WHAT IS EVOLUTION?WHAT IS EVOLUTION?

WHAT IS YOUR OPINION?WHAT IS YOUR OPINION?

How would you explain the evolution of this trait?How would you explain the evolution of this trait?

• Cave salamanders are blind (their eyes are non-Cave salamanders are blind (their eyes are non-functional). How could a biologist explain how this functional). How could a biologist explain how this inability evolved from sighted ancestors?inability evolved from sighted ancestors?

PRE-DARWIN IDEASPRE-DARWIN IDEAS

• Earth is youngEarth is young

• Earth is not changingEarth is not changing

HISTORY: In the beginning…HISTORY: In the beginning…

Plato and AristotlePlato and Aristotle (mid 300 B.C.) (mid 300 B.C.)

• Scale of NatureScale of Nature

EVIDENCE FROM GEOLOGYEVIDENCE FROM GEOLOGY

James HuttonJames Hutton• He proposed the theory of uniformitarianismHe proposed the theory of uniformitarianism

Charles LyellCharles Lyell• 1830 wrote Principles of Geology that Darwin 1830 wrote Principles of Geology that Darwin

read on his journey supporting Hutton’s workread on his journey supporting Hutton’s work

JUDEO CHRISTIAN CULTUREJUDEO CHRISTIAN CULTURE

Exploring God’s workExploring God’s work• Carlos LinnaeusCarlos Linnaeus (1700s): (1700s):

______________________________________________________

• George CuvierGeorge Cuvier (late 1700s): (late 1700s): - Paleontology: Found that fossils were dissimilar - Paleontology: Found that fossils were dissimilar

to modern lifeto modern life - Species can become _________________- Species can become _________________ - Species can ___________________________- Species can ___________________________

Erasmus DarwinErasmus Darwin

• Grandpa!Grandpa!• Termed _______________Termed _______________• Life developed from a single Life developed from a single

sourcessources• Humans close to primates (how Humans close to primates (how

dare he!)dare he!)

O.K. ORGANISMS EVOLVE BUT O.K. ORGANISMS EVOLVE BUT WHAT WHAT MAKESMAKES THEM EVOLVE? THEM EVOLVE?

MECHANISMS BEHIND EVOLUTIONMECHANISMS BEHIND EVOLUTION

Jean Baptiste Pierre Antoine de Monet, Chevealier Jean Baptiste Pierre Antoine de Monet, Chevealier de Lamarck…a.k.a. de Lamarck…a.k.a. Lamarck!Lamarck!

• Published in 1809 when baby Darwin was born Published in 1809 when baby Darwin was born • ______________________________________________________________________________

______________________________________________________________________________

• Idea #1: _______________________________Idea #1: _______________________________• Idea #2: _______________________________Idea #2: _______________________________• Idea #3:________________________________Idea #3:________________________________

LAMARCK’S IDEALAMARCK’S IDEA

Charles Darwin (1809-1882) Charles Darwin (1809-1882)

• Beagle voyage Beagle voyage around the worldaround the world

• Looked at living Looked at living organisms and organisms and fossil recordfossil record

VOYAGE ON THE BEAGLEVOYAGE ON THE BEAGLE

PATTERNS IN DIVERSITYPATTERNS IN DIVERSITY

1. 1.

Rheas in South AmericaEmu in Australia Ostrich in Africa

Darwin questioned why are marsupials Darwin questioned why are marsupials only found in Australia even though only found in Australia even though Europe had a similar environment.Europe had a similar environment.

Unique South American Unique South American CharacterCharacter

• A South American A South American tropical lizard more tropical lizard more similar to a S.A. similar to a S.A. desert lizard than desert lizard than another lizard another lizard elsewhereelsewhere

2. Species Vary Locally2. Species Vary Locally

• What does the What does the difference in difference in structure structure between the between the two tortoises two tortoises tell you about tell you about the island they the island they occupy?occupy?

Galapagos Tortoises

3. Species vary over time3. Species vary over time

• Ancestor of Ancestor of armadillo armadillo was much was much biggerbigger

• Darwin also observed the Darwin also observed the geological process Hutton and geological process Hutton and Lyell observed on his journeyLyell observed on his journey

Working towards a theory of Working towards a theory of Natural SelectionNatural Selection

• Malthus’ work: Malthus’ work: population size can population size can increases increases exponentially but it exponentially but it remains stable remains stable over time…why?over time…why?

• Today known as Today known as “evolution”“evolution”

Darwin - Descent with ModificationDarwin - Descent with Modification

3 Points To Darwin’s Theory of 3 Points To Darwin’s Theory of Natural Selection (Mechanism)Natural Selection (Mechanism)

1. 1.

2. _________________________________2. _________________________________

The environment plays a The environment plays a role in keeping role in keeping populations in checkpopulations in check

• Natural selection __Natural selection ______________________________________________________________________________________________________________________________________________________________________• ““Survival of The Fittest”: Survival of The Fittest”:

those that can survive those that can survive and reproduce the most and reproduce the most viable offspring are the viable offspring are the most fitmost fit

3. _________________________3. _________________________

Alfred Wallace (1823-1913)Alfred Wallace (1823-1913)

• I have this theory about natural selection I have this theory about natural selection charlsey boy, what do you think?charlsey boy, what do you think?

Darwin’s Origin of SpeciesDarwin’s Origin of Species• Decent with modification (evolution)Decent with modification (evolution)• Natural SelectionNatural Selection

• Decent of Man was also then publishedDecent of Man was also then published

Lamarck vs. DarwinLamarck vs. Darwin