An Introduction toAn Introduction to

EvolutioEvolutionn

What do you want to know?What do you want to know?

• Write down what you know about evolution

• Write down what you want to know about evolution

How did life begin?How did life begin?

• Theory A. “Primordial Soup” model

• This theory states that the first life on earth appeared in a "primordial soup" consisting of water loaded with chemicals necessary for the start of life. This "warm little pond" was believed to have been struck by an electrical discharge (most likely from lightning) which caused the chemicals to form complex protein molecules, which eventually evolved into other life forms.

• Simulated by Miller & Urey

How did life begin?How did life begin?

•Theory B. “Bubble” Model:•Gases from undersea volcanoes rose to surface of oceans and reacted with UV radiation and lightning producing existing gases

•(Proposed by Louis Lerman)

III. From chemicals to us!III. From chemicals to us!

• Over the course of a billion years, simple organic molecules changed and created primitive (simple) cells

• Very slowly, these cells became more complex and genetically changed into different species

• A brief review of history…

Eubacteia & Archeabacteria Eubacteia & Archeabacteria (~3500 (~3500 mya)mya)

Early Eukaryotes (~1500 Early Eukaryotes (~1500 mya)mya)

Diverse Protists (~1000 Diverse Protists (~1000 mya)mya)

Early multicellular organisms Early multicellular organisms (~700 mya)(~700 mya)

Precambrian Period (~570 Precambrian Period (~570 mya)mya)

Cambrian period (~520 Cambrian period (~520 mya)mya)

Ordovician period (~480 Ordovician period (~480 mya)mya)

Silurian Period (~420 mya)Silurian Period (~420 mya)

Devonian Period (~380 Devonian Period (~380 mya)mya)

CarboniferousCarboniferous Period (~330 Period (~330 mya)mya)

Triassic Period (~220 mya)Triassic Period (~220 mya)

Jurassic Period (~180 mya)Jurassic Period (~180 mya)

Cretaceous Period (~120 Cretaceous Period (~120 mya)mya)

Tertiary Period (~40 mya)Tertiary Period (~40 mya)

Quaternary Period (~.5 mya-Quaternary Period (~.5 mya-today)today)

IV. Who discovered IV. Who discovered Evolution?Evolution?JEAN-BAPTISTE

LAMARCKCame up with the theory that parents could pass on acquired characteristics. Acquired characteristics are things that happen to you during your lifetime, they are not inherited.

IV. Who discovered IV. Who discovered Evolution?Evolution?This theory is no longer This theory is no longer accepted it has been accepted it has been disproved by an experiment disproved by an experiment where mice had their tails cut where mice had their tails cut off (aquired characteristic). off (aquired characteristic). Would that be passed on to Would that be passed on to offspring? Why? Why not?offspring? Why? Why not?

IV. Who discovered IV. Who discovered Evolution?Evolution?JEAN-BAPTISTE

LAMARCKHe also founded the principle of use and disuse: If an organ is used, it will become stronger, and if it is not used, it will weaken and may disappear in future generations.

Who discovered evolution?Who discovered evolution?

CHARLES DARWIN A scientist that traveled the seas

observing nature.His theories are more widely

accepted than Lamarck’sCame up with “Natural Selection”

while observing the finches of the Galapagos Islands.

Natural Selection also known as survival of the fittest.