The testimony of Kevin Padian in Kitzmiller v. Dover

Edited by Nick Matzke, National Center for Science Education
Version 1.1

Note from the editor: This webpage contains the slides used by U.C. Berkeley paleontologist Kevin Padian during his direct testimony in the 2005 Kitzmiller v. Dover case. Padian is also the president of the board of directors of the National Center for Science Education. These slides were introduced into evidence in the case as plaintiffs' exhibit P-855. The slides were assembled by Padian and the graduate students in his lab (see Acknowledgements).

The captions for the slides were added by me in early 2007. New scientific developments that took place after the October 2005 trial are noted in some captions. Any errors that remain in the captions are mine. A few slides received minor corrections, and in a few cases graphics from an unknown source were replaced with similar public domain graphics (e.g. the dolphin). Please send corrections and comments to me at matzke(AT)ncseweb.org.

The full transcript of Padian's testimony, with the slides embedded, is available at this link. A PDF containing all 102 slides in one file can be downloaded here (right-click, Save As).

-- Nick Matzke, National Center for Science Education

Sections:
Copyright information
Introduction
Classification, Ancestors, And Relationships
Creationism and the Fossil Record
     I. "Irreducible Complexity" and the evolution of major adaptations
     II. The "Cambrian Explosion"
     III. How vertebrates gained land (the “fish-amphibian” transition)
     IV. The Origin of Birds
     V. Fossil Mammals
          The Evolution of the Ear in Mammals
          The Origin of Whales
Creationist misrepresentations of Homology and Analogy
     Pandas on homology: the real wolf and Tasmanian “wolf”
     IDCers prefer the explanation of special creation over descent
Acknowledgements

Copyright information

Notes on copyright: All slides are copyright 2005 by Kevin Padian and reproduced with permission. However, many of the slides contain images from copyrighted sources; see individual slides for references and, where possible, permissions (primarily journals and museum specimens). Many slides also contain fair use material, such as small graphics of book covers, or quotes from exhibit material that is receiving academic criticism during the court testimony; the citation information is typically given within the slide.




Introduction (slides without transcript)

Slide 1: Summary of why "intelligent design" is a form of creationism.
(Right-click to download pdf.)


Slide 2: Pandas on Macroevolution.
(Right-click to download pdf.)


Slide 3: Summary of speciation and macroevolution.
(Right-click to download pdf.)


Slide 4: ID says there are strict limits to evolutionary change.
(Right-click to download pdf.)


Slide 5: Scientific creationist Duane Gish also claimed limits to evolutionary change.
(Right-click to download pdf.)


Classification, Ancestors, And Relationships

Slide 6: Beginning section on modern classification, cladistics, and how evolutionary relationships are reconstructed.
(Right-click to download pdf.)


Slide 7: Summary of what ID proponents do not understand about phylogeny reconstruction.
(Right-click to download pdf.)


Slide 8: Two kinds of ancestry, lineal and collateral. Collateral ancestor "is a legal term referring to a person not in the direct line of ascent, but is of an ancestral family" (Encyclopedia of Genealogy). Parents are lineal ancestors; siblings are collateral ancestors. Padian's point is that both are informative about ancestry - you share 1/2 of your genome with your mother, but also share 1/2 with your sister. Similarly, you share 1/4 of your genome with both your grandparent and your cousin. Creationists claim that paleontologists must find direct ancestors to document common ancestry, but this can be done equally rigorously with cladistic methods that identify "sister" and "cousin" groups on the basis of shared characters.
(Right-click to download pdf.)

Credits: Graphic by Liz Perotti, U.C. Berkeley. Reproduced with permission.


Slide 9: A vertebrate cladogram showing a few of the many characters that unite major groups. This is just an educational example; actual research cladograms incorporate hundreds of characters. Using large datasets allows researchers to quantify the statistical support for a given phylogenic hypothesis.
(Right-click to download pdf.)

Credits: Graphic by Liz Perotti, U.C. Berkeley. Reproduced with permission.


Slide 10: A few of the characters shared by humans and apes.
(Right-click to download pdf.)

Credits: Graphic by Liz Perotti, U.C. Berkeley. Reproduced with permission.


Slide 11: Primates are closer relatives of cows than lions, based on the shared character of a stirrup-shaped ear bone.
(Right-click to download pdf.)

Credits: Graphic by Liz Perotti, U.C. Berkeley. Reproduced with permission.


Slide 12: All placental mammals are united by a placenta.
(Right-click to download pdf.)

Credits: Graphic by Liz Perotti, U.C. Berkeley. Reproduced with permission.


Slide 13: All mammals are united by several characters, including hair, mammary glands, and a synapsid opening in the skull (synapsids have one opening on the side of the skull behind each eye; diapsids (birds and most "reptiles") have two.
(Right-click to download pdf.)

Credits: Graphic by Liz Perotti, U.C. Berkeley. Reproduced with permission.


Slide 14: All amniotes (all tetrapods except for amphibians) are united by the amnion (a membranous sac which surrounds and protects the embryo).
(Right-click to download pdf.)

Credits: Graphic by Liz Perotti, U.C. Berkeley. Reproduced with permission.


Slide 15: Birds and dinosaurs like Tyrannosaurus rex are united by the shared character of a hole in the hip socket.
(Right-click to download pdf.)

Credits: Graphic by Liz Perotti, U.C. Berkeley. Reproduced with permission.


