1. 2. The discovery of the past
To study evolution means to dig in the past.
The science of past organims is paleontology (greek: palaews: old, logos: science)
Paleontology deal with fossils (lat. fodere = to dig)
Charles Lyell
Georges Cuvier
Early paleontology mainly described ancient life within the Linnean framework
Modern paleontology tries to reconstruct ancient life.
It links therefore ecology and taxonomy.
Mary Anning ( )
Richard Owen ( )

2. How do animals fossilize?
Taphonomy (Greek: tafos: burial; nomos: law)
Immediate burial
Living organism
Death
Fossil
Remains
Buried remains
Mineralization
Decomposition Decay Bleaching
Delayed burial
Exposed remains
Stratinomy
Ginkgo biloba
Ginkgo adiantoides
Much less than 1% of all organisms fossilize
Coral fish
Coral fish from Jura
Bioerosion

3. Fossilized Cyanobacteria (stromatolites) from South Africa
A fossil forest in Dorset, England formed by fossilized bacteria around old tree stumps.
Fossilized Cyanobacteria (stromatolites) from South Africa
A fossilized dinosaur footprint from New Mexico
A mammoth coprolith (fossilized excrements)

4. Immediate and delayed buriages
From B. Ziegler: Allgemeine Paläontologie. Thieme, 1975.

5. What fossilizes? Hard body materials Soft body materials
Substance Examples
Calcite (CaCO3) Octocorallia Bryozoa Brachiopoda Polychaeta Ammonita Belemnita Echinodermata
Aragonite (CaCO3) Hydrozoa Gastropoda
Calciumphosphate Vertebrata (Ca5(OH)(PO4)3) Trilobita Crustacea
Opal (SiO2.H2O) Radiolaria Diatomea Porifera
Chitin Algae Fungi Arthropoda Cnidaria Priapulida Annelida
Cellulose Plantae Tunicata
Soft tissues very seldom fossilize
Exceptions are
Fast drying out in very arid climates
Permanent frozen
Preservation in amber or asphalt
A feathered Dinosaur:
Sinosauro-pteryx

6. How complete is the fossil record?
Without hard skeleton
Fossils
With hard skeleton
Fossils
Cephalochordata
Unknown
Vertebrata
Often
Tunicata
Rare
Echinodermata
Often
Chaetognatha
Rare
Tentaculata
Often
Pentastomida
Unknown
Arthropoda
Often
Tardigrada
Unknown
Mollusca
Often
Onychophora
Rare
Cnidaria
Often
Pogonophora
Unknown
Porifera
Often
Sipunculida
Rare
Rhizopoda
Often
Echiurida
Unknown
Hard skeleton infrequent
Nematoda
Rare
Plathelminthes
Unknown
Branchiotremata
Some taxa often
Ctenophora
Unknown
Annelida
Some taxa often
Mesozoa
Unknown
Ciliata
Some taxa often
Sporozoa
Unknown
Flagellata
Some taxa often

7. Under what conditions do organisms fossilize?
Probability of fossilization
Moisture gradient
Nutrient rich soils
River sediments
Anaerobic conditions (moorlands)
Volcanic ashes
Salinity gradient

8. How complete is the fossil record?
Benton MJ, Willis MJ,  &  Hitchin R Quality of the fossil record through time. Nature 403:
Divergence time inferred from cladogram
Divergence time inferred from fossils
SCI: Quotient of consistent to inconsistent nodes
RCI: Relative completeness index
GAP: Gap excess index
Alba DM, Jordi A, Moya-Sola S Completeness of mammalian fossil record in the Iberian neogene. Palaeobiology 27: 79-83
Neogene Iberian mammals
The completeness of the fossil record PT can be calculated from the probability R that a fossil species is preserved at least in one geological layer:
Species level: 77%
Genus level: 91%

9. The tectonic plates (from David Sanfwell, Scripps Inst. Oceanography)
Continental drift
Alfred Lothar Wegener ( )
The tectonic plates (from David Sanfwell, Scripps Inst. Oceanography)
Evidence for plate tectonics:
Fit of coastlines
Distribution of mountains
Continuity of fossils
Continuity of geological features
Isostasy: Earth acts like a fluid
From Press et al Understanding earth,

10. Continental drift
From C. R. Scotese:

11. How to match phylogeny and plate tectonics

12. Relative dating methods
Fossil dating
Relative dating methods
Relative dating uses geological strata to infer whether fossils are older or younger than a given stratum
Layer 1
Younger
Layer 2
Time
Layer 2
Older
Stratigraphy
Morphological primitivism

13. Absolute dating methods
Radiometric dating
Most minerals which contain radioactive isotopes are in igneous rocks.
The dates they give indicate the time the magma cooled.
Potassium 40 is found in:
potassium feldspar (orthoclase)
muscovite
amphibole
glauconite
Volcanic rocks
Sometimes in sediments
Uranium may be found in:
zircon
urananite
monazite
apatite
sphene
Carbon 14 is used for bones

14. How to use radiometric dating?
The Rb/Sr System
= 1.42 x a-1, 
t1/2 = 4.8 x 1010 a
b-decay
Pt: Amount of daughter atoms through decay
Total
Decay
Original
86Sr is an isotope that is
not radioactive
not radiogen

15. Recognition of unique events to subdivide time
Radiometric dating
Stratigraphy
Relative time scale
Absolute time scale
Geological time scale
Recognition of unique events to subdivide time
Calibrating geological time
Radiomtric dating of layers
Raw data
Modified from Andy MacRae: Radiometric Dating and the Geological Time Scale.

16. Dendrochronology analyses tree-ring growth patterns.
Fission track
Dendrochronology
Fission Tracks (FT) are micrometer-sized, linear damage tracks that occur in insulating minerals and that are caused by the spontaneous fission of heavy, unstable nuclides (mostly 238U in natural minerals).
Dendrochronology analyses tree-ring growth patterns.

17. History of the earth Steno founded stratigraphy by stating that
geological layers are horizontal and superposed.
Deeper layers are older.
Nicolas Steno ( )
The Red Rock Canyon, California

18. The geological time scale
Eon
Era
Period
Age at Base (Mya)
Duration (Mya)
Phanerozoic
Cenozoic
Quaternary
1.6
Tertiary 65
63.4
Mesozoic
Cretaceous
140 75
Jurassic
205
Triassic
250 45
Paleozoic
Permian
290 40
Carboniferous
355
Devonian
410 55
Silurian
440 30
Ordovician
510 70
Cambrian
540
Proterozoic
Neoproterozoic
Ediacaran (Vendian)
630 90
Cryogenian
850
220
Tonian
1000
150
Mesoproterozoic
1600
600
Palaeproterozoic
2500
900
Archean
3800
2950
Hadean
4550
750

19. Today’s reading
History of palaeontology:
History of earth:
Radiometric dating details:
Geological time scale: