Non-genetic Inheritance, the Dutch Famine of 1944-45 and Operation Market Garden: Antony Beevor’s book 'Arnhem'

It is not often I get the chance to write a science article combined with a book review.

I have used the Dutch Famine in the winter of 1944-45 to illustrate talks on intergenerational maternal effects* for the past twenty-five years. For those unaware of this tragic ‘natural’ experiment, individuals who were in utero during the famine were found to be at increased risk of metabolic and cardiovascular disease when adult and of cognitive decline with age. The important finding was that these conditions were also more prevalent in the next generation—the children of those children who were first affected.

Inheritance other than through maternal and paternal genes is now the hot topic of epigenetics. However, there are all sorts of possible mechanisms by which these effects may work. I use epigenetic in the wide sense of any non-genetic effect of mother or father on the phenotype of their offspring. Unfortunately, the molecular geneticists have defined the term more narrowly to mean an effect on the chromosomes, i.e. by activating or deactivating the genes. Confusion therefore abounds and we can have an epigenetic effect in the widest sense that is not an epigenetic effect in the narrowest. 

Research on the intergenerational effects of the Dutch Famine continues. The mechanism or mechanisms of the epigenetic, in the wide sense, effect(s) remains controversial but the important point here is that the phenomenon itself—long-term deleterious effects on the health of individuals one or more generations down the line from those originally affected, is a solid observation and one that has from tragic circumstances provided vital insights into the developmental origins of health and disease.

Given the importance of the Dutch Famine to the biological word I was surprised when I read Antony Beevor’s book, Arnhem, late last year that while he described the appalling suffering and bravery of the civilian population of the Netherlands after Operation Market Garden in September 1944, the long-term effects of the Dutch Famine only made a footnote and then only in relation to the incidence of schizophrenia in girls born to women who were pregnant during the famine, along with an inaccurate interpretation of the results of eating tulip bulbs or wheat in relation to coeliac disease.

The Famine came after the failed Arnhem Campaign and a railway strike in support of the Allied effort as a direct result of military action and deliberate retaliation by the German occupiers on the civilian population. Rations in the western region of the Netherlands, including Amsterdam, were reduced to over the months to reach a low of between less than a quarter to about one-third of the required energy intake per day. Deaths caused directly by under-nutrition were estimated as 18,000. In the late stages, a deal between the German occupiers and Allied Forces was done which allowed air drops of food by the Royal Air Force, Royal Canadian Air Force and U.S. Army Air Force in return for not bombing German positions. Proper relief and recovery only came after the Germans surrendered in the west on 4 May 1945.

I learnt a lot from Beevor’s book, the effectiveness of the Nottinghamshire Yeomanry (Sherwood Rangers) and the success of the British Firefly tank (a British 17-pounder anti-tank gun mounted in the turret of an American Sherman tank), for example. Beevor, as other have in the past, comes down heavily on the British generals and air marshals and their staffs involved in planning and executing Operation Market Garden—the daring bid to get into northern Germany by crossing the Rhine and thus bringing an early end to the War. The Americans also wanted to see their airborne forces used, almost come what may. Landing zones chosen by Royal Air Force planners were too far away from the vital bridges but the planners were not over-ruled. There was simply no slack in what was an already inadequate but ambitious plan. Every aspect had to go well and to time. But it didn’t. Beevor has nothing really new to say here but every work on Arnhem brings forth a barrage of criticism from those armchair generals who think Montgomery could do no wrong followed by a counter-blast from those who think the field-marshal could do no right.

Strategic failure though should cast no shadow over the often brilliant military tactics employed by units and individuals in the field and it is this aspect that Beevor captures in his account of Operation Market (the air-drop to take the bridges including the final one at Arnhem) and of Operation Garden (the race by land forces to reach those dropped by air). However, the book suffers from a dearth of maps. There are maps but many more are needed, containing all the place-names mentioned in the text, in order for the narrative to flow. I have noticed that professional historians seems loathe to illustrate books and talks as part of the narrative. They seem to prefer to rely on the written or spoken word with a few illustrations thrown in at the end. With complicated stories of simultaneous actions in an operation like Market Garden, the reader can easily be confused about what is happening to whom and where. This is where a good book editor, playing the part of the average reader, is essential to inject a greater degree of clarity.

*’where the mother makes a contribution to the phenotype of her progeny over and above that which results from the genes she contributes to the zygote’.

