Alfred Russel Wallace and his legacy

Dr George Beccaloni, Natural History Museum, UK

Abstract

This talk will largely focus on the first, and most interesting, half of Wallace's life - his childhood, the development of his interests in natural history and ‘species transmutation’, his four year trip to the Amazon with Henry Walter Bates, and finally his eight year expedition to the Malay Archipelago and the important discoveries he made there.

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Natural selection a la Wallace

Professor Janet Browne, Harvard University, USA

Abstract

Wallace's ideas about natural selection were very much his own. They differed somewhat from Darwin's. In particular Wallace came to feel that natural selection was insufficient on its own to explain human evolution.

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Wallace and Darwin: what really happened?

Dr John van Wyhe, National University of Singapore, Singapore

Abstract

Since the mid-20^th century many conflicting stories about the co-discovery of natural selection and even extreme accusations against Darwin have appeared and continue to circulate widely. In this talk I will briefly set the record straight. Which one wrote to the other first, Wallace or Darwin? Who first broached the subject of evolution? Why did Wallace send his famous Ternate essay to Darwin of all people? And when did Darwin actually receive it? Were their papers arranged in an improper way? Finally, are there any grounds to the claims that Darwin might have borrowed from Wallace?

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Wallace and the Limits to Natural Selection

Professor Steve Jones FRS, University College London, UK

Abstract

Wallace, great biologist as he was, had odd ideas about human evolution. He felt that although our physical selves might have evolved through natural selection, this was not enough to explain what we are. He was sure that some higher power – the spirit – was involved.  That notion had a strong connection with earlier ideas, such as those of Lamarck, who invoked a “law of necessary progress” the feeling that all animals tried to better themselves as they strove to a higher goal. Darwin hated such vague theories and relied on his simple mechanism of natural selection as the engine of evolutionary change. He was right, and our own species gives plenty of evidence that he was; but in the light of modern cladistics Wallace, although he was probably not right, cannot be proved wrong.

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Colouration today

Professor Tim Caro, University of California, Davis, USA

Abstract

Wallace’s Classification Of Organic Colours was a first attempt to outline different functions of colouration in nature. I describe how mechanisms for different aspects of protective colouration were subsequently sketched out by workers at the beginning of the 20th century; and how, during a rapid phase of experimental work in the last two decades, many mechanisms underlying his protective, warning and sexual colours have now been shown to occur in nature. However, we understand less about Wallace’s typical colours, and even less about the distribution of different forms of colouration across taxa, the ecological drivers of colouration, and the physiological consequences of colouration patterns. My talk therefore shows what we have learnt and have yet to learn since Wallace’s pathbreaking ideas.

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Early Humboldtian Influences on Alfred Russel Wallace’s Scheme of Nature

Professor Charles H. Smith, Western Kentucky University, USA

Abstract

Alfred Russel Wallace’s 1858 Ternate paper on natural selection is a famous work in the history of science. Beyond his co-discovery of the principle, moreover, Wallace is known for a large number of early applications of the idea, both to biological and biogeographical subjects. Yet how much do we really know about Wallace’s own evolution of thought, and his actual intentions before his views were swallowed up by the inertia of Darwin’s influence? A number of differences between Wallace’s and Darwin’s views are apparent and have been much treated over the years, but related discussions dwell more on effects than on causes.  In this presentation, Wallace in his early years is shown to likely have been heavily influenced by the writings of Alexander von Humboldt and his disciples.

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The Modern Biogeographical Legacy of Alfred Russel Wallace

Professor Lynne Parenti, National Museum of Natural History, Smithsonian Institution, USA

Abstract

Modern biogeography flickered with Alfred Russel Wallace’s 1858 hypothesis that the western part of the Malay Archipelago was “… a separated portion of continental Asia while the eastern part is a fragmentary prolongation of a former west Pacific continent.”   Two principles—endemism and terrane fidelity –came together to bolster Wallace’s theory of organic evolution and to illustrate that life and Earth evolved together.  Ironically, Wallace (1876) subsequently adopted a classification of six global zoogeographical  regions even though he knew that it contradicted broad biogeographic patterns, such as trans-oceanic distributions. Today, our goal is to name biogeographical regions that reflect, not contradict, shared distribution patterns.  We combine concepts such as endemism, terrane fidelity, and area relationships to discover biotic history.  Inferred mechanisms of distribution –dispersal versus vicariance—are secondary.  The Malay Archipelago, with Sulawesi in its centre, remains a biogeographical hotspot, which means that Wallace, too, remains at the centre of modern biogeography.

