Histories of Stickleback Research - Tom Reimchen

Retrospection - by Prof. Tom Reimchen (University of Victoria, BC, Canada)

I was a second year undergraduate student at the University of Alberta in 1967 and interested in evolution but indecisive as to majoring in biology or geology. Students were given an opportunity to assist graduate students in summer projects.  I applied with Ric Moodie who was doing his PhD on Haida Gwaii (then called the Queen Charlotte Islands) studying the evolution of a giant black stickleback at Mayer Lake (I had read about stickleback in the journal Evolution). Other students applied for this position as well but I got the job. Ric later told me later that I was the only applicant who expressed no interest in sport fishing but a strong interest in evolution, so he hired me.

Ric’s research exposed me to methods of studying variation in natural populations. One of the techniques involved gill-netting cutthroat trout from the lake, extracting the stickleback from the stomachs and then measuring their size and various defense traits including the bony lateral plates on the side of the fish.  Ric got the impression that stickleback with seven lateral plates, which comprised the modal (most common) phenotype in the population, were captured by trout at a lower rate than stickleback with fewer or greater number of plates. He suspected that fish with different numbers of plates differed in their behaviour  and that this variation might account for the trends in trout stomach contents.  He assigned me the task of locating stickleback nests in the shallows of this large lake, after which we would capture the territorial males. Ric scored the males for nuptial colour, number of lateral plates on both sides, and body size. I did not really understand the rationale for this but it gave me the first exposure to the idea that individual phenotypes differing by a single lateral plate might be acting in different ways.

Over the three summers that I worked as Ric’s assistant, I found many nests and Ric scored many male stickleback. Ric thought it might be interesting to sample some of the neighbouring lakes to see if there were any other interesting stickleback. We hiked into the interior of the island across Sphagnum bogs and through forests using survey maps and compass bearings occasionally missing lakes altogether. One of these isolated lakes was much smaller than Mayer Lake, lacked littoral vegetation, and was appropriately named Drizzle Lake.  As we walked along the shoreline, speculating on whether there would be any fish in this small lake, I found a dead stickleback on the shore that looked superficially like the giant black Mayer Lake stickleback. I thought Ric had dropped a Mayer Lake stickleback to fool me into thinking that we had discovered another example of gigantism. He assured me that he had done no such thing. The genetic work years later showed that this was an independent origin of gigantism from that at Mayer Lake. On inspection of this dead stickleback, we could see that it had only 4 lateral plates, lower than the lowest plate count that Ric had ever seen at Mayer Lake, and we concluded (naively) that there would be minimal predation in the lake.

In my free time, I hiked to some additional unsampled lakes. One of these was the small Boulton Lake that lacked predatory fish. I put some traps in, waited a few hours, and when I checked them, to my absolute amazement, I found that most of the stickleback had no pelvis and many were missing some of the dorsal spines. Excitedly I returned to Mayer Lake to tell Ric who told me that such a stickleback had not been previously found in North America or Europe. We continued these lake surveys and got stickleback from 22 lakes, and many of the populations were distinctive to each lake. Such variability across such short distances exceeded the known morphological diversity of stickleback throughout Canada and Europe. The provincial environmental agency got wind of our ‘discoveries’ and asked us to recommend three lakes with unusual stickleback, one of which would be established as an Ecological Reserve for long term protection of the entire watershed and opportunity for research. We proposed Mayer Lake, where Ric was doing his study, Drizzle Lake, with the other giant stickleback in the north of the island, and Boulton Lake, which had stickleback with a missing pelvis. The government made a decision that Drizzle Lake would be established as an Ecological Reserve as it had the fewest administrative conflicts with other agencies. I was happy with this decision as the undisturbed lake was remote with no road access and had a small old log cabin near the lake that would provide a living place if I ever were to do research on the fish in this lake.

In May 1970, after completing my Zoology undergraduate degree at the University of Alberta, I convinced my friend Joe Rasmussen to come with me to Haida Gwaii for several weeks to sample more lakes for stickleback. During this trip, we discovered a small acidic bog pond with stickleback that were very unusual: not only were the lateral plates missing but the entire trunk was covered in a unique dinoflagellate parasite. We called this locality Rouge Lake as the nuptial colour of the males was outlandishly red;  it turned out with later studies to be also very atypical with respect to its genetic structure. On this expedition, I also made detailed collections of the Boulton Lake stickleback and saw that the relative expression of the pelvic girdle differed from one part of this lake to another, variation that I was later able to relate to spatial differences in the predation landscape.