Slide 16: All tetrapods are united by a four-legged ancestor. Some tetrapods (such as snakes and whales) have lost limbs, but they descended from legged ancestors.
(Right-click to download pdf.)

Credits: Graphic by Liz Perotti, U.C. Berkeley. Reproduced with permission.


Slide 17: Vertebrates with jaws form a related group that excludes jawless fishes such as lampreys.
(Right-click to download pdf.)

Credits: Graphic by Liz Perotti, U.C. Berkeley. Reproduced with permission.


Slide 18: All vertebrates share a vertebral column.
(Right-click to download pdf.)

Credits: Graphic by Liz Perotti, U.C. Berkeley. Reproduced with permission.



Creationism and the Fossil Record

Slide 19: Figure 4-4 from page 99 of Pandas (1993) alleges that the fossil record shows only sudden origin followed by stasis.
(Right-click to download pdf.)

Credits: Stasis diagram from Pandas Figure 4-4, p. 99. ©1993 by Foundation for Thought and Ethics, Richardson, TX 75083-0721


Slide 20: Padian argues that Behe's "irreducible complexity" argument, if not the exact term, is clearly found in both the first (1989) and second (1993) editions of Pandas, and that the fossil record can speak to this argument.
(Right-click to download pdf.)



I. "Irreducible Complexity" and the evolution of major adaptations

Slide 21: Pandas argues that "adaptational packages" have multiple required parts, therefore could not have evolved gradually, and thus must have been intelligently designed (specially created) all at once. This is the same argument as Behe's "irreducible complexity."
(Right-click to download pdf.)


Slide 22: Behe's claim that the "irreducible complexity" argument applies only at the molecular level is contradicted by Pandas, which applies the argument to whole organs and organisms.
(Right-click to download pdf.)


Slide 23: Examples of Pandas making the IC argument above the molecular level, at the organismal level.
(Right-click to download pdf.)


Slide 24: Pandas used the giraffe as an example of an adaptational package (pp. 69-70).
(Right-click to download pdf.)

Credits: Giraffe from Pandas Figure 2-3, p. 70. ©1993 by Foundation for Thought and Ethics, Richardson, TX 75083-0721


II. The "Cambrian Explosion"

Slide 25: Padian addresses the "Cambrian Explosion," a favorite argument of creationists/ID proponents.
(Right-click to download pdf.)


Slide 26: Assertions from Pandas on the origin of phyla at the beginning of the Cambrian.
(Right-click to download pdf.)


Slide 27: Henry Morris, the founder of scientific creationism and co-founder of the Institute for Creation Research, made the same argument.
(Right-click to download pdf.)


Slide 28: Duane Gish also makes the Cambrian Explosion argument in an ICR publication.
(Right-click to download pdf.)


Slide 29: Pandas claims there is no fossil evidence for common ancestry, only naturalistic philosophy, and argues for special creation ("an intelligent cause made fully-formed and functional creatures, which later left their traces in the rocks").
(Right-click to download pdf.)


Slide 30: This figure from Pandas attempts to depict the Cambrian "Explosion," but leaves out crucial data such as the time scale and Precambrian fossils.
(Right-click to download pdf.)

Credits: Cambrian Explosion figure from Pandas Figure 4-2, p. 95. ©1993 by Foundation for Thought and Ethics, Richardson, TX 75083-0721


Slide 31: This figure, from a 2005 paper in Paleobiology, shows the data that Pandas ignored, including Precambrian fossils, and the fact that even on a narrow definition based on the appearance of clear bilaterian fossils, the "explosion" took at least 30 million years. The chart also shows that fossil diversity (the blue and yellow bars) increased relatively rapidly, but not all at once.
(Right-click to download pdf.)

Credits: Diagram from Figure 2, page 4 of: Peterson, Kevin J.; McPeek, Mark A.; and Evans, David A. D. (2005). "Tempo and mode of early animal evolution: inferences from rocks, Hox, and molecular clocks." Paleobiology 31(2_Suppl), 36-55. (DOI) Copyright 2005, the Paleontological Society. Reproduced with permission.


Slide 32: Fossils spanning the late Precambrian and early Cambrian. The early Cambrian was preceded by Ediacaran fossils, the tracks and burrows of wormlike fossils, and the beginning of the "small shelly" fauna, which increases rapidly in diversity in the early Cambrian, mostly before recognizable body fossils (e.g. trilobites) are found.

(Note: A 1998 paper in Nature claimed that fossils in the Doushantuo formation in China were early-stage metazoan (animal) embryos (Xiao et al., 1998). This would push fossil evidence of animal life back to perhaps 590 million years ago as shown in the slide. However, this interpretation was questioned by another paper in Nature, published in January 2007, which made a substantial case for the idea that the "embryos" are actually clumps of giant sulphur bacteria (Bailey et al.). This interpretation has some issues as well, since a recent Science paper has claimed that nuclei can be observed in some of the fossils, which would indicate that they are not bacteria (Hagadorn et al. 2006). See Donoghue's (2007) summary in Nature for a semi-technical overview of the issues.)
(Right-click to download pdf.)

Credits:

Trilobite (Olenoides serratus) and oncychophoran (Aysheaia) reproduced with permission from Pamela Gore's Burgess Shale Page.

Primitive arthropod (Fuxianhuia protensa) from Figure 1, p. 4 of: Babcock, Loren E.; Zhang, Wentang; Leslie, Stephen A. (2001). "The Chengjiang Biota: Record of the Early Cambrian Diversification of Life and Clues to Exceptional Preservation of Fossils." GSA Today, 11(2), 4–9. (DOI) Reproduced with permission.

