living fossils

255 Pages·2006·3.7 MB·English

THE UNIVERSITY OF CHICAGO
ODDITIES, WONDERS, AND OTHER TALL TALES
OF “LIVING FOSSILS”
A DISSERTATION SUBMITTED TO
THE FACULTY OF THE DIVISION OF THE BIOLOGICAL SCIENCES
AND THE PRITZKER SCHOOL OF MEDICINE
IN CANDIDACY FOR THE DEGREE OF
DOCTOR OF PHILOSOPHY
COMMITTEE ON EVOLUTIONARY BIOLOGY
BY
L. H. LIOW
CHICAGO, ILLINOIS
JUNE 2006
Copyright © by Lee Hsiang Liow
All rights reserved
TABLE OF CONTENTS
LIST OF TABLES ..........................................................................................................vii
LIST OF FIGURES .......................................................................................................viii
ACKNOWLEDGMENTS ................................................................................................x
Chapter
� I.� LINEAGE PERSISTENCE AND “LIVING FOSSILS” - A SEMANTIC
EXPOSITION ....................................................................................................1
� I.1.� What is the meaning of “living fossils?”�..................................................2
� I.2.� Distribution of purported “living fossils” in the literature�....................... 3
� I.3.� Distribution of “living fossils” on the hierarchical tree of life �................4
I.4. Related concepts and their correlates. ......................................................5
� I.5.� “Living fossils” as artifacts�.................................................................... 11
I.6. How to make a geologically long-ranging lineage .................................13
� I.7.� Dissecting “living fossils”�......................................................................15

� II.� A TEST OF SIMPSON’S “RULE OF THE SURVIVAL OF THE
� � RELATIVELY UNSPECIALIZED” USING FOSSIL CRINOIDS�.................21
II.1. Introduction. ........................................................................................... 21
II.2. Material and Methods .............................................................................25
II.2.1. The data ..................................................................................26
II.2.2. Data units ...............................................................................28
II.2.3. Data treatment. .......................................................................31
II.2.4. Morphological deviations from group means ........................32
II.2.5. Morphological deviations from basal morphology ...............35
II.3. Results and Discussion. ..........................................................................35
II.3.1. Morphological deviations from group means ........................35
II.3.2. Morphological deviations from basal morphology ...............40
II.3.3. Influence of taxonomic hierarchy ......................................... 42
II.3.4. Temporal divisions and mass extinctions. ............................. 44
II.3.5. Potential biases ......................................................................46
II.3.6. Explicit definitions of long-lived taxa ...................................49
II.4. Conclusions.. .......................................................................................... 51
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III. DO DEVIANTS LIVE LONGER? MORPHOLOGY AND LONGEVITY IN
TRACHYLEBERIDID OSTRACODES ........................................................54
III.1.Introduction. .......................................................................................... 54
III.2.Data and Methods ..................................................................................60
III.2.1. The organisms and the raw data ............................................ 60
III.2.2. Data treatment and analysis: discrete character data .............66
III.2.3. Removal of oversplit taxa. .....................................................67
III.2.4. Data treatment and analysis: outline data. .............................68
III.2.5. Defining long-lived genera ....................................................68
III.3.Results. .................................................................................................. 70
III.3.1. Morphological deviation of genera from group means (discrete
characters). .............................................................................70
III.3.2. Morphological deviation of genera from group means (discrete
characters): temporal subsets .................................................77
III.3.3. Principal Coordinate Analysis of discrete morphological data
................................................................................................82
III.3.4. Morphological deviation of genera from group means (outline
analyses) ................................................................................ 84
III.4. Discussion .............................................................................................87
III.5. Conclusions .......................................................................................... 90
IV. DOES VERSATILITY AS MEASURED BY GEOGRAPHIC RANGE,
BATHYMETRIC RANGE AND MORPHOLOGICAL VARIABILITY
CONTRIBUTE TO TAXON LONGEVITY? ..................................................93
IV.1. Introduction. ..........................................................................................93
IV.2. Methods and Materials..... .....................................................................97
IV.2.1. Taxonomic and morphological data. ......................................97
IV.2.2. Geographic range data ...........................................................99
IV.2.3. Bathymetric range data...... ..................................................100
