Professor William G Hill OBE FRS FRSE (1940 – 2021)

A collection of anecdotes and memories from friends and colleagues of an esteemed geneticist and gentleman who will be much missed by the quantitative genetics research community and beyond.

photo: Anne-Katrin Purkiss

Read also Prof Hill’s  Mendel Medal award comments here and an obituary in Heredity here.

Watch an interview of Prof Hill with Geoff Simm discussing Bill’s career here.

Kay Boulton:

My own memories of Bill are of the kindest and most supportive person.  When I first met Bill he was chairing a steering group and I was merely taking minutes.  I had no idea of his stellar fame, and I know he had commented to Steve Bishop on how refreshing that had been.  We hardly talked about science, but chatted about our families and shared farming backgrounds. 

Later, Bill supported my change of career by providing references for the Quantitative Genetics MSc and later my PhD at Edinburgh.  I was thrilled that Bill was awarded the Mendel Medal by the Genetics Society in 2019, and that I was able to organise the event.  My everlasting memories of Bill will be as Jarrod and Andrea describe below – a master of mumble, surprise, with a leaning tower of papers on his desk.  I feel honoured to have known Bill and been able to call him a colleague and friend.

Photo: Prof Hill with Kay Boulton, Sara Knott, Sue Brotherstone and Ian Whyte

Sara Knott

Bill was my University PhD supervisor, then PI and for nearly 30 years we occupied neighbouring offices.  Throughout he has been a great influence.  Our first meeting was not a great success as he stunned me to silence (not a response Bill appreciated) by giving an impressive stream of information mostly (I think) on published work relevant to my PhD.  The few names I did pick up meant nothing to me!  Only later I understood that if I had just stopped him, he would have been happy to repeat or explain as necessary.

Despite this start we authored a review paper together for a meeting in Australia to which Bill had been invited; he invited me to present it in a genetics seminar in Edinburgh.  I must have looked terrified at the prospect because he offered to step in if (when?) I failed.  His aid was not required, luckily perhaps as he gave the impression of being fast asleep – but perhaps he was in deep thought.  I decided against stopping mid sentence to see how he reacted but I’m sure he could have jumped up and taken over.

Later I saw him perfect the art of being apparently asleep throughout a presentation and then asking the killer question at the end.  In journal clubs, I would feel pleased with myself when I felt I understood something Bill was questioning – but always with the unease that he was not understanding at a level deeper than I would ever comprehend.  I attended the lectures he gave to the MSc students, it was before the days of powerpoint presentations – we used chalk and a blackboard (a far too small blackboard so it transpired).  Bill would start in the top lefthand corner and work his way down to cover the whole board.  Then he would start again from the top left, rubbing out as he went (amidst screams from students who hadn’t copied that bit).  Perhaps he had notes, I don’t recall that he did, and obviously he thought it through as he went, including the occasional statement that he had made an error in an equation a board or so earlier!  A great performance – perhaps not appreciated at the time by the MSc students.  As a postdoc Bill gave me the freedom to do the work I was interested in and I am grateful for that, he also supported my move to part-time work (rather unusual at the time) and, when able to join him for coffee, he enlightened me beyond the confines of science.  His presence is missed.

Sue Brotherstone and Ian MS White

Bill used to have a steady stream of high profile visitors from home and abroad and they would sometimes join in the departmental coffee break. The conversation ranged freely but usually took on a strong scientific slant whenever Bill was present.

After Bill retired he moved to a shared office and his conversation started to include other matters: politics, religion, the state of the world. But above all else, he liked to discuss football. During the World Cup, the frequency of emails between Bill and Dan Gianola rose to an unprecedented level. It is possible that they were discussing genetics but we suspect that the correspondence was more to do with goal averages, or the probability that Ecuador would survive against Brazil.

Occasionally we could observe a great mind at work. When deep in thought, Bill would sit motionless, staring into the middle distance. Then a long sigh, and we knew that another genetically knot had been untied, another problem solved.

Over the years, we learned more from casual conversation with Bill (and his visitors) than from any number of formal lectures or seminars. He will be much missed, both as a colleague and a friend.

Jarrod Hadfield

I moved to Edinburgh soon after Bill’s retirement.  In those first few years I must have asked him hundreds of questions, all of which he answered with patience and from an encyclopaedic knowledge of the literature.  Even in his 70’s he would devour the latest advances in quantitative genetics – his desk was like an arcade coin pusher, with an improbable overhang of recently printed papers.

He loved to discuss these advances also, but you had to work hard to understand him.  He mumbled and chuckled in equal measure, and in the 15 years I knew him, the only vowels I heard him pronounce were the e in Ne and the a in Va.  He used these a lot, and equations would be spoken mid-sentence without any real indication that he had switched from English to Maths.  Ne, Va, LD, h-squared were like the names of his children, and always used as if the listener had the same level of familiarity and affection.  He found quantitative genetics ‘endlessly fascinating’ and still without answers to the big questions.  Why, for example, was heritability concentrated around 0.25 and not uniform from 0 to 1?  He always said the answers would be simple and obvious once we knew them, and so he kept chipping away.  Although he never did find the mother lode, plenty of substantial nuggets were found along the way: Hill-Robertson interference, of course, but many others too.

Bill was probably the single most important person in my academic development.  He taught me a huge amount of population and quantitative genetics, but more importantly he inspired me.  His small eyes in a large face still sparkled when he talked about things he’d been studying for over 50 years. Bill is gone, but his legacy will outlive us all.

Andrea Doeschel-Wilson

My first encounters with Bill were in the early 2000s at the weekly quantitative genetics journal club in Edinburgh, which Bill attended diligently. For novices in quantitative genetics like me, this was a gold mine to get the insight opinion of giants like Bill about the latest QG studies. We were quite nervous presenting the papers, all too aware of our ignorance in the midst of a genius.

But Bill never put us to shame. Instead he generally pretended to sleep through the presentations, and ever so gently planted a few key questions or comments when he ‘woke up’ to set us in the right direction. I cherish my memories of Bill as the humble genius with the highest qualities of a proper English gentleman.

Jean-Luc Jannik

A paper from the year I was born! Hill, W.G., and A. Robertson. 1966. The effect of linkage on limits to artificial selection. Genet. Res. 8(3): 269-294. The Atlas Computer, on which the simulations were done, was one of the world’s first supercomputers, in use from 1962 until 1971. Atlas’ capacity promoted the saying that when it went offline, half of the United Kingdom’s computer capacity was lost.

“A computer simulation study has been made of selection on two linked loci in small populations, where both loci were assumed to have additive effects on the character under selection with no interaction between loci”

In gratitude to you Bill!

Daniel Gianola

I met Bill Hill for the first time in 1976, during the first world conference in quantitative genetics in Ames, Iowa.  Of course, I knew who he was, as I had struggled with some of his Biometrics on design of selection experiment when I was a PhD student.  At some point, during one of the evenings, some of us were chatting in a sort of university lounge or dorm.

Bill pointed out that there was nothing to drink.  I had a bottle of mundane whisky (Red Label) and I brought to the meeting (just in case), to make the conversation livelier.

I saw him again in 1982 and eventually became friends.  I spent two months in Edinburgh in 1998, and he kindly shared his office with me during our stay.  At that time, he was Dean of Biological Sciences, but made time for discussion.  One of the points which was perplexing to Bill (and even more to me, an ignoramus of population genetics and of other matters) was how in the world Sewall Wright had seen that the Fokker-Plack equation could be used solve the problem of the equilibrium distribution of allelic frequencies under some idealized conditions.