Small shellies from: Figure 8, page 272 of: Steiner, M.; Li, G.; Qian, Y.; and Zhu, M. (2004). "Lower Cambrian Small Shelly Fossils of northern Sichuan and southern Shaanxi (China), and their biostratigraphic importance." Geobios, 37(2), 259-275. (DOI) Copyright 2004 Elsevier. Reproduced with permission.

Ediacaran 'vendobiont' (Dickinsonia) courtesy of Lisa-Ann Gershwin and the UC Museum of Paleontology (source page). Reproduced with permission.

Precambrian embryo from Figure 5g, page 556 of: Xiao, Shuhai; Zhang, Yun; Knoll, Andrew H. (1998). "Three-dimensional preservation of algae and animal embryos in a Neoproterozoic phosphorite." Nature 391(6667), 553-558. (DOI) Reprinted by permission from Macmillan Publishers Ltd., copyright 1998.



Slide 33: Recently published advances in research on the origin of phyla.
(Right-click to download pdf.)


III. How vertebrates gained land (the “fish-amphibian” transition)

Slide 34: Padian will now cover the origin of tetrapods -- the first vertebrates to walk on land. In traditional classification, this was known as the "fish-amphibian" transition. This terminology is problematic in cladistics because technically tetrapods are just a subgroup of "fish" and thus are "fish," cladistically speaking.
(Right-click to download pdf.)


Slide 35: Pandas, p. 22, asserts that no transitional fossils exist between fish and something else.
(Right-click to download pdf.)


Slide 36: Pandas, p.104, claims that "two large gaps" exist, one on each side of crossopterygians (lobe-finned fishes related to tetrapods).
(Right-click to download pdf.)


Slide 37: Pandas, p. 103, compares Ichthyostega and Eusthenopteron.
(Right-click to download pdf.)

Credits: Image #: 3211693, Drawing by: Helen Ziska. American Museum of Natural History Library - Special Collections. Reproduced with permission.


Slide 38: A series of fossils with transitional features exist between "fish" and modern tetrapods. Padian lists a number of the claims Pandas makes (pp. 103-104) and compares them with the fossils.
(Right-click to download pdf.)

Credits:

Neoceratodus modified from p. 135 of Long, J. (1995). The Rise of Fishes, Johns Hopkins University Press. Original photo credit: Dr. Alex Ritchie, Australian Museum.

Panderichthys, Tulerpeton, phylogeny, modified from p. 58 of: Clack, Jennifer A. (2004). "From Fins to Fingers." Science 304(5667), 57-58. (DOI) Art by Emese Kazar -- http://www.emesekazar.com/, reproduced with permission.

Acanthostega (2005 reconstruction) from Figure 1c, page 137 of: Ahlberg, Per Erik; Clack, Jennifer A.; Blom, Henning (2005). "The axial skeleton of the Devonian tetrapod Ichthyostega." Nature, 437(7055), 137-140. (DOI) Reprinted by permission from Macmillan Publishers Ltd., copyright 2005.

Ichthyostega (2005 reconstruction) from Figure 1a, page 137 of: Ahlberg, Per Erik; Clack, Jennifer A.; Blom, Henning (2005). "The axial skeleton of the Devonian tetrapod Ichthyostega." Nature, 437(7055), 137-140. (DOI) Reprinted by permission from Macmillan Publishers Ltd., copyright 2005.

Greererpeton from Figure 1a, p. 77 of: Godfrey, S. J. (1989). "The Postcranial Skeletal Anatomy of the Carboniferous Tetrapod Greererpeton burkemorani Romer, 1969." Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences. 323(1213), 75-133. Reproduced with permission of the Royal Society and Stephen Godfrey.

Ensatina salamander photo © 2005 Tom Devitt, U.C. Berkeley Department of Integrative Biology and Museum of Vertebrate Zoology. Reproduced with permission.

Thunnus modified from this image at the Monterrey Bay Aquarium.



Slide 39: Pandas' claim about "two large gaps" in the fossil record of the fish-amphibian transition, one on each side of the crossopterygian Eusthenopteron, is challenged. Panderichthys and Acanthostega fill in the gap on the tetrapod side (they were joined by Tiktaalik in 2006), and fossils in the stem groups of both lobe-finned and ray-finned fishes fill in the gap to "ordinary fish."
(Right-click to download pdf.)


Slide 40: The fossils show transitional features specifically in the limbs, where Pandas' figure 4-9 claims there is a gap.
(Right-click to download pdf.)

Credits:

Phylogeny, forelimbs, Panderichthys, Tulerpeton modified from p. 58 of: Clack, Jennifer A. (2004). "From Fins to Fingers." Science 304(5667), 57-58. (DOI) Art by Emese Kazar -- http://www.emesekazar.com/, reproduced with permission.

Fin/forelimb figure from Pandas Figure 4-9, p. 104. ©1993 by Foundation for Thought and Ethics, Richardson, TX 75083-0721

Greererpeton forelimb from Figure 26b, p. 118 of: Godfrey, S. J. (1989). "The Postcranial Skeletal Anatomy of the Carboniferous Tetrapod Greererpeton burkemorani Romer, 1969." Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences. 323(1213), 75-133. Reproduced with permission of the Royal Society and Stephen Godfrey.