During the spring of 1970, I started looking at samples of the giant stickleback from Drizzle Lake and noticed that some of the anterior lateral plates underlay the basal support structures for the dorsal and pelvic spines. One atypical fish had spines that were easily laterally deflected from their erect position. This fish was missing one of the lateral plates and it immediately became clear that the plates would buttress the dorsal and pelvic spines from lateral forces exerted during predator manipulation. I shelved my idea about this for several years, returning to it in the late 1970’s and  eventually publishing these observations in 1983 (Evolution 37: 931-946 - Figure 1).  

Figure 1: Relationships between lateral plates and spine supports.

Ric Moodie suggested I read EB Ford’s recent book on ecological genetics. This completely hooked me on studying adaptation and measuring selection in real time in the field. Fortunately, the University of Alberta had just hired Kennedy McWhirter, who was Ford’s colleague at Oxford. I took the courses Ecological Genetics and Population Genetics from Kennedy and this further cemented my interest in this emerging discipline. Kennedy encouraged me to do graduate work at the University of Liverpool in the UK where Arthur Cain and Philip Shepard had recently arrived from Oxford and were developing a graduate program in Ecological Genetics.  My subsequent four years in the UK resulted in a DPhil on the ecology and genetics of two sibling species of intertidal gastropods. This research greatly emphasized to me the importance of spatial and temporal scale for interpreting polymorphic variation within and among populations, an approach that would structure my subsequent studies on stickleback.

During my graduate program, I became friends with Paul Handford and Graham Bell who were both at Oxford;  over several years, we hatched an outlandish research plan in which we would go to Drizzle Lake on Haida Gwaii, and with our partners, live in an old log cabin, and undertake a multi-year study on the giant stickleback from the lake;  Paul would focus on the behavioural adaptations of the fish, Graham on the demography of the population and myself on predator-prey interactions in relation to phenotypic variability. Paul joined me on Haida Gwaii in late 1975 and 1976. Paul, who had just finished a post-doc on songbird dialect in the dry mountains of Argentina, did not take well to living in a small dark cabin in the midst of a wet and cool rainforest. Graham at this time had just finished his DPhil at Oxford and with Sue, his partner, initiated the process of immigrating to Canada. They got as far west as Edmonton where Paul was staying. It was clear that the logistics of potentially six of us living at Drizzle Lake were unreasonable. Paul and Graham got sensible and each got jobs, Paul at the University of Western Ontario and Graham at McGill University.

Figure 2a. Haida Gwaii with Drizzle Lake and research cabin (inset)

Not as well-anchored in reality, I took up residency at the Drizzle Lake cabin in 1976 (Figure 2a) and began the research program. I wanted to extend principles from some of my thesis work involving polymorphic traits and felt that sources of mortality and microsite adaptations might also be operating with traits that were continuous, such as lateral plates, rather than only discontinuous traits like the colour of  intertidal snails. With a $2000 support from the Ecological Reserves Unit (BC government) as well as similar amounts from Joseph Nelson at the University of Alberta, my partner Sheila Douglas and I equipped the 80 year old Drizzle Lake cabin with solar panels, a small wind generator, lights, microscopes as well as a ‘portable’ Osborne computer. In 1985, I was successful at getting an NSERC operating grant that allowed us to continue the research. 

Figure 2b. The lab at Drizzle Lake.

Our year round residency at Drizzle Lake from 1976 to 1985 and then summer residency from 1986 to 1990 yielded substantial evidence of repeatable temporal and spatial variation in the predation regime and the potential influence on the selection landscape affecting the stickleback population. Within several years, we had identified over 20 species of predators on stickleback in the lake, including 16 species of avian piscivores as well as resident salmonids (Figure 3). Most of these predators differed seasonally and they differed as to where they foraged in the lake and what size classes of stickleback they consumed. This high diversity of predators was not because the lake was a predator ‘hotspot’ but rather, evidence for this diversity emerged only as a consequence of the extended time duration (multiple years, multiple seasons) of the study. I summarized these data in a chapter for an Oxford publication that Mike Bell and Susan Foster put together in 1994. 