I was very fortunate during the Edinburgh period, because Laurie and Priscilla Piper were there on sabbatical, and we socialized a lot with the Piper and Hill couples.  It was a great time, and I had quite a few pints with Bill and Laurie.

Hill has been, and will continue to be, one of the scientists whom I have admired the most.  His contributions were monumental, and his contributions to discussions were always milestones.  A brilliant and a super-fast mind, coupled with a powerful intuition were his most notable assets as a scientist. He was always humble, and aggressive intellectually but not scary.  Last but not least, Bill was generous and hospitable and had an admirable sense of integrity as a person.

His legacy is extremely important to us. Hill’s papers and volumes will continue providing much and needed guidance to both young and seasoned scientists.

Professor Geoff Simm

I first met Bill in the early 1980s, when I arrived in Edinburgh to do a PhD at the Animal Breeding Research Organisation.  I attended classes in the MSc programme in Animal Breeding that Bill co- directed at the time.  I was elected class rep and urged regularly to ask Bill to slow down and repeat parts of what he had said.

So, lectures often involved me doing that, and Bill asking ‘does anyone else apart from Geoff Simm not understand this’, followed by complete silence from the rest of the class!  I think for most of the hundreds of students who studied on that course, it was tough at the time, but it laid important and valued career-long foundations.

Later, in the East of Scotland College of Agriculture (later part of SAC and SRUC), I ran a number of farm animal breeding research projects and Bill provided regular, highly-valued advice to me and a growing number of colleagues working on these.  It was a privilege to co-supervise with Bill and others, a series of great MSc and PhD students, many now leaders in their fields.  Most of Bill’s PhD students started their studies with some trepidation, given his scientific reputation, but that soon morphed to enormous and lasting respect and affection.

It is notable that genetics in Edinburgh, under Bill’s leadership and Alan Robertson’s before him, involved a two-way street between theory and practice.  Both had farming interests and were passionate about application of science in livestock breeding – which has been to the great benefit of breeders and breeding organisations in the UK and abroad.  (Bill was a much respected and trusted formal or informal consultant to many globally important breeding organisations, training many of their staff, and advising government departments on a range of important livestock topics.) The challenges in application have often stimulated developments in theory.  In Bill’s case, the sustained responses to selection in farm animals over many generations, provided both a stimulus and valuable evidence for his theoretical work in that area.

Bill was a longstanding supporter of technical societies in animal breeding – including the British Cattle Breeders’ Club, the British Society of Animal Science (he was President in 1999-2000) and especially the World Congresses on Genetics Applied to Livestock Production.  He served on the WCGALP international advisory committee until a few years ago, and chaired the local organizing committee for the 1990 Congress in Edinburgh.

Bill was the principal flag bearer of Edinburgh’s longstanding international reputation in genetics for over 30 years. Despite this, and his many responsibilities, he always gave very generously of his time, experience and considerable intellect to students and colleagues in academia, industry and government – something that was, and remains, hugely appreciated.  He wore his brilliance lightly, liked people, and enjoyed the humorous side of life’s events.  Rosemary and Bill Hill were fantastic hosts to generations of students and visiting scientists coming to Edinburgh, and helped make it such a great place to study and work.

It has been a great honour to call Bill a mentor, colleague and friend – he will be sorely missed.

Bill Hill
Photo: Douglas Vernimmen

Dr Victor Olori

On the broad stairs of Ashworth labs, Kings building, he turn to me sharply and said “Don’t call me SIR, just Bill”.  For a young African student fresh out of Nigeria, this was another rude shock.  How can I address my mentor, my supervisor, a most senior professor, dean of college and this giant of a man as “Just Bill”?

But I soon came to know, that was the nature of the man.  Kind, humble and willing always to come down to your level with joy to help.   Although it was the name of Douglas Falconer through his book that first brought the University of Edinburgh into my radar in Faraway Nigeria, It was Bill Hill that brought me to study in Edinburgh.  Yet I first encountered the man in Guelph, Ontario, at the 5th World Congress on Genetics Applied to Livestock Production.  Having just journeyed From Lagos via Frankfurt and experiencing serious jet lag for the first time, seeing and talking to Bill was the only thing I could remember from the opening ceremony of the WCGALP in August 1994.

From that day till my latest visit to Bill’s office before the onset of the ravaging COVID and forced incarceration of people, Bill was always there listening, probing and helping to solve problems concerning the theory and practice of animals breeding.  He patiently nurtured and imparted knowledge into me throughout my study days.  Long after graduating as one of Bills numerous students, I was lucky be in and around Edinburgh throughout my career to date which meant I have continued to have close association and collaborations with Bill.  It is therefore particularly painful to hear of his transition even though we all know death is inevitable.  This is one loss too much and the only consolation is that Bill has left behind a great legacy.  He lives on in his children and family but also in all his academic children collaborators and friends.  Not surprised that even in death, he has chosen to continue to further the cause of knowledge with his body.

I pray that the Lord will grant Rosemary and his family the fortitude to bear his loss.  Rest in Peace Sir W. G. Hill, for you are indeed a Knight of the genetics and animal breeding round table.

Carlos Lopez-Fanjul de Arguelles

I met Bill for the first time in 1968, as a lecturer in the Diploma Course at the Institute of Animal Genetics in Edinburgh.  He impressed me so much that, after finishing the course, I asked him to be the supervisor of my Ph. D. thesis.  Susan Hayter and myself were the first Bill’s PhD students, finishing in 1972.  Sadly, Susie died a few years afterwards and Bill usually referred to me as his older student alive.

Under joint authorship, I presented some preliminary results of my thesis work in the Population Genetics Group meeting in Bangor, December 1971, which Bill could not attend.  After my talk was finished and the chairman asked for questions, Kenneth Mather took the occasion to launch a furious attack, not particularly to my paper but to the Edinburgh group, one of the many episodes of the vivid debate carried out in the time between the confronted views of the Edinburgh and Birmingham schools.  Before I could utter a single word, Dick Lewontin who was then visiting in Edinburgh, made a conclusive defence, as Bill undoubtedly would have done if present.  After the session finished, I was comforted by Alan Robertson who said to me: “you have been well understood”.  I still don’t know what he meant by this but, from them onwards, Bill and Alan’s work had been the main source of inspiration of my research along 40 years, and, much more important, I have always enjoyed with gratitude their friendship and generous advice.

Bill was the model of the scientist to imitate. Rest in peace.

Bruce Walsh

Bill will indeed be missed.  His legacy as a titan in the field of quantitative genetics is secure, and the impact of his work will only grow over time.  For example, a rather (at the time) obscure paper he did with Alan Robertson on the impact of tight linkage on selection response in an animal breeding context– the so-called Hill-Robertson effect – now underlies the population-genetic analysis of genomic data (selection at nearby sites makes a region more neutral).

Our two textbooks on quantitative genetics (Lynch & Walsh 1998; Walsh and Lynch 2018) would not have been possible with the guidance (and careful review!) from Bill.  In particular, Bill prodded us (well, mainly me) for years with “Keep writing” on the second volume, and read the entire manuscript (several times), keeping us from a making a number of stupid mistakes.  Much of this volume covers material that can directly be traced back to Bill.

As impressive as he was as a scholar, Bill was more impressive as a person.  One of my fondest memories of Bill was from the Illinois long-term selection meeting in 2002.  My wife (a PhD in linguistics, not biology) accompanied me and mentioned that she had the most delightful conversation about the on-going world cup with a “fellow from England”.  They made a friendly wage on the US team’s chance in a match.  Bill (unlike his namesake gambling company) lost the bet and very graciously bought her a drink.  On relating this interaction, she asked me if I had ever heard of a “Bill Hill”!  That was typical Bill.  Very genuine as well as very generous with his time, just as happy to spend time talking to a new graduate student as with a senior Professor (indeed, he was likely more happy to spend time with the student!).