Slide 41: Pandas also claimed a gap between the two-part skull of fishes and the one-part skull of tetrapods. These fossils are also transitional in this feature, where the skull shifts from two mobile parts, to two immobile parts, to two fused parts, to finally the "one part" skull of early tetrapods.
(Right-click to download pdf.)

Credits:

Eusthenopteron neurocranium from: Jarvik, E. (1980). Basic Structure and Evolution of Vertebrates, vol. 1, Academic Press.

Panderichthys neurocranium from Figure 2a, page 62 of: Ahlberg, Per E.; Clack, Jennifer A.; Luksevics, Ervins (1996). "Rapid braincase evolution between Panderichthys and the earliest tetrapods." Nature, 381(6577), 61-64. (DOI) Reprinted by permission from Macmillan Publishers Ltd., copyright 1996.

Ichthyostega neurocranium from Figure 3c, page 68 of: Clack, J. A.; Ahlberg, P. E.; Finney, S. M.; Dominguez Alonso, P.; Robinson, J.; Ketcham, R. A. (2003). "A uniquely specialized ear in a very early tetrapod." Nature, 425(6953), 65-69. (DOI) Reprinted by permission from Macmillan Publishers Ltd., copyright 2003.



Slide 42: The fossils also show how the rear fins first became attached to the backbone via the sacral rib, and how this attachment was enlarged. Panderichthys specimens, in press in October 2005, filled in an additional piece of this transition in December (see Boissert 2005 in Nature).
(Right-click to download pdf.)

Credits:

Eusthenopteron pelvis from: Jarvik, E. (1980). Basic Structure and Evolution of Vertebrates, vol. 1, Academic Press.

Acanthostega pelvis from Figure 1c, page 137 of: Ahlberg, Per Erik; Clack, Jennifer A.; Blom, Henning (2005). "The axial skeleton of the Devonian tetrapod Ichthyostega." Nature, 437(7055), 137-140. (DOI) Reprinted by permission from Macmillan Publishers Ltd., copyright 2005.

Ichthyostega pelvis from Figure 1a, page 137 of: Ahlberg, Per Erik; Clack, Jennifer A.; Blom, Henning (2005). "The axial skeleton of the Devonian tetrapod Ichthyostega." Nature, 437(7055), 137-140. (DOI) Reprinted by permission from Macmillan Publishers Ltd., copyright 2005.



Slide 43: A number of the important papers published on the fish-amphibian transition.
(Right-click to download pdf.)


Slide 44: The famous quote from Pandas, pp. 99-100, which said that intelligent design "means that various forms of life began abruptly," including "birds with feathers, beaks, and wings," which Padian will cover in the next section. This quote also explicitly contrasts ID with "natural cause" explanations
(Right-click to download pdf.)


Slide 45: Again on p. 100, Pandas contrasts ID with natural causes, saying that ID "suggests that a reasonable natural cause explanation for origins may never be found."
(Right-click to download pdf.)


IV. The Origin of Birds

Slide 46: Padian will now discuss the origin of bird from dinosaurs, and the origin of feathers.
(Right-click to download pdf.)


Slide 47: Pandas takes note of Archaeopteryx (the famous Berlin specimen is shown at right), but complains "[i]f only we could find a fossil showing scales developing the properties of feathers" then "we would have more to go on." "But," concludes Pandas, "the fossil record gives no evidence for such changes."
(Right-click to download pdf.)

Credits: Photo author unknown (various versions widespread on the web). This is the famous Archaeopteryx Berlin Specimen, Museum fuer Naturkunde, Berlin, Germany. See the museum website for the Berlin specimen.


Slide 48: A number of recent discoveries of fossil dinosaurs -- with feathers -- published in Nature in the last ten years.
(Right-click to download pdf.)


Slide 49: Padian will show a number of feathered dinosaur fossils, showing where cladistic analysis places them in the phylogeny. The phylogeny allows the ancestral states (the stages, marked in red on the phylogeny) to be reconstructed. Here, a compsognathid fossil (Sinosauropteryx) with hairlike protofeathers down its back. This is exactly what Pandas demanded, a fossil "developing the properties of feathers."
(Right-click to download pdf.)

Credits:

Feather drawing by Patricia J. Wynne. From pp. 90-91 of: Prum, R. and Brush, A. (2003). "Which Came First, the Feather or the Bird?" Scientific American, 288(3), 84-93.

Sinosauropteryx neck/head/feathers from Figure 2a, page 148 of: Chen, Pei-Ji; Dong, Zhi-Ming; Zhen, Shuo-Nan (1998). "An exceptionally well-preserved theropod dinosaur from the Yixian Formation of China." Nature, 391(6663), 147-152. (DOI) Reprinted by permission from Macmillan Publishers Ltd., copyright 1998.



Slide 50: Protofeathers become more complex with a branching structure, represented in the tyrannosaurid Dilong. The "stages" come from the evo-devo work of Richard Prum and Alan Brush.
(Right-click to download pdf.)

Credits:

Feather drawing by Patricia J. Wynne. From pp. 90-91 of: Prum, R. and Brush, A. (2003). "Which Came First, the Feather or the Bird?" Scientific American, 288(3), 84-93.

Dilong feathers from Figure 3a, page 683 of: Xu, Xing; Norell, Mark A.; Kuang, Xuewen; Wang, Xiaolin; Zhao, Qi; Jia, Chengkai (2004). "Basal tyrannosauroids from China and evidence for protofeathers in tyrannosauroids." Nature, 431(7009), 680-684. (DOI) Reprinted by permission from Macmillan Publishers Ltd., copyright 2004.