Beevor A. 2018. Arnhem. The Battle for the Bridges, 1944. Viking.

Protein deficiency in early life. Experiments from 1960s Hong Kong

When I was writing the post of 8 March on the classic experiments in malnutrition and the intergenerational effects that ensued, I could not help thinking I was vaguely aware of earlier experiments that also explored the effects of a shortage of protein in the diet on a rat’s ability to navigate. I then realised who was doing it and where but I had no idea of the background or the outcome. It was actually in the next room of the animal house we occupied at the University of Hong Kong (it was air conditioned!) and just getting started on it by the time we left was the new, and first, Professor of Psychology. He was known then as John Dawson. I only spoke to him a couple of times but I had him down as a good guy since he spoke in terms of evolutionary psychology. But what was he doing and why?

I knew for that he was using the colony of rats in the Department of Zoology, an inbred strain founded from animals flown in from the University of Sheffield about eighteen months earlier*. I also knew that the zoology workshop (brilliant with perspex constructions) had built the test maze.

John Binnie-Dawson in 1969
from a family tree on ancestry.com

From the university newsletters that arrived over the years (long discontinued) I realised that the John Dawson we knew was being referred to as Professor J.L.M. Binnie-Dawson. Therefore, in tracking what he did I had to use the two names since I discovered he published under both.

It is clear that he had observed the feminising effect of kwashiorkor, the result of extreme protein deficiency after weaning, on children in West Africa. Dawson had worked in Sierra Leone. From his publications it is also clear that he was interested in differences between the sexes in spatial ability and so the two fields were brought together in studying effect of protein deficiency and sex hormones in rats.

I have not read the papers, having been content to see if my memory was correct but it seems that he pulled the whole story together in a paper in Psychologia in 1984 of which this is the published summary:

The author presents empirical evidence, mainly from his own research conducted from 1963 to 1975, to support the biosocial hypothesis, which argues that the normal sex difference between males and females in spatial ability has a 2-way sex hormone basis. This higher level of male spatial ability is also held to be biologically adaptive for the human group: In subsistence hunting societies, the male must generally be able to hunt food and locate water to ensure the survival of the group. This hypothesis also postulates that the actual level of male spatial ability in a particular biological subsistence environment will be influenced by the spatial requirements of that environment. Three specific studies are reviewed: (1) a study to determine whether Arunta individuals living in the semi-desert environment of Central Australia have developed high spatial ability and a permissive social system, as contrasted with the strict group orientation of West African Temne rice agriculturalists, who do not need spatial ability to grow and accumulate rice; (2) a study of the effects of the Kwashiorkor-induced endocrine dysfunction and feminization of males on the development of feminine spatial ability; and (3) a study using rats to test this suggested endocrine basis of spatial ability under controlled laboratory conditions. It is concluded that these biosocial studies have provided extensive evidence for the biosocial hypothesis.

Other research interest included handedness, as well as a number of other areas in cross-cultural psychology, much of relevance to the people of Hong Kong.

While in Hong Kong, he was instrumental in proposing and then hosting in 1972 the inaugural meeting of what became the International Association fo Cross-Cultural Psychology. He was its first Secretary-General and later its President.

John Lewis Mervyn Binnie was born in 1930 in Sydney. According to genealogy websites the name Dawson was that of his paternal step-grandfather, Edwin Dawson, who adopted him after his father died and shortly before his mother died. This is the name he published under until 1980 when he changed his name to Binnie-Dawson.

Before he arrived in Hong Kong, he published from Edinburgh in the early 1960s where he was Research Lecturer in the Department of Social Anthropology; it seems it was while based there that he worked in Sierra Leone. He also served as a Lieutenant in the Royal Navy Reserve. Later in the 1960s, he was in the Department of Psychology at the University of Sydney. It was from there that he was appointed to the new chair in Hong Kong.

John Binnie-Dawson retired in the mid-1980s to Kingswear in Devon. He died in Torbay Hospital on 29 December 1987, aged 57.

John Binnie-Dawson was one of a small group who during the 1960s lifted the University of Hong Kong from being a largely teaching institution to one recognised internationally in research and scholarship.

…And he was another to demonstrate how important it is to be given a good start in life.

*The rats provided a good source of income for the department under a wheeze devised by John Phillips (1933-1987) (FRS 1981). Excess were preserved in large numbers and charged—in advance—to the ‘A’ level Examinations Board (then run by the University) against their possible use in practical examinations. The charge per rat was not small.

