Theories, Evidences and Patterns of Evolution

1. Isabel V. Neri

2. What is Evolution?
 It is the gradual change from one form to
another through a period of time.

4. Lamarck’s Theory
Darwin’s Theory

5. Lamarck’s Theory
 Jean Baptist de Lamarck

6. Lamarck’s Theory
 Acquired traits can be inherited
 He proposed that:
Organisms change as their environment
changes

7. Darwin’s Theory
 Charles Darwin

8. 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

9. Variation exists within species. For example,
some gorillas have longer arms than others.
Natural Selection - The environment
selects organisms with beneficial traits.
Adaptation

11. Adaptation

12. Adaptation

13. 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.

14. EVOLUTION
NATURAL SELECTION
ADAPTATION

15. EVOLUTION
NATURAL SELECTION
ADAPTATION

16. 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

17. Evidences of Evolution
 Any preserved part or tissue of an
organism that once lived.
FOSSIL

20. CASTS
MOLDS
IMPRINTS
PETRIFIED FOSSILS

21. Biochemical Evidences
 Indicate that some organisms have
similar DNA sequences, which suggest
common ancestry
DNA

24. VARIATION

27. Divergent Evolution

29. Convergent Evolution