Figure 3: Predator assemblage at Drizzle Lake.

During the research program, Sheila and I circumnavigated Haida Gwaii several times and sampled about 800 lakes, ponds and streams, of which about 15% had stickleback, all of which were morphologically different from each other. Each lake offered a distinctive set of biophysical parameters (predators, diet, parasites, lake morphometry, spectra, etc) that had the potential of structuring the selective landscape (Figure 4).

Figure 4: Geographical survey of Haida Gwaii for stickleback with representative examples of habitats. Symbols: blue- stickleback present, black- stickleback absent

I was able to recruit some excellent students  including Carolyn Bergstrom on the role of asymmetry in defensive traits, Patrik Nosil on fluctuating selection and Mark Spoljaric on plasticity and predictability of body shape. We summarized the adaptive radiation of these 100+ allopatric populations in 2013 (Evolutionary Ecology Research 15: 241–269). Essentially, the selective landscape at each locality was defined by the relative importance of puncturing, compression or grappling piscivores combined with water spectra (reaction distance) and lake size (Figure 5).

Figure 5: Summary of major processes influencing the selective landscapes of Haida Gwaii stickleback defense structures. 

While it was clear to me that large differences in morphology, from fully-armoured to unarmoured among and within these populations, were adaptive; it remained ambiguous whether this represented genetic variation or plasticity. Axel Meyer had recently shown a major role of adaptive plasticity in jaw and skull morphology of central American cichlids, and such plasticity could not be ruled out for these divergent Haida Gwaii populations.  In 1989, I asked a new graduate student, Patrick O’Reilly, to examine the mtDNA of some of the most divergent populations of stickleback, including the unarmoured stickleback in small acidic ponds that I discovered back in 1970. It was reassuring that these unarmoured fish had a very distinctive mtDNA haplotype from most other stickleback populations (although it was similar to those in Japan), and were potentially relictual but this did not resolve whether the unarmoured phenotype was heritable. Subsequently, advances in DNA sequencing techniques allowed David Kingsley at Stanford to develop genome-wide SNP arrays for stickleback. My post-doc, Bruce Deagle, was able to use the arrays to show extensive genomic differentiation among the morphologically divergent populations, including three different lake-stream species pairs (Proc. Roy. Soc.  279 : 1732 1277), although this did still not rule out adaptive plasticity for divergence in morphological traits.

The repeated evidence for adaptive differentiation among and within populations would have more conceptual context if I had some  experimental data that allowed estimates of strength of selection and rates of change. In the mid-1980’s, I sketched out a plan to transplant limnetic giant stickleback with robust armour from a large lake into a small ‘barren’ fishless pond that differed in multiple ecological axes from the source lake. Ideally, I wanted to create a shift in the ecological theatre involving predation landscape (salmonids/birds to macroinvertebrates), trophic regime (limnetic/plankton to benthic/macrobenthos), spectral regime (dystrophic/heavily stained to eutrophic/non-stained waters) and water chemistry (lower to higher conductivity), expecting that subsequent generations might reveal phenotypic changes in the direction predicted from the differences I observed in the geographical surveys (Figure 6). Eventually, I identified four suitable barren ponds that generally met the criteria and in 1992 initiated the first of the transplant experiments. 

Figure 6: Transplant experiment from Mayer Lake with giant stickleback into a barren roadside pond.

The colonists successfully reproduced, yielding numerous generations that I sampled over time. In 2007, an outstanding student (Steven Leaver) began a graduate program with me and photographed and measured all the samples for meristic and metric traits. The results produced striking evidence for shifts in all defense and trophic traits over nine generations, all in the direction predicted. Some of the traits shifted in the first generation, consistent with adaptive plasticity, and other traits shifted across generations, more consistent with genetic changes (Biol. J. Linnean Society. 107:494-509 - Figure 7).  David Kingsley offered to do whole-genome sequences and I sent him 56 stickleback, including the source and transplant populations as well as representative stickleback from morphologically divergent Haida Gwaii populations. I needed a post-doc to do the genomics of these samples and fortunately Katie Peichel encouraged David Marques to apply. Remarkably skilled, David was able to complete the analyses of these fish identifying trait-specific genetic markers across the genome. These results gave novel insight into opsin evolution, as well as evidence for genome-wide shifts, all in the direction that were predicted by the genomic differences among the allopatric populations differing in ecological conditions. I feel this paper (Marques et al. 2017, Nature, Ecology and Evolution) has been the most substantive to emerge from my research program as it exemplifies the efficacy of natural selection and predictability of evolutionary changes among populations in remarkably few generations. This theme greatly contrasts to that of the famous orator, Stephen J. Gould, who concluded in 1985 that “….some geographic variation within a species is clearly adaptive, but much is a non-adaptive product of history."

