Grade 7 Evolution

1. Evolution
Changes in inherited characteristics of a
SPECIES over time

2. Lamarck's Theory of
Evolution
●Proposed by Jean Baptiste de Lamarck
●Suggested that characteristics or traits
developed during an organisms life
time and inherited by his offspring
●His hypothesis was called inheritance
of acquired characteristic

4. Darwin's Model of Evolution
Plants and animals on Coast of south American
islands originally came from Central and South
America.
Species of finches on the island looked similar to
mainland finches
Members of a population best able to survive
and reproduce will pass their traits to the next
generation resulting in differences in species.

5. Natural Selection
● Organisms with traits best suited to
their environment will more likely
survive and reproduce.

6. Principles of Natural Selection
● Overproduction
● Variation
● Adaptation

7. Overproduction
● More offspring than can be supported
by the environment are produced
therefore many die
●

8. Variation
● Within a species there can be a variety of traits
● Some variations are better for survival than
others
● Those with better variations survive and
reproduce

9. Adaptation
● Any variation that makes an organism
better suited to its environment

10. Over Time
● Genetic make up of species may
change
● Environmental factors can cause
changes in source of genes
● Geographic isolation can make two
populations so different they become
different species.