Han Mulder

I visited Bill for the first time in spring 2005 as a PhD-student from Wageningen University to discuss with him opportunities for a sabbatical in autumn 2005.  So I stayed from September until December in Edinburgh.  He was already retired but with a great and sharp mind with respect to almost everything, but especially quantitative genetics.

It was in the beginning still a bit of search for a topic that we both liked and were able to see the light.  Finally, I started simulations about genetic variation in environmental variance.  Step by step we were trying to understand the results and this led to what became my biggest contribution to quantitative genetics so far: prediction of breeding vales and selection responses with genetic heterogeneity of environmental variance (Genetics 175:1895-1910).  I could not have done it without him.  Later when I was back in Wageningen I continued with Bill on email distance and also that worked.  Later I wrote with him the review Hill and Mulder 2010 (Genet. Res. 92:381-395), for which I stayed a couple of days with him in his house.  He was so energetic, unbelievable.  Every evening, we spent some time at Kings buildings to make the most work hours as we could.  This review is now one of my most cited papers.  When I became assistant professor and decided to develop my research line about genetics of environmental variance, I visited Bill regularly (2013, 2014, 2015, 2018), which resulted in one extra paper (Mulder, H. A., W. G. Hill, and E. F. Knol. 2015. Heritable environmental variance causes non-linear relationships between traits: application to birth weight and stillbirth of pigs. Genetics 199:1255-1269).  He became a mentor for me and I enjoyed every minute speaking with him. Also in between we at least emailed a couple of times a year.

One of the things that we have in common is interest in farming, so he always talked with me about his farm as I did with respect to my father’s farm.

Reading his papers is always inspiring, so his early papers on de novo mutations were a great inspiration for my recent work on de novo mutations and their impact on quantitative traits (H. A. Mulder, S. H. Lee, S. Clark, B. J. Hayes and J. H. van der Werf. 2019.  The Impact of Genomic and Traditional Selection on the Contribution of Mutational Variance to Long-Term Selection Response and Genetic Variance. Genetics early online).

Bill’s greatest contributions to animal breeding:
I think his greatest contributions are his research on maintenance of genetic and environmental variance, so this includes things like genetics of Ve, maintenance of genetic variance, e.g. contribution of DNM, but also the variability in relationships which is of great importance for predicting accuracy of genomic prediction.

Bill as a person:
– Very friendly, helpful and gentle
– Great and sharp mind
– Interest in family life
– Hard working, workaholic
We will miss him as being one of the giants of quantitative genetics.  It was an honour to work with him, probably as one of the last PhD-students and younger generation scientists.  Without him, I would never have developed so much interest in quantitative genetics of Ve.

Armando Caballero

I started working with Bill as a postdoc in 1990.  I had visited him a few months before and the first time I spoke with him I thought that I would not be able to understand him in my whole life.  Fortunately, when I arrived at the Institute, he installed me for a few months in an office shared with a predoctoral student of Chinese nationality, whose thesis supervisor had been the recently deceased Alan Robertson.

Every time Bill came into the office and said something to me, I would assent to everything without understanding anything, and when he left, my office mate repeated to me what he had said with a Chinese accent that I could understand much better.  I was able to survive the first month in that way until I started understanding him little by little.  Later, they told me that sometimes the British themselves could not understand him, which left me less worried. What it was to be initially a two-year stay turned out to be almost a seven-year one.  I was extremely lucky to be able to work with him for so long because this allowed me to achieve a theoretical background that I could have never got otherwise.  Bill had an infinite capacity for work.  Despite his numerous obligations of all kinds, he had time to talk to me almost every day, even if only for a few minutes, which encouraged me to work harder.  Bill maintained a pleasant work environment due to his kindness and his sense of humour, and is scientific capacity was incredible, both in knowledge and in deductive and mathematical ability.  Any questions I had were resolved instantly or he would tell me where I could find the solution.  That made it very easy to work in a difficult field such as quantitative genetics.  His way of doing science and his human quality are the fundamental principles that I learned from him and that I try to teach to my own students.

Peter Keightley

One thing I remember very well from doing my PhD with Bill from 1986-1989 (nominally part time as a Research Assistant) was that he would come into the office I shared with Sue Brotherstone almost every morning before the coffee break (which was in Alan Robertson’s office along the corridor) and ask the same question: “What have you discovered?”.

This was not because he expected anyone to actually discover something every day, instead I think it was a nice way of opening the conversation about where we were with my project.  We would then talk about what results I had produced and what I might do next.  He took an incredibly keen interest, but I never felt that it was too much and he was happy for me to go my own way with it.  For example, my project was part of a grant on the impact of new mutations under directional selection and was never intended to be about stabilizing selection, but ended up focusing a lot on that.

Photo: Karin Meyer

Karin Meyer

Bill was an amazing person. His contributions to quantitative genetics were enormous, spanning the great breadth from theoretical developments to the implementation of livestock improvement programmes.

A specific area of Bill’s interest was the estimation of genetic parameters.  For instance, he made geneticist aware of the need for covariance matrices to be positive definite and the effects of sampling errors on response to selection on indices.  Moreover, while he tended to stay clear of the computational side, he championed the uptake of maximum likelihood based estimation fitting linear mixed models.  Edinburgh has been at the forefront of making REML the standard method for variance component estimation in quantitative genetics no doubt to a substantial extent due to Bill’s involvement.

Bill was known for his unfailing dedication and rigorous approach to science.  In addition to his own seminal contributions, he had a profound impact through his numerous postgraduate students and postdocs.  Bill had the uncanny knack of pushing his students to realms of genetics and statistics they would have never imagined or reached otherwise.  In addition, his utmost interest in and emphasis on scientific papers instilled sound publication habits.  Truly invaluable gifts which shaped the careers of many.

I am privileged to have had Bill as supervisor and mentor for my Ph.D. and a postdoc.  “I am not interested in how fast you can compute the wrong answer” was a no-nonsense, characteristic comment of Bill’s which has become a fond memory.

Roel Veerkamp

My first getting to know Bill was in August 1990, even without meeting him.  As a young naive student from Wageningen, coffee table talk in Roslin was that Bill must have read and edited all the papers for the WCGALP that year.  The first time we met was at the journal club, where Bill always had a preferred seat at the corner.

Discussions were always special when Bill was there, and that was most of the time.  When I gave al seminar about my thesis work (crosses between mice lines), he raised his eyebrows when I called the preliminary analysis “Jan Boerenfluitjes”, but was awake during the whole seminar.

After finishing my  MSc, I started working at SRUC.  An interesting combination, because Bill Hill was not only one of my PhD supervisor, he was also partner in a project that aimed to develop new selection indices for UK dairy cattle.  Given all the politics and organizations involved, it costed quite some time to get final industry support for the project.  I never forget the first project meeting.  When a technical director confused us when explaining what he expected from the project, Bill politely told him that he was at the wrong project meeting.  Bill had a strong interest and involvement in practical animal breeding, and as a PhD supervisor we spent a lot of time discussing dairy cattle genetics.  I was amazed how much time he took, also to discuss other things, even when he was Dean of Biological Science.

