In the grand sweep of evolution, the origin of radically new kinds of organisms in the fossil record is the result of a relatively simple process: natural selection marching through the ages. Or is it? Does Darwinian evolution acting over a sufficiently long period of time really offer a complete explanation, or are unusual genetic events and particular environmental and ecological circumstances also involved? With The Origin of Higher Taxa, Tom Kemp sifts through the layers of paleobiological, genetic, and ecological evidence on a quest to answer this essential, game-changing question of biology.
Looking beyond the microevolutionary force of Darwinian natural selection, Kemp enters the realm of macroevolution, or evolution above the species level. From the origin of mammals to the radiation of flowering plants, these large-scale patterns—such as the rise of novel organismal design, adaptive radiations, and lineage extinctions—encompass the most significant trends and transformations in evolution. As macroevolution cannot be studied by direct observation and experiment, scientists have to rely on the outcome of evolution as evidence for the processes at work, in the form of patterns of species appearances and extinctions in a spotty fossil record, and through the nature of species extant today. Marshalling a wealth of new fossil and molecular evidence and increasingly sophisticated techniques for their study, Kemp here offers a timely and original reinterpretation of how higher taxa such as arthropods, mollusks, mammals, birds, and whales evolved—a bold new take on the history of life.
Author(s): T. S. Kemp
Publisher: Oxford University Press
Year: 2015
Language: English
Pages: 213
City: Oxford
Cover
Contents
1. Introduction
1.1 The question
1.2 The context
1.3 The available evidence
1.4 Synthesis
2. The nature of higher taxa
2.1 The Linnean hierarchy, the phylocode, and higher taxa
2.2 Disparity and morphospace: a phenotypic view of higher taxa
2.3 The adaptive landscape: an ecological view of higher taxa
2.4 Molecular taxonomy and higher taxa
2.5 The pattern of evolution of higher taxa
2.6 Conclusion: are higher taxa real?
3. The nature of organisms
3.1 The atomistic model
3.1.1 Limitations of the atomistic model
3.2 The modularity model
3.2.1 Evidence for the reality of the modularity model
3.2.2 The implications of the modularity model for evolution
3.2.3 The limitations of the modularity model
3.3 The correlated progression model
3.3.1 Implications of the correlated progression model for evolution
3.3.2 Evidence for the correlated progression model
3.4 Conclusion
4. The palaeontological evidence
4.1 Fossils, phylogeny, and ancestry
4.1.1 Incompleteness
4.1.2 Phylogeny
4.1.3 Fossils and molecules
4.2 Functional anatomy and physiology of fossils
4.3 Palaeoenvironmental and palaeoecological reconstruction
5. The developmental evidence
5.1 A brief history
5.2 Ancestral stages and the pattern of character acquisition inferred from embryos
5.2.1 Recapitulation
5.2.2 Heterochrony
5.2.3 Heterotopy
5.2.4 Allometry, miniaturization, and gigantism
5.3 Developmental mechanisms for the maintenance of phenotypic integration
5.3.1 Embryonic cellular and tissue interactions
5.3.2 The role of molecular genetic mechanisms
5.3.3 Phenotypic plasticity
5.4 Summary
6. The ecological perspective
6.1 The correlated progression model and adaptive landscapes
6.2 Multidimensional gradients in the adaptive landscape
6.3 Case studies: aquatic to terrestrial habitats
6.4 Case studies: low-energy to high-energy life styles
6.5 Case studies: the origin of modern invertebrate body plans
7. The invertebrate fossil record
7.1 The phylogenetic tree of crown invertebrate phyla
7.2 The Cambrian explosion
7.3 Lophotrochozoa: Mollusca
7.3.1 Kimberella
7.3.2 Odontogriphus
7.3.3 Halkieria, Wiwaxia, and Orthrozanclus: Halwaxiidae
7.3.4 Crown Mollusca
7.4 Ecdysozoa: Arthropoda
7.4.1 Opabinia
7.4.2 Anomalocaridida (Radiodonta)
7.4.3 Nereocaris, Canadaspis, and other bivalved arthropods
7.4.4 Fuxianhuids: Chengjiangocaris, Fuxianhuia, and Shankouia
7.4.5 Megacheirans
7.4.6 Conclusion: the evolution of arthropod characters
7.5 Deuterostomia
7.5.1 Vetulicolia: possible stem-group deuterostomes
7.5.2 Cambroernids: possible stem-group ambulacrians
7.5.3 Vetulocystids: possible stem-group echinoderms
7.5.4 Carpoids: the asymmetric echinoderms
7.5.5 Crown Echinodermata
7.5.6 Yunnanozoons: possible stem-group chordates
7.5.7 Pikaea: possible stem-group chordate
7.5.8 Conodonts: possible stem-group vertebrates
7.5.9 Myllokunmingia, Haikouichthys, and Metaspriggina: stem-group vertebrates
8. The vertebrate fossil record
8.1 Mammals
8.1.1 The grades of fossil stem mammals
8.1.2 The origin of the mammalian body plan
8.1.3 The pattern of evolution of mammalian characters
8.2 Birds
8.2.1 The grades of fossil stem birds
8.2.2 The origin of the avian body plan
8.2.3 The pattern of acquisition of avian characters
8.3 Tetrapods
8.3.1 The grades of fossil stem tetrapods
8.3.2 The pattern of acquisition of tetrapod characters
8.4 Turtles
8.4.1 The grades of fossil stem chelonians
8.4.2 The pattern of acquisition of chelonian characters
8.5 Cetacea
8.5.1 The grades of fossil stem cetaceans
8.5.2 The pattern of acquisition of cetacean characters
9. A synthesis
9.1 The nature of palaeobiological explanation
9.1.1 Combining the evidence
9.1.2 Missing and conflicting evidence
9.1.3 Evaluating palaeobiological hypotheses
9.1.4 It may be true but is it science?
9.2 A summary of the evidence
9.2.1 Evidence from the nature of living organisms
9.2.2 Evidence from computer simulations of the evolution of complex systems
9.2.3 Evidence from the fossil record
9.2.4 Evidence from developmental biology
9.2.5 Evidence from ecology
9.3 Conclusion: a general picture of the origin of higher taxa
References
Index
