?????? Bilingual teaching program

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??????Bilingual teaching program Lecture notes
forPaleoecology
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Instructor Hong HUA (?
?)Email huahong_at_nwu.edu.cn Office Room 430,
Geological building
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Scientific Method

• When solving problems scientifically we follow a
  series of steps to avoid wasting time, effort,
  and resources. These steps include
• 1. Defining the ________ (may include research or
  observation)
• 2. Stating a ____________ (explanation of
  observation must be able to be tested)
• 3. _________ the hypothesis (involves measurement
  of one variable at a time)
• 4. Analyzing the _________ (data organized in
  graphs, tables, and charts)
• 5. Drawing _____________ (returning to step 2 as
  needed)
• This is not a rigid, step-by-step outline.

problem
hypothesis
Testing
results
conclusions
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Schedule of Topics
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Topic
Introduction
The Earth as a system
How Real is Global Warming?
Cultural Responses to Climate Change What we have learnt from the Holocene
Gigantism Dwarfism Thoeries about biogeography
The modern-Day Mass Extinction Lessons from the past
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Invasive Species Whats the Problem
All things are not equally nice to eat Evolutionary Patterns
The Pandas thumb Functional morphology
Trace Fossils Reconstructing Animal Behavior
Evolutionary Paleoecology
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Examinations and Grading Grading 1 tests at 70
points plus 1 presentations at 30
points Presentation will be evaluated by the
instructor and by the students20 points By
Instructor and 10 points by Average of student
evaluations Final examination l  Writing test
for 3 hours l Open to textbooks, dictionary and
any other material. l  Questions and answer are
in English
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Topic 1 Introduction
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• 1. What is Paleoecology?
• 2. The data base in paleoecology
• 3. The operational base in paleoecology
• 4. The nature of the fossil record

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Study of fossils
?What? What are fossils?
Morphological paleontology
?When? When did a particular fossil live?

Stratigraphical paleontology
?Whence(????) and whither(????)? in other words,
what were the ancestors of a particular fossil
and what were its descendants?

Evolutionary paleontology
? How and where? How and where animals and
plants lived in the past ?
Paleoecology
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1. What is Paleoecology? Ecology is the study of
the interactions of organisms with one another
and with the physical environment Paleoecology
is the study of the environmental relationships
of organisms in the geological past
 
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• ecology of the past where our understanding of
  the present is the key to understand the past
• Theory paleoecology is the understanding of
  relationships between past organism and the
  environment in which they lived
• Practice paleoecology is the practice of
  reconstruction of past environments

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Two dominant subject areas in paleoecology
?The study of organism-environment interactions
? The study of the more strictly biological
attributes of the organisms their individual
life histories, their interactions with one
another, and their integration into
communities(??)
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Levels of ecological organization and examples of
the kinds of questions asked by ecologists
working at each level
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Individuals
Physiological ecology Behavioral ecology
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Population

• Study the factors influencing population
  structure and process
• Adaptation
• Extinction
• Distribution
• abundance
• population growth

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interaction

• Predation
• Parasitism
• competition

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How do Ecology and Paleoecology differ Can we
observe the actual ecosystem?
Ecological study yes, Paleoecological study
no Can we select the organism and / or community
for study? Ecological study yes,
Paleoecological study only sometimes Are our
observations based upon repeatable experiments?
Ecological study yes, Paleoecological
study no Do our studies operate within a
defined timescale and space? Ecological
study yes, Paleoecological study no
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Evolution
Biogeography
Physical environment
Diagenesis
Biota
Rock facies
Ecosystem
Causal influence
Palaeoecosystem
Causal relationships in biology and geology
pertinent to ecology and paleoecology
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What are some problems inherent in paleoecology
reconstruction?
One of the major limitations of the study of
paleoecology Not all species are preserved as
fossils The Biocoenosis (life assemblage) does
not equal the Thanatocoenosis (death assemblage)
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(1) What we don't see may be as important as what
we do Not every creature was fossilized (2)Fossil
beds are composites of fossils (3)The older the
material, the more likely it was modified, or
destroyed by geological events or biological
intrusions (4)At best you are sampling just a
portion of what existed
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A lot of assumptions must be made given the
paucity(??) of data available in order for
paleoecologists to generate ecosystems of the
past. They must assume
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The ecological relationships we use today to
describe system dynamics are those that held in
the past Trophic dynamics energy flow
transfers competition predation
parasitism and so on where common controlling
determinants of ecosystem functioning We have no
real reason to doubt this at this time
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That animal, plants microbes had more or less
the same environmental habitats and to an extent
niches as those today - fish live in water etc
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Since all that is left generally is the
morphology of bones, pollen, wood etc. that these
morphological adaptations to environment fit the
pattern existent today
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• what is the importance of paleoecological study
  for ecologists?

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It tells us how we got to where we are todayIt
shows us the range of natural variation of
communities and climatesIt gives us hints of
where we might be headed in the future,
especially during a period of potentially rapidly
changing climate
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• 1. What is Paleoecology?
• 2. The data base in paleoecology
• 3. The operational base in paleoecology
• 4. The nature of the fossil record

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Paleoenvironmental reconstruction depends on
three ingredients ? a well-established
stratigraphic framework ? good taxonomy ? a
comprehensive ecologic background
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? The stratigraphic setting provides the spatial
and temporal relationships(????) for the
comparison of fossils within geologic history ?
The basic data of paleoecology are the fossils,
adequately identified and correctly positioned
within the stratigraphic framework
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The necessary ecology(?????) consists of an
understanding of ? the ways in which living
organisms function within their ecosystem ? how
their morphology and physiology is adaptive to
their conditions of life ? the ways in which
they may interact with one another ? and the
ways in which they may modify their life history
to fit the environment
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? At one end of the spectrum general ecologic
"laws" developed inductively from the living
world are applied deductively to the fossil
record ? At the other end of the spectrum the
present day significance of a particular species
or morphologic feature is applied to the same
species or biotic characteristic in the fossil
record
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• 1. What is Paleoecology?
• 2. The data base in paleoecology
• 3. The operational base in paleoecology
• 4. The nature of the fossil record