Binnie-Dawson, J. L. [1984]. Bio-Social and Endocrine Bases of Spatial Ability. Psychologia: An International Journal of Psychology in the Orient 27: 129-151. 

Malnutrition: Classic experiments from the 1970s—and what happened next

John Waterlow at 93 (from Millward, see below)

I was reading the recently-published biographical memoir of John Waterlow CMG FRS (1916-2010) written by Joe Millward, when I realised I needed to look something up—the outcome of a conversation I had with John over lunch at his club, the Savile, a couple of years before he died.

He was one of the authors of a paper in an important series from the 1970s written by members of his department at the London School of Hygiene and Tropical Medicine. Most of his work had centred on the nature, treatment and consequences of infant malnutrition, notably in Jamaica from 1954 until 1970 when he returned to London.

During the 1990s I became interested in maternal effects, and especially those where some change in the mother affected not just her offspring but those of one or more subsequent generations, that is, intergenerational effects. The field, then largely ignored, is now the huge band-wagon of epigenetics (using the term epigenetics in its wide sense and not the narrow definition employed by some molecular geneticists who restrict its use—and thereby cause confusion—to the switching of genes on and off by methylation).

Some non-genomic effects are now known to be transmitted from the father as well as from the mother. Thus, parental effects can be defined as arising when the parent makes a contribution to the phenotype of its progeny over and above that which results from the genes it contributes to the zygote. Thus in subsequent generations, if the effect persists we have grand-parental effects and so on. The essence of such an effect is that it involves no difference in the genome—the basis of genetic inheritance.

Unfortunately, while Lamarckian in character, there are those who overstate the importance of epigenetics in terms of evolutionary mechanisms, arguing that the generally accepted neo-Darwinian orthodoxy should be changed. But intergenerational effects are usually restricted to a few generations and there is still on evidence that changes in phenotype during a lifetime can affect the DNA of the germ line. I regard parental effects simply as part of the genetically controlled and therefore subject-to-natural-selection suite of options available to a parent to maximise the chances of survival and reproductive success of its offspring.

There is now considerable evidence for important parental effects of considerable importance in such fields as human health and welfare, conservation biology, farm animal health and welfare and in plant sciences. But back to London and John Waterlow’s department in London.

To explore the effects seen in malnourished human populations, the group in London kept rats on a low-protein diet for 10-12 generations. There was a rapid change in size and shape of the animals which stabilised after two or three generations. Males were 40% lighter than well-fed controls; females 30%. There were changes in the weights of various organs except the eyes. Changes also occurred in the endocrine system, in the reaction of the rats to noise and in their ability to learn.

These findings were interesting and important in mimicking the effects in children born in malnourished communities but the effects of rehabilitation to a normal diet were even more so. Mothers previously malnourished were given a normal diet from about two-thirds the way through pregnancy or pups born to malnourished mothers were fostered from birth by well-fed mothers. Physical recovery was fairly rapid but still took 2-3 generations to be complete. However—and this was the point stressed to me by John Waterlow—complex behavioural deficiencies were still evident. In fact he said, as far as he could remember the behavioural effects were not followed up further because the animals had been passed on to somebody in the U.S.A. to explore the long-term effects further—but he could not remember who. Remember he was around 90 at the time of our chat.

It is what happened to that colony of rats that Joe Millward’s memoir prompted me to find out.

Janina Galler in 2016 (Wikipedia)
Photograph: MaynardClark

The work was continued by Janina Galler at Harvard. She described in a chapter of a book published in 2001 the background:

Approximately 30 years ago, I first began working with an important colony of rats that originated with R.J.C. Stewart at the London School of Tropical Hygiene. When Reg Stewart was forced to retire at age 65, I inherited the colony. The rats were then in their thirteenth generation of malnutrition, and I had the privilege of bringing the colony from England to the United States. This animal model was particularly relevant to human populations where malnutrition is usually not a one-time event, but rather a chronic, insidious process present throughout the life span and across generations.

I will not describe the test procedures for behavioural differences suffice it to say that with simple tasks there appeared no difference between well-fed and previously malnourished rats. Complex tasks were a different matter, with a clear deficiency in the previously malnourished animals. The differences in behaviour and ability to cope with the world were not confined to the pups. Mothers paid more attention to previously malnourished foster pups; they seemed to compensate for the inability of the young pups to find their way back to the nest (a standard test).

