View
216
Download
0
Category
Preview:
Citation preview
EARTH’S HISTORYCHAPTER 13
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
• 13.1-13.2 Earth’s history has been unveiled by founding scientists applying critical thinking. Key evidence for past life is preserved in fossils.
• 13.3-13.5 Evolution is shown by several lines of evidence, including modern molecular biology. Five global mass extinctions have altered the course of evolution.
• 13.6-13.10 The Geologic Timescale is a calendar of events in Earth’s history, largely marked by biota (or absence of) that lived at different times.
Learning Objectives: You will have a basic knowledge of how fossils preserve evidence for past life, the proven process of evolution, and the dominant events in Earth’s history.
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
James Hutton (1726-1797)• Proposed that geologic time was
indefinitely long• Believed the Earth was self-renewing
(basis of rock cycle). “...no vestige of a beginning--no prospect of an end”
• Formulated the concept of uniformitarianism.
“The present is key to the past” -Sir Archibald Geikie (1835-1924)
13-1 Earth’s history has been unveiled by scientists applying the tools of critical thinking.
“come on Jimbo, lighten up would ya”
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
13-1 Earth’s history has been unveiled by scientists applying the tools of critical thinking.Nicholas Steno (1638-1686)• Father of geology and stratigraphy (and the
right hand shaka)
• First to suggest that fossils had once been living organisms
• Developed the stratigraphic principles of....Exercise 1:
(A)
(B)(C)
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
Charles Lyell (1797-1875)• Father of modern geology
• Wrote Principles of Geology, an seminal reference for every 19th century earth scientist
• Popularized uniformitarianism
• Developed the stratigraphic principals of...
13-1 Earth’s history has been unveiled by scientists applying the tools of critical thinking.
“Uhgg.. I hope my sideburns aren’t
showing yet”
Exercise 1 (continued):
(D) (E)
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
Charles Darwin (1809-1882)
• Naturalist aboard HMS Beagle • Studied Principles of Geology (by Charles Lyell)• Wrote On the Origin of Species by Means of Natural
Selection • Credited with the theory of evolution
13-1 Earth’s history has been unveiled by scientists applying the tools of critical thinking.
No Charles. For the 4th time, its an
IGUANA, there are no geckos here yet!
Darwin observed that all living things reproduce rapidly, and yet no one group of organisms had been able to overwhelm Earth’s surface. This led Darwin to conclude that not all individuals in a generation will survive.
But, which survive and which do not?
Nature must select those with the most favorable variations. Darwin proposed that evolution occurred by natural selection.
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
Photos of undergraduate Geology & Geophysics majors on various field trips.
13-1 Earth’s history has been unveiled by scientists applying the tools of critical thinking.
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
13-2 Fossils preserve a record of past life.
Fossils preserve a record of past life.
Fossils are the remains of animals and plants, or traces of their presence, that have been preserved in the crust.
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
• Fossilization is the process that turns a once-living thing into rock.
• Preservation is typically by replacement, formation of mold, or cast.
• Fossil record is biased:• Rapid burial required• Usually only hard
tissue (shell, teeth, bone) is preserved
13-2 Fossils preserve a record of past life.
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
In rare cases, soft-part preservation occurs. This is dinosaur skin, preserved inside a fossilized egg.
Brachiopod (a marine inverte-brate) fossils are preserved as molds in dolomite.
13-2 Fossils preserve a record of past life.
Molds of Dinosaur feathers
EARTH’S HISTORYCHAPTER 13
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
• 13.1-13.2 Earth’s history has been unveiled by founding scientists applying critical thinking. Key evidence for past life is preserved in fossils.
• 13.3-13.5 Evolution is shown by several lines of evidence, including modern molecular biology. Five global mass extinctions have altered the course of evolution.
• 13.6-13.10 The Geologic Timescale is a calendar of events in Earth’s history, largely marked by biota (or absence of) that lived at different times.
Learning Objectives: You will have a basic knowledge of how fossils preserve evidence for past life, the proven process of evolution, and the dominant events in Earth’s history.
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
Evolution occurs bynatural selection: “..the
process by which favorable traits that are heritable (passed on to
offspring) become more common in successive generations...”
13.3-13.5 Evolution is shown by several lines of evidence, including modern molecular biology. Five global mass extinctions have altered the course of evolution.
• It is the incremental adaptation to environmental or community “pressures, whatever they may be.
• “Primitive” indicates prior and different not inferior (or superior) in general.
• “Evolved” indicates an adaptation to more recent conditions, not superior (or inferior) in general.
Genetic Mutations(random changes to DNA)
Genetic Variation(differences in inherited traits)
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
• Early proponents of Darwin’s theory had trouble convincing colleagues that evolution was at work. Evolution can take generations to reveal changes, making it difficult to observe as it is occurring.