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Wallace and Colouration

Professor R.I. Vane-Wright, Natural History Musuem, UK

Abstract

Wallace had clear knowledge of the physical and chemical basis of colour, and great awareness of the important roles that colour and pattern play in the lives of organisms, including inter- and intra-specific communication. Following a review of Wallace’s understanding of colour and perception, the presentation will briefly address the one area of evolutionary theory where Wallace disagreed fundamentally with Charles Darwin, sexual selection, and the potential importance of colouration in that debate.

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Old and new views on human evolution

Professor Chris Stringer FRS, Natural History Museum, UK

Abstract

Darwin and Wallace both wrote about human evolution when there was little relevant fossil evidence available, and none at all from the continent of Africa. Although both accepted that natural selection had produced many of the distinctive features of humans, Darwin developed a much more detailed model for the origins of bipedalism, tool-making, canine reduction and brain enlargement through feedback mechanisms stemming from selection to free the hands for manipulation, rather than locomotion. 
Darwin also proposed that ‘racial’ features had largely been added through the action of sexual selection. Wallace demurred over the importance of sexual selection in Homo sapiens, arguing that consistent tastes were unlikely to have persisted long enough and widely enough for it to operate on any scale. He also doubted that the correlated ‘perfection’ of human characteristics could have been produced by natural selection alone, and that “unknown causes” must also have been at work. In the case of the human brain, in particular, he came to argue that spiritual, rather than natural, forces must have been responsible for the evolution of the highest human faculties.

In the light of subsequent fossil and archaeological discoveries, it is possible to critique the views of both Darwin and Wallace concerning human evolution. We now know that canine reduction, bipedalism, tool-making and brain enlargement did not evolve in concert, but were spread out over several million years of evolution in Africa, with different species showing distinct combinations of traits. Thus these features probably developed through multifarious causes, rather than being locked in a feedback system. And while natural selection does seem to lie behind the evolution of the human brain and of many regional (‘racial’) features, sexual (or cultural) selection also seems to have played its part. Some of the issues with which Darwin and Wallace struggled have been resolved by new evidence, while the richness of the current fossil, genetic and archaeological records has raised many new issues which they could never have contemplated.

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Wallace and human evolution

Professor Ted Benton, University of Essex, UK

Abstract

In 1859 Darwin had been evasive about human evolution, but Wallace addressed the question in 1864. His paper addresses two issues: the origin and significance of racial differences and the great mental gulf between humans and apes, despite the striking physical resemblances between them. The theory of evolution by natural selection can be used to explain both. At a certain point in the development of social dispositions and mental abilities in our ancestors, natural selection would have increasingly acted on these features, rather than bodily form. Cranial capacity would have increased greatly, leaving the rest of the body little changed. This approach was influential on Darwin’s argument in the Descent of Man, but in the meantime Wallace had become convinced that natural selection was insufficient to explain ‘higher’ human attributes. Darwin was horrified, but in fact their views had more in common than either recognised.

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Wallace, Darwin and female choice

Professor Tim Birkhead FRS, University of Sheffield, UK

Abstract

Wallace didn’t rate Darwin’s idea of sexual selection, at least, not as a much as Darwin. Wallace’s reservations – particularly with regard to female choice - anticipated the bumpy ride that sexual selection endured since Darwin. From the mid-1970s however, with a clearer view of how selection operates, sexual selection has enjoyed a spectacular Renaissance and is now considered to be as important as natural selection. I will explore the history of sexual selection, including Wallace’s criticisms, and discuss its rebirth, especially with respect to something neither Darwin nor Wallace even contemplated: the idea that sexual selection might continue beyond the choice of partner: post-copulatory sexual selection.