Janina Galler then compared the findings in rats with those in the long-term studies she was doing on the human population of Barbados in relation to the alleviation, treatment and long-term effects of malnutrition. Her study began in 1973 using data on every child born between 1967 and 1972 who had suffered malnutrition. At that time the incidence of malnutrition increased when the price of sugar decreased. While the physical effects were relatively quickly reversed, differences in behaviour (attention deficit and poor performance in the 11+ exam) were not and indeed persisted, just as in the rat, into, at least, the next generation.

Thanks to that work alongside and in collaboration with Sir Frank Ramsey (1926-2009) on the public health side, malnutrition has been eliminated from Barbados. But clearly the effects persist with the question being: for how long?

Those rats in the studies started in London by Reginald J.C. Stewart have certainly played an invaluable part in demonstrating the immediate and intergenerational—and sometimes cryptic effects—of malnutrition.

Galler, J. 2001. The early experience. In, The Origins of Creativity, edited by K.H. Pfenninger and V.R. Shubik, pp101-116. Oxford University Press.

Millward DJ. 2018. John Conrad Waterlow. 13 June 1916-19 October 2010. Biographical Memoirs of Fellows of the Royal Society 69, 429-448.

Stewart RJC, Sheppard H, Preece R, Waterlow JC. 1980. The effect of rehabilitation at Merent stages of development of rats marginally malnourished for ten to twelve generations. British Journal of Nutrition 43, 403-412.

European Hamsters and Maize Fields. A Nutritional Route to Local Extinction?

I have not seen a European Hamster (Cricetus cricetus) in the wild despite having twice looked for them at dusk in a hedgerow in Hungary where they had previously been seen—a classic case of, ‘if only you had been here last week’.

European Hamster photographed at Vienna Central Cemetery
by katanski (image used by Wikipedia)

Observations of the hamster in the wild have indicated they feed on cereal crops, tubers and invertebrates. Hamsters hoard large amounts of food in their burrows and they hibernate. There is evidence that after hibernation female hamsters do not emerge from their burrows before their first pregnancy of the season, relying until then on their hoarded seeds. During gestation and lactation they emerge and supplement their diet of seeds with fresh plants like clover and invertebrates such as earthworms.

Using females from a captive colony of European Hamsters, the group first studied the effect of four different diets after emergence from hibernation: wheat+clover; wheat+earthworms; maize+clover; maize+earthworms. Similar numbers of young were born with all four diets. However, there was a marked difference in their early survival. On the wheat+earthworm diet, 80% of young survived to weaning while on the other three diets survival to weaning was under 12%. Clearly, something was missing from the diet; protein at about 18% of the diet one would guess with the clover supplement (compared with over 40% with earthworms). However, there was a clear difference between wheat and maize in terms of survival of the young.

At this point, human nutritionists would be bouncing up and down to tell you that there is a key difference between wheat and maize: the content and bioavailability of niacin (Vitamin B₃ or nicotinamide) are much lower in maize and that, given the supply of earthworms rich in other nutrients that are relatively low in maize, the most likely nutrient lacking would be niacin.

The next season, a simple experiment was done. The maize+earthworm diet was compared with the same to which niacin was added. The results were clear. From a mean of less than two surviving until weaning with the maize+earthworm diet, supplementation with niacin increased that survival to over four.

The authors continued:

…regarding the European hamster, given that wild populations of this species are surrounded by 55–80% of intensively managed maize monoculture in Alsace (France), with sized field of 1.4 ha that corresponds to seven times the home range of a female, extremely low crop rotations (i.e. sometimes more than seven successive years of maize cultivated in the same plot) and high use of herbicides—dramatically reducing the proportion of adventive species—wild hamsters are undoubtedly constrained in their diet.

Now, you may ask, having demonstrated that nutritional deficiency can affect the survival of young hamsters to weaning, do the authors have any evidence that is a key cause of the decline of the species in France? In other words, do observations in the wild show the number of young emerging from the burrow, particularly from the first litter of the season, to be low?

The discursive paper (some of the data presented are irrelevant to the main story) which could have benefitted from a benignly dictatorial editor, raises several other questions. For example, nowhere I can see is any comparison made with data from the captive colony fed a presumably ‘complete’ diet. What was the litter size, survival to weaning etc. compared with the best performing experimental groups?

