Evolution and the Fossil Record

36 Pages·2001·1.255 MB·English

by  John Pojeta Jr., Dale Springer

John Pojeta, Jr.
Dale A. Springer
American Geological Institute
The Paleontological Society
About the Authors
John Pojeta, Jr.has been an active paleontologist Dale A. Springeris a
since 1957. He is a Scientist Emeritus with the U.S. paleontologist and Professor
Geological Survey (USGS) and Research Associate of Geosciences at Bloomsburg
with the Department of Paleobiology, Smithsonian University in Bloomsburg,PA. She
Institution. He earned his B.S. degree at Capital earned her B.A. degree at Lafayette Trilobite
University, Bexley, OH, majoring in biology and College, Easton, PA, her M.S. degree (Ordovician)
chemistry and earned his M.S. and Ph.D. degrees at the University of Rochester, NY, and
from the University of Cincinnati, majoring in geol- her Ph.D. at Virginia Polytechnic Institute
ogy and paleontology. In 1963, he joined the USGS, and State University, Blacksburg. She was a visit-
Branch of Paleontology and Stratigraphy, where he ing faculty member at Amherst and Smith Colleges
spent his career. His research has centered on early before joining the Bloomsburg faculty in 1985.
Paleozoic mollusks, and has taken him to many Her major research interest lies in understanding the
American states, Antarctica, Australia, Canada, factors controlling temporal and spatial changes in
China, Czech Republic, Senegal, Sweden, United fossil and modern marine invertebrate communities.
Kingdom, and elsewhere. He has been Secretary and Dr. Springer has a long standing interest in geo-
President of The Paleontological Society; President science education. She has served as Chairperson of
of the Paleontological Research Institution; Chief, the Paleontological Society(cid:146)s Education Committee,
Branch of Paleontology and Stratigraphy, USGS; as well as on several committees of the American
and a member of the National Academy of Sciences Geological Institute.
Committee on Paleontological Collecting.
Credits
Front cover (cid:151) Adapted from (cid:147)Fossils Through Time,(cid:148) a Pages 10-11 (cid:151) Shark(cid:146)s tooth, Fossil seed fern, Petrified
U.S. Geological Survey poster and photographic col- wood (G. James)
lage of life on Earth over the past 600 million years.
Pages 12-13 (cid:151) Hubble image, Earthrise over moon
Inside Cover and title page (cid:151) Ammonite fossil (G. James), (NASA), Trilobite (J. Pojeta, photo: G. James)
Modern coral reef (J. Pojeta, Jr.), Ferns (Adobe)
Pages 14-15 (cid:151) Ammonite (G. James), Block diagram
Page ii-iii (cid:151) Trilobite (M.L. Pojeta, photo: G. James), (Springer/De Atley), Stratigraphic ranges table
Fossils (J. Pojeta, Jr.) (modified from Edwards and Pojeta, 1994)
Page iv-v (cid:151) Ammonite, fossil fern (G. James) Pages 16-17 (cid:151) Half-life diagram (modified from Bushee
and others, 2000), Ordovician limestone and shale
Page vi (cid:151) Geologic Time Scale (De Atley), Adapted (J. Pojeta)
from various sources
Page 19 (cid:151) Forelimb comparison (modified from Daeschler
Page 1(cid:151) Ammonite (G. James) and Shubin, 1998)
Pages 2-3 (cid:151) Chesapectenfossils (adapted From Ward Pages 20-21 (cid:151) Comparison of bird and dinosaur skeletons
and Blackwelder, 1975; Bryce Canyon (M. Miller) and limbs (modified from Ostrom, 1975 and 1994;
Diagram comparing skulls of reptiles to mammals
Pages 4-5 (cid:151) Trilobite, brachiopod (J. Pojeta, photo: (modified from Savage and Long, 1986)
G. James), Tyranosaurus rexskull (Smithsonian
Institution); Jurassic Dinosaur Footprints (modified Pages 22-23 (cid:151) Reconstruction of the (cid:147)walking whale that
from Haubold, 1971), Devonian and Ordovician swims(cid:148) (modified from Thewissen and others, 1996),
trilobites (adapted from Moore, 1959) Sequoia National Park, California (Digital Vision)
Pages 6-7 (cid:151) Charles Darwin (1875 portrait), Silurian and Pages 24-25 (cid:151) Brachiopod (G. James),
Design: De Atley Design
Devonian fishes (modified from Fenton and Fenton, Dragonfly and Amphibian Fossils
Printing: CLB Printing
1958), Eocene fish fossil (G. James), Jurassic/ (Hemera)
Cretaceous fishes (modified from Romer, 1966)
Copyright '2001
Page 26 (cid:151) Nautilus (G. James)
All rights reserved.