Slide 51: The next stage is the development of a central vein, or "rachis," in the protofeather. These structures are symmetrical and not aerodynamic.
(Right-click to download pdf.)

Credits:

Feather drawing by Patricia J. Wynne. From pp. 90-91 of: Prum, R. and Brush, A. (2003). "Which Came First, the Feather or the Bird?" Scientific American, 288(3), 84-93.

Protarchaeopteryx feather from Figure 3a, page 756 of: Qiang, Ji; Currie, Philip J.; Norell, Mark A.; Shu-An, Ji (1998). "Two feathered dinosaurs from northeastern China." Nature, 393(6687), 753-761. (DOI) Reprinted by permission from Macmillan Publishers Ltd., copyright 1998.



Slide 52: In stage 4, barbules link the barbs together. Still symmetrical. Representative: Caudipteryx.
(Right-click to download pdf.)

Credits:

Feather drawing by Patricia J. Wynne. From pp. 90-91 of: Prum, R. and Brush, A. (2003). "Which Came First, the Feather or the Bird?" Scientific American, 288(3), 84-93.

Caudipteryx feathers from Figure 8b, page 760 of: Qiang, Ji; Currie, Philip J.; Norell, Mark A.; Shu-An, Ji (1998). "Two feathered dinosaurs from northeastern China." Nature, 393(6687), 753-761. (DOI) Reprinted by permission from Macmillan Publishers Ltd., copyright 1998.



Slide 53: In dromaeosaurs like Microraptor -- still phylogenetically basal to Archaeopteryx and more modern birds -- asymmetrical feathers have developed with aerodynamic properties.
(Right-click to download pdf.)

Credits:

Feather drawing by Patricia J. Wynne. From pp. 90-91 of: Prum, R. and Brush, A. (2003). "Which Came First, the Feather or the Bird?" Scientific American, 288(3), 84-93.

Microraptor feather from Figure 3c, p. 338 of: Xu, X.; Zhou, Z.; Wang, X.; Kuang, X.; Zhang, F.; and Du, X. "Four-winged dinosaurs from China." Nature 421(6921), 335-340. (DOI) Reprinted by permission from Macmillan Publishers Ltd., copyright 2003.



Slide 54: What good is half a wing? Feathers have many known functions besides flight.
(Right-click to download pdf.)


Slide 55a: The pattern of digits in groups sister to birds. Digits were lost progressively -- first V, then IV.
(Right-click to download pdf.)


Slide 55b: The fossil record preserves not only bones -- sometimes it even preserves behavior. This 1995 Nature paper shows an Oviraptor sitting on a nest.
(Right-click to download pdf.)

Credits: Oviraptor from Figure 1a and Figure 2, page 775 of: Norell, Mark A.; Clark, James M.; Chiappe, Luis M.; Dashzeveg, Demberelyin (1995). "A nesting dinosaur." Nature, 378(6559), 774-776. (DOI) Reprinted by permission from Macmillan Publishers Ltd., copyright 1995.


Slide 55c: Another example of behavior preserved in the fossil record. This 2004 Nature paper shows a small troodontid dinosaur, Mei long, displaying "the earliest recorded occurrence of the stereotypical sleeping or resting behaviour found in living birds." The head is tucked under the wing.
(Right-click to download pdf.)

Credits: Mei long from Figure 1c-1d, page 839 of: Xu, Xing; Norell, Mark A. (2004). "A new troodontid dinosaur from China with avian-like sleeping posture." Nature, 431(7010), 838-841. (DOI) Reprinted by permission from Macmillan Publishers Ltd., copyright 2004.


V. Fossil Mammals

Slide 56: Padian will now address the origin of mammals. In classical taxonomy, the ancestors of mammals were called the "mammal-like reptiles," but so many fossils with transitional features are now known drawing a line between mammals and "reptiles" became arbitrary. In cladistic classifications, mammals and their fossil relatives are called therapsids.
(Right-click to download pdf.)


The Evolution of the Ear in Mammals

Slide 57: The mammalian middle ear contains three tiny bones: the stapes, the incus, and the malleus (popularly analogized with a stirrup, an anvil, and a hammer). Other vertebrates have only the stapes in middle ear, but anatomical consensus for over 100 years has been that the incus and malleus are homologous to the quadrate and articular, bones found in the jaw of the other vertebrates. Pandas denies that this amazing transition is documented in the fossil record.
(Right-click to download pdf.)


Slide 58: A 1969 paper by the famous paleontologist Alfred Romer describes the existence of a fossil with just such transitional features.
(Right-click to download pdf.)


Slide 59: A paper by Edgar Allen also discusses the evolution of the mammalian middle ear.
(Right-click to download pdf.)


Slide 60: A third paper suggests that one step in the evolution of the middle ear -- separation of the bones from the mandible -- may have even happened twice, in two related lineages.
(Right-click to download pdf.)


Slide 61: Three early therapsid skulls, plus a modern possum skull, show the changes that occurred in the quadrate (blue, "q") and articular (red, "art") bones. As the quadrate and articular decrease in size, the squamosal (yellow, "sq") and dentary (purple, "d") bones will take over the function of jaw joint.
(Right-click to download pdf.)

Credits: Skulls modified from: Carroll, R.C. (1987). Vertebrate Paleontology and Evolution. W. H. Freeman and Co., New York.


Slide 62: The skulls in phylogenetic arrangement. Probainognathus and Morganucodon document exactly the transitional stage that Pandas claimed was undocumented. These fossils have jaws in which quadrate-articular and dentary-squamosal joints function simultaneously.
(Right-click to download pdf.)