I must admit to being confused on the ‘normal’ litter size at birth of the European Hamster which is why a comparison with the breeding colony would have been informative. I have found value of 4-18 young, with numbers declining since about 1980³. I have also found an account that there is a strong genetic element determining litter size in captive colonies⁴.

The reduction in litter size after parturition seemed to vary from a gradual loss on the wheat+clover diet, for example, to a complete lack of lack of maternal care in most of the animals on maize+clover. It is well known that if nutrition is inadequate or other environmental conditions are not right, female rodents kill and eat their young thereby conserving their resources to try again when the chances of producing fit young are better. Indeed a great deal of effort in he past went into devising diets for laboratory rodents, including hamsters, of course, to overcome such problems. So to those of us who have kept rodents the lack of maternal care in the malnourished hamsters was to be expected. However, true to form that British comic which masquerades as a newspaper, the Daily Mail, was on form when it picked up this story:

There is evidence in Syrian Hamsters that the sex ratio is manipulated after parturition by maternal cannibalism in different environmental conditions⁵. Having some proprietorial interest in mechanisms controlling the sex ratio in rodents, in my case the selective reabsorption of embryos in the Guinea Pig⁶, it would be of interest to know the sex ratio of the young surviving to weaning in the different experimental groups.

Again back in the real world, how many animals could be affected by niacin-deficiency from eating cultivated maize as a staple in the wild, Tissier et al. wondered. American Black Bears with young, as opposed to bears without young, avoid eating maize and other cultivated crops. They also suggested that bees could be adversely affected by feeding too heavily on maize pollen.

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Updated 9 November 2019

1 Tissier ML, Handrich Y, Dallongeville O, Robin J-P, Habold C. 2017 Diets derived from maize monoculture cause maternal infanticides in the endangered European hamster due to a vitamin B3 deficiency. Proc. R. Soc. B 284, 20162168. http://dx.doi.org/10.1098/rspb.2016.2168

2 Tissier ML, Handrich Y, Dallongeville O, Robin J-P, Weitten M, Pevet P, Kourkgy C, Habold C. 2016. How maize monoculture and increasing winter rainfall have brought the hibernating European hamster to the verge of extinction. Scientific Reports 6 25531 doi: 10.1038/srep25531

3 Surov A, Banaszek A, Bogomolov P, Feoktistova N, Monecke S. 2016. Dramatic global decrease in the range and the reproduction rate of European hamsters Cricetus cricetus. Endangered Species Research 31, 119-145 doi 10.3354/esr00749

4 La Haye MJJ, Koelwijn HP, Siepel H, Verwimp N, Windig JJ. 2012. Genetic rescue and the increase of litter size in the recovery breeding program of the common hamster (Cricetus cricetus) in the Netherlands. Relatedness, inbreeding and heritability of litter size in a breeding program of an endangered rodent. Hereditas 149, 207-216

5 Beer AK, Zucker I. 2012. Sex ratio adjustment by sex-specific maternal cannibalism in hamsters. Physiology & Behavior 107, 271-276 doi: 10.1016/jphysbeh.2012.09.001

6 Peaker M, Taylor, E. 1996. Sex ratio and litter size in the guineapig. Journal of Reproduction and Fertility 108, 63-67

Nutrition, Exercise and Survival in an Extreme Environment: Scott, Wilson, Bowers, Oates and Evans of the Antarctic in 1911-191

As a result of my blog posts on the search for Emperor Penguin eggs that continued for decades in the 20th Century, I have been reading more and more about Scott, Amundsen and Shackleton and their expeditions. Every schoolboy knew the bare bones of the stories of the fatal end of Scott’s party and of how Amundsen got to the South Pole first. Indeed the memory of Captain Oates is evoked regularly but irreverently on the golf course as one of our party trudges off gloomily into the deep rough muttering to his companions, ‘I may be gone for some time’.

A few years ago I tried to get some impression of Scott from Fiennes’s book Captain Scott but I found it unreadable and quickly gave up. It was with some trepidation that I worked my way through hagiographies from the 1920s and 30s, the attempted demolition of Scott and all his works of the 1980s and 1990s, and the more balanced accounts of the 21st Century. The best is Apsley Cherry-Garrard’s (who was with Wilson and Bowers on the horrendous winter journey to the penguin colony at Cape Crozier) The Worst Journey in the World, first published in 1922. Before I started reading on this topic I was aware that the rations for the journey were, with hindsight, markedly inadequate for the energy expended in hauling sledges. I was not aware that scurvy was such a problem.

