This page is dedicated to the memory of
Prof. William Donald (Bill) Hamilton

On this site you will find texts, photographs, poems and other material collected by friends of Bill Hamilton. They are meant to keep the memory of Bill alive. If you want to contribute to the site (memories, pictures, texts, comments, anecdotes, ...) please send material to Dieter Ebert (



Pictures by Luiz Claudio Marigo
Picture by Jose Marcio Ayres


        Marco Archetti: Memories

        David Hughes: The value of a broad mind: some natural history meanderings of Bill Hamilton (pdf file)

Mary Bliss: In memory of Bill Hamilton

'Truth and Science' by Luisa Bozzi

Hamilton memorial in Annales Zoologici Fennici.

'Die Gen-Revolution in der Evolutionsbiologie' von Paul Schmid-Hempel, ETH Zürich (NZZ, in German)

'Stories with Bill Hamilton in them' by Mike Orlove

Thoughts about "Hamiltonian inspiration" by Jacobus J. (Koos) Boomsma

Memorial Service for Bill, in the Chapel of New College, Oxford, on Saturday 1. July, 2000, at 2.30 pm.

'Last words' by Luisa Bozzi

Poems for Bill, from Janet Hamilton

A Letter for The Memorial Event for Bill Hamilton at New College by Yosiaki Ito

'A Tribute to W. D. Hamilton'  The Times, London, 9 March 2000

Obituary by Robert Trivers (Nature)

Obituary by Olivia Judson (The Economist)

'In Darwin's footsteps' by Andrew Brown (The Guardian)

Obituary by Alan Grafen (The Guardian)

Obituary (The Daily Telegraph)

Obituary by Richard Dawkins (The Independent, London)

Obituary by Natalie Angier (New York Times)

Anecdote by Judy Wearing Wilde

'Encounter with the Red Queen' by Dieter Ebert

'My most memorable conversation with Bill' by Michael Hochberg

'A Day in Taiwan' by Shigeyuki Aoki

'Three days with Bill' by Steve Stearns

Biologist who died after Congo expedition was leading Darwinian theorist who explained how natural selection acts on social behaviour

Alan Grafen,  Thursday March 9, 2000, The Guardian

Bill Hamilton, who has died aged 63 after weeks in intensive care following a biological expedition to the Congo, was the primary theoretical innovator in modern Darwinian biology, responsible for the shape of the subject today.

Educated at Tonbridge school, he came across RA Fisher's Genetical Theory Of Natural Selection while a Cambridge university undergraduate. When he prompted one of his tutors about the book, he was told it was mistaken and that the author, still then lecturing in Cambridge, had "no standing to write about biology".

Bill was captured by the intellectual excitement of this remarkable book, and spent his working life pursuing its line. In so doing, he provided the conceptual foundation for our understanding of how natural selection acts on social behaviour, opened up the area of "extraordinary" (that is, unequal) sex ratios, transformed thinking on sexual selection and produced a corpus of work that demonstrates the capacity of parasite-host interactions to support the maintenance of sexual reproduction. These are the primary Darwinian themes of the second half of the 20th century, and can be understood only in the context of Bill's contributions. He, like Fisher before him, took many steps at once away from conventional paths, and found that eventually biologists would change their conventions.

The career of a typical Hamilton paper can be caricatured as follows. In review, it is panned by referees who demand shortenings and revisions. Immediately after publication, it attracts criticism for obscurity. Its significance slowly emerges through secondary works, further work is inspired, and one or more literatures develop around its themes. Later more mathematical work may even be rather patronising about the paper, and emphasise discrepancies, while the primary finding is that the original idea is abundantly confirmed. The original paper is frequently, indeed often obligatorily, cited in papers in the new literatures, but is not read nearly as often as it deserves to be, since it retains a reputation for obscurity. The joy of reading the original paper is becoming aware of remaining steps.