• Fossils provide clues to understanding this process:(1) Phylogeny (forward progression of physical traits)(2) Homologous (similar) structures(3) Vestigial (remnant) structures(4) Embryology (similarities among embryos)
13.3-13.5 Evolution is shown by several lines of evidence, including modern molecular biology. Five global mass extinctions have altered the course of evolution.
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
Fossils provide clues to understanding this process:(1) Phylogeny (forward progression of physical traits)(2) Homologous (similar) structures(3) Vestigial (remnant) structures(4) Embryology (similarities among embryos)
13.3-13.5 Evolution is shown by several lines of evidence, including modern molecular biology. Five global mass extinctions have altered the course of evolution.
FIGURE 13.8 The phylogeny of the horse family shows consistentchanges in the lower leg area, the development of molars designed for chewing tough grasses, and an increase in body size and strength.
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
Fossils provide clues to understanding this process:(1) Phylogeny (forward progression of physical traits)(2) Homologous (similar) structures(3) Vestigial (remnant) structures(4) Embryology (similarities among embryos)
13.3-13.5 Evolution is shown by several lines of evidence, including modern molecular biology. Five global mass extinctions have altered the course of evolution.
FIGURE 13.9 The limbs of various animals are modified for different functions. Notice that individual bones have been modified in different ways to accomplish specific types of tasks (grasping, walking, flying, and paddling). All limbs possess the same basic set of bones in the same order.
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
Fossils provide clues to understanding this process:(1) Phylogeny (forward progression of physical traits)(2) Homologous (similar) structures(3) Vestigial (remnant) structures(4) Embryology (similarities among embryos)
13.3-13.5 Evolution is shown by several lines of evidence, including modern molecular biology. Five global mass extinctions have altered the course of evolution.
FIGURE 13.10 (a) Whales possess a vestigial pelvis & femur originally designed for walking. Proof that modern whales have evolved from walking ancestors was found in 1994 in the form of a fossil whale that had flippers for front legs and long hind limbs with elongate toes for webbed feet. (b) Boa constrictors also have vestiges of legs.
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
Fossils provide clues to understanding this process:(1) Phylogeny (forward progression of physical traits)(2) Homologous (similar) structures(3) Vestigial (remnant) structures(4) Embryology (similarities among embryos)
13.3-13.5 Evolution is shown by several lines of evidence, including modern molecular biology. Five global mass extinctions have altered the course of evolution.
FIGURE 13.11 Many animals display remarkably similar
features during their development as embryos.
Human embryos, for instance, have a tail and
primitive gill slits.
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
(5) Molecular genetics provide evidence for evolution and allow us to define evolutionary relationships among all life.
13.3-13.5 Evolution is shown by several lines of evidence, including modern molecular biology. Five global mass extinctions have altered the course of evolution.
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
HIV evolves new drug-resistant strains. It hijacks a cell’s machinery to duplicate itself; the new virus particles (yellow) then burst from cell membrane (blue), killing it.
13.3-13.5 Evolution is shown by several lines of evidence, including modern molecular biology. Five global mass extinctions have altered the course of evolution.
Flu viruses evolve very quickly: that’s why a new flu vaccine is introduced every year
Anti-biotic resistant bacteria on the rise
13.3-13.5 Evolution is shown by several lines of evidence, including modern molecular biology. Five global mass extinctions have altered the course of evolution.
Exercise 2: What are the 5 forms of evidence for evolution?
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
Mass extinctions: Large numbers of species permanently die out within a very short period of time.
13.3-13.5 Evolution is shown by several lines of evidence, including modern molecular biology. Five global mass extinctions have altered the course of evolution.
Hypothesized causes include meteor impacts and massive flood volcanism, both of which would alter global climate.
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
Mass extinctions influence the evolution of life.
13.3-13.5 Evolution is shown by several lines of evidence, including modern molecular biology. Five global mass extinctions have altered the course of evolution.
440-450 Mya: Shortly after
life immerged onto land
360-375 Mya
251 Mya, most catastrophic
200 Mya, may have been caused by massive volcanism
65 Myr, killed the dinosaurs,
possibly caused by Chicxulub
impact
13.3-13.5 Evolution is shown by several lines of evidence, including modern molecular biology. Five global mass extinctions have altered the course of evolution.
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
Mass extinctions influence the evolution of life.
13.3-13.5 Evolution is shown by several lines of evidence, including modern molecular biology. Five global mass extinctions have altered the course of evolution.
440-450 Mya: Shortly after
life immerged onto land
360-375 Mya
251 Mya, most catastrophic
200 Mya, may have been caused by massive volcanism
65 Myr, killed the dinosaurs,
possibly caused by Chicxulub
impact
??
13.3-13.5 Evolution is shown by several lines of evidence, including modern molecular biology. Five global mass extinctions have altered the course of evolution.
Exercise 3: How many major mass extinctions have their been? Which one killed the dinosaurs?