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Wallace's understanding of species and speciation

Professor James Mallet, University College London and Harvard University, UK and USA

Abstract

Soon after his return from the Malay Archipelago, Alfred Russel Wallace published one of his most significant papers. The paper followed many of the themes opened up by Henry Walter Bates 3 years earlier, and used butterflies as a model system to understand the evolution of mimicry and the origin of species. In a very important section, Wallace laid out what is perhaps the clearest definition by an early Darwinian of the differences between species, geographic subspecies, and local 'varieties.' He also discussed what is now termed 'reproductive isolation.' While he accepting it as a cause of species, he rejected it as a definition. Instead, species were recognized as forms that overlap spatially and lack intermediates, as had Darwin. This morphological distinctness argument appears to break down for discrete polymorphisms, but Wallace correctly diagnosed conspecificity of non-mimetic males and polymorphic female Batesian mimics in Papilio butterflies for the first time. Also in the 1860s Wallace wrote to Darwin about a suggestion that natural selection could lead to reproductive isolation, which the older man firmly rejected. When G.J. Romanes later published his theory of 'physiological selection' (a selective model for the origin of reproductive isolation), Wallace rebutted the idea in the pages of Nature. In his book Darwinism (1889), however, Wallace wrote up his own theory in a manner almost identical to what he'd outlined to Darwin in the 1860s, without apparently discussing why Darwin had rejected the idea. The problem with both Romanes' and some of Wallace's ideas is that they are inherently group selectionist; however, one part of Wallace's idea survives as today's model of 'reinforcement' in speciation.

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The Vaccination Controversy

Professor Sir Leszek Borysiewicz FRS, University of Cambridge, UK

Abstract

Smallpox vaccination was introduced at the start of the 19th century.  Its application to wider populations caused considerable debate towards the end of that century, and a significant anti-vaccination campaign arose, to which Alfred Russel Wallace was a notable contributor. The introduction of compulsion through legislation exposed tensions which are still evident today in national vaccination policies.

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The Wallace legacy

Dr Andrew Berry, Harvard University, USA

Abstract

This talk will attempt to draw together the many themes addressed both at this meeting and, in life, by Wallace.  I will review Wallace's contributions in light of subsequent developments both in science and in the social sciences.  What is often impressive is the robustness of his conclusions despite his ignorance of subsequent developments: his insights on disjunct biogeographic distributions, for example, have typically survived the addition of continental drift to our list of processes affecting distributions.  Given the continued vitality of his work, Wallace's current obscurity relative to Darwin is all the more puzzling.  I will review some of the factors that have contributed.  My conclusion is that perhaps his most important legacy is the way in which he combined science and activism.  Though certainly not always, with hindsight, right in the causes that he backed, Wallace should serve as a role model for the social engagement of science and scientists.

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Wallace and the universe

Lord Martin Rees FRS, Past President of the Royal Society and Emeritus Professor of Cosmology and Astrophysics, University of Cambridge

Abstract

In his later years, Wallace's restless intellect ventured far beyond the Earth. Especially in his two books "Man's Place in the Universe' and 'Is Mars Habitable?' he speculated on whether other planetary systems existed, whether they might be inhabited, and whether our cosmos was 'biofriendly'. This talk will describe some of Wallace's ideas, and place them in the context of recent discoveries about cosmology, extra-solar planets, and the emergence of life which would certainly have fascinated him.

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Wallace, a social scientist’s perspective

Dr David Stack, University of Reading, UK

Abstract

This is an exploration of Wallace's contribution to social science and how this related to his more celebrated work as a natural scientist. In a wide-ranging paper, Prof. Stack outlines what 'social science' meant to Wallace and his generation; delineates the early intellectual influences, including Robert Owen and Thomas Malthus, which framed Wallace's thought; and argues that, beyond any conventional account of Wallace's reading, we must give due weight to his work and experiences as a collector and field scientist in shaping his social science. The paper concludes by asserting the significance of Wallace's distinct contribution as a biologist philosopher; noting the differences between Wallace's 'social science perspective' and Darwin's 'political economist's perspective'; and by demonstrating the value of 'remembering' 
Wallace as a social scientist.

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