IV.2.4. Data subsets....... ..................................................................102
IV.2.5. Analyses ...............................................................................105
IV.3. Results....................................................................................... ..........108
IV.3.1. Longevity and ecological versatility I: geographic spread ..108
IV.3.2. Longevity and ecological versatility II: bathymetric spread 111
IV.3.3. Longevity and evolutionary versatility I: species richness. .116
IV.3.4. Longevity and evolutionary versatility II: subspecies richness
..............................................................................................116
IV.3.5 Longevity and evolutionary versatility III: extreme species
morphological variability. ....................................................118
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IV.3.6. Which factors are stronger? ................................................. 118
IV.3.7. Are species patterns enough to explain genus patterns? ...... 119
IV.4.Discussion ............................................................................................123
IV.4.1. Caveats. ................................................................................127
IV.5.Conclusions ..........................................................................................129
V. LINEAGES WITH GREAT LONGEVITIES ARE OLD AND AVERAGE: AN
ANALYSIS OF MORPHOLOGICAL AND TAXON LONGEVITY
DISTRIBUTIONS USING MULTIPLE DATASETS ................................... 130
V.1. Introduction. ......................................................................................... 130
V.2. Methods............... .................................................................................134
V.2.1. Data ......................................................................................134
V.2.2. Data treatment. .....................................................................142
V.3. Results ..................................................................................................150
V.4. Discussion ............................................................................................ 158
V.4.1. Phylogenetic implications. ...................................................162
V.4.2. Biases and sources of error ..................................................162
V.5. Conclusions ..........................................................................................164
VI. LINEAGE PERSISTENCE - A THEORETICAL FRAMEWORK AND
EMPIRICAL RESEARCH PROGRAM .......................................................165
LITERATURE CITED .................................................................................................168
Appendices
A. Description of characters and character matrix for seven crinoids not
represented in Foote (1999) ........................................................................... 198
B. Crinoid genera in orders (and suborders of cladids) and their morpho-duration
plot distributions, relative to basal genera ......................................................209
C. Periods in geologic history sampled and morpho-duration plot distributions of
the crinoid genera within those periods ......................................................... 214
D. Identities of long-lived crinoid genera in each order and the orders and families
to which they belong ...................................................................................... 215
E. Description of discrete morphological characters and character states for
trachyleberidid genera ........................................................................... (on CD)
� F.� Characters states for trachyleberidid genera �..........................................(on CD)
� G.� Sources of outline data �.......................................................................... (on CD)
H. First and last fossil appearances of trachyleberidid genera ................... (on CD)
I. References cited in appendices G and H ............................................... (on CD)
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J. Table of resampled correlations .....................................................................219
K. Character matrices for trachyleberidid ostracode species ..............................220
L. Short descriptions of morphological characters of trachyleberidid ostracode
species ............................................................................................................225
. M. References used in Appendix K .....................................................................228
O. Correlations between morphology and longevity ..........................................234
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LIST OF TABLES
Table II.1. Crinoid (sub)orders and the morpho-duration plot distributions of their
genera ..................................................................................................... 29
Table II.2. Crinoid families and their morpho-duration plot distributions .............. 43
Table III.1. Summary statistics for the durations of subsets of trachyleberidids ......71
Table III.2. Deviation from trachyleberidid group mean (discrete morphology) ......72
Table III.3. Deviation from trachyleberidid group mean (discrete morphology) with
oversplit genera removed.. ..................................................................... 76
Table III.4. Deviation from trachyleberidid birth cohort mean (discrete morphology)
................................................................................................................79