Bill was the only permanent member of the WCGALP permanent committee.  In 2010 during the Leipzig conference, Bill hinted to me that it was time to take responsibility to organise WCGALP in the Netherlands.  So we did and organised a bid in Auckland.  In 2017 he politely declined to become a member of our WCGALP advisory board (“it is time for a new generation”), and over time it became clear that his health made it unlikely for him to participate in 2022 in Rotterdam.  Now he will be missed even more, although many of us will recollect and benefit from his incredible contribution to our scientific field.

Emeritus Professor Richard Frankham, Macquarie University, Sydney Australia

I was deeply saddened by Bill Hill’s passing.  Bill was a giant of quantitative genetics and animal breeding and an important figure in population genetics.  Less well known are his important impacts in conservation genetics, with the following three being especially notable.

First, his single sample method for estimating effective population size from linkage disequilibrium predominates in the discipline.  Second, his prediction of response to selection from new mutations is important with regard to conservation of genetic diversity and evolutionary potential.  Third, the Hill-Robertson effect has attained enhanced prominence in the genomic era in the context of linked selection effects.  In addition to his scientific contributions, Bill was a very pleasant and civilized person.

Frank Nicholas, University of Sydney

My wife, Jan, and I met Bill and Rosemary soon after we arrived in Edinburgh late in 1971. Bill was then in full flight as a young lecturer.  Although my PhD supervisor was Alan Robertson, Bill was equally supportive throughout my candidature, not only scientifically but also socially.

Indeed, he and Rosemary introduced us to their solicitor, Mr Cochrane, who enabled Jan and me to purchase a delightful Victorian cottage in Haddington, where we lived for most of our all-too-short stay in Scotland.

Like me, Bill had grown up on a farm.  When my parents came to the UK to visit us in 1973, Bill arranged for my parents to visit his parents on their farm – a magical meeting of farmers from the opposite ends of the world.

Perhaps the most important lesson I learned under Alan’s and Bill’s mentorship was to understand what it is like not to understand!  I was forever struggling to understand concepts that Alan and Bill understood instinctively.  Although that lesson was a bit down-heartening at the time, neither Alan nor Bill ever showed any signs of despair!  Importantly, I have since come to appreciate that understanding what it is like not to understand is a valuable attribute for any teacher.

Within a few months of our arrival, Bill got me involved in a project that had nothing to do with my thesis work, but which I found just as interesting.  Under his never-ending encouragement, my propensity for attention-to-detail (pedantry?) was put to good use in checking every line of algebra, making the occasional suggestion here and there, and doing all the calculations in what became my first Edinburgh paper, published soon after I returned to Sydney.

I remain forever grateful for Bill’s tolerance, mentorship and friendship.

Adam Eyre-Walker

Bill was my PhD supervisor during my studies at Edinburgh University during the early 1990a.  Given that I had dropped out of a PhD after just 10 days the previous year, Bill took quite a chance taking me on.  I then proceeded to start working on DNA sequence analysis a field he was not involved in!

However, he very generously allowed me to pursue my own path and supported me throughout my studies.  He was insightful, generous with his time and efficient – give him a manuscript and you would comments back within 24 hours.  I am very grateful to him for supporting me early in my career and allowing me to find my own path.

Jack Dekkers

Dr. Bill Hill has obviously made numerous important contributions to the field of animal breeding, which I’ll focus on.  From predicting response to selection and rates of inbreeding, to gene flow methodology, the impact of mutations, linkage disequilibrium, variance of relationships, etc.

What has always struck me is that, on the one hand, Bill was obviously a genius when it comes to the theory of quantitative genetics, but on the other hand, he could relate extremely well to the application of that theory to practical animal breeding and also made numerous contributions to that field.  Apart from his scientific contributions, his legacy of course resides in all the students that he has trained over the decades.

My first interaction with Bill was towards the end of my PhD.  I had of course read many of Bill’s papers but had never met him.  As part of my PhD, I derived predictions of asymptotic rates of response to selection on BLUP EBV, accounting for the Bulmer effect.  My results disagreed with results in a paper of one of Bill’s students due to an oversight on their part.  I presented my work at a WCGALP and remember how nervous I was because I assumed he would be in the audience.  He was, however, extremely gracious and afterwards, took the time to write me a very nice personal letter, acknowledging their oversight and congratulating me on my work.  That was the start of a very congenial and long-lasting relationship.

John Webb

I arrived at Edinburgh University’s Institute of Animal Genetics in 1970, with Bill as my university PhD supervisor at the nearby A.B.R.O. (AFRC Animal Breeding Research Organization). For the next 50 years Bill has been my key mentor at every step of my professional life.

He was always there to provide active help, first at ABRO, then with commercial pig breeding programmes, and most recently with probabilities for a novel DNA traceability scheme for Canadian pork in Japan.What was it that made Bill unique?  It was his endless curiosity, coupled with enormous deductive ability and ruthless scientific integrity.  Bill was a great teacher.  After a year as his student, to my astonishment I was able to derive the analysis of variance from first principles, and then do it in front of his MSc class.I will really miss Bill’s unique brand of earthy logic and good sense.  I always wondered how Bill managed to combine numerical brilliance with such a street-wise view of life.  I tried to picture him driving the combine on the family farm which I know he used to do.  But it was his uncompromising integrity in science and life that set Bill apart, and has provided a role model for so many of us.

Robin Thompson

My collaboration with Bill mainly arose through the guise of helping with the statistical analysis of the  order of 20 Ph. D thesis involved with the analysis  of selection experiments and animal breeding schemes.  It was exciting times with the ability for the first time  to fit interesting and more relevant genetic models using the animal model. 

Most of this work used computer programs written by Karin Meyer, one of our first joint students.  Bill was a rigorous and  exceptionally conscientious supervisor.  The discussions with students I  always found illuminating (sometimes more for me than the student).  I quickly learnt not to immediately read a document a student gave me.  Within a day Bill would send a corrected manuscript with scribbles for corrections and suggestions for improvement.  One student had not got the self confidence to write up their work and was reluctant to even come to work.  Bill suggested  a fellow student to go round and encourage the student to come to work. The student was still reluctant to complete her thesis.  Bill showed the student a thesis with essentially each chapter based on a paper.  The student had completed several papers so Bill suggested she could something similar.  The student then essentially pasted the papers complete with references in each chapter.  When the external examiner read the thesis he asked if this format was acceptable.  Bill replied that there was nothing in the university  regulations to stop it. The student got their Ph. D. but Bill changed the university regulations the day after the students oral.A sample important paper is Hill, W. G. (1972). Estimation of genetic change. I. General theory and design of control populations. Animal Breeding Abstracts40, 1–16 .  It is one of a series of papers in the early seventies that enabled Bill to set the theoretical framework for the design, analysis  and interpretation of selection experiments.

John James

I first heard of Bill in the early 1960s. My friend Cam McPhee was in Edinburgh doing a Ph.D. with Alan Robertson and in a letter to me wrote ‘ The Institute has a new wunderkind named Bill Hill’. By the time I first met Bill in 1970 when I was on study leave in Edinburgh I had read several of his papers and knew that Cam’s description was accurate.

One particular occasion stands out in my memory. I was looking after Laurie Piper’s Drosophila while he was away. One Saturday morning I went to the lab to collect virgin flies. At morning coffee Bill talked about work he was doing on using discounted cash flows for investment appraisal of breeding programs. It occurred to me that it might be possible to use this approach to optimise the intensity of selection in breeding programs. Over the weekend I checked this out and found a solution. So at the Monday coffee session I explained what I had done. When I finished Bill commented “Perhaps you could extend that to optimise the size of the breeding program”. I was a bit sceptical, but after lunch went to my desk in the corridor and with a bit of effort found that Bill’s
suggestion worked.