We can look forward to decades of catching up with Bill's biological thoughts. He fused mathematics and natural history. He had a vast personal knowledge of insects and was pretty good on plants too. He kept a vast card index system. He once led an expedition through Wytham Woods, near the village where he lived, and showed an entranced audience the range of organisms that lived in rotting wood in which, he believed, most important events in insect evolution had occurred.

He loved living in Wytham, latterly with his partner Luisa, an Italian journalist. He gave dinner parties during the periods Luisa was in Oxford to spare guests his own cooking, and they were charming hosts.

Much of his thinking was mathematical in nature. He covered pages in algebra, and often drew scribbled diagrams to help his line of thought. His grasp of biological theory was extremely firm, and all his major works draw on mathematical structures. There are many biologists who are better mathematicians, but Bill more than made up in vision and purpose for any lack of formal skills. To take one example that will appeal to recreational mathematicians, his paper Geometry For The Selfish Herd is based on the idea that herds of animals are arranged on the principle that each individual tries to maximise the chance that, if a predator appears at random and strikes at the nearest prey, somebody else gets eaten. He saw genes everywhere. On a train in New England in 1980, he pointed out clumps of sumac trees. Some had smooth crowns over the whole clump, while others had furrows between individual trees. He was sure that furrows existed between genetically different trees, while trees from the same clone had a smooth crown. Everything he saw in nature was viewed through a genetic lens.

He was a lecturer in genetics at London university's Imperial college from 1964-77, a professor at Michigan university from 1978 to 1984, and then became a fellow and later a research professor of the Royal Society and fellow of New College Oxford. He received many international scientific prizes, but the time-scale of recognition led to difficulties.

In his early life, when none of his work was properly recognised, he even doubted his sanity, as he reports in the first volume of his collected papers (Narrow Roads Of Gene Land). Later, he had difficulty obtaining grants and publishing papers. The time-lag could have entertaining consequences, which occasionally gratified Bill.

The authors of one paper who made rather patronising comments waited 15 years to find the criticised theory accepted as commonplace by their own graduate students. Bill's world had different theoretical presuppositions to the worlds of those around him, and a far-seeing prophet can be a poor teacher. He would often speak so quietly that only the front couple of rows could hear properly. If supplied with a microphone, he would often speak more quietly to maintain the same level of general inaudibility. More than once, I have seen him stop in front of a slide with a graph on it, and become so engaged in contemplation of a particular data point that he grew oblivious of the audience. On the other hand, even these talks were inspiring to the few. And sometimes Bill would prepare a lecture that inspired everyone.

At the end of one such talk at the Royal Society, he showed a slide with a male and female parrot, one bright red and one bright green. Conventional theories could explain why one sex was bright, but not why both were. He ended: "When I understand why one sex is red and the other green, I will be ready to die," and seemed to mean every word.

He often referred to his own death. He said to me that he would not grow old, both in discussions of his paper on senescence ("I feel bucked when anyone refers to that paper") and discussions touching on personal safety. He refused to wear a cycle-helmet, even once they became fashionable and he had been thrown from his bike through a car windscreen. He fantasised in print about being buried by one of his favourite organisms, burying beetles, in his favourite place, the Amazonian rain forest.

In late 1999, Fisher's Genetical Theory was republished, and Bill supplied three paragraphs for the back dust-jacket. After blaming the book for his second class degree, he moves on to ask whether "by the time of my ultimate graduation, will I have understood all that is true in this book, and will I get a first?".

The circumstances of his last fatal expedition are characteristic. He became interested in the theory that HIV arose through poorly conducted vaccination trials in Africa in the 1950s, and felt this theory received less attention than it deserved because of entrenched interests in the medical establishment. The implications of this theory for xenotransplantation are very serious. He went to the jungle to collect chimpanzee faeces with the aim of finding a related virus, and testing whether it was very close to the human virus. While there he contracted malaria, and then collapsed after returning to London. He lived for ideas, was especially partial to unpopular ideas, and thought little of his own safety. His focus of interest was always genes, and it was genes he went to collect.

