Transcript 32-3 Fossils - McGraw Hill Higher Education

Chapter 32: Evolving earth
Copyright  2010 McGraw-Hill Australia Pty Ltd
PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint
Slides prepared by Karen Burke da Silva, Flinders University
32-1
History of life on earth
• Fossils provide information about past life
– preserved remains or indications of organisms
• Whole organisms or parts of organisms
– shells, bones, leaves, pollen
• Tracks and traces
– footprints, burrows
• Chemical fossils
– organic compounds
Copyright  2010 McGraw-Hill Australia Pty Ltd
PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint
Slides prepared by Karen Burke da Silva, Flinders University
32-2
Fossils
• Organisms are preserved when they are protected
from decay
– buried in sediment
– encased in resin
• Compaction and chemical changes turn sediments
into rock
• Depending on type of rock, fossils may
–
–
–
–
–
–
retain their shape
be flattened
be carbonised (soft parts preserved as a carbon film)
be filled in with minerals
dissolve out, leaving an empty mould
be replaced with other material, such as silica (opal)
Copyright  2010 McGraw-Hill Australia Pty Ltd
PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint
Slides prepared by Karen Burke da Silva, Flinders University
32-3
Time scales
• Rock layers (strata) contain characteristic sets
(suites) of fossils
– rocks with the same suite of fossils are of the same age
• Fossils are used to divide the geological time scale
into eras and periods
• Ages of rocks and fossils are determined using
radiometric dating
Copyright  2010 McGraw-Hill Australia Pty Ltd
PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint
Slides prepared by Karen Burke da Silva, Flinders University
32-4
Fig. 32.5: Modern geologic time scale
(based on the 2000 edition of the International Stratigraphic Chart)
(cont.)
Copyright  2010 McGraw-Hill Australia Pty Ltd
PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint
Slides prepared by Karen Burke da Silva, Flinders University
32-5
Fig. 32.5: Modern geologic time scale (cont.)
(based on the 2000 edition of the International Stratigraphic Chart)
Copyright © T Itoh & R M Brown Jr, Planta Journal, vol. 160, pp. 372–81. Springer-Verlag, 1984
Copyright  2010 McGraw-Hill Australia Pty Ltd
PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint
Slides prepared by Karen Burke da Silva, Flinders University
32-6
Eras
• Major divisions of geologic time
–
–
–
–
Precambrian (4500–545 m.y.a.)
Palaeozoic (545–250 m.y.a.)
Mesozoic (250–65 m.y.a.)
Cenozoic (65–0 m.y.a.)
• Divided into periods
Copyright  2010 McGraw-Hill Australia Pty Ltd
PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint
Slides prepared by Karen Burke da Silva, Flinders University
32-7
Precambrian era
• Archean eon (4500–2500 m.y.a.)
• Proterozoic eon (2500–545 m.y.a.)
• Oldest fossils 3500–3300 m.y.a.
– prokaryotes: cyanobacteria (including stromatolites)
• Photosynthesis released oxygen into atmosphere
– changed composition of atmosphere
– 2300–1800 m.y.a.
Copyright  2010 McGraw-Hill Australia Pty Ltd
PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint
Slides prepared by Karen Burke da Silva, Flinders University
32-8
Eukaryotes
• Prokaryotes only form of life for 2100 m.y.
• Oldest eukaryote fossils 1400 m.y.a.
– single-celled protists with chloroplasts
• Multicelled organisms
– metaphytes (red algae) 1260–950 m.y.a.
– animals 680–640 m.y.a.
Copyright  2010 McGraw-Hill Australia Pty Ltd
PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint
Slides prepared by Karen Burke da Silva, Flinders University
32-9
Ediacaran fauna
• Fossils of soft-bodied animals
– impressions
– tracks and burrows
– no hard exo- or endoskeletons
• Difficult to classify some fossils
– do not resemble living phyla
• Fossils first recorded from Ediacara Hills, South
Australia
– fauna on all continents
Copyright  2010 McGraw-Hill Australia Pty Ltd
PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint
Slides prepared by Karen Burke da Silva, Flinders University
32-10
Palaeozoic era
• ‘Ancient life’ (545–250 m.y.a.)
