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Each generation of evolutionary biologists has brought a fresh wave of attempts to answer the evolutionary riddle of altruism. However, none describe how such a condition could incrementally evolve from a prior condition of non-cooperation. This chapter describes a mechanism that could spontaneously and incrementally give rise to a synergistic codependence among individuals within a social group. It shows that prolonged social living in the absence of reproductive cost can mask selection-maintaining traits important for autonomous living, causing them to drift and degrade to the point where individuals can no longer succeed outside the social context. This ‘social addiction’ will subsequently favour traits that maintain social cohesion because of the high cost of group dispersion. This mechanism contributes a missing complementary component to existing selection-based explanations of the evolution of pro-social and altruistic behaviours.

This chapter describes the warty hammer orchid, a plant with an amazingly unflower-like flower that attracts a particular wasp, which is deceived into attempting to mate with the flower. Darwin’s method of studying the pollination of other orchids is described, and used to illustrate how evolutionary biologists can test hypotheses on the adaptive value of the attributes of living things.

This chapter examines the significance of epigenetic inheritance in evolutionary biology. It focuses on the differing theoretical goals and commitments of mechanistic molecular biologists and quantitative evolutionary biologists on the relative significance claims about the role of epigenetic inheritance in evolution.

This chapter investigates whether Niles Eldredge and Stephen Jay Gould's theory of punctuated equilibrium challenges the central foundations of Darwinism. It argues that punctuated equilibrium has successfully influenced important work on hierarchy in natural selection that was instrumental in gaining recognition and respect for paleobiology among evolutionary biologists. This chapter also discusses what it means to be a Darwinian.

This chapter discusses the strong criticism received by the Gaia theory and geophysiology from neo-Darwinian evolutionary biologists. Given that until very recently evolutionary theory was dominated by neo-Darwinism, it is usually assumed that Gaia theory and evolutionary biology are not compatible. It is shown here that this is a false impression. This chapter shows that evolutionary theory is much more heterogeneous than commonly assumed, and that various theories of biological evolution are not incompatible with Gaia theory. Many of these theories, which in no way deny Darwinian evolution even though they reject the extremist neo-Darwinian spin of it, seem to be perfectly complemented by and integrated with Gaia theory. It is also argued here that because one of the main reasons for the dominance of neo-Darwinian theory so far has lain in the ability of its proponents to frame their theories within a sound mathematical framework, any alternative theory of evolution must be developed within a sound mathematical framework as well.

The fossil record was widely considered as an imperfect text for supporting evolutionary theory by evolutionary biologists, so paleobiologists came up with the strategy to “reread” that text in a manner that could produce reliable evolutionary insight to gain greater acceptance. This chapter identifies and discuses the three main approaches for “rereading” the fossil record that were developed by paleobiologists. The first approach, attempted by paleobiologists is a “literal reading” in which the fossil record, with all its renowned gaps and inconsistencies, was taken at face value as a reliable document. The second approach is known as “idealized rereading”, and here the physical particulars of the fossil record were ignored, and the history of life—the species, genera, families, etc., that make up the actual record—was modeled as a series of homogeneous data points. The final or third approach is known as a “generalized rereading”, this approach encompasses a combination of the other two approaches, and it ultimately became the dominant methodology in analytical paleobiology.

John Maynard Smith (1920–2004) was one of the great evolutionary biologists, making many important contributions, including the application of game theory to understanding evolutionary strategies, and a clear definition of the major transitions in the history of life. This chapter presents an edited transcript of an interview conducted on 21 May 2003, in his office in the John Maynard Smith Building at the University of Sussex. Maynard provides insight into the spirit of science immediately after the Second World War as well as into the early influence of cybernetics on developmental and evolutionary biology.

This chapter aims to identify the most likely candidates for critical steps – truly difficult events that may have determined the pace of evolution through Earth history. A good place to start is the list of ‘SMS’ transitions: these are critically important events in the increasing complexity of life, at least according to the two eminent evolutionary biologists Eors Szathmary and John Maynard Smith. However, these transitions are defined differently from our critical steps, and we cannot simply take their list as our definitive answer. SMS are interested in how the unit of natural selection changed through time, and they define their transitions as occurring when a new type of reproductive unit evolves, such as the gene, the cell, or the colony. There is a good theoretical reason why such transitions from a lower to a higher unit of reproduction can be very difficult – selection at the lower levels usually acts to destabilise higher-level units.