He was separated from his wife Christine, who he married in 1967. She and their three daughters survive him, together with his partner Luisa.

William Donald Hamilton, biologist, born August 1 1936; died March 7 2000

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Obituary from the Daily Telegraph

Evolutionary biologist who explained how selfish genes could produce altruism

PROFESSOR WILLIAM HAMILTON, who has died aged 63, was the most influential evolutionary biologist of his generation.

Bill Hamilton's paper on "the genetical evolution of social behaviour" (1964) became the most cited paper in all science. He was responsible almost single-handedly for a revolution in the study of animal behaviour. He remained in frontline research until his death, caused by an infection caught while on a research expedition in the Congo.

The full story of how Hamilton came to write his classic paper only emerged in his autobiographical sketches published in 1995. As a shy and lonely graduate student dividing his time between the London School of Economics and University College London, Hamilton was ignored at one institution and mistrusted at the other.

He later wrote of his time at University College: "I never had a desk there nor was ever invited to give any presentation to explain my work or my occasional presence to others. Most of the time I was extremely lonely. Sometimes I came to dislike my bed-sitting room so much that I would go to Waterloo Station, where I continued reading or trying to write out a [mathematical] model sitting on the benches among waiting passengers in the main hall."

The question that obsessed Hamilton, if none of his peers, was how altruism could evolve as an instinct. The prevailing mood in evolutionary biology saw animal behaviour as always devoted to the "good of the species".

Hamilton, who was influenced by the writings of the great Cambridge statistician and biologist, Sir Ronald Fisher, thought this made no sense, because an animal's closest competitor was often a member of its own species, so evolution should produce selfish, not altruistic individuals. Yet it plainly did not. As Darwin had been worried to observe, the extreme co-operation seen in the social insects - termites, bees and ants - seemed hard to explain.

The answer that Hamilton came up with was that animals might be selected to have altruistic instincts towards relatives, whose genes they share, because that would cause the spread of those instincts. So altruism will evolve in rabbit warrens if on average the rabbits are sufficiently closely related.

This was expressed in what is now known as Hamilton's rule, encapsulated in the formula k>1/r. In other words altruism is favoured when k is greater than 1 divided by r - where r is the relatedness between individuals and k is the ratio of gain to loss of the behaviour.

He illustrated his theory, which became known as kin selection or inclusive fitness, with a study of the social Hymenoptera - ants, bees and wasps - whose unusual genetics put them in the strange position of being more closely related to their sisters than their daughters and who have delegated reproduction to each colony's queen.

Hamilton's paper was rejected out of hand by Nature magazine. The mathematics was dense and the prose denser. It was eventually published in two parts in 1964 in the comparatively obscure Journal of Theoretical Biology. It was the first clear statement of what has since become known variously as the "gene's eye view" of evolution, the "selfish gene" school, or "sociobiology" - the theory that sees individuals as vehicles for competing genes.

Edward O Wilson, who was later to launch a fierce controversy that splits academia to this day with his book Sociobiology (1975), remembers reading the Hamilton paper on a train from Boston to Florida and spending two days trying to spot what was wrong with its reasoning. By the time the train reached Miami he had given up the struggle and become a convert to Hamilton's theory.

William Donald Hamilton was born on August 1 1936 and went to Tonbridge School. He devoted his spare time to collecting insects in the countryside. He read Zoology at Cambridge, then after National Service and his lonely spell doing the work on altruism in London, made the first of many expeditions to Brazil to teach and to study bees and wasps. There he fell in love with the rich insect fauna.

On his return he got a job as a lecturer at Imperial College and published a series of important papers on genes and behaviour, including one on "extraordinary sex ratios". This foreshadowed a now fashionable theory known as intragenomic conflict, which is used to explain many details of the newly emerging human genome.
He also befriended a self-taught American, George Price, an ardent atheist who became an equally ardent biblical scholar. In between, Price managed to do brilliant work to improve and expand the mathematics of Hamilton's theory, while railing against its implications.