• Aquatic groups
–
–
–
–
trilobites
brachiopods
nautiloids, ammonoids (cephalopod molluscs)
jawless and jawed fish (‘Age of Fish’)
Copyright  2010 McGraw-Hill Australia Pty Ltd
PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint
Slides prepared by Karen Burke da Silva, Flinders University
32-11
Fig. 32.11: Trilobite
Copyright  2010 McGraw-Hill Australia Pty Ltd
PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint
Slides prepared by Karen Burke da Silva, Flinders University
32-12
Palaeozoic era (cont.)
• Life moves onto land in Silurian period
–
–
–
–
arthropods
amphibians
reptiles
land plants
• Ended with mass extinction
– Permian period (250 m.y.a.)
– trilobites, many invertebrate groups
Copyright  2010 McGraw-Hill Australia Pty Ltd
PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint
Slides prepared by Karen Burke da Silva, Flinders University
32-13
Mesozoic era
• ‘Middle life’ (250–65 m.y.a.)
• Plants and invertebrates
–
–
–
–
–
ferns, conifers, cycads
flowering plants
bivalves, predatory gastropods
ammonoids
reef-building corals
Copyright  2010 McGraw-Hill Australia Pty Ltd
PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint
Slides prepared by Karen Burke da Silva, Flinders University
32-14
Mesozoic era (cont.)
• Vertebrates
– mammal-like reptiles, dinosaurs, marine reptiles, flying
reptiles (‘Age of Reptiles’)
– birds
– mammals
• Ended with mass extinction
– K–T boundary
– ammonites (shelled cephalopods), many large reptiles
Copyright  2010 McGraw-Hill Australia Pty Ltd
PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint
Slides prepared by Karen Burke da Silva, Flinders University
32-15
Fig. 32.18: Archaeopteryx
Copyright  2010 McGraw-Hill Australia Pty Ltd
PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint
Slides prepared by Karen Burke da Silva, Flinders University
32-16
Question 1:
Why was Archaeopteryx such an important find in
the fossil record?
Copyright  2010 McGraw-Hill Australia Pty Ltd
PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint
Slides prepared by Karen Burke da Silva, Flinders University
32-17
Cenozoic era
• ‘Modern life’ (65–0 m.y.a.)
• Major groups
– mammals diversify (‘Age of Mammals’)
– hominids
– modern forms of most organisms
Copyright  2010 McGraw-Hill Australia Pty Ltd
PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint
Slides prepared by Karen Burke da Silva, Flinders University
32-18
Biogeographic regions
Areas of the earth occupied by characteristic biota
Terrestrial
Marine
Palaearctic
Arctic/Antarctic
Oriental
Cool temperate
Ethiopian
Warm temperate
Australian
Tropical
Nearctic
Neotropical
Copyright  2010 McGraw-Hill Australia Pty Ltd
PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint
Slides prepared by Karen Burke da Silva, Flinders University
32-19
Fig. 32.20: Biogeographic regions
Copyright  2010 McGraw-Hill Australia Pty Ltd
PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint
Slides prepared by Karen Burke da Silva, Flinders University
32-20
‘New World’ regions
• Nearctic
– North America, Greenland
– examples:
 kangaroo rat
 pronghorn
 turkey
• Neotropical
– South America, Central America
– examples:
 New World monkeys
 sloth
 rhea
Copyright  2010 McGraw-Hill Australia Pty Ltd
PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint
Slides prepared by Karen Burke da Silva, Flinders University
32-21
‘Old World’ regions
• Palaearctic
– Europe, Asia
– examples:
 desman
 saiga
• Ethiopian
– Africa, Madagascar, Arabia
– examples:
 hippopotamus
 giraffe and okapi
 lemurs (Madagascar)
Copyright  2010 McGraw-Hill Australia Pty Ltd
PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint
Slides prepared by Karen Burke da Silva, Flinders University
32-22
‘Old World’ regions (cont.)