It was always worth taking notice of what Bill said.

Photo: Joe Felsenstein

Emeritus Professor Richard Frankham, Macquarie University, Sydney Australia

I was deeply saddened by Bill Hill’s passing.  Bill was a giant of quantitative genetics and animal breeding and an important figure in population genetics.  Less well known are his important impacts in conservation genetics, with the following three being especially notable.

First, his single sample method for estimating effective population size from linkage disequilibrium predominates in the discipline.  Second, his prediction of response to selection from new mutations is important with regard to conservation of genetic diversity and evolutionary potential.  Third, the Hill-Robertson effect has attained enhanced prominence in the genomic era in the context of linked selection effects.  In addition to his scientific contributions, Bill was a very pleasant and civilized person.

Brian Charlesworth

Deborah and I first met Bill at our first Population Genetics Group meeting in Bangor, in December 1971, when I was a beginning lecturer at Liverpool.  As always, he was very friendly, and took an interest in my work at a time when I was really only just getting started.

He had, of course, already established a reputation as a rising star in theoretical population genetics with his early work on linkage disequilibrium and on the Hill-Robertson Effect.  After that, we met from time to time at Population Genetics Group and Genetics Society meetings, and on a few occasions when I examined PhDs or honours students in Edinburgh.  I remember one occasion when Bill recounted with glee how John Maynard Smith was a PhD examiner in Edinburgh, and planned to read the thesis on the train journey up to Edinburgh, but found that his briefcase was locked and the key was missing.  The exam had to be postponed for several hours while John read the thesis.  We got to know him much better when Deborah and I moved to Edinburgh from Chicago in 1997; Bill was instrumental in making the move possible.

Bill was famous for his ability to ask penetrating (and sometimes devastating) questions of seminar speakers, often after apparently slumbering throughout the talk.  He was an excellent person with whom to discuss science.  He had a sharp eye for bullshit and bullshitters.  I was immensely proud when Rosemary Hill once told me that I was the first person she had met who was more cynical than Bill.  One of his favourite sayings about a paper or talk that he disliked was “What is the question to which this is the answer?”  His sense of humour and his realism were refreshing.  Although we disagreed strongly about politics (Bill being a Tory), we had common ground in a dislike of Tony Blair and Boris Johnson, and never quarrelled over politics.  It was a privilege to have had him as a colleague and friend.

Mike Lynch

My involvement with Bill began when I was just starting to teach myself pop/quant gen, and I started corresponding with Bill via regular post (this was before email had been developed).  I was interested in extending the neutral theory to quantitative traits, which required incorporating a lot of new complexities like dominance, inbreeding, and linkage disequilibrium.

A you know, quant gen has a lengthy history of technical developments, and I did not yet know a lot of them, so I would spend hours and hours carefully deriving equations from first principles, and then sending the final results to Bill to get his take.  He generally responded about as rapidly as possible with snail mail, with a few scribbled down steps, along with simple approximations, that reduced my dozen or so pages of derivations down to just a couple of lines that he probably pulled off in a few minutes.  Unfortunately, his handwriting was very bad, so I would then have to spend hours more trying to decipher what he had done.  He must have found this a bit hilarious, but never showed any loss of patience with me.  These experiences had a huge effect on me, and helped ease my way further into quant gen.

As Walsh and Lynch literally developed over a period of three decades, we were subject to periodic ribbing by Bill, who was beginning to doubt that the thing would ever be completed, and justifiably so.  He also provided very valuable feedback on a number of difficult subjects.  I hope he did have some chance to glance at the final product, and wasn’t too disappointed.

His lasting legacy seems to be the Hill-Robertson effect, but those who know the field of theoretical quantitative genetics will understand that there is hardly an area in which he didn’t make seminal contributions.  Many of these on experimental design and analysis have had a huge influence in applied areas of breeding.

Mike McGrew

Prof. Paul Hocking (RIP) invited me speak at a World Poultry Society meeting in Chester to a gathering of poultry feed producers.  Bill Hill was also there as an invited speaker.  Bill spoke on population genetics.  I spoke on germ cells and biobanks.  The audience clearly did not understand a word of either of our talks but enjoyed themselves nonetheless.

On the train back to Edinburgh I ran into Bill, introduced myself, and we had a great discussion (non-stop) all the way back to Waverley.   He was very entertaining and he turned a mundane five hour train journey into a great experience.

Photo: Carlos López-Fanjul, 2009

Alan Archibald

Despite over a decade at the Animal Breeding Research Organisation, as a molecular geneticist talking about genetic modification of sheep, I was on unfamiliar territory at the 40th Annual Meeting of the European Association for Animal Production in Dublin in 1989.  So Bill Hill was a welcome familiar face at one of the social events.

We sat in a booth within arm’s reach of the bar that was dispensing free Guinness.  The conversation flowed freely with the third person in the booth keeping Bill and myself regularly supplied with Guinness.  I do not recall the range of topics discussed but I agreed with Bill that it would be a good idea to expose quantitative geneticists to some practical molecular biology.  Before the night was over he had successfully recruited me to deliver a course for this purpose.  An Erasmus Course on ‘Gene Structure and Function’ with a mix of lectures, seminars and simple molecular biology laboratory work followed in 1990 with students including Carole Charlier, Sara Knott, Theo Meuwissen and Peter Visscher.  An evolving version of this week-long course was delivered as part of the MSc in Animal Breeding for the next five years.  It was a privilege to know Bill and I raise a glass in remembrance – sláinte.

David Hume

I met Bill Hill on many occasions during my time at Roslin and enjoyed his sharp mind and gentle wit.  I was well aware of the respect he commanded from my colleagues in quantitative genetics and his pioneering contributions that underpinned the core focus of the Institute.

Those contributions were well-recognised by Fellowships, Awards and Medals and his ideas have been translated into modern advances in animal breeding, more than meeting the current funder’s obsession with commercial impact.   But the true measure of his impact comes from the numerous scientists he mentored and influenced and who all speak of him with genuine affection.  Truly a gentleman as well as a scholar.

Andrew Leigh-Brown

The mid-1980s were uncertain times for genetics, particularly population genetics, in the UK.  Brian and Deborah Charlesworth had moved to Chicago, Liverpool was no longer influential and Nottingham struggled for funding.  In Genetics at Edinburgh, Douglas was long retired, Alan’s illness was progressing, and the molecular biologists who had been so prominent in the previous decade had been late to join the recombinant DNA revolution.

Against this background, Bill became the lynchpin not only of his subject, but of the whole department.  His intellectual leadership was unchallenged, his energy almost relentless, and he saw a future that others did not.  He provided support for new arrivals, including myself, that was much appreciated.  He maintained an intellectual environment where Henrik Kacser’s idiosyncratic approach to creating a new field in genetics (later called Systems Biology) could flourish.  He was an inspiration to those around him.  He provided leadership, as others have mentioned, not just for Genetics but for the then ABRO as well, the development of which led to the Roslin Institute.  As the decade closed, two things became obvious with the rapid changes in biology: first, that maintaining the then 7 departments in biological
sciences at Edinburgh made no sense and also that genetics by then had infiltrated all of biology.  Bill shortly after, entirely obviously, became the leader of the Division, the forerunner of Schools at Edinburgh, and then was the equally obvious choice for Dean of the Faculty of Science (now College of Science and Engineering).  And at every point in that progression of responsibility and influence, and long after, he would listen to visitors’ seminars, or the MSc students’ presentations, with a sympathetic ear and then offer one of his questions.  To answer which, one always had to think

Kevin Atkins

Edinburgh in 1981-84 was an exciting time for my PhD, with Bill Hill as supervisor and then acquiring Robin Thompson as a co-supervisor later.  In an early lecture to his post-graduate Statistics class, Bill asked us what was the principal role of statistics.