Figure 7: Results of phenotypic shifts in the transplant population relative to the original colonists after 8 generations.

One of the important concepts  that emerged during our many years in the ecological theatre at Drizzle Lake and Haida Gwaii was the persistent reminder that inter- and intra population variability in defense morphology could not be reliably understood without context to age-specific sources of mortality. Presence of multiple species of piscivores that differed spatially and seasonally, as well as in their foraging and prey capture behaviour, creates an opportunity for diversifying selection on the traits that can differ spatially within populations and fluctuate over short periods of time. The tendency of researchers, including Ric and myself in the early formative years, to classify populations as either with or without predators was simply wrong. There were localities without predatory fish but there were none that lacked one or more species of piscivorous birds or macroinvertebrates (Figure 8). 

Figure 8: Routine morning observations of Common Loons foraging on stickleback at Drizzle Lake. Inset shows adult stickleback that escaped after capture by a Common Loon. These exhibit different lateral plate phenotype than uninjured fish and have elevated fitness relative to modal phenotypes (Evolution 2023, 77(4), 1101–1116).

Researchers, editors and reviewers still uncritically accept the flawed dichotomous characterization of the predation landscape (yes/no or high/low) despite the lack of evidence to warrant the dichotomy. While It is unlikely that  future researchers will embrace my approach -  living in an old cabin at the study lake for year-round observations on the abundance and behaviour of the predator assemblage,  I am optimistic for the future. New technologies, such as hi-resolution field cameras and e-DNA  will hopefully contribute to the understanding of the subtle but real temporal and spatial variability in selective landscapes, the motivation for the extended field studies on Haida Gwaii stickleback.

Sheila Douglas putting in the work.

Ole Kristian Berg - Memories

When a colleague and friend passes on, those of us left behind wish to honor them with some of our favorite memories. With Ole Kristian Berg, those memories are many and vivid. He was an excellent colleague and a genuinely wonderful man, who not only brought a creative originality to his (and our) research but also an undimmed sense of wonderment about the natural world, especially salmonid fishes (salmon, trout, and charr). Most importantly, he was someone who loved and lived life to the fullest, and never ceased to help us all remember how lucky we are to have careers and lives that can be so fun.

This post has memories from myself (Andrew Hendry), Sigurd Einum, Thomas Quinn, Trond Amundsen, Gunnbjørn Bremset, Jan Grimsrud Davidsen, Tor G. Heggberget, Sten Karlsson, Line Elisabeth Sundt-Hansen, and Eva Marita Ulvan - as well as (at the end) a collection of Ole's most cited papers. Note: many more remembrances from family, friends, and colleagues are HERE in Norwegian.

Ole Kristian Berg (11.04.1954 - 26.02.2023)

Andrew Hendry

I was a pretty green first-year graduate student in 1993 when I first met Ole - and I remained his close friend and collaborator for another 10 years. I worked with him four different years in Alaska (over the span of 10 years) and I spent months (over several trips) with his family in Trondheim, Norway. He was my first real international collaborator - and a more wonderful and personal entre into such collaborations could not have been imagined. Ole was an important and innovative scientist, with some truly influential work that you can peruse below. Ole was about so much more than science though, and he was such a fun and novel individual that capturing the spirit of who he was is perhaps best served by a series of personal anecdotes.  

Field work with Ole and his family

My most intimate experiences with Ole were during field work at a remote camp on Lake Nerka, Alaska, in 1995, 1996, and 2000. For much of that time, it was just me and Ole and Ole's family, and it was one of the most memorable and rewarding of times for me. We worked long hours, ate good food, and had lots to drink, while playing games and watching nature. And we laughed and laughed and laughed. And nothing made him laugh so hard as watching his young kids teach me how to swear in Norwegian. 

