PaleontologyEarth History

What is Evolution

• Genetic change over time

• Resulting in new species

• There is more to evolution than Change

• Trees change, mountains change

• Evolution is a change in genes that control traits in an organism

Why

• The Environment changes

• A trait which is good for one environment may not be good for different environment

• Basketball v. Football

• Playing a guitar v. Flute

• Geometry v. Algerbra

How do changes take place

• Natural Selection– Nature chooses– Conditions in nature select for traits in

organism which will make that organism the most successful.

– Selected for…Passed on– Selected against…extinct

Natural Selection v. Artificial Selection

• Natural…Nature chooses

• Artificial Selection…Humans choose

Artificial Selection

• All that you see are things that humans have chosen

• The stuff you don’t see are items we have not selected for…they may become extinct...or retro in twenty years.

• Music, clothes, TV, etc. Anything “popular” has been selected for. The unpopular…not around.

Natural Selection…How does it work?

• More organism are born than can survive.• All of the organisms (offspring) will have

genetic changes due to sexual reproduction and mutation

• Some of these changes will be beneficial to an organism. These benefits lead to a stronger organism.

• These stronger traits are pass down to future generations.

Paleontology

• What happened

• Why did it happen

• When did it happen

• Order of occurrence

SuperpositionOldest on Bottom…Youngest on top

Superposition In Chicago

Uniformitarianism

• Process going on today have been going on since the earth formed 4.5 bya– Weathering– Erosion– Plate Tectonics

vs. Catastrophisma series of catastrophes created the earth

Relative Dating

• No…its not something they do in Kentucky

• Compare several items of first to occur to last to occur

• No exact age is applied

• I am older than you. My dad is older than me

Oldest to Youngest

Absolute dating

• How many years ago

• Assign and age to a fossil

How to assign age

• Tree rings

• Radioactive decay– Process by which a radioactive material

becomes stable– Nothing effects the rate of decay– Excellent tool to measure age– Isotope (parents) decay (become stable) into

daughter C-14 decays into N-14

Cladistics

• Uses absolute age

• Uses DNA (comparative Genetic Material)

• Create a Logical progression of the evolution of similar species

Cladistics

Another Vert Evolution

Vert Evolution

Evol of dinos

Dinosaurs

Primate Evolution

Humans did not evolve from “ApesThey have a common ancestor

Human Migration…out of Africa

• SPECIES TIME PERIOD• Ardipithicus ramidus 5 to 4 million years ago

Australopithecus anamensis 4.2 to 3.9 million years ago

• Australopithecus afarensis 4 to 2.7 million years ago

• Australopithecus africanus 3 to 2 million years ago• Australopithecus robustus 2.2 to 1.6 million years

ago• Homo habilis 2.2 to 1.6 million years ago• Homo erectus 2.0 to 0.4 million years ago• Homo sapiens archaic 400 to 200 thousand years

ago• Homo sapiens neandertalensi 200 to 30 thousand

years ago• Homo sapiens sapiens 200 thousand years

ago to present