Being young and trying to impress we offered opinions such as testing hypotheses, defining a population, predicting the future based on past performance.  Bill’s response was the main role was to summarise a lot of data – typical Hill, simple and to the point.

I also had the pleasure of sharing a hotel room with him in downtown Madrid for the World Congress on Genetics Applied to Livestock Production in 1982, quite an experience for a young student.  Bill encouraged me to expand my mind by attending a range of sessions and introduced me to a host of people who till then were just names on scientific papers.
Bill’s legacy for me was that I should read for my degree and that the research should develop understanding several steps outside my comfort zone – lessons that have sustained my later career.

John Woolliams

It was my loss that I never wrote a paper with Bill, it would have been something I would have valued.  Although we were both ‘of Edinburgh’, and worked for Edinburgh-based organisations, we never shared the same buildings, which made our conversations infrequent, and often in passing.

Yet Bill’s perspectives on quantitative genetics and his incisive comments were an influential guide to me in my scientific career, and he gave me his support at critical times e.g. at promotion boards!  Bill’s objective, rational thinking extended beyond science.  He once told me that he thought it strange that we had silver and golden wedding anniversaries, representing ¼ of a century and ½ a century, yet 1/3 of century was overlooked.  Indeed he had taken his wife Rosemary on special holiday just to mark, to the day, their 1/3 of a century of marriage.  A guide in science and a guide in anniversaries – Carol and I enjoyed a marvellous week in Florence for our 1/3 of a century.  It is a small consolation to me that I know Bill and Rosemary were able to celebrate their golden ½ century.

Professor Alistair Lawrence

I have known Bill since I first came to Edinburgh in 1979 to start my PhD on hill sheep behaviour with Professor David Wood-Gush (a contemporary of Bill’s). David thought I should get some extra training in animal science and a part of this was to sit in on Bill’s statistics lectures to the MSc in Animal Breeding (in those days run from the Crewe Building).

I still remember feeling somewhat overwhelmed by the complexity of the concepts but some of it stuck and certainly helped me through my PhD and beyond.  After those early days I came across Bill partly through his involvement in animal science teaching but also because I was becoming interested in animal welfare and breeding.  As a result we had conversations about concepts such as genetic x environment interactions and robustness and how we thought about these from our different perspectives.  These discussions helped lead to successful grant applications on breeding for robust dairy cows and Bill continued to influence my thinking by attending our project meetings.  When retirement came for Bill I continued to hear of him as he shared an office with Professor Aubrey Manning.  They became close friends and when Aubrey died Bill helped organise and speak at his memorial service.  Our connection continued to very last period of his life as he and Rosemary moved into their flat in Salisbury Heights and became our neighbours.  Initially we would stop and chat on the street but rather quickly I could see the visible decline in Bill’s health.  One last memory: I gave my SAC inaugural in 1999.  In the midst of my heightened agitation giving this talk in front of peers and family I caught a glimpse of Bill – it looked like he was sound asleep.  Afterwards he came up and praised me for my lecture.  I will never know whether he was just being nice or whether in fact he had been listening with his eyes shut – but praise from Bill is praise indeed and I cherish that memory.

Dr Maurice Bichard, OBE

Bill was a little younger than me, but we both entered Quantitative Genetics at about the same time through first degrees in Agriculture.  It was the period when that new subject was starting to be applied on a large scale to several species of farm livestock.  Edinburgh was emerging as an important centre, home to at least four interacting groups.

We had different talents, and his much greater statistical ability allowed him to soon make valuable theoretical contributions in the same way as Alan Robertson before him.  I believe I was having a sabbatical year in Minnesota with Ralph Comstock when Ralph was asked to act as external examiner for Bill’s PhD thesis.  That completed, he remained in Edinburgh, but a part-time advisory role with the earthy world of the UK’s largest dairy cattle Breed Society was soon abandoned in favour of full-time academic work.  I often enjoyed his hospitality.

Lacking his alternatives however, after early retirement, I too ventured into the same area, trying to persuade cattle breeders that the methods successfully used with poultry and pigs could also be applied to their dairy cows.  I still bear the scars!

We both learned that working through trained staff in professional breeding organisations, whether cooperative or corporate, is a much less stressful way to help create genetic improvement.

Bill Hill
Photo: Lutz Bunger, April 2018

Lutz Bunger

My first encounter with Bill was in 1990 at the WCGALP in Edinburgh.  I then came for a few months in 1992 on a sabbatical to learn from Bill and his team before I moved to Edinburgh ‘for good’ in 1994 after receiving a job offer from Bill.  At that time I did not know that I would stay in Edinburgh for more than 27 years, most of the time working with Bill, directly and indirectly, and even sharing an office with him for many years.

I have been wondering whether I should write again about my memories of my time with Bill, as I already did this in 2019 on the occasion of his being awarded the Mendel Medal, when he was still able to read these little stories and memories himself.  It is so sad that he won’t know about everything we have written down here.

But don’t they say, ‘Behind every successful man is a strong woman’ or better even, beside him!?  Indeed, Rosemary and Bill were always fantastic hosts to all the many students and visiting scientists who came to Edinburgh, and they helped to make it such a great place to study and work in.  I wonder if Bill could have done all this without Rosemary’s support and encouragement.  And at the same time, she always showed great tolerance, as for example during his long hours in the office, and even on weekends and Public Holidays.

So, I have decided to write some words again, this time rather for Rosemary and for Bill’s family.

When I arrived and finally settled in Edinburgh I was already 44 years old and not a young postdoc anymore.  The first thing I learnt here was how little I really understood about Population Genetics.  Grown up in a cocoon-like environment in my own little country, I had no idea how much I was going to learn from Bill while I worked with him.  He encouraged me and my contemporaries in our thinking, research, writing up and publishing.  Bill was never pushy but rather asserted himself in a very helpful way.  Earlier, I had always kept a few half-written ‘papers’ with concepts or data in my drawer, but when I worked with Bill this never happened.  He also made me, as it were, empty my mental and physical drawers: old papers (still from my former work at the Research Centre in Dummerstorf) finally got published.  Mentored by Bill, my publication record increased a lot, and I should perhaps mention that my draft manuscripts, co-authored by Bill, always shrunk by 30 to 50% after he had commented on them.  He not only spotted redundancies but he was also a master of words: after he had deleted half a sentence, the sentence still said exactly the same.  To revise a manuscript after Bill had commented on it was quite hard in the earlier days, as he scribbled with all kinds of pens in all directions, using every free space he could find on the paper.  Unfortunately, I don’t have a copy of any of those, but insiders will know what I mean.  After Bill became increasingly computer literate and WinWord got its ‘Track changes’ options, life became much easier.  It is of note that Bill’s handwriting was at times quite a long way from being readable, but this is seen by a famous graphologist as a sign of independent thinking, outstanding creativity and exceptionality.  Anyhow, this was certainly true for Bill.

But Bill was not only an exceptional scientist and scientific mentor.  He was also for most of us a role model, and his street-wise view of things (as John Webb put it) helped me a lot on my way, for example, when I later acted as a supervisor/mentor myself and had to handle difficult mentees or work with somewhat cumbersome colleagues or bosses.  Bill always gave me excellent advice.