They collaborated on a pair of important papers. When Price eventually committed suicide with nail scissors in an abandoned building near Euston Square at Christmas 1974 having given all his money to the homeless, the police contacted Hamilton, whose name they found among his few effects.

In 1977 Hamilton moved to the University of Michigan, where he experienced at first hand the controversy stirred among radical students by opponents to the sociobiological theories he had spawned, enduring protests and sit-ins. In Michigan he published two immensely influential theories. One, with the political scientist Robert Axelrod, was on how co-operative strategies succeed in the prisoner's dilemma game - this became known as the "tit-for-tat" debate. The other was on the evolution of sexual reproduction as a means of combating parasites - known as the Red Queen theory. In 1984 he returned to take up a Royal Society Research Professorship at Oxford, where was based until his death.

Hamilton was a distinctive figure with his heavy shock of white hair, stooped figure, low monotone voice and unworldly air. This did not make him an inspiring lecturer, but he was fortunate that his ideas were taken up by more lively teachers, notably John Maynard Smith, Richard Dawkins, Edward Wilson and Robert Trivers, all of whom dated their conversion to gene-centred thinking to their first encounters with Hamilton's work. Gene-centred thinking has come to dominate the study of both evolution and behaviour in animals, though it is repeatedly repelled with force when it tries to invade the territory of psychology and sociology.

Hamilton himself disliked the late 20th century's obsessive preference for nurture explanations over nature explanations, and was an enthusiast for evolutionary psychology, though his own work remained focused largely on the animal kingdom. Not for him the well trodden path through administration into professorships and knighthoods. He remained an active researcher, never happier than when collecting a little-known burying beetle or fig wasp deep in the rain forest. He was oblivious of risk. His last expedition, to the war-torn Congo, was to test the theory that the origin of the human Aids epidemic lay with the polio vaccine.

The lonely student eventually gained great renown, though it never changed him. He was awarded numerous prizes by academies all over the world, including the Darwin Medal of the Royal Society and the Crafoord Prize from the Swedish Academy of Sciences.

He married, in 1967, Christine Friess. They had three daughters.

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Obituary by Richard Dawkins published in The Independent (London), 10/3/2000

 W D Hamilton is a good candidate for the title of most distinguished Darwinian since Darwin. Other candidates would have to include R A Fisher, whom Hamilton revered as a young student at Cambridge. Hamilton resembled Fisher in his penetrating biological intuition and his ability to render it in mathematics. But, like Darwin and unlike Fisher, he was also a superb field naturalist and explorer. I suspect that, of all his twentieth century successors, Darwin would most have enjoyed talking to Hamilton. Partly because they could have swapped jungle tales and beetle lore, partly because both were gentle and deep, but mostly because Hamilton the theorist was responsible for clearing up so many of the very problems that had intrigued and tantalised Darwin.

 William Donald Hamilton FRS was Royal Society Research Professor in the Department of Zoology at Oxford, and a Professorial Fellow of New College. He was born in 1936, spent a happy childhood botanising and collecting butterflies in Kent, was educated at Tonbridge, then Cambridge where he read Genetics. For his Ph.D. he moved to London where he was jointly enrolled at University College and LSE. He became a Lecturer at Imperial College in 1964, where his teaching skills were not highly rated. After a brief Visiting Professorship at Harvard, he accepted a Museum Professorship at the University of Michigan in 1977. Finally, in 1984 he moved to Oxford at the invitation of Richard Southwood, who had been his Professor at Imperial.

