THE ORIGIN AND EVOLUTION OF LIFE UNIT 8
THE ORIGIN AND EVOLUTION OF LIFE
UNIT 8
1. The beginning of life
Francesco Redi, 1668
Theory of spontaneous generation
1. The beginning of life
Louis Pateur, 1859
Theory of spontaneous generation
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
1. The beginning of life Miller’s experiment
1. The beginning of life
Panspermia theory
Life came form extra terrestrial spores transported by meteorites
1. The beginning of life
Hydrothermal vents provided energyMuddy soils provided mineralsVesicles with organic molecules were formedSelf reproduction of vesicles started at a certain rateRNA was supposed to be the first nucleic acid
Current theory
2. Evolutionary theories
Carl von Linné S. XVIII
George Cuvier S. XVIII
CREATIONISMSpecies are staticFossils are due to catastrophes
2. Evolutionary theories
Lamarck
Animals develop structures and organs they need to adapt to the environmentThose characteristics are transmited to the offspring
LAMARCKISM
2. Evolutionary theories
Charles Darwin
Individuals in a population are differentOrganisms produce more offspring than neededThey struggle for existenceIndividuals with the most advantageous characteristics will surviveThose favourable variations will be transmited to the offspring
DARWINISM
3. Evidences of evolution
HOMOLOGOUS ORGANS
3. Evidences of evolution
ANALOGOUS ORGANS
VESTIGIAL ORGANS
3. Evidences of evolution
3. Evidences of evolution
FOSSILS
3. Evidences of evolution
EMBRYOS RESEMBLANCE
3. Evidences of evolution
BIOGEOGRAPHY
3. Evidences of evolution
MOLECULAR SIMILARITIES
3. Evidences of evolution
CONVERGENCE
4. Present-day theories
SYNTHETIC THEORY
Mutations
Theodosius Dobzhansky
4. Present-day theories
THE SELFISH GENE THEORY
Richard Dawkins
4. Present-day theories
ENDOSYMBIOTIC THEORY
Lynn Margulis
4. Present-day theories
PUNCTUATED EQUILIBRIUM THEORY
4. Present-day theories
NEUTRAL THEORY
Motoo Kimura
5. Speciation
5. Speciation
MICROEVOLUTION AND MACROEVOLUTION
6. The appearance of human beings
6. The appearance of human beings
6. The appearance of human beings
6. The appearance of human beings
6. The appearance of human beings
A. Africanus H. erectus h. sapiens