EARTH’S HISTORYCHAPTER 13
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
• 13.1-13.2 Earth’s history has been unveiled by founding scientists applying critical thinking. Key evidence for past life is preserved in fossils.
• 13.3-13.5 Evolution is shown by several lines of evidence, including modern molecular biology. Five global mass extinctions have altered the course of evolution.
• 13.6-13.10 The Geologic Timescale is a calendar of events in Earth’s history, largely marked by biota (or absence of) that lived at different times.
Learning Objectives: You will have a basic knowledge of how fossils preserve evidence for past life, the proven process of evolution, and the dominant events in Earth’s history.
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
Geologic Column Drag and Drop Animation
13.6-13.10 The Geologic Timescale is a calendar of events in Earth’s history, largely marked by biota (or absence of) that lived at different times.
Like a calendar divided into days, weeks, months & years
The Geologic calendar is divided into epochs, periods, eras, and eons
But these divisions are defined stratigraphically, largely by biota, and are not fixed intervals in time
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
Hadeon Eon (4.6-3.8 Bya)
• Extraterrestrial barrage• Formation of the moon
• Loss of first atmosphere (H2, He) and formation of new noxious atmosphere (rich in water vapor, CO2, NH3-ammonia, CH4-methane, but no O2)
Iron catastrophe• Magma “ocean”
• Earliest crust and H2O oceans
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
Archian Eon (3.8-2.5 Bya)
Continental Cratons Form
• Noxious 2nd atmosphere (methane, ammonia, carbon dioxide, and water vapor) from extraterrestrial bombardment & volcanic outgassing.
• Continental cratons formed.• Life first appeared as bacteria (stromatolites)
in oceans.• Photosynthesis was triggered, producing O2
in atmosphere.
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
Proterozoic Eon (2.5 Bya – 542 Mya)
• Continents developed. First supercontinent (Rodinia) in the southern hemisphere.
• Mountains were built.
• Noxious gases were displaced by oxygen-rich atmosphere.
• Eukaryotes and multicellular life flourished with much biologic diversification. Soft-bodied animals first appeared.
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
Paleozoic Era (542-251 Mya)
Complex life flourished, the first land animals emerged and the continents reorganized
Cambrian explosion burst of a highly diverse, multi-celled animal assemblage is recorded in the Burgess Shale (BC-Canada).
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
Paleozoic Era (542-251 Mya)
Complex life flourished, the first land animals emerged and the continents reorganized
Cambrian explosion: burst of a highly diverse, multi-celled animal assemblage is recorded in the Burgess Shale.
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
Paleozoic Era (542-251 Mya)
Complex life flourished, the first land animals emerged and the continents reorganized
Cambrian explosion: burst of a highly diverse, multi-celled animal assemblage is recorded in the Burgess Shale.
First land animals
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
Paleozoic Era (542-251 Mya)
Complex life flourished, the first land animals emerged and the continents reorganized
Massive coal deposits, store sun’s energy from
the Pennsylvanianand sequester A LOT of
CO2
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
Mesozoic Era (251-65 Mya)
Pangea breaking into Tethys Ocean
Early Jurassic, ~190 Mya
Gondwanaland
Laurasia
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
Mesozoic Era (251-65 Mya)
Pangea breaking into Tethys Ocean
Early Jurassic, ~190 Mya
Gondwanaland
Laurasia
Tethys Ocean
Cretaceous, ~90 Mya. Warm climate & high sealevel. Oldest Hawaiian volcanoes are active.
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
Cenozoic Era (65 Mya-present)
Dinosaurs are extinct. Mammals flourish.
Collision of India hypothesized to enhance weathering, drawing down atmospheric CO2, cooling of atmosphere, and lowering sea level
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
Cenozoic Era (65 Mya-present)
Quaternary Epoch is noted for its glacial (ice age) and interglacial cycles, about every 100,000 yrs
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
Cenozoic Era (65 Mya-present)
Humans arose starting in the late Piocene
Sahelanthropus tchadensis, “Toumai”, 6-7 Mya
Australopithecus afarensis: 3.9-3.0 Myr
Homo Erectus:1.8-0.3 Myr
Homo Sapiens: 200,000 yrs to present
EARTH’S HISTORYCHAPTER 13
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
• 13.1-13.2 Earth’s history has been unveiled by founding scientists applying critical thinking. Key evidence for past life is preserved in fossils.
• 13.3-13.5 Evolution is shown by several lines of evidence, including modern molecular biology. Five global mass extinctions have altered the course of evolution.
• 13.6-13.10 The Geologic Timescale is a calendar of events in Earth’s history, largely marked by biota (or absence of) that lived at different times.
Learning Objectives: You will have a basic knowledge of how fossils preserve evidence for past life, the proven process of evolution, and the dominant events in Earth’s history.
Recommended