 Hamilton was showered with medals and honours by the academies and learned societies of the world. He won the Kyoto Prize, the Fyssen Prize, the Wander Prize, and the Crafoord Prize -- instituted by the Swedish Academy because Alfred Nobel unaccountably failed to include non-medical Biology in his list of eligible subjects. But honours and recognition did not come early. ?The autobiographical chapters of Hamiltonís collection of papers, Narrow Roads of Gene Land, reveal a lonely young man driven to self-doubt by lack of comprehension among his peers and superiors. To epitomise the Cambridge of his undergraduate days, where "many biologists hardly seemed to believe in evolution" he quotes one senior professor: "Insects do not live for themselves alone. Their lives are devoted to the survival of the species . . ." This is "Group Selection", a solecism which would cause todayís biology undergraduates to wince, but they have the advantage of a post-Hamilton education. The young Hamilton felt that in Cambridge he was wincing alone. Only the cantankerous Fisher made sense to him, and he had been advised that Fisher "was good with statistics but knew nothing about biology."

 For his doctoral work he proposed a difficult mathematical model with a simple conclusion now known as "Hamiltonís Rule." It states that a gene for altruistic self sacrifice will spread through a population if the cost to the altruist is outweighed by the benefit to the recipient devalued by a fraction representing the genetic relatedness between the two. Hamiltonís original paper was so difficult and innovative that it almost failed to be published, and was largely ignored for a decade. When finally noticed, its influence spread exponentially until it became one of the most cited papers in all of biology. It is the key to understanding half the altruistic cooperation in nature. The key to the other half -- reciprocation among unrelated individuals -- is a theory to which Hamilton was later to make a major contribution, in collaboration with the social scientist Robert Axelrod.

 The great obsession of his later career was parasites -- their evolutionary rather than their medical impact. Over twenty years, Hamilton convinced more and more biologists that parasites are the key to many outstanding problems left by Darwin, including the baffling riddle of the evolution of sex. The sexual shuffling of the genetic pack is an elaborate trick for outrunning parasites in the endless race through evolutionary time. This work led Hamilton into the arcane world of computer simulation, where his models were as richly textured, in their way, as his beloved Brazilian jungle. His spin-off theory of sexual selection (how Darwin would have relished it!) was that bird of paradise tails and similar male extravaganzas are driven by the evolution of female diagnostic skills: females are like sceptical doctors, actively seeking parasite-free males to supply genes for their shared posterity. Male advertisement is an honest boast of health.

 Hamiltonís mathematical models never became arid; they were laced with, and often inspired by, bizarre natural history. Would that every mathematical lump were leavened, as Hamiltonís were, by eye-witness accounts of, say, the male mite who copulates with all his sisters and then dies before any of them are born. Or of aphid females who give live birth to their daughters and granddaughters simultaneously.

 For most scientists, good ideas are a scarce commodity, to be milked for everything they are worth. Hamilton, by contrast, would bury, in little throwaway asides, ideas for which others would kill. Sometimes he buried them so deeply that he overlooked them himself. Extreme social life in termites poses a particular evolutionary problem not shared by the equally social ants, bees and wasps. An ingenious theory exists, widely attributed to an author whom I shall call X. Hamilton and I were once talking termites, and he spoke favourably of X's theory. "But Bill", I protested, "That isn't X's theory. It's your theory. You thought of it first." He gloomily denied it, so I asked him to wait while I ran to the library. I returned with a bound journal volume and shoved under his nose his own discreetly buried paragraph on termites. Eeyorishly, he conceded that, yes, it did appear to be his own theory after all, but X had explained it much better. In a world where scientists vie for priority, Hamilton was endearingly unique.

 Those who loved him saw a Felix with nine lives. Charmingly accident-prone, Bill would always bounce back. A childhood experiment with explosives cost him several finger joints of his right hand. He was frequently knocked off his bicycle, probably because of misjudgements by Oxford motorists who couldnít believe a man of his age with a great shock of white hair could possibly cycle so fast. And he travelled dangerously in wilder and more remote places than Oxford. He hiked through Rwanda at the height of the civil war, and was treated as a spy, so implausible was his (true) story that he was looking for ants. Held up at knife-point in Brazil, he made the mistake of fighting back, and was viciously wounded. He jumped into an Amazon tributary when his boat was sinking, in order to plug the hole, like the little Dutch boy, with his thumb (the ferocity of Piranha fish, he explained, is over-rated). Finally, to gather indirect evidence for the theory (of which he was a strong supporter) that the AIDS virus was originally introduced into the human population in an oral polio vaccine tested in Africa in the 1950s, Hamilton went, with two brave companions, to the depths of the Congo jungle in January this year. He was rushed back to London, apparently with severe malaria, seemed to recover, then collapsed into complications and coma. This time, he didn't bounce back.