Table III.5. Deviation from trachyleberidid contemporaneous cohort mean (discrete
morphology) ...........................................................................................81
Table III.6. Deviation from trachyleberidid means (PCO of discrete morphology) . 83
Table III.7. Results from trachyleberidid outline analyses ....................................... 85
Table IV.1. Bathymetric zones ................................................................................101
Table IV.2. Data subsets ..........................................................................................103
Table IV.3. Geographic spread and longevity .........................................................110
Table IV.4. Bathymetric range versus longevity .....................................................113
Table IV.5. Results of multiple regression ..............................................................120
Table V.1. References used in the analyses ........................................................... 135
Table V.2. Datasets where morphological distances are negatively, positively, or not
correlated with longevity. .....................................................................152
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LIST OF FIGURES
Figure I.1. The relationship between longevity, cladogenesis and morphological
distance ...................................................................................................16
Figure. I.2.� Combinations of clade types where “living fossils” are detectable�....... 19
Figure II.1. Translating stratigraphic ranges and multivariate morphology into a plot
of morphological deviation versus duration. ..........................................24
Figure II.2. Morphological deviations of monobathrid and disparid genera versus
their durations. ........................................................................................36
Figure II.3. Euclidean distances between genera of Sagenocrinida and taxa with
alleged basal morphologies, versus their durations ................................41
Figure II.4. Changing relative occupation of morpho-duration plot quadrants through
time .........................................................................................................45
Figure II.5. Percentages of unknown and inapplicable characters in crinoid genera as
a function of their fossil durations ..........................................................47
Figure II.6.� Frequency of occurrence of long-lived genera of monobathrids,
� depending on the definition of “long-lived.”�..........................................50
Figure III.1. A lower probability for long-lived taxa to be distant from the average
morphology of their group.. ................................................................... 59
Figure III.2. Literature sampling curve for trachyleberidid genera .......................... .63
Figure III.3. A generalized trachyleberidid ostracode.. ...............................................65
Figure IV.1. Genus longevity plotted versus genus latitudinal ranges for the whole
dataset ..................................................................................................109
Figure IV.2. Histograms of genus longevities as subdivided by whether they occupy
only shallow waters, only deep waters, or both .................................. 114
Figure IV.3. Histograms of species longevities as subdivided by whether they occupy
only shallow waters, only deep waters, or both . ................................. 115
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Figure IV.4. Distribution of species occupying various depth zones during the
Cretaceous, Paleogene and the Neogene .............................................. 117
Figure IV.5. Genus versus species longevity ............................................................122
Figure V.1. Hypothetical plot of morphological distance versus stratigraphic ranges
illustrating the sampling of groups and individual lineages. ................143
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ACKNOWLEDGMENTS
My gratitude to all those who have helped me one way or another during the
conception, construction and conclusion of this thesis, even if I fail to mention them in
print.
� In partial chronological order, I thank Tim Wootton and Larry Heaney who first
encouraged me to apply to this school and Matthew Leibold who made me feel very
welcome here during my interview as a prospective student. I thank Jerry Coyne and
Nipam Patel, who almost became my committee members, Barry Chernoff and Joel
Martin who were my committee members for short periods of time, Michael Foote
whom I had no courage to put on my committee, but who has subsequently contributed
as much to this thesis as my committee members, and last but not least, my committee
members, Scott Lidgard, Leigh van Valen, Peter Wagner and David Jablonski. I can
never say enough “Thank Yous” to my advisor, Scott, who is an ever patient friend, a
mentor and a counsellor, forgiving even my worst behavior. Leigh was the light-house
(with functional light-bulbs of course) during my very numerous dark and foggy spells.
I thank David Rowley for helping with paleo-coordinate rotations and all the other
University of Chicago faculty who have given me some of their precious time. Alumni
were an indispensable resource during my sojourn in Chicago: Charles Marshall
carefully reviewed chapters two and three and gave me the encouragement I needed;
Arnie Mille found time to wade through a very dense draft of chapter four; Dan
McShea is a constant source of inspiration even from my early days in the CEB office.
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