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The operational base in paleoecology
?uniformitarianism(???) ?analogy(????) ?simplicit
y(???) or Parsimony
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Uniformitarianism
Hutton (1726-1797)
Lyell (1797-1875)

• James Hutton, Scottish farmer, physician, and
  geologist father of geology published The
  Theory of the Earth (1785)
• Charles Lyell, English geologist, published
  Principles of Geology (1830-1833)
• The past history of our globe must be explained
  by what can be seen to be happening now
• The present is the key to the past (Sir
  Archibald Geike, 1835-1924)
• Giving enough time, modern Earth processes were
  capable of having produced the record of the past
• Implies deep time

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Uniformitarianism can be classified as either
substantive or methodological (Gould, 1965). ?
Substantive uniformitarianism (?????) implies
that the materials, conditions, and rates of
processes during earth history have remained
constant ? Methodological uniformitarianism
(?????) implies that the laws of nature (such as
gravity, the properties of fluid flow, and
thermodynamics) have been constant in their
operation through geologic time
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Four Meanings of Uniformitarianism

• Methodological
• Uniformity of Law Foundation of historical
  science
• Uniformity of Process Actualism(????)
• Substantive
• Uniformity of Rate and magnitude Gradualism
• (Things do change, but at constant rate)
• Uniformity of Condition nondirectionism
• (Things do not change or the Earth system has
  been maintaining the same equilibrium state)

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Catastrophism
Cuvier (1769-1832)
Brongniart (1770-1847)

• Baron Georges Leopold Cuvier (1769-1832) and
  Alexander Brongniart (1770-1847)
• Studied fossils in the Paris Basin
• Dramatic changes in successive fossil assemblages
• Believed that these changes were caused by total
  extinction resulted from catastrophes akin to the
  Noachian Deluge, followed by successive creations
  of new species
• We now know that these abrupt changes are largely
  due to unconformities or missing record
• Catastrophism has not been totally abandoned it
  is particularly instructive in later studies on
  mass extinctions

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Analogy (or actuopaleontology(??????)) involves
the application of modern organismic features to
ancient organisms. This principle may be applied
to individuals (with regard to form and
function) community structure (species
diversity, organizational and trophic
structure(????) and population dynamics
(response to time-independent environmental
factors), and is inferred to represent
response to time-independent environmental forces
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Whenever we find, in two forms of life that are
unrelated to each other, a similarity of form or
of behavior patterns which relates to more than a
few minor details, we assume it to be caused by
parallel adaptation to the same life-preserving
function
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Simplicity or Parsimony
Principle of simplicity everything else being
equal, the best explanation is the simplest one
Simplicity in this sense is that the most
probable explanation is generally the one with
the fewest steps from cause through intermediate
causes and effects to the final result
Ockham's Razor
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• This simplifying procedure should be valid in
  paleoecology because it is exactly that used in
  ecology, and in science in general
• It saves us from the despair of attempting to
  derive from the limited paleontologic data an
  explanation incorporating the myriad of
  environmental parameters

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• 1. What is Paleoecology?
• 2. The data base in paleoecology
• 3. The operational base in paleoecology
• 4. The nature of the fossil record

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A fossil assemblage may be only a small and
biased representation of the original community
Destruction by various processes after death of
the organism, a potential fossil may not be
preserved
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Taphonomy

• It helps in understanding the relationship of
  the fossil assemblage to the original community
  and thus allows to some extent the reconstruction
  of the community
• (2) Recognition of taphonomic processes that have
  formed the fossil assemblage provides insight
  into the depositional and postdepositional
  environment

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Subsidiary topics within taphonomy are
necrolysis(???), which deals with the
decomposition of the organism upon death,
biostratinomy(?????), which deals with the
sedimentational history of the fossil, and fossil
diagenesis, which deals with chemical and
mechanical alteration of the fossil between the
time of its burial and collection
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During each of these stages of the post-mortem
history, mechanical, chemical, and biological
processes are reshaping the original community
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Two opposing views on processes that form from
the original community the assemblage of fossils
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One is that a fossil assemblage accumulates
slowly through the year-by-year preservation of
some fraction of the community Thus the
assemblage represents a time-averaged sampling of
a sequence of communities over a period of years
and of perhaps a considerable range of
environments (Fürsich, 1978)
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The opposing view is that preservation is in
general so poor, the fossil record is much more
likely the result of occasional chance
preservation of an individual community Thus an
assemblage may be a fairly reasonable
representation of the community existing during a
short interval rather than the accumulation of
meager sampling during a longer time interval
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• 1. What is Paleoecology?
• 2. The data base in paleoecology
• 3. The operational base in paleoecology
• 4. The nature of the fossil record

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Text books and references   ???,1992.
???????. ??????? ???,? ??, 1993.
?????.?????????. ???, 1983. ??????????.
????????????. ????,1988. ????????.??????????? Bou
cot, A.J., 1981, Principles of Benthic Marine
paleocology, Academic Press. Dodd, J.R. and
Stanton, R.J., 1981, Paleoecology, Concepts and
Applications. John Wiley and Sons. Allmon W. D.,
Bottjer D. J.,2001. Evolutionary paleoecology-
The ecological context of macroevolutionary
change.New York Columbia University Press.