He is survived by his wife, Christine, from whom he had been amicably separated for some time, by their three daughters Helen, Ruth and Rowena, and by his devoted companion of recent years, Luisa Bozzi.

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N.Y. Times, March 10, 2000

William Hamilton Dies; an Evolutionary Biologist


William Donald Hamilton, one of the towering figures of modern biology and the man who helped to unify Darwin's principles of natural selection with a rigorous understanding of Mendelian genetics, died on Tuesday in Oxford, England. He was 63.

Dr. Hamilton was best known for a theory offering a genetic basis for altruism, the inspiration for Richard Dawkins's best-selling popularization, "The Selfish Gene," and for such well-known work by E. O. Wilson as "Sociobiology."

Middlesex Hospital in London, where Dr. Hamilton had spent the previous six weeks, said the cause of death was malaria contracted on a recent expedition to Congo. He was there seeking evidence to bolster a radical hypothesis that the AIDS epidemic can be traced to contaminated polio vaccines.

Those who knew Dr. Hamilton said his zealous pursuit of the theory was characteristic of his unslakable intellectual curiosity and his interest in ideas that others might initially dismiss as half-baked.

"He believed that if you have a weird idea that sounds wrong at first, you should give it a chance before you throw it out," said Nancy Moran, a biologist at the University of Arizona who studied with Dr. Hamilton.

Dr. Hamilton, a professor at Oxford University since 1984, burst into the field of evolution while still a graduate student at Cambridge University.

In 1963 and 1964, he published two papers based on his doctoral work that have proved so seminal to evolutionary biology that it is virtually impossible to read a contemporary study in the discipline without encountering his name and the term he coined, inclusive fitness, also known as kin selection.

Through the model of inclusive fitness, Dr. Hamilton proposed an elegant and mathematically sophisticated way of understanding altruistic behavior, a problem that had baffled naturalists from Darwin onward.

If organisms are inherently selfish, and supposedly devoted to personal survival and reproduction, why, scientists wondered, do so many species display seemingly self-sacrificial behavior? Why, for example, do worker bees forsake the opportunity to breed in favor of caring for the queen's young? And why will those infertile auntie bees commit suicide in defense of the hive?

Dr. Hamilton realized that the unusual genetic structure of the bees resulted in the workers being so closely related to one another that, in slaving for the hive, they were essentially slaving for the persistence of their own gene pool. In other words, although they appeared altruistic, they were, from a gene's-eye view, behaving with characteristic selfishness.

Dr. Hamilton thus recast the concept of fitness, that is, an individual's success in reproducing, to incorporate the survival and reproductive success of the creature's close relatives -- hence the term inclusive fitness.

In so doing, he merged Darwin's focus on individual animals competing for the privilege of siring the next generation with Mendel's studies of how distinct genetic traits are transmitted over time.

The idea can be roughly understood by one biologist's remark in a pub that he would "gladly die for two brothers, four cousins or eight second cousins," each of them carrying the requisite percentage of the individual's genes to compensate for the mortal deed.

Though human altruism is more complicated than that, and people are capable of behaving with profound self-sacrifice for nonrelatives, research has shown that the general principles of inclusive fitness and kin selection apply throughout the natural world, and in many human transactions as well.

Dr. Hamilton also published important papers explaining what he called "extraordinary" sex ratios, which occur when an organism produces far more offspring of one sex than the other.

More recently, he sought to understand the existence of sex, and why most species propagate sexually rather than asexually.

He suggested that sexual reproduction, by continually shaking up the genome, helps to keep organisms one step ahead of their parasites, which might be capable of annihilating a population of asexually spawned clones.

