Isabel V. Neri

What is Evolution?

It is the gradual change from one form to another through a period of time.

Lamarck’s Theory

Darwin’s Theory

Lamarck’s Theory Jean Baptist de Lamarck

Lamarck’s Theory

Acquired traits can be inherited

He proposed that:Organisms change as their environment

changes

Darwin’s Theory

Charles Darwin

Darwin’s Theory

Published “Origin of Species” Traveled around the world in the Beagle He proposed that:

Organisms produce more offsprings than the available resources can support

Organisms fight for limited resources like food, territory, and other necessities of life. Only those who survive can produce their own offspring

Variation exists within species. For example, some gorillas have longer arms than others.

Natural Selection - The environment

selects organisms with beneficial traits.

Adaptation

Adaptation

Adaptation

Lamarck vs Darwin

Jean Baptist de Lamarck

Charles Darwin

1809 1859

French Naturalist English Naturalist

Acquired traits can be inherited by an organism

Organism adapts to changes in the environment. Only the fittest organisms survive through natural selection.

EVOLUTION

NATURAL SELECTION

ADAPTATION

EVOLUTION

NATURAL SELECTION

ADAPTATION

Gradual change from one form to another through a period of time

The environment selects organisms with beneficial traits

A form modified to fit a changed environment

Evidences of Evolution

Any preserved part or tissue of an organism that once lived.

FOSSIL

CASTS

MOLDS

IMPRINTS

PETRIFIED FOSSILS

Biochemical Evidences

Indicate that some organisms have similar DNA sequences, which suggest common ancestry

DNA

VARIATION

Divergent Evolution

Convergent Evolution