Pages 8-9 (cid:151) Early Jurassic mammal skeleton (modified
American Geological Institute
from Jenkins and Parrington,1976), Diversification Back Cover (cid:151) Grand Canyon, Arizona
Alexandria, Virginia
diagram (modified from Novacek, 1994) (Digital Vision)
www.agiweb.org
ii E V O L U T I O N A N D T H E F O S S I L R E C O R D ISBN 0-922152-57-8
Acknowledgments
Many persons have helped us as we assembled this report. We gratefully recognize artist Julie De Atley for
the graphic design and illustration, photographer George James, Robert E. Weems (who provided the fossil
footprints), and Julia A. Jackson, Editor. We also extend our sincerest thanks and appreciation to the
following individuals for reviewing the manuscript:
David Applegate Patricia H. Kelley Kevin Padian
American Geological Institute University of North Carolina, University of California, Berkeley
Wilmington
Mel M. Belsky Kim L. Pojeta
Brooklyn College, CUNY Christopher G. Maples Smithsonian Institution
Indiana University, Bloomington
David J. Bohaska Linda Pojeta
Smithsonian Institution Sara Marcus Northport, New York
University of Kansas
Alan H. Cheetham Robert W. Purdy
Smithsonian Institution James G. Mead Smithsonian Institution
Smithsonian Institution
Daniel Dreyfus Vicki Quick and her students
Smithsonian Institution Marcus E. Milling Marshall, VA
American Geological Institute
J.T. Dutro, Jr. Bruce N. Runnegar
U.S. Geological Survey Don Munich University of California, Los Angeles
Charlestown, IN
Alan Goldstein Judy Scotchmoor
Falls of the Ohio State Park, Charles Naeser University of California, Berkeley
Clarksville, IN U.S. Geological Survey
Colin D. Sumrall
Pat Holroyd Norman D. Newell Cincinnati Museum of Natural
University of California, Berkeley American Museum of Natural History History and Science
John Keith William A. Oliver, Jr. Frank C. Whitmore, Jr.
U.S. Geological Survey U.S. Geological Survey U.S. Geological Survey
The American Geological Institute and The Paleontologial Society thank the following organizations for
supporting the production and distribution of Evolution and the Fossil Record.
Publishing Partners Supporters
Paleontological Research Institution Association for Women Geoscientists
Howard Hughes Medical Institute National Association of Geoscience Teachers
California Science Teachers Association SEPM (Society for Sedimentary Geology)
University of California Museum of Paleontology The Society for Organic Petrology
Society of Vertebrate Paleontology
Sponsors Soil Science Society of America
American Institute of Biological Sciences
American Association of Petroleum Geologists
Society for the Study of Evolution
American Geophysical Union
Cleveland Museum of Natural History
Geological Society of America
Denver Museum of Nature and Science
California Academy of Sciences
E V O L U T I O N A N D T H E F O S S I L R E C O R D iii
Foreword v
Geologic time chart vi
1
Contents Introduction
3
The Fossil Record
4
Change Through Time
6
Darwin(cid:146)s Revolutionary Theory
10
A Mechanism for Change
11
The Nature of Species
12
The Nature of Theory
13
Paleontology, Geology, & Evolution
16
Dating the Fossil Record
18
Examples of Evolution
23
Summary
24
Glossary
26
References/Readings
iv E V O L U T I O N A N D T H E F O S S I L R E C O R D
Foreword
Evolution is one of the fundamental underlying concepts of
modern science. This powerful theory explains such phenome-
na as the history of life preserved in the fossil record; the genetic,
molecular, and physical similarities and differences among organ-
isms; and the geographic distribution of organisms today and in the past.
Indeed, evolution forms the foundation of modern biology and paleontology and
is well documented by evidence from a variety of scientific disciplines.
Evolution is also one of the most misunderstood and controversial concepts in the eyes of
the general public. This situation is unfortunate, because the controversy surrounding evolution
is unnecessary. Resistance to evolution stems in part from misunderstanding science and how it
is distinct from religion. Science and religion provide different ways of knowing the Earth and
universe. Science proceeds by testing hypotheses and thus is restricted to natural, testable expla-
nations. By definition, science is unable to confirm or deny the existence or work of a Creator;
such questions are beyond the realm of science. As a scientific concept, evolution therefore
can make no reference to a Creator. Many people of faith, including scientists, find no conflict
between evolution and their religion; in fact, many religious denominations have issued
statements supporting evolution. Science and religion need not conflict.