Slide 63: Another mistake in Pandas. At top, Figure 5-7, p. 121 of Pandas says that "according to Darwinian theory" the quadrate and articular jawbones were relocated as the incus and stapes. But examination of a near-identical figure in Carroll's Vertebrate Paleontology and Evolution shows that it is actually the incus and the malleus that correspond to the quadrate and articular.
(Right-click to download pdf.)

Credits:

Middle ear from Pandas Figure 5-7, p. 121. ©1993 by Foundation for Thought and Ethics, Richardson, TX 75083-0721

Middle ear, scientific version from: Carroll, R.C. (1987). Vertebrate Paleontology and Evolution. W. H. Freeman and Co., New York.




The Origin of Whales

Slide 64: Padian moves on to the origin of whales. Pandas claims "there are no clear transitional fossils linking land mammals to whales." (pp. 101-102)
(Right-click to download pdf.)


Slide 65: Recent journal articles on fossil whales with legs.
(Right-click to download pdf.)


Slide 66: As with birds and mammals, Padian will display the fossil relatives of modern whales and dolphins (cetaceans) in their phylogenetic context. The origin of whales was long debated, but in recent years molecular and fossil data converged to support the hypothesis that whales evolved within the artiodactyl group. Traditionally, the artiodactyl group included the even-toed ungulates (hoofed animals) -- animals like goats, cows, and hippos. These animals are large, herbivorous, and have thick hooves, but some fossil artiodactyls were small, with small hooves, and omnivorous (as are modern pigs). Shown in the slide are Diacodexis, the first artiodactyl (about the size of a rabbit) and an oreodont, another early artiodactyl.
(Right-click to download pdf.)

Credits:

Diacodexis reconstruction from Figure 1, page 259 of: de Muizon, Christian (2001). "Walking with whales." Nature, 413(6853), 259-260. (DOI) Reprinted by permission from Macmillan Publishers Ltd., copyright 2001.

Reproduced with permission of the UC Museum of Paleontology. Source: http://www.ucmp.berkeley.edu/mammal/artio/artiofr.html.



Slide 67: Hippos are the closest living relatives of cetaceans. This relationship was indicated by molecular evidence in the 1990s, and confirmed by key morphological features shared between anthracotheres (the fossil ancestors of hippos) and early whales in 2005.
(Right-click to download pdf.)

Credits:

Photo by Aaron Logan (source: http://en.wikipedia.org/wiki/Image:Lightmatter_hippo.jpg), licensed under Creative Commons Attribution 2.0).

Photo by Paul Maritz (source: http://en.wikipedia.org/wiki/Image:Hippo_pod_edit.jpg), available under the GNU Free Documentation License.



Slide 68: Pakicetus is a whale from Pakistan, sharing key skull features with fully aquatic whales.
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Credits: Pakicetus skulls from Figure 3, page 279 of: Thewissen, J. G. M.; Williams, E. M.; Roe, L. J.; Hussain, S. T. (2001). "Skeletons of terrestrial cetaceans and the relationship of whales to artiodactyls." Nature, 413(6853), 277-281. (DOI) Reprinted by permission from Macmillan Publishers Ltd., copyright 2001.


Slide 69: However, Pakicetus was a whale with legs.
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Credits:

Pakicetus and Ichthyolestes reconstruction from Hans Thewissen's whale evolution page, http://darla.neoucom.edu/DEPTS/ANAT/Pakicetid.html (public access granted)

Pakicetus attocki fossil in the collection of: Northeastern Ohio Universities College of Medicine c/o Howard University - Geological Survey of Pakistan Collection. Photograph from http://www.researchcasting.ca/pakicetus.htm, reproduced with permission.



Slide 70: Oxygen isotope ratios from the tooth enamel of fossils indicates that Pakicetus probably fed in the shallow Tethys sea and its estuaries.
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Credits: Figure 4, p. 15467, from: Bajpai S.; Gingerich, P.D. (1998). "A new Eocene archaeocete (Mammalia, Cetacea) from India and the time of origin of whales." Proceedings of the National Academy of Sciences, 95(26), 15464-15468. (PNAS) Reproduced with permission. Copyright 1998 National Academy of Sciences, U.S.A.


Slide 71: Ambulocetus was fully aquatic or nearly so, but still had reduced limbs.
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Credits:

Ambulocetus reconstruction from Hans Thewissen's whale evolution page, http://darla.neoucom.edu/DEPTS/ANAT/Ambulocet.html (public access granted)

Ambulocetus fossil in the collection of the Northeastern Ohio Universities College of Medicine. Photograph from http://www.researchcasting.ca/ambulocetus.htm, reproduced with permission.

Ambulocetus fossil photo modified from Hans Thewissen's whale evolution page, http://www.neoucom.edu/DEPTS/ANAT/Thewissen/publ.html (public access granted)



Slide 72: The hands and feet are large and paddle-like.
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Slide 73: Top and middle: Rodhocetus reconstruction and Artiocetus clavis skull. The bottom photo shows the ankle bones of Rodhocetus, a modern pronghorn antelope, and Artiocetus. Remarkably, all three show a "double-pulley" astragalus. The astragalus is the bone with the deep, rounded groove in it (imagine a rope fitting into the groove of a pulley wheel). This groove, called a trochlea, fits another bone to form a sliding joint. The artiodactyl astragalus -- in both the modern pronghorn and these ancient swimming whales -- has the unique feature of having two trochleas, one on each end. This is the "double-pulley." These protocetid whales were definitely not runners, but they retain a clear mark of their ancestry as hoofed running animals. See Gingerich's website and paleos for more details.
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Credits:

Rodhocetus from Figure 3, p. 2241 of: Gingerich, P. D.; M. Haq; I. S. Zalmout; I. H. Khan; and M. S. Malkani (2001). "Origin of Whales from Early Artiodactyls: Hands and Feet of Eocene Protocetidae from Pakistan." Science 293(5538), 2239-2242. (DOI) Reproduced with permission.