Scott's party at the South Pole, from left: Oates (standing), Bowers (sitting),
Scott (standing), Wilson (sitting), Evans (standing).
Bowers used a piece of string attached to the camera shutter

I then found the recent essay by Halsey and Stroud, 100 years since Scott reached the pole: a century of learning about the physiological demands of Antarctica, published in Physiological Reviews in 2012. That essay shows plainly just how short the rations fell compared to modern measurements of energy expenditure made by Stroud during man-hauling in Antarctica. It seems that the polar party (Scott, Wilson, Bowers, Oates and Petty Officer Evans) wasted away in their efforts to reach the next and then the next food depot containing daily rations that were themselves inadequate. Add to that the effects of lack of vitamin C, and the unseasonal extreme cold to which the polar party are now known to have been exposed, and it is fairly easy to see how they did not survive.

In 1992-93 on a one-way journey to the pole, Stroud and Fiennes were burning an average of 6,000 kcalories per day. Over a 10-day period ascending to the plateau they were expending nearly 11,000 kcalories per day—that’s over 7 times basal metabolic rate and that, of course, included periods of rest. The rate of expenditure during man-hauling the sledges (10-12 hours per day) must have been extremely high by any standard. By contrast, Scott’s rations provided 4,200 kcalories per day on the ice-shelf and 4,500-4,600 on the summit.

Halsey and Stroud take into account the various factors that would have affected the polar party and the deterioration in their condition that became manifest after those chosen not to reach the pole turned for the journey home across the Antarctic Plateau, down the Beardmore Glacier and across the ice-shelf. Extreme cold, inadequacy of food and water, lack of vitamin C, sleep deprivation and high altitude must have all contributed to the steady and vicious circle of decline of all members of the party, starting with Petty Officer (to distinguish him from Lieutenant Evans—see later) Evans, then Oates and finally Scott, Wilson and Bowers.

I had not previously realised that the polar plateau is so low in oxygen; the partial pressure is only about 510 mm mercury, 30% lower than at the coast and lower than would be predicted from its average altitude of 2,300 m. The effective altitude in terms of the partial pressure of oxygen is about 2,800 m (over 9,000 ft). About 1 in 50 present-day travellers to the Amundsen-Scott Research Station suffer chronic altitude sickness.

Adélie Penguin and chick. Brown Buff, Antarctic Peninsula
26 January 2005

In reading Halsey and Stroud’s account, a few questions came to mind. Firstly, how long does it take the appetite to increase and the gut to adapt and thereby process the amount of energy-dense food needed to match the very high expenditure? Or, if indeed, given the combined effects of cold, altitude and exercise, can any such adaptation be sufficient? Halsey and Stroud noted that some individuals in Scott’s expedition could not  absorb a high-fat diet and that even though they must have been in a state of negative energy balance by Christmas Day 2011, Scott and Wilson could not finish their special dinner. But I can see why those who could not take a high-fat diet did not persist in order to see whether they could become adapted to it; diarrhoea, which a number in the expedition suffered at various times, at an average summer temperature of -25°C does not bear thinking about.

Secondly, what was the importance of the lack of vitamin C on their survival. My impression is that it was more important, perhaps, than some commentators, but not others, have argued. Petty Officer Evans’s initial decline appears attributable to scurvy, from the malaise and lethargy to the lack of healing. In this respect, the condition of Lieutenant ‘Teddy’ Evans (later Admiral Lord Mountevans), one of the Last Supporting Party which turned for the trek back to the coast on 4 January 1912, is worth noting (Halsey and Stroud concentrated on the five members of the polar party). He became ill, clearly of scurvy, with obvious signs by 22 January and only got back to recover because of the truly heroic efforts of his companions, Petty Officers Crean and Lashly and then the medical care given by Atkinson. Lieut. Evans and Petty Officer Evans (according to the reference to Fiennes for the latter in Halsey and Stroud) were averse to eating raw or nearly raw meat, unbeknown to them their only source of Vitamin C. However, the concentrations of Vitamin C in muscle meat are very low any my guess is that lightly-cooked meat from the ponies killed and left at their supply depots would have provided the merest smidgeon of ascorbate. Much has also been made of the absence of the classic clinical signs of scurvy in the polar party but there could well have been subclinical effects at work. In trying to find evidence on the latter I have been bedevilled by the plethora of claims from the dietary supplements industry, quacks and conspiracy theorists.

