Ancient History 10

Your Thoughts…

Where did we come from?

What is the difference between a theory and a fact?

Theory vs. Fact

Theory: A proposed explanation whose

status is still hypothetical and subject to experimentation.

Fact: A truth known by actual

experience or observation; something known to be true.

Theories on how it began ... • Evolutionary theory did not begin

in 1859 with Charles Darwin and The Origin of Species.

• Evolution-like ideas had existed since the times of the Greeks

• Darwin's time the idea of evolution - called "descent with modification“– Not completely controversial, since

there was other evolutionary theories had already been proposed.

Theories – The Greeks • Greeks had a philosophical

notion of descent with modification.

• Greek philosophers argued that all things originated from water or air.

• All things descended from one central, guiding principle. – Aristotle: transition between the

living and the nonliving, and theorizes that in all things there is a constant desire to move from the lower to the higher, finally becoming the divine.

Theories- Medieval • Talks of evolution during the

Medieval times was uncommon• Era was dominated by the

Christian theory of creation. • Spontaneous generation

– Living things can appear fully formed from inorganic matter. • Maggots came from rotting meat,

frogs came from slime, etc. • Prevented both genetic thinking and

speculation about evolution or descent with modification.

Theories- I. Kant 1724-1804

• His concept of descent was close to modern thinking– Anticipated Darwinian thinking.

• Based on similarities between organisms– Come from a single ancestral

source. • Speculated that an orang-

outang or a chimpanzee may develop may evolve to the structure of man.

Theories- C. Linnaeus 1707-

1778

Father of modern taxonomy for his work in hierarchical classification of various organisms.

Believed in the fixed nature of species.Because of hybridization

experiments in plants, which could produce new species.

Support of the Christian belief of creation

Theories – T. Malthus 1766-1834

• Theory of population growth was in the end what inspired Darwin to develop the theory of natural selection. – Populations produce many more

offspring than can possibly survive– Poverty, famine, and disease were

natural outcomes that resulted from overpopulation.

• Divine forces were ultimately responsible for such outcomes.

Theories- Creation

Genesis Story (Christian Bible)Old testament

God created the world in 6 days and rested on the 7th day. Adam (clay or dust) and Eve (Adam’s rib) Garden of Eden (Paradise)

Tree of knowledgeSin

Taken from paradise

Theories–Darwin and Wallace Charles Darwin and Alfred Russel

Wallace Developed the idea of the

mechanism of natural selection Darwin thought about the issue for

20+years before he first published The Origin of Species.

Darwin was interested in exploring the implications of natural selection.

Charles Darwin: Father of Evolution

12 February 1809 – 19 April 1882

When he was 22, he embarked on a 5 year journey around the world, as a Naturalist on the HMS Beagle

The distribution of wildlife and fossils he saw on his journey was later used to develop his theory of Evolution.

This evidence was then used to publish his theory in his 1859 book On the Origins of Species

Evolution Gradual change over many generations

Widely held notion that all life is related and has descended from a common ancestor.

Natural Selection (Survival of the Fittest) = Random genetic mutations occur and the “good” aspects are kept to aid survival

Failure to evolve in response to the environmental changes can and often does lead to extinction.

Brain Pop:http://www.brainpop.com/science/famousscientists/charlesdarwin/preview.weml

Big Bang Theory: http://www.youtube.com/watch?v=B409mw3mzI4