Artiocetus clavis photograph from Philip Gingerich's whale evolution page. ©2001 Philip Gingerich. Reproduced with permission.

Protocetid ankles from Philip Gingerich's whale evolution page. Photograph ©2001 Philip Gingerich. Reproduced with permission.



Slide 74: In the protocetids, the hips are decoupled from the backbone. They definitely were not running animals.
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Slide 75: Artiocetus clavis skull. The nose is still at the front of the skull, unlike modern whales.
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Credits: Artiocetus skull from Figure 1, p. 2240 of: Gingerich, P. D.; M. Haq; I. S. Zalmout; I. H. Khan; and M. S. Malkani (2001). "Origin of Whales from Early Artiodactyls: Hands and Feet of Eocene Protocetidae from Pakistan." Science 293(5538), 2239-2242. (DOI) Reproduced with permission.


Slide 76: The drawing shows the astragalus of Artiocetus (A) and full ankle of Rodhocetus balochistanensis (C) (astragalus bone near the top). Rodhocetus's foot was certainly a swimming flipper, but still retained small hooves.
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Credits: Protocetid hindlimb/ankle reconstructions from Figure 2, p. 2241 of: Gingerich, P. D.; M. Haq; I. S. Zalmout; I. H. Khan; and M. S. Malkani (2001). "Origin of Whales from Early Artiodactyls: Hands and Feet of Eocene Protocetidae from Pakistan." Science 293(5538), 2239-2242. (DOI) Reproduced with permission.


Slide 77: Mounted skeleton of Dorudon atrox, a basilosaurid, and Basilosaurus isis fossil excavation in Egypt. Basilosaurus was first discovered in the southern U.S. in the early 1800s and was originally thought to be a reptile (thus the "saurus").
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Credits:

Dorudon from Philip Gingerich's whale evolution page. Photograph ©1998 Philip Gingerich. Reproduced with permission.

Basilosaurus in situ from Philip Gingerich's whale evolution page. Photograph ©2005 Philip Gingerich. Reproduced with permission



Slide 78: In the basilosaurids, the nostrils have moved further back along the skull.
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Slide 79: The hind limbs of the basilosaurids were vestigial. These whales were fully aquatic and could not even drag themselves onto a beach.
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Slide 80: Incredibly, the hind limbs still retain the "double-pulley" astragalus in the ankle.
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Credits: Basilosaurus hindlimb from Philip Gingerich's whale evolution page. Photograph ©1991 Philip Gingerich. Reproduced with permission.


Slide 81: In living dolphins and whales, the nostrils are at the top of the skull, and they have completely lost their hind limbs, except for rare atavisms.
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Credits:

Dolphin is a public domain image from NOAA, source: http://en.wikipedia.org/wiki/Image:Common_dolphin.jpg

Humpback whale reproduced under the Creative Commons Attribution ShareAlike License v. 2.5. Source: http://en.wikipedia.org/wiki/Image:DSC_7334.JPG



Slide 82: Having reviewed the evidence, Padian returns to Pandas' claim that "there are no clear transitional fossils linking land mammals to whales" (pp. 101-102).
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Creationist misrepresentations of Homology and Analogy

Slide 83: In the final section, Padian turns to homology and analogy, fundamental concepts in comparative biology. Chapter 5 of Pandas attempts to overturn the idea that homology is strong evidence for common ancestry.
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Slide 84: Figure 5-2 of Pandas (p. 117) compares the skulls of a domestic dog (Canis lupus familiaris, a wolf (Canis lupus) and the marsupial "wolf" (also known as the Tasmanian wolf/Tasmanian tiger, or thylacine; scientific name: Thylacinus cynocephalus), a dog-sized marsupial carnivore. The standard evolutionary phylogeny says that the thylacine is more closely related to a kangaroo than a dog, and dogs and wolves are more closely related to humans and other placental mammals (whales, bats, etc.) than to any marsupial. Pandas says this relationship is doubtful and arbitrarily determined, claiming that the skulls of thylacines and wolves are more similar to each other than to their allegedly marsupial and placental relatives.
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Credits: Dog/wolf/thylacine skulls modified from Pandas Figure 5-2, p. 117. ©1993 by Foundation for Thought and Ethics, Richardson, TX 75083-0721


Pandas on homology: the real wolf and Tasmanian “wolf”

Slide 85: Pandas claims that the similarity of the "wolf" skulls shows that biologists cannot objectively distinguish homology (similarity due to common ancestry) and analogy (similarity not due to common ancestry), and therefore common ancestry and phylogenetic reconstruction are dubious concepts.
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Slide 86: Pandas claims that the skull of a wolf is more similar to that of a Tasmanian "wolf" than to a dog skull. Looking at a photo of a live Tasmanian "wolf" shows that they are substantially different from any wolf or dog.
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Credits: The sources for these photos are unknown, they seem to be stock photos. See: http://www.naturalworlds.org/thylacine/index.htm for many thylacine photos.