The parasite-avoidance hypothesis of sex remains debatable, but many studies of how animals choose their mates at least partly support it.

Dr. Hamilton, who made insects the focus of his work, was as renowned as a natural historian as he was as a theorist.

"He was the best field biologist I've ever met," said Marlene Zuk, a biologist at the University of California at Riverside who studied with him in the 1980's at the University of Michigan. "If you went out with him in England, he could identify every bird, every plant, every insect, practically every microorganism he encountered."

He had feelings of fraternity with the objects he studied, even when they were, say, wingless male fig wasps in combat.

In a 1996 collection of his papers called "Narrow Roads of Gene Land," he wrote, "A male's fighting movements can be summarized thus: touch, freeze, approach slowly, strike, and recoil."

Although the wasp's fighting style might look cowardly, he continued, it becomes understandable if one likens it "in human terms to a darkened room of full of jostling people" among whom are "a dozen or so maniacal homicides armed with knives."

William Donald Hamilton was born on Aug. 1, 1936, in Cairo, but moved to England as a young child. He was educated at Tonbridge School and St. John's College, Cambridge.

He was a large, vigorous man with a full head of white hair, who could be seen in the early morning doing pull-ups from a tree. Friends said he was reclusive, almost shy, but that he was also a risk-taker, physically as well as intellectually. As a teenager, he blew off parts of two fingers in an experiment with explosive chemicals.

Dr. Hamilton's close observations of the natural world made him rethink phenomena that others took for granted.

Recently, he suggested that autumn leaves turn brilliant colors not simply as a result of their loss of green chlorophyll, as is commonly believed, but as a way to warn off insect pests that might lay eggs on the tree, red and orange being common warning colors in nature.

He has also argued that cloud formations are actually bacterial dispersal vehicles, for microbes have been found in abundance in clouds.

Dr. Hamilton was a member of the Royal Society of London and the winner of many prizes, including the Darwin Medal, the Linnean Medal and the Crafoord Prize, awarded by the Swedish Academy of Sciences.

He was separated from his wife, Christine Friess. He is survived by their three daughters and by his partner, Luisa Bozzi.

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Judy Wearing Wild wrote:

The following story about Bill was relayed to me by Martin Birch. Martin had intended to attend a talk he had seen advertised, that Bill was to have given the day before to the virology folks. When he and Bill perchanced to meet in the elevator the next day, Martin told Bill that he had meant to go, but had forgotten. Bill replied, "that's okay, I forgot too".

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Encounter with the Red Queen (by Dieter Ebert)

In 1992 I arrived in Oxford to start a postdoc with Bill Hamilton. My plan was to find evidence for the Red Queen hypothesis. Surprisingly, it took me only a few days to find her. During a walk along the river Thames I found the Red Queen floating on the water (see picture). Next day, I told Bill about my finding and he decided to look for it as well. The following day he told me that he did not find her. Jokingly he added, that this is excatly what the theory predicts. Where ever the Red Queen is involved things change rapidly.

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My most memorable conversation with Bill was at Oxford in 1990. We were  talking about the evolution of parasite virulence, and I asked him if he new of a convincing example of evolution to intermediate levels of  virulence other than the few so often described in the literature. He didn't think long and replied: "Religion."

Michael Hochberg

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A Day in Taiwan

On 22 July 1986, Bill Hamilton and I, together with Naomi Pierce and Andrew Berry, visited Sun Moon Lake, central Taiwan.  The main purpose of the trip was to show him live aphid-soldiers, in particular, soldiers of the aphid Ceratoglyphina styracicola, which forms white galls on the evergreen Styrax suberifolia.  It was a nice summer day.  After walking around the beautiful lake, we eventually found a good tree harboring many galls, but at a height of about 5 m above the ground.  He went into the bush without hesitation, and skillfully climbed the tree.  Because of my inability to climb up, I wished I could hire him as a climber for my research.  He cut off a branch with several galls and took them carefully down to the ground.  He then made two galls, one of which had been collected from another tree, in contact with each other.  There were many soldiers on the surfaces of the two galls.  He watched what would happen when soldiers of one gall encountered soldiers of the other.  Nothing happened, however, and this was what I had expected from my previous experience.