But there is more that can be added to this story. Dogs were used by Amundsen and by Scott, and ponies by Scott. Neither species needs exogenous vitamin C but both were underfed. The dogs were often driven, like the ponies, to complete exhaustion*. Amundsen saved his men from the fate of Scott’s man-hauling party at the cost of 41 of his 52 dogs used to pull the sledges to the Pole and back.

Halsey and Stroud conclude their essay by considering whether current physiological knowledge and technological advances would protect present-day man-haulers on a similar journey to that nearly completed by Scott in 1911-12. They conclude that they would not:

…the return journey to the South Pole from the Antarctic coast is only just within reach for the most capable of people. The four-month summer window each year, during which man-haulers must inevitably pull insufficient food in environmental conditions that conspire to induce rapid wasting, today still represents an enormous, potentially life-threatening physiological challenge.

While Halsey and Stroud provide a cogent explanation for the gradual decline of the polar party with time, I think they could have made more of their statement:

This cycle would have been accelerated during the final weeks both due to dehydration because of reduced resources to melt water and due to the unusually cold temperatures that they suffered during February and March; these would have served to further decrease pulling power, and increase the energy costs of sledge-pulling due to the friction of snow when below around 􏰀30°C 

Susan Solomon's† analysis of the weather records to me at least indicates the reason for the failure of the polar party (except of course for Petty Officer Evans who had already died, and possibly for Oates who already had, but did not report, frostbite that eventually limited his mobility) to reach safety. On the Ross Ice Shelf the weather was very cold, much colder than a few weeks earlier and much colder than average. Apart from the direct effect of the cold, the deterioration in the surface conditions meant that the huge effort of hauling a sledge did not translate in the coverage of sufficient distance each day. As frostbite in Oates and, eventually, Scott, supervened, the vicious circle of decline accelerated rapidly.

All writers on the fate of the polar party are left with the question of whether Bowers and Wilson could have survived had they left Scott in the tent who by then had a badly frost-bitten foot. I think the odds were on their survival, heavily in the case of Bowers, slightly less so for Wilson. Why they did not opt for a push to the depot is, though, a question best left to those with expertise in group psychology. My reading of it is that both found it impossible to leave Scott.

The relatively rapid end to the hopes of Scott and his party is well summed-up by Susan Solomon and Stearns in their concluding remarks to their paper in PNAS:

The observations of the extremely cold temperatures reported by Scott and his companions in March of 1912 do not imply that these frigid conditions alone caused their deaths. Indeed, one man perished before these challenges were encountered and another was already suffering from frostbite, as has been noted. But the unusually cold temperatures that prevailed over an extended period of several weeks substantially contributed to the tribulations faced by Scott and his team during the final stages of their battle for survival. In spite of their plight, the party continued to record the scientific data that provide key information regarding their fate. Those measurements show that they endured minimum temperatures more than 10°F lower than the average that can now be derived from multiple years of automated measurements for the period from February 25 to March 19 near 80°S on the Ross Ice Shelf. On some particular days in March, the daily minimum temperatures in 1912 were more than 20°F colder than the climatological average. These conditions likely contributed to frostbite and extreme fatigue in the men, as well as to the friction of the very cold snow surface that amplified the physical demands of the strenuous task of man-hauling their supplies by sledge, and thereby slowed their progress. Scott and his last two companions died near the 29th of the month, after enduring what might be dubbed “the coldest march.”

On reading the various suggestions—which often turned into assertions—of the causes of the loss the the polar party, writers have tended to promote a single cause while dismissing others. My firm impression is that it what was not a case or either/or but of a combination of circumstances that formed the perfect storm of a positive feedback loop, with the weather accelerating that final phase, and the descent, to mix metaphors, into a never-ending bottomless pit.

†The Coldest March. 2001. Yle university Press. Solomon S & Stearns CR. 1999.On the role of the weather in the deaths of R. F. Scott and his companions. Proceedings of the National Academy of the USA 96 13012-13016

*In this respect it is interesting to note the studies on Alaskan sled dogs covering 490 km in a race over 70 hours at -35 to -10°C; their energy expenditure was an enormous 11,200 kcalories/day. http://www.ncbi.nlm.nih.gov/pubmed/9401699

South Shetlands. Livingston Island from Half Moon Island
27 January 2005