This document summarizes theories about the origin and evolution of life. It discusses early theories from the 1600s-1920s about spontaneous generation and the formation of organic molecules in the primitive atmosphere. It also describes the Miller experiment and panspermia theory. Current theories propose that hydrothermal vents provided energy and vesicles formed that could self-replicate, with RNA as the first nucleic acid. The document then outlines evolutionary theories from Lamarck to Darwin and modern synthesis. It lists evidence of evolution such as homologous/analogous structures, vestigial organs, fossils, and molecular similarities. Finally, it discusses present-day theories including punctuated equilibrium and neutral theory, as well as speciation and the appearance of human beings

1. THE ORIGIN
AND EVOLUTION OF LIFE
UNIT 8

2. 1. The beginning of life
Francesco Redi, 1668
Theory of spontaneous generation

3. 1. The beginning of life
Louis Pateur, 1859
Theory of spontaneous generation

4. 1. The beginning of life
Oparin’s theory, 1922
Methane, ammonia, hydrogen
and water vapour were the
components of the primitive
atmosphere
Electricity from storms, volcano
eruptions and UV radiation provided
energy to start chemical reactions
As a result, organic
molecules were
formed and fell with
the rain to the
primitive ocean Bigger organic molecules were
formed in the ocean and
isolated form the water in a kind
of spheres called coacervates
that were the ancestor of cells
Oparin’s theory

5. 1. The beginning of life Miller’s experiment

6. 1. The beginning of life
Panspermia theory
Life came form
extra terrestrial
spores transported
by meteorites

7. 1. The beginning of life
Hydrothermal vents provided energy
Muddy soils provided minerals
Vesicles with organic molecules were formed
Self reproduction of vesicles started at a certain rate
RNA was supposed to be the first nucleic acid
Current theory

8. 2. Evolutionary theories
Carl von Linné S. XVIII
George Cuvier S. XVIII
CREATIONISM
Species are static
Fossils are due to catastrophes

9. 2. Evolutionary theories
Lamarck
Animals develop structures and organs they need to adapt to
the environment
Those characteristics are transmited to the offspring
LAMARCKISM

10. 2. Evolutionary theories
Charles Darwin
Individuals in a population are different
Organisms produce more offspring than needed
They struggle for existence
Individuals with the most advantageous characteristics will
survive
Those favourable variations will be transmited to the offspring
DARWINISM

11. 3. Evidences of evolution
HOMOLOGOUS ORGANS

12. 3. Evidences of evolution
ANALOGOUS ORGANS

13. VESTIGIAL ORGANS
3. Evidences of evolution

14. 3. Evidences of evolution
FOSSILS

15. 3. Evidences of evolution
EMBRYOS RESEMBLANCE

16. 3. Evidences of evolution
BIOGEOGRAPHY

17. 3. Evidences of evolution
MOLECULAR SIMILARITIES

18. 3. Evidences of evolution
CONVERGENCE

19. 4. Present-day theories
SYNTHETIC THEORY
Mutations
Theodosius Dobzhansky

20. 4. Present-day theories
THE SELFISH GENE THEORY
Richard Dawkins

21. 4. Present-day theories
ENDOSYMBIOTIC THEORY
Lynn Margulis

22. 4. Present-day theories
PUNCTUATED EQUILIBRIUM THEORY

23. 4. Present-day theories
NEUTRAL THEORY
Motoo Kimura

24. 5. Speciation

25. 5. Speciation
MICROEVOLUTION AND MACROEVOLUTION

26. 6. The appearance of human beings

27. 6. The appearance of human beings

28. 6. The appearance of human beings

29. 6. The appearance of human beings

30. 6. The appearance of human beings
A. Africanus H. erectus h. sapiens