• Oriental
– India, South-East Asia
– examples:
 tree shrew
 gibbon
 leafbird
• Australian
– Australia and adjacent areas
– examples:
 echidna, platypus
 kangaroo
 emu
Copyright  2010 McGraw-Hill Australia Pty Ltd
PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint
Slides prepared by Karen Burke da Silva, Flinders University
32-23
Question 2:
What defines a mammal?
a) endothermic
b) mammary glands
c) internal fertilisation
d) scales
Copyright  2010 McGraw-Hill Australia Pty Ltd
PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint
Slides prepared by Karen Burke da Silva, Flinders University
32-24
Australian region
• More than Australia
– New Zealand, islands of Western Pacific, New Guinea,
eastern Indonesia archipelago
– biota determined by history and proximity
• Wallace’s Line
– boundary between Australian and Oriental biogeographic
regions
 Oriental biota dominates to west, Australian biota to east
– approximates collision zone between tectonic plates
Copyright  2010 McGraw-Hill Australia Pty Ltd
PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint
Slides prepared by Karen Burke da Silva, Flinders University
32-25
Fig. B32.6: Wallace’s Line
Copyright  2010 McGraw-Hill Australia Pty Ltd
PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint
Slides prepared by Karen Burke da Silva, Flinders University
32-26
Plate tectonics
• Earth’s surface formed from mobile plates
– tectonic plates
• Move relative to one another
– plate tectonics
– continental drift
• Configuration of land masses has changed over
geologic time
– still changing
Copyright  2010 McGraw-Hill Australia Pty Ltd
PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint
Slides prepared by Karen Burke da Silva, Flinders University
32-27
Fig. 32.6: Distribution of plates
Copyright  2010 McGraw-Hill Australia Pty Ltd
PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint
Slides prepared by Karen Burke da Silva, Flinders University
32-28
Sea-floor spreading
• Plate movement driven by sea-floor spreading
• Lava rises from mantle to surface at oceanic
ridges
– forms new oceanic crust on either side
• Continents pushed away from oceanic ridges
– example: Indian–Antarctic ridge in Southern Ocean
separating Australian and Antarctic plates
Copyright  2010 McGraw-Hill Australia Pty Ltd
PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint
Slides prepared by Karen Burke da Silva, Flinders University
32-29
Subduction zones
• Where edges of plates meet
• One plate slides beneath the other into mantle
– subduction zone
– deep-water trenches
– examples: Marianas Trench, Java Trench
• Plates slide past each other
– major fault zones
– example: San Andreas Fault
Copyright  2010 McGraw-Hill Australia Pty Ltd
PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint
Slides prepared by Karen Burke da Silva, Flinders University
32-30
Fig. 32.7: Cross-section of
lithosphere and asthenosphere
Copyright  2010 McGraw-Hill Australia Pty Ltd
PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint
Slides prepared by Karen Burke da Silva, Flinders University
32-31
Ancient earth
• Movement of continents over geologic time
• Land masses accreted into different configurations
at different times
– Gondwana: southern masses
– Laurasia: northern masses
– Pangea: southern + northern land masses
Copyright  2010 McGraw-Hill Australia Pty Ltd
PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint
Slides prepared by Karen Burke da Silva, Flinders University
32-32
Fig. 32.8: Position of the world’s land
masses
Copyright  2010 McGraw-Hill Australia Pty Ltd
PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint
Slides prepared by Karen Burke da Silva, Flinders University
32-33
Summary
• Fossils provide a record of past organisms and
their ages
• Geologic eras mark major events in the evolution
of life
• The evolution of life has been influenced by the
history of the earth
• Changes in earth’s atmospheric composition and
the position of its continents have influenced the
evolution and distribution of organisms
• Biogeographic regions of the world are
characterised by unique biotas
Copyright  2010 McGraw-Hill Australia Pty Ltd
PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint
Slides prepared by Karen Burke da Silva, Flinders University
32-34