the Earth's chemically reducing atmosphere into a chemically oxidizing one\cr 2400 & Rise in the concentration of oxygen molecules stops the deposition of uraninites (since they are soluble when combined\cr & with oxygen) and starts the deposition of banded iron formations\cr 2000 & The Oklo natural fission reactors in Gabon go into operation and run for about 1 Myr\cr 2000 & The Magellanic Clouds tidally interact with the Milky Way thereby starting the Magellanic Stream (MNRAS 198, 710)\cr 1600 & The last reserves of reduced iron are used up by the increasing atmospheric oxygen---last banded iron formations\cr 1500 & Eukaryotic cell organisms develop\cr 1500--600 & Rise of multicellular organisms\cr 1100 & Formation of the supercontinent Rodinia\cr 700 & Break-up of the supercontinent Rodinia\cr 580--545 & Fossils of Ediacaran organisms are made\cr 550 & Formation of Gondwana \cr 545 & Cambrian explosion of hard-bodied organisms\cr 528--526 & Fossilization of the Chengjiang site\cr 517--515 & Fossilization of the Burgess Shale\cr 500--450 & Rise of the fish---first vertebrates\cr 440 & Ordovician mass extinction\cr 430 & Waxy coated algae begin to live on land\cr 420 & Millipedes have evolved---first land animals\cr 375 & The Appalachian mountains are formed via a plate tectonic collision between North America, Africa, and Europe\cr 375 & Appearance of primitive sharks\cr 365 & Devonian mass extinction\cr 350--300 & Rise of the amphibians\cr 350 & Primitive insects have evolved\cr 350 & Primitive ferns evolve---first plants with roots\cr 300--200 & Rise of the reptiles\cr 300 & Winged insects have evolved\cr 280 & Beetles and weevils have evolved\cr 250 & Permian period mass extinction\cr 230 & Roaches and termites have evolved\cr 225 & Modern ferns have evolved\cr 225 & Bees have evolved\cr 210 & Triassic mass extinction\cr 200 & Pangaea starts to break apart\cr 200 & Primitive crocodiles have evolved\cr 200 & Appearance of mammals\cr 145 & Archaeopteryx walks the Earth\cr 136 & Primitive kangaroos have evolved\cr 100 & Primitive cranes have evolved\cr 90 & Modern sharks have evolved\cr 65 & The Chicxulub impact occurs\cr 65 & K-T Boundary---extinction of the dinosaurs and beginning of the reign of mammals\cr 60 & Rats, mice, and squirrels have evolved\cr 60 & Herons and storks have evolved\cr 55 & Rabbits and hares have evolved\cr 50 & Primitive monkeys have evolved\cr 28 & Koalas have evolved\cr 20 & Parrots and pigeons have evolved\cr 20--12 & The chimpanzee and hominid lines evolve\cr 10--4 & Ramapithecus exist\cr 4 & Development of hominid bipedalism\cr 4--1 & Australopithecus exist\cr 3.5 & The Australopithecus Lucy walks the Earth\cr 2 & Widespread use of stone tools\cr 2--0.01 & Most recent ice age\cr 1.6--0.2 & Homo erectus exist\cr 1--0.5 & Homo erectus tames fire\cr 0.3 & Geminga supernova explosion at a distance of roughly 60 pc---roughly as bright as the Moon\cr 0.2--0.03 & Homo sapiens neanderthalensis exist\cr 0.05--0 & Homo sapiens sapiens exist\cr 0.04--0.012 & Homo sapiens sapiens enter Australia from southeastern Asia and North America from northeastern Asia\cr 0.025--0.01 & Most recent glaciation---an ice sheet covers much of the northern United States\cr 0.02 & Homo sapiens sapiens paint the Altamira cave and the Chauvet cave\cr 0.017 & Homo sapiens sapiens paint the Lascaux cave\cr 0.012 & Homo sapiens sapiens have domesticated dogs in Kirkuk, Iraq\cr 0.01 & First permanent homo sapiens sapiens settlements\cr 0.01 & Homo sapiens sapiens learn to use fire to cast copper and harden pottery\cr 0.006 & Writing is developed in Sumeria\cr 0.0046 & Oldest known Bristlecone Pine tree starts to grow\cr } % \vfill % \eject \vskip 0.5 in \halign{ \hbox{#}&\quad\hbox{#}\cr Time (Myr ago) & Event\cr & \cr 5000--1500 & Archeozoic (Archean) era\cr % 1500--545 & Proterozoic era\cr % & Paleozoic era ``Ancient life''\cr 545--505 & \hskip 0.2 in Cambrian period\cr 505--438 & \hskip 0.2 in Ordovician period\cr 438--410 & \hskip 0.2 in Silurian period\cr 410--355 & \hskip 0.2 in Devonian period\cr 355--290 & \hskip 0.2 in Carboniferous (Mississippian/Pennsylvanian) period\cr 290--250 & \hskip 0.2 in Permian period\cr % & Mesozoic era ``Middle Life''\cr % 250--205 & \hskip 0.2 in Triassic period\cr 205--135 & \hskip 0.2 in Jurassic period\cr 135--65 & \hskip 0.2 in Cretaceous period\cr % & Cenozoic era ``Recent Life''\cr % & \hskip 0.2 in Tertiary (Paleogene/Neocene) period\cr % 65--55 & \hskip 0.4 in Paleocene epoch\cr 55--38 & \hskip 0.4 in Eocene epoch\cr 38--26 & \hskip 0.4 in Oligocene epoch\cr 26--6 & \hskip 0.4 in Miocene epoch\cr 6--1.8 & \hskip 0.4 in Pliocene epoch\cr % & \hskip 0.2 in Quaternary period\cr % 1.8--0.01 & \hskip 0.4 in Pleistocene epoch\cr % 0.50--0.25 & \hskip 0.6 in Lower Paleolithic\cr 0.25--0.06 & \hskip 0.6 in Middle Paleolithic\cr 0.06--0.01 & \hskip 0.6 in Upper Paleolithic\cr % 0.01--0 & \hskip 0.4 in Holocene epoch\cr } \end