Probably not too many people know that Bill attempted several times to write a kind of autobiography.  However, his approach was divided and he could not make up his mind about it.  At one point he wanted to write it from a scientific point of view, looking at his work and publications and their possible contributions to the science of genetics.  At other times his intention was to write the autobiography rather for the family and friends.  The latter approach would be similar to Douglas Falconer’s, who recorded his reminiscences on tape in the year 2000, primarily for his son John, who got it typed and who later illustrated it.  You might remember that Douglas’ sight made it impossible at that stage for him to write them down himself.  Anyway, Bill started to draft various versions, mainly in 2018, and we spoke about it several times.  I tried to encourage him and hoped also to act a bit as a facilitator, but this project fell victim to what was probably too late a start; Bill’s health deteriorated soon after and with it his will to finish any version of an autobiography.  Unfortunately, then, nothing saw the light of day, and Bill’s impressive progress from a farm boy (all his ancestors were farmers) to a top scientist in animal breeding and genetics remains largely untold.  I would have loved to learn about the full story, but sadly, this won’t be possible anymore.  It has been a great honour to call Bill a colleague and friend – he will be sorely missed.  My own memories of Bill are of the kindest and most supportive person, a highly respected boss who was never bossy.

Photo: Joe Felsenstein, 1969

Joe Felsenstein

I first met Bill the day I arrived at the Institute of Animal Genetics in October, 1968.  It will be no surprise that he was immediately friendly and helpful, and that continued for 5 decades after that.  I was Alan Robertson’s postdoc, and Bill and he had recently published the paper on the Hill-Robertson Effect, the name I gave it in my 1974 paper.

I had worked on deterministic effects of gene interaction for fitness, and was sure that this explained why so many simulations showed that tight linkage slowed down the response to selection.  Bill and Alan were sure that their effect was the real reason.  I kept trying to understand the logic of their discovery.  Every time I lost track of how it worked they patiently re-explained it to me, until one of the explanations finally stuck.  It was very fortunate that they were so friendly and tolerant!  Soon after that I realized that it was also the phenomenon underlying R.A. Fisher’s and H.J. Muller’s theories of why recombination was advantageous, and we all came to understand that it also predicted the phenomenon of “background selection”.  Which shows how far you can get if in addition to simulating you think hard about what is going on, as Bill and Alan certainly did.

I don’t suppose I’m the only person here who considered Bill an especially good friend.  Rosemary and he were wonderful hosts over the years.  I visited Edinburgh multiple times, and spent my sabbatical year (1982-1983) at the Institute.  When I arrived I went to Bill and Rosemary’s house, and he helped me contact Henrik Kacser who owned the apartment where I was to live.  There was a delay in contacting Henrik.  I was jet-lagged out of my mind but tried to remain conscious by remaining on my feet and talking with Bill.  Several times I actually nodded off while standing up talking.  Bill later said it was one of the funniest things he had ever seen.  It was wonderful that in recent years Bruce Weir and Bill had a project with grant money that frequently brought Bill and Rosemary to Seattle.

Bill kept listening to people and helping them, and thinking very hard about what was going on in populations under selection.  Most of the results he got now seem obvious, but were so only after he got them and then explained how obvious they were.   He did the first EM algorithm for inferring linkage disequilibrium, and a particularly simple formula for the effective population size when generations overlapped, which made clear why that overlap reduced the effective size.  A few years ago he explained to me why the alleles in a population that contributed to the genetic variance of a character were expected to be in a shallow U-shaped distribution of gene frequencies.  I hope he published that somewhere, otherwise it will take us all a lot of hard thinking to see why it really is obvious.

Neil Cameron

I was lucky to be working in Edinburgh and could attend Bill’s quantitative genetics lectures and wait for Bill’s poignant questions at the end of a seminar, which very often had a practical basis.  Lunchtime journal club meetings were always better when Bill attended.  I had the opportunity to meet and chat with established international scientists who were visiting Edinburgh, primarily because they wanted to work with Bill.

Bill’s scientific contributions are widely acknowledged and that is part of his legacy.  In ABRO and Roslin, when I was reading Bill’s papers, such as those on experimental design or parameter estimation, there was always the question “How did he work that out?”.  When a problem I was working on seemed unsolvable, it was often suggested “Ask Bill” and with patience Bill would produce some formula, on the back of an envelope, that would lead to a solution.  Bill’s relaxed manner and ability to clearly discuss a whole variety of topics is well illustrated in the recorded interview with Bill (see  Bill was always generous with his time and I was extremely grateful that he took the time to comment on my manuscript on Selection Indices.  Bill quickly replied with both technical comments and advice to improve general aspects of each chapter.  On several occasions, Bill gave me career advice, which proved to be totally sound.  I liked Bill and had enormous respect for him.

Photo: Naomi Wray, 2018

Peter M. Visscher and Naomi R. Wray, The University of Queensland, Brisbane, Australia

To the international quantitative genetics community, Professor Bill Hill, FRS, was a pre-eminent scientist.  We and others highlight his scientific contributions in detail elsewhere, but here we provide a few more personal recollections.  We feel incredibly fortunate that Bill supervised both our PhDs (Naomi 1986-9, Peter 1988-91). 

(We also benefitted enormously from having Robin Thompson as a joint supervisor and really had the dream team of PhD advisers).  Bill was a caring and engaged supervisor, who visited us daily for progress updates on his morning rounds of the lab and never failed to provide feedback on draft manuscripts within a day.  He and Rosemary were generous hosts regularly inviting us and other students to their home for drinks and/or dinner.  We met in Edinburgh and Bill and Rosemary attended our wedding, now more than 30 years ago.

Naomi first met Bill in 1984 as an undergraduate on an agricultural field trip, where Bill explained to her the difference between contemporary comparison and improved contemporary comparison (pre-BLUP methods to estimate breeding values).  She didn’t really understand, but being so junior felt able to ask “Can you say that again?”, and Bill was more than happy to explain a second time.  This gave the confidence to frequently request for explanations to be repeated in conversations with Bill – he had a nuance of understanding that was several notches higher than ours (not helped by a bit of mumbling here and there).  Many times, others thanked us for being the ones to ask him “to please say it again”!

Peter first met Bill in 1987, at the start of the 1-year Master of Science (MSc) course in animal breeding at the University of Edinburgh.  We have Bill to thank for his admittance to the MSc course because Peter’s background was unusual – a first degree from the equivalent of a “polytechnic agricultural college” in the Netherlands, a completely unknown entity.  Needless to say, we have been grateful for that decision ever since.  In October 1995 Peter started a lectureship at the University of Edinburgh with an agreement from the Head of Institute that the teaching load in the first year would be light.  It was therefore an unpleasant surprise to be instructed by the University teaching organisation that he was to teach and provide tutorials for a first-year course of 400+ student, starting January 1996.  His Head of Institute confirmed that this was not what had been agreed and so Peter complained to the Dean (= Bill).  Bill’s response was “tough, you just have to do it”.  Since this was a matter of principle, Peter (in typical (Dutch) style) told him he would resign if he were forced to do it.  Three hours later Bill phoned back and said “you’re off the hook”.  It was only much later that the details became clear – Bill had stepped in himself to give the 1st-year lectures.  This was vintage Bill and typifies his general approach to getting the job done – someone has to do it and if there is nobody else around who is sufficiently qualified (and willing!) then he would take it on.  We note that he did later complain how much work it had been, and we doubt if the 1st-year students were too happy either!

