Jean-Baptiste Lamarck

Life started out simple and became more complex.The Theory of Transformation:– Use and disuse:

Use of a characteristic prefects it, disuse removes it.

– Characteristics changed or acquired over time by an individual can be passed down to its offspring.

Jean-Baptiste Lamarck

Use and Disuse

A giraffe could, over a lifetime of straining, to reach high branches, develop an elongated neck.This acquired characteristic is then transmitted to the giraffe’s offspring: its young will have long necks.What about bald heads and circumcisions?

Jean-Baptiste Lamarck

Life started out simple and became more complex.The Theory of Transformation:– Use and disuse:

Use of a characteristic prefects it, disuse removes it.

– Characteristics changed or acquired over time by an individual can be passed down to its offspring.

Natural Selection

Exercise: answer 3) now.

Charles Darwin

This is a picture of a theory of how dinosaurs evolved into birds.

The Evolution of the Universe

From the Big Bang to galaxies, to the birth of our sun and the creation of planet Earth: 15 billion years.

The Origin of Life on Earth

Two theories — with many subtheories — attempt to account for the origin of life on our earth.

Spontaneous generation somewhere on the early earth

Panspermia: brought to earth from space.

Spontaneous generation in a primeval soup: Miller's Experiment

Stanley Miller, a graduate student in biochemistry, built the apparatus shown here. He filled it with

water (H2O

methane (CH4)

ammonia (NH3) and

hydrogen (H2)

but no oxygen

Miller’s Experiment

He hypothesized that this mixture resembled the atmosphere of the early earth.The gases passed through a chamber containing two electrodes with a spark passing between them. Video Stanley-Miller Experiment.

Miller’s Experiment

At the end of a week, Miller showed that the flask now contained several amino acids as well as some other organic molecules. Amino acids are the building blocks of proteins.Proteins are the building blocks of life.

Miller’s Experiment

New information (2008):http://www.sciencedaily.com/releases/2008/10/081016141411.htm

Early evolutionUnicellular organisms developed into multi-cellular ones and then into plants and animal life forms.

Fossils help clarify Earth’s History

Skeletal design

Vestigial Organs

Humans have muscles to move their ears Humans have a vestigial tailbone

Vestigial toes in the horse

Vestigial limbs in whales and snakes

Embryo development

The Evolution of Man

Darwin did not have any proof of man’s descent from apes.

Since then many fossils of hominids have been found, supporting Darwin’s theory.

Evolution?

The End