Change is Inevitable

Evidence of Evolution

EvolutionDefined as: Change over time

Geological•Earth Science

Biological•Living things

Chucky D. in 1854

Fossil EvidenceExtinct: No longer found anywhere (alive)

Extant: Living specimens

still found

Mastodon giganteus

Trichodops kerhonsonensis

Types of fossilsMolds and casts

Dents in the mud; some get filled in

Probably T. rex Rhamphorhynchus

Types of fossilsPetrification – literally means “turn to stone”

A mineral facsimile

Types of fossilsAmber, Ice and Peat bogs

Contain actual material from the organisms

Oligochlora semirugosa

Putting the fossils in order:Relative dating

Law of superposition: Oldest fossils below newer ones.

“Older/younger than”

Index fossils: Fossils of a known time of existence to compare with unknown fossilsCorrelation: Using mineral characteristics of rock layers that are no longer connected

Radiodating: Carbon-14 breaks down at a known rate.

Putting the fossils in order:Absolute dating

How many years old

Evidence From Living Things

Comparative anatomy: looking at the structure of different organisms for differences and similarities of form and function

Evidence From Living Things

Comparative Embryology: Similarities/differences during development

Evidence From Living Things

Comparative Biochemistry: Similarities/differences in chemical structures i.e. DNA, proteins, etc.,

Comparative Anatomy

Similar internal structure and development

Different external appearance and use

Show a STRONG evolutionary relationship (recent common ancestor)

Homologous structures

Comparative AnatomyAnalogous structuresDifferent internal structure and development

Similar external appearance and use

Show a WEAK evolutionary relationship (more distant common ancestor)

Comparative AnatomyVestigial structuresA type of homologous structure

The “use” of the structure has changed so much it no longer has one.

Also show a STRONG evolutionary relationship (recent common ancestor)