He was not satisfied with the fact that no war broke out, or that soldiers of C. styracicola did not discriminate between clonemates and non-clonemates.  He told me that the experiment was not sufficient, and suggested another experiment: Watch what will happen when soldiers of one gall encounter non-soldiers from another gall.  I did not take the suggestion seriously. Nor did he put his idea in practice, although we could have done it on that day.

Four years later, I found a very good gall for observation.  It was formed at a height of 1.5 m.  I felt compelled to do something, and my wife and I agreed to carry out that very experiment.  Soldiers of the gall did not attack any soldiers placed on the gall surface as usual, but did attack all non-soldiers taken from other galls.  On the gall surface, soldiers even attacked non-soldiers taken from the gall itself.  This means that soldiers of C. styracicola discriminate between soldiers and non-soldiers, and is a strong positive evidence for the hypothesis that aphid soldiers cannot discriminate between kin and non-kin, or between clonemates and non-clonemates.

When I was writing our 1991 paper on the discrimination between soldiersand non-soldiers, I completely forgot that the key idea had come from Bill Hamilton.  I should have thanked him in the paper, though he would not care about this.

Shigeyuki Aoki (

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Letter for Bill by Steve Stearns (Basel University)

In the spring of 1980 Bill came from Michigan to Portland Oregon to give a talk at Reed College and to make a little expedition into the Cascades to look for insects that live under the bark of old-growth timber.  The trip took three days.

Bill bounded about the giant Douglas firs and Sitka spruce with energy and enthusiasm, but he did not find any protosocial woodroaches.  We proceeded to a hot spring high in the Cascades east of Eugene.  After passing a pool filled with naked University of Oregon undergraduates drinking whiskey and smoking dope, we made our way upstream to a more private pool.  It had a hot and a cold intake stream that could be mixed to preference by arranging stones, which we did.  Then we stripped and got into the pool.  I noticed that Bill's back was covered with scar tissue, and asked him why. There in the pool, steam rising from the water and firs towering high into the grey Oregon sky, naked undergraduates frolicking downstream, he told me how he had played with the explosives that his father had in the garage during World War II to manufacture grenades for the home guard.  One blew up in his stomach by accident.  He staggered into the kitchen, clutching his belly, and collapsed in a pool of blood on the floor.  His mother, who was in the kitchen, was a doctor, and if she had not been, Bill probably would not have survived.  She stitched him together as best she could and rushed him into the hospital, where it took him months to recover - 6 months, if I remember correctly.  He told me he was 12 when it happened, so the year would have been 1949 or 1950.  We very nearly did not have him at all after that.

On the trip we had a total of about memorable 20 hours in the car together, during which we talked at length about his discovery of kin selection and his feelings about his lack of recognition in the UK.

Seven years later Bill attended the meeting in Basel, Switzerland, at which the European Society of Evolutionary Biology was founded.  On the Sunday morning after the congress we had a brunch in our garden for all the invited speakers, about 40 people.  My wife Bev and I were shuttling in and out of the house to get food and drink on the table in the garden.  At the time Bill had a good position in Oxford but did not have enough money to buy a nice house - it was before he got the big prizes in Japan and Sweden. As Bev came up behind him carrying a large watermelon loaded with fruit salad, Bill gazed unknowingly up at our house and said, "You know, if Steve died, there would be an opening in Basel."  He barely escaped having the melon, with its juicy salad, being brought down firmly on his head.

I found Bill unfailingly friendly, courteous, and insightful.  His encounters with danger started early.  As the above anecdote makes clear, he was also direct, honest, and unguarded.  He is sorely missed.

Steve Stearns
University of Basle,Switzerland

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