Slide 87: Unlike creationist argumentation, comparative biology is a rigorous science. Rather than just "eyeballing" similarity as creationists do, biologists systematically identify specific characters. Padian shows five of the standard skull features that dogs and wolves share. For example, tooth formulas are a standard feature used for classifying mammals. Dogs and wolves both have two molars in the upper jaw.
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Credits: Photos by Andrew Lee, U.C. Berkeley. Skulls from the U.C. Museum of Paleontology and the Museum of Vertebrate Zoology. Reproduced with permission.


Slide 88: A direct comparison of a North American wolf and a Tasmanian "wolf," on the other hand, shows that these two species differ in each of these characters. For example, the tasmanian wolf has four molars instead of two.
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Credits: Photos by Andrew Lee, U.C. Berkeley. Skulls from the U.C. Museum of Paleontology and the Museum of Vertebrate Zoology. Reproduced with permission.


Slide 89: Dogs and wolves both have pinched nasals and three incisors on one side of the jaw.
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Credits: Photos by Andrew Lee, U.C. Berkeley. Skulls from the U.C. Museum of Paleontology and the Museum of Vertebrate Zoology. Reproduced with permission.


Slide 90: On the other hand, the Tasmanian "wolf" has wide nasals and four incisors (another difference in tooth formula).
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Credits: Photos by Andrew Lee, U.C. Berkeley. Skulls from the U.C. Museum of Paleontology and the Museum of Vertebrate Zoology. Reproduced with permission.


Slide 91: Viewing the skull from below shows the same pattern. Dogs and wolves do not have holes in the center of the palate (the roof of the mouth). The Tasmanian "wolf" does have palatal holes.
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Credits: Photos by Andrew Lee, U.C. Berkeley. Skulls from the U.C. Museum of Paleontology and the Museum of Vertebrate Zoology. Reproduced with permission.


Slide 92: Comparing the lower jaws shows another difference in tooth formula. Dogs and wolves have three molars and four premolars, whereas the Tasmanian "wolf" has the opposite, four molars and three premolars.
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Credits: Photos by Andrew Lee, U.C. Berkeley. Skulls from the U.C. Museum of Paleontology and the Museum of Vertebrate Zoology. Reproduced with permission.


Slide 93: Now the Tasmanian "wolf" is compared to a kangaroo -- according to modern biology a much closer evolutionary relative. Pandas claims that "the determination of homologies [is] a matter of subjective judgment" (p. 122) and therefore "the determination of relationship rests upon a subjective judgment" (p. 124). If this is true, the comparative biologist should have difficulty finding the homologies that unite the Tasmanian "wolf" with the kangaroo. Padian shows that these two marsupials share the exact characters that were different between the placental wolf and marsupial "wolf." For example, both have four molars in the upper jaw instead of two.
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Credits: Photos by Andrew Lee, U.C. Berkeley. Skulls from the U.C. Museum of Paleontology and the Museum of Vertebrate Zoology. Reproduced with permission.


Slide 94: The same characters are found to be shared between the Tasmanian "wolf" and the common Virginia opossum.
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Credits: Photos by Andrew Lee, U.C. Berkeley. Skulls from the U.C. Museum of Paleontology and the Museum of Vertebrate Zoology. Reproduced with permission.


Slide 95: A front view of the three marsupial skulls. The number of incisors varies, but all three have wide nasals.
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Credits: Photos by Andrew Lee, U.C. Berkeley. Skulls from the U.C. Museum of Paleontology and the Museum of Vertebrate Zoology. Reproduced with permission.


Slide 96: All three marsupials share palatal holes.
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Credits: Photos by Andrew Lee, U.C. Berkeley. Skulls from the U.C. Museum of Paleontology and the Museum of Vertebrate Zoology. Reproduced with permission.


Slide 97: All three marsupials share four molars and reflected laminae.
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Credits: Photos by Andrew Lee, U.C. Berkeley. Skulls from the U.C. Museum of Paleontology and the Museum of Vertebrate Zoology. Reproduced with permission.


Slide 98: The skeletal similarities shared by marsupials have been known for generations, but recent gene sequence comparisons have confirmed the longstanding view, originally based purely on morphology, that marsupials form a closely-related group separate from placentals.
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Slide 99: Pandas claims that marsupials share only a pouch and supporting bones, but in fact skull anatomy and DNA points in the same direction. Even with only a skull or a blood sample, marsupials can be easily distinguished from placental mammals by competent biologists.
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IDCers prefer the explanation of special creation over descent

Slide 100: Pandas (p. 125) argues against common ancestry because the authors clearly prefer special creation as an explanation for homology, even though they can answer none of the obvious questions raised by this notion.
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Slide 101: Pandas claims that using homology to support common ancestry is circular reasoning, again ignoring that marsupial homologies extend far beyond just the pouch, and that DNA sequences have independently confirmed the longstanding conclusion of the morphologists.
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Slide 102: Pandas invokes teleology as the explanation the authors prefer, clearly signaling what they are after.
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Acknowledgements

Thanks to Kevin Padian and his students Jann Vendetti, Liz Perotti, Brian Swartz, Randy Irmis, Jenny McGuire, Nick Pyenson, Alan Shabel, and Andrew Lee for assembling the original presentation, and to Brian Swartz for looking up copyright owners. Thanks also to Mike Hopkins and Alex Wing for help with organization and coding.