Comprehensive Evolution and Dating Methods in Paleontology and Geology

Radiometric dating

a method of determining the age of a sample from the amount of a radioactive isotope of the same element in a sample

index fossil

A distinctive fossil used to compare the relative ages of fossils

relative dating

Method of determining the age of a fossil by comparing its placement with that of fossils in other layers of rock

extinct

A term that typically describes a species that no longer has any known living individuals.

half-life

length of time required for half of the radioactive atoms in a sample to decay

geologic time scale

timeline used to represent Earth's history

era

major division of geologic time; usually divided into two or more periods

period

division of geologic time into which eras are subdivided

plate tectonics

geologic processes, such as continental drift, volcanoes, and earthquakes, resulting from plate movement

macroevolutionary

changes in anatomy, phylogeny, and behavior that take place in clades larger than a single species

patterns:

adaptive radiation

convergent evolution

background extinction

extinction caused by slow and steady process of natural selection

mass extinction

event during which many species become extinct during a relatively short period of time

Gradalism

The evolution of a species by the gradual accumulation of small genetic changes over long period of time

punctuated equilibrium model

Pattern of evolution in which long stable periods are interrupted by brief periods of more rapid change

adaptive radiation

process by which a single species or a small group of species evolves into several different forms that live in different ways

convergent evolution

Process by which unrelated organisms independently evolve similarities when adapting to similar environments

Coevolution

Process by which two species evolve in response to changes in each other

endosymbiotic theory

theory that proposes that eukaryotic cells formed from a symbiotic relationship among several different prokaryotic cells

Major divisions in geologic time scale

eons, eras, periods

Haden eon

1. first rocks formed (times of earths formation)

Archean Eon

2. First Life appeared

Proterozoic eon

3. stable continents start, eukaryotic cells evolved

Phanerozoic

4. began —→ goes into modern day

Precambrain time

90% earth’s history

Rapid evolution

genetic drift and mass extinction

Miller-urey experiment

Test of organic compounds produced on early earth (were wrong but could be right)

RNA

First info carrying molecule (fundamental molecule of early life)

Genetic drift

the random change in the frequency of gene variants (alleles) in a population from generation to generation

Natural selection

core mechanism of evolution where organisms better adapted to their environment are more likely to survive, reproduce, and pass advantageous traits to their offspring, causing populations to change and develop adaptations over time

Cenozioc Era

(most recent) Period:

Quaternary, End of the Ice Age (complex human societies)

Tertiary: Age of Mammlels begin

Events: ,

Mesozioc Era

(second most recent) Period:

Cretaceous: First flowing plants (all dino extinct)

Jurassic: Dinosaurs are dominant

Triassic: Dino first appear

Events:

Paleozoic Era

(third most recent) Periods:
Permian: Pangea comes together (mass extinction)

Carboniferous (Pennsylvanian, Mississippian)

Devonian

Silurian

Ordovician

Cambraim: Advanced forms of marine life

Events: (development) (vertebrates) Cockroroches

Precambrian Time

(first) (makes up over 90% of earth history) Formation of the earth