Evolution: the orderly changes that have shaped the earth and that have modified the living species that inhabit the earth. |
Terms related to the study of evolution: organic evolution....changes that have taken place in living organisms. inorganic evolution...nonbiological changes that have taken place in the earth. radioactive dating....knowing that certain elements disintegrate by giving off radiations spontaneously and at a regular rate, the age of fossils can be determined using the half-life of the radioactive material. half-life....the rate at which half of radioactive material will decay and become a stable compound. ** Do you know the half life for Carbon 14? For uranium 238? fossil...any remnant or remain of a preserved plant or animal. ** Do you know how fossils are formed by the following? amber petrified wood refrigeration hard fossils tar imprints casts Vestiges....the remains of structures no longer used by an organism but indicative of its ancestral past. ** Do you know what these vestiges were used for in humans? nictitating membrane appendix ear muscles natural selection...when the organism best suited or adapted to its environment survives. "Survival of the Fittest. gene flow...responsible for variation, it is an agent of evolution caused by the introduction of new genes into a population. |
Precambian Era... the earth cooled; there were shallow seas, eukaryotes evolve, cyanobacteria and bacteria are life forms. Paleozoic Era... 570 million years ago:Begins iwth primitive marine algae and marine invertebrates in large numbers. 500 million years ago: The climate becomes mild and the seas cover the continents. Plants invade the land, and the jawless fishes appear. 430 million years ago: Mountains rise in Europe, the continents are flat, and the fist vascular plants appear on the lnad. Arthropods emerge. 395 million years ago: The U.S. is covered by oceans, Europe is mountainous, there are primitive tracheophytes and the first seed plants appear. Sharks and fish are beginning to become bountiful. 345 million years ago: The climate is now subtropical with swamps, great forests, where ferns and gymnosperms are found. The reptiles evolve with amphibians becoming dominant. Insects have arrived as well as fungi. 280 million years ago: Glaciers are in the southern hemispheres, the appalachians are rishing as the first conifers, cycads, and ginkos emerge. Reptiles become more diverse and there is a decline of the amphibiians. The trilobites become extinct. Mesozoic Era... 225 million years ago: There are areas of mountains and arid plains. Land is dominated by gymnosperms as the first dinosaurs appear. Mammals arrive. 190 million years ago: Europe is covered by ocean waters, gymnosperms and repitles dominate, birds emerge. Dinosaurs are now abundant. 136 million years ago: Rise in angiosperms, decline of the gymnosperms. Dinosaures see extinction and there is a great radiataion of insects. Cenozoic Era... 65 million years ago:first primates and carnivores 54 million years ago:small horses and mild weather 38 million years ago:Mammals dominate, lots of birds and insects. 26 million years ago: angiosperms are dominant. 7 million years ago hominoid apes and first humans appear. 2.5 million years ago The first "homo" genus appears. .01 million years ago, Homo sapiens. |
The Principles of Evolution |
Evidence for Evolution Theory: ...homology of structures and organs. ...embryo similarities ...DNA and RNA ...biochemi- cal similarities between organisms. ...vestiges. |
Do you know: ...the difference between homologous and analogous structures? ...the theory proposed by Jean Baptiste Lamarck regarding evolution? ...who wrote "On the Origin of the Species", the abridged name for "On the Origin of Speices by means of Natural Selection? |
This page
was last
updated
on: March
14, 2003
North Warren Regional High School |
Mrs. Johnnie Bennett, Science Teacher |
Pioneers in evolution: |
Charles Darwin. |
Sir Charles Lyell |
Learn about each man's contribution by clicking on his portrait. |
.Jean Baptiste LaMarck |
Internet Resources: Evolution Powerpoint: http://info.citruscollege.com/LC/subjects/BIOL/Goodman104/Examtopics4/EVOLUTION.ppt http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/E/EvolutionPrinciples.html http://www.scidiv.bcc.ctc.edu/rkr/Biology101/lectures/EvolutionPrinciples.html http://www.mhhe.com/biosci/genbio/maderbio6e/outlines/ch19out.mhtml |