Bill took a long-term interest in our careers and was a much-valued mentor, a “scientific father figure”, and we very much benefitted from his wise counsel over the years.  His advice was essentially to always focus on the science, to address interesting questions and to publish papers.  There is much discussion these days about the role of women in science and we feel fortunate that Bill was a prominent supporter of women in science throughout his career.  We only disagreed once on an important career matter and that’s when Peter told him in 2004 that he was resigning from his then faculty position at the University of Edinburgh to take up a fixed term 5-year position in Australia at the Queensland Institute for Medical Research (Brisbane).  In typical style, Bill conceded later that he had been wrong (“when the facts change, you can change your opinion”).  He visited us in Brisbane at least 3 times providing stimulating discussions for our teams.

We have a sort of code of Bill-isms that fall into our work conversations on a regular basis that make us smile when we think of him:

  1. a) “What is the scientific question to which this is the answer?” – a question that becomes ever more relevant in the era of big data where many things can be estimated, but the difficulty can be in posing the question.
  2. b) “Use both simulation and theory as you can make mistakes in both but when they agree at least you understand your model” (while recognising of course that the wrong model could have been applied to both).  This has proven to be helpful many times.
  3. c) “If you don’t understand the theory focus on the extremes – set the parameters to their boundary values and evaluate” – a good place to start.
  4. d) ”That ***** factor of two” – somehow getting things wrong by a factor of two is a curse of quantitative genetics (ultimately attributed to the fact that a parent passes a half of their genetic material to each child).
  5. e) “Have you put enough steps in your derivation” – Bill never put enough in steps for mere mortals like us to follow, so we try to not to emulate this characteristic!
  6. f) “Look at your data”- simple data summaries and data visualisation to get a feel of what you have is another critical step easily overlooked in the big data era.  It is surprising how often we ask a student or postdoc what the mean and standard deviation are of the trait they are looking at and they don’t know!
  7. e) “How do I organise my work? Each day I focus on what interests me most” – wise words to remember when the admin load gets too high, push it aside and do what we are really paid to do.  Perhaps it also reflects the luxury of times when the pressure to obtain grant funding and publish papers was not what it is today.

Bill was a giant in the field.  His contribution will live on not just in the scientific literature but also through his hundreds of students, postdocs, visitors and collaborators.  We are proud to be a part of that legacy.

Bruce Weir

Photo: Naomi Wray, 1989

For over 30 years Bill and I spent at least a week each year working together: in Edinburgh, or Raleigh or Seattle.  Over the years we developed a routine: we would each arrive at the other’s airport with a bottle of duty-free scotch and some half-formed ideas about our next project.  The first night we would crack the scotch and catch up on the family news.

Then we would spend the week at work, often going home to Rosemary or Beth to moan about our lack of progress.  We often managed to indulge our common interest in theatre, especially on those occasions when Beth or Rosemary made the transatlantic trip.  Personal highlights in the early years were year-long sabbaticals for the whole Hill or Weir family in Raleigh or Edinburgh.  Once the children had grown, we were able to explore new places together: Orkney one year and Alaska another.

In spite of our moaning, we did on occasion make some progress, bookended by “Effect of mating structure on variation in linkage disequilibrium” in 1980, and “Variation in actual relationship among descendants of inbred individuals” in  2012.  Maybe not a great deal of variation in topic, but always immensely satisfying.  Bill’s deep intuition is well-known.  Coupled with his superb computing and algebra skills, and long nights of hard work, some good papers came from our weeks together.  A couple of them have even been well cited.  I’m very proud of our work, but much prouder of a long period of friendship and collaboration with the leader of our field.

Josephine Pemberton

My first ever meeting with Bill was at a Population Genetics Group meeting, a small annual UK conference which the Genetics Society regularly sponsors.  I gave my first ever PhD talk about my protein electrophoresis study of European fallow deer.  Afterwards, Bill found me out and explained, in the nicest possible way, that my interpretation of band patterns on gels was entirely wrong – he was of course completely right.

Perhaps not the best augury for the next meeting with him that I can remember.  Bill was head of the Institute of Cell, Animal and Population Biology (predecessor to the current IEB and IIIR) when I answered an advertisement for a lectureship and came for an interview.  This was a gruelling process, which we still follow, in which the candidates all meet each other and sit through each others’ job talks – even asking each other questions!  Before I had left the building, Bill was kind enough to invite me into his office and offer me the job.  I was thrilled and have not applied for any other job since.

Exposure to Bill and the field of quantitative genetics, which was barely taught to undergraduate biologists in most UK universities at the time (and I suspect still isn’t), led myself and colleagues to an interest in the topic in the wild animal populations we were studying, including the red deer on the Isle of Rum and the Soay sheep on St Kilda.  Having recovered pedigrees, we were able to use techniques derived by animal breeders, notably the ‘animal model’ to investigate the genetics of complex traits, and how they respond to selection, in natural populations.  The influence has not stopped there: Edinburgh has remained an epicentre for quantitative genetics, both in humans and farm animals, and we evolutionary biologists have continued to benefit from the latest developments across the field.

The lecture slide I will forever associate with Bill depicts cross sections of two plucked broiler (meat) chickens from control and selection lines, said to have been fed the same diet.  The selected chicken was huge compared with the control.  Bill revelled in the power of selection in farm animals, and even in failing health was very excited by the gains due to the latest technique, genomic selection.  Personally, I am a bit squeamish about the welfare aspects of where this selection has taken farm animals to, but there is no doubting the fantastic science done along the way when selecting for milk production and broiler growth, and breeding objectives are much more attentive to welfare issues today.

Bill was a fantastic mentor, always happy to give advice on a manuscript or grant proposal.  He commented enthusiastically on a draft proposal for a grant I hold right now, I am just so sad has not lived to see its results.

Photo: Graham Plastow, 1992, China

Chris Haley

I met Bill for the first time when I arrived in Edinburgh to take up a post at the Animal Breeding Research Organisation (ABRO) in 1984.  As others have said, Bill’s farming background meant that the application of quantitative genetics to livestock improvement was one of his interests.

Bill provided great support to the directors of ABRO (Roger Land when I arrived, and later Grahame Bulfield once ABRO had evolved into the Roslin Institute) and sat on the Director’s Advisory Group for many years.  Bill was also a great support to me too as a relatively junior scientist, despite the occasional gentle ribbing as my education in quantitative genetics had all been in Birmingham, which some years earlier had been great rivals of Edinburgh in the field of quantitative genetics.

Bill gave me my first experience of co-supervising a PhD student and soon inveigled me into teaching (unpaid!) on the MSc in Animal Breeding.  Later on, we imported Meishan pigs from China in order to study the causes of their high litter size and Bill joined a small party of us on a trip to China to discuss animal breeding and look at pigs.  We visited Beijing, Harbin and Shanghai and Bill was the star turn of our visit of course, but typically joined in as just one of the team.  Bill treated us to a trip across the river in Shanghai (I think it cost about 5p each at the time), led the karaoke in Harbin and generally enjoyed the hospitality and good (and sometimes extraordinary) food on the trip along with the rest of us.  At the end of the day the Meishan pigs we imported to Edinburgh proved more influential in underpinning our genome mapping and QTL studies than for their reproductive abilities.

At an early stage of the genome studies Bill was asked how many genes might be found to influence the typical quantitative trait.  “All of them” came the reply from Bill, and this prediction has since been shown to be more-or-less the case.  Bill never lost his interest and enthusiasm for quantitative and population genetics and their applications.  He was always there to support the science and its practitioners, turning out for meeting and seminars however early or late in their careers were the speakers.  Bill’s support, insight and friendly questioning and camaraderie is greatly missed.