And then there was the electric drill. In 1995, Ole's main goal was to analyze the energy content of salmon and how it changed as they returned from the ocean to spawn in freshwater. To measure this energy content, we need to create a slury (or smoothie, if you will) of many many individual salmon. So Ole bought a Dewalt DW101 drill and hooked it up to a meat grinder. Powered by a generator, that amazing drill ran hours and hours each day making salmon smoothie. The result was a very influential paper (Hendry and Berg. 1999. CJZ 7:1663-1675). When he left Alaska, Ole proudly presented me with the drill, and it has been a valued household tool to this very day.

Ole's drill 27 years later.

I feel compelled to comment again about how creative Ole was as a scientist. We had written a series of papers about how natural selection influences female reproductive life span in salmon. That is, a female couldn't just lay her eggs and die because she had to live somewhat longer to defend her nest site against other females who might dig on top and thus displace and destroy the earlier female's eggs. Yet no one had a good estimate of this selection on life span due to "nest superimposition." Ole had the amazing idea to inject females with colored food dye, which would bind to the eggs. Then we could dig up the females' nests to see how many of the colored eggs remained depending on whether another female later dug her nest in the same spot. This study was one of my favorites to this very day (Hendry et al. 2004. PRSB. 271:259-266).

Ole digging up salmon nests (above) to look for dyed eggs (below).

Visiting Ole and his family in Trondheim. 

I have many memories of my trips to Norway, but two come immediately to mind and put a big smile on my face. The first was when we took a long hike up into the mountains to camp at a lake Ole and colleagues were studying. We arrived at dusk and crowded into a small one-room cabin, with beverages all round. Not having seen an outhouse, I eventually worked up the courage to ask "Where do I go to the bathroom"? Ole laughed and shouted "Oh, just go anywhere over in Sweden." It turned out we were right beside the cairns that marked the border with Sweden, and anywhere past that border was the outhouse. It was my first visit to Sweden. 

The other memory I want to share is how - when I spent several weeks staying with Ole and his family, they took great pleasure it introducing me to all of the traditional Norwegian "delicacies" - laughing at me as I tried them and telling stories about how Ole (and his kids) would weaponize food (mainly Surströmming) as practical jokes during military training (the whole barracks had to empty), at school (the police were called), and at athletic events (dropped on the opposing rowing team from a bridge above). Here is the menu and tasting notes that I generated from those days. Yes, they really cooked each of these dishes for me - mostly just to laugh at my reaction. 

Sigurd Einum

In remembrance of my dear friend and colleague Ole

It is now 30 years since I met Ole for the first time, I was a bachelor student in biology, and he was faculty. It’s funny how the teachers seemed old to me back then, he was only 38, and I’m now 50! Anyways, I already then noticed how he was able to establish a rapport with the students that few others did. I’m not sure how he did it, but I believe his rather informal manner and a good (or bad?) sense of humor was part of it. One of his more infamous pedagogic tricks was applied during lectures when he noticed students closing their eyes and appearing to fall asleep. He would then continue his lecturing in a normal voice while slowly approaching the unsuspecting student, and once there yell something really load and slamming his hands into the bench next to the sleeping head. Of course, he did this with a smile on his face, raising laughs, and it usually ended well. As another example, during a lecture on marine fish stocks in a class of about 100 students he, upon coming to a part about cod, got the students to participate in singing a kid’s song that describes components of the life-cycle and ecology of that species (Torskevise by Thorbjørn Egner). The thousands of students that experienced this probably remembers a thing or two about cod, and at the same time felt a bond to their professor that contributed to their motivation. While it is tempting to try to replicate this, I’m afraid that only someone with Ole’s personality can pull it off, and I would probably fail miserably.

Ole Kristian Berg in his element

When I joined our department in 2007 I came to know Ole as a colleague. He was incredibly helpful whenever I was having questions about how things were done in the department, and with respect to access to labs and equipment. We quickly initiated collaborations both with respect to teaching and science, and I have benefited greatly from his broad knowledge about, ecology, life and basically everything. In 2010 he invited me to join his expedition to Bear Island, which of course was excellently organized, well stocked with equipment, food and drinks, and required very little planning from my side. We also collaborated on our freshwater ecology course, and the annual field course at remote Lake Snåsa was always a highlight of the semester. I know Ole also appreciated these trips with the students, and he continued to participate on the field course after he retired. There we would teