Bio Antrho Exam 2 part 1

Paleoanthropology

Study of ancient humans (biology and behavior)

Trace Fossils

remnants of past organisms- evidence of an organism

ex: footprints, coprolites

Casts or Molds

when an original materal is cast or molded from surronding rock

Replacment

mineral replace the hard part of the original organic material

What is the most common rock to cover bones

sedimentary- soft of the fossils

What is the processes that occur after an organism dies?

Taphonomy

3 taphonomic biases

incomplete fossil record

factors leading to preservations are by chance and luck

choise of searching area, when and where

What are the two dating methods catagories

relative dating and absolute dating

Stratigraphy

Adding layers can give us an idea of time.

Law of Superposition

The oldest the layer the lower it is, newer is higher up.

provenience

the original location or context of the artifact or fossil

Biostratigraphic dating

fauna used to date the layers

2 types of Relative Dating

Cultural and Fluroine

Cultural Dating

being able to use artifacts to determine how much older/younger things are

Fluorine Dating

when a bone underground looses nitrogen and gaines flourine

bad for providing absolute dates, good for providing realtive dates for things found together.

Piltdown Man

a skull that looks like a Orangutan and human, they were able to tell it was put together based on the fluorine levels

Absolute Dating

relies of radioactive isotopes

Radioactive Decay

radioactive isotopes of one element that are unstable, then disinagrate, to form an isotope variation of another element.

NOT stable → wanting to change into another element

Radiocarbon Dating

Carbon 14 is unstable. Carbon 12 is not

So when an organism dies, carbon-14 decays. 12 stays the same

We can compare the 14 and 12 to see how many years ago

**only organic material contains carbon

Radiopotassium Dating

used to date igneous rocks (volcano) → not the fossil directly

Potassium 40 decays in Argon 40

very very old sites only

macroevolution

changes that lead to speciation

Pyletic Gradualism

Slow, gradual changes over time resulting in speciation

Puntuacted Equilibrium

Period of statis punctuated by rapid periods of change

Phylogeny

evolutionary relationships, how they are related to eachother

Geological Time scale Eras

Pre-Cambrian

Paleozoic

Mesozoic

Cenozoic