Fossils are amazing how they are formed. The process is fossilization. I was surprised to discover that a series of mistakes must happen in order for a fossil to be created. First some living creatures must die and must some how escape the scavengers that have a roll in the food chain. The once living has to then become entombed in mud and sand. The shroud must lie undisturbed for years so that mineralization can take place in which the tissue or cast gets filled in with sediment. Then this body turns to stone.
The scientists that study these relics are called paleontologist. Dates in paleontology are usually revised backward in time, since a new find may revise an event earlier then what was discovered previously. Examining articles for the first multi-cellular organisms, First vertebrates or the pollination of insects to flowering plants. The strata of rock in which they are found date the fossils. Measuring the extent of radioactive decay in certain isotopes they contain dates the rocks. The element carbon can exist in three different forms, Carbon 12 six protons and six neutrons, Carbon 13 six protons and seven neutrons. 12C and 13C are not radioactive.
The rare 14C is radioactive, its atom decay by the loss of an electron to nitrogen 14. Theirs a half-life 14C is approximately 5,730 years, this is how long it takes for half the atoms in and quantity to decay. The earth gains 14C from cosmic radiation and losses it as a result of radioactive decay. Volcanic ash can be used for dating. Ash known as mazama, with an age of 6,720 radiocarbon years, and Glacier Peak B ash located in glacier peak Washington with an age of 11,250 radio carbon years. Another method of dating is called molecular clock examine for genes which are descended from a common ancestral gene. Although very new this method sometimes clashes with conventional methods because its not well calibrated. I would like to refer to an article I read in Newsday health and discovery section by Tamie Talan.
Radioactive Decay, Nuclear Fission and Nuclear Fusion When elements undergo radioactive decay the atoms of one element are changed into the atoms of another element when an alpha or beta particle is emitted from an unstable nucleus. When a nucleus disintegrates and emits an alpha particle it is alpha decay, the alpha particle emitted contains two protons and two neutrons which is equivalent to a ...
A fossil named SM3. A group of anthropologists at Mount Sinai School of Medicine study a skull that is believed to from the species of homoerectus which goes back 1.8 million years and individuals disappeared about 100,000 years ago. Homo sapiens evolved after homoerectus. The discovery of how the brain was organized by examining folds in the skull. The homoerectus indicates the brain must have had cognitive specialization and ability to language. The fossil was discovered in Indonesia and bizarrely shows up in Manhattan into a collectors hand that dies and his collection brought by a natural shop called Maxilla Amandidle.
The owner realized that the cranium may be very important for study and turned it over to the museum. Perhaps this unlocks missing pieces of the puzzle for paleoantropologist or changes the series of events as new finds often do.
Sources of References 1. The Science Times Book of Fossils and Evolution CO. 1998 By the New York Times Edited by Nicholas Wade 2. After the Ice Age by E.C.Pielou 3.
Newsday Health and Discovery, Tuesday November 14, 2000.