Numerous lines of evidence show that life has changed through time. Evolution is the best
scientific explanation for this change. This booklet describes a small portion of the evidence
for this change, especially as documented by the fossil record, and outlines the processes
involved in evolution. Many fascinating questions remain concerning the history of life and the
process through which it has developed. As we continue to learn about life on Earth, the theory
of evolution will itself evolve. That is the strength, adventure, and excitement of doing science!
Patricia H. Kelley
Paleontological Society President, 2001-2002
Marcus E. Milling
AGI Executive Director
E V O L U T I O N A N D T H E F O S S I L R E C O R D v
Boundaries ~ Million Years Ago
Holocene
0.01
Quaternary
Modern humans Pleistocene
2
Pliocene
c Neogene 5
i
o
z Miocene
o Tertiary
n 23
e
C Mammals Oligocene
diversify;
early 34
hominids Paleogene Eocene
55
Paleocene
65
Flowering plants common;
Cretaceous major extinction including dinosaurs
c & ammonoids
i
o
z
oic so
oz Me 144
r Early birds & mammals;
e Jurassic
n abundant dinosaurs
a 206
h
P Abundant coniferous trees,
Triassic
first dinosaurs; first mammals
250
Mass extinction of many marine animals
Permian
including trilobites
290
Carboniferous Pennsylvanian
Fern forests; insects; first 314
reptiles; crinoids; sharks;
Mississippian
large primitive trees
c
i 360
o
z
o Devonian Early tetrapods, ammonoids, & trees
e
al 409
P
Silurian Early land plants & animals
439
Ordovician Early Fish
500
Abundant marine invertebrates;
Cambrian
trilobites dominant
540
Single-celled and, later, multi-celled,
Proterozoic
(cid:148) soft-bodied organisms; first invertebrates
n
a
i
r
b
m 2,500
a
c
e
r
P
(cid:147) Archean Oldest fossils; bacteria
& other single-celled organisms
Oldest known fossils 3,800
iv E V O L U T I O N A N D T H E F O S S I L R E C O RADlthough these dates have an accuracy range of about +/(cid:150) 1%, boundary dates
continue to change as geoscientists examine more rocks and refine dating methods.
Tyrannosaurus
no longer stalks its
prey across North
America. There are no
pterosaurs sailing majesti-
cally overhead. Trilobites no
longer crawl on the sea floors of
Earth. Today, other predators roam in
search of a meal. Birds soar the skies,
and crabs scuttle across the ocean bed.
Life on Earth has changed through time. It
has evolved. Change through time is a widely
accepted meaning of the word evolution. We speak of the
evolution of the English language, the evolution of the automobile, or the evolution of
politics in the United States. In natural history, biological or organic evolution
means change in populations of living organisms on planet Earth through time.
Charles Darwin defined biological evolution as (cid:147)descent with modification,(cid:148) that is, change
in organisms in succeeding generations. Another way of saying this is, (cid:147)species of organisms
originate as modified descendants of other species(cid:148) (Hurry, 1993).Biological evolution
is the derivation of new species from previously existing ones over time.
Evolution is the central unifying concept of natural history; it is the foundationof all
of modern paleontology and biology. This booklet presents a non-technical
introduction to the subject of evolution. Here you will find straightforward definitions of
important terms as well as discussions of complex ideas.
This brief introduction to the rich and fascinating history of the theory of
evolution cannot present in detail the vast body of evidence that has led to the
current understanding of evolutionary processes. Our aim is to
provide a sense of the history, strength, and power of this important
scientific theory. We hope that this booklet will help you
sense the wonder and excitement that
paleontologists and other students of evolutionary
science feel when they contemplate the long
and intricate history of life on
EEarathr.th.
E V O L U T I O N A N D T H E F O S S I L R E C O R D 1
e
n
e
c
o
i
l Changes in
P
r
e Chesapecten Chesapecten the fossil scallop
w
o septenarius madisonius
L Chesapecten through
about 13 million years,
shown particularly by
the variation in the (cid:145)ear(cid:146)
on the upper right of
Chesapecten
jeffersonius
each shell (see arrows)
and in the ribs on
the shell. Modified
Chesapecten from Ward and
middlesexensis
Blackwelder
(1975).
e
n
e
c
o
i
M
Chesapecten
r
e middlesexensis
p
p
U
Chesapecten
santamaria
Chesapecten
e
n nefrens
e
c
o
i
M
e
l
d
d
i
M
Chesapecten
coccymelus
Chesapecten
2 E V O L U T I O N A N D T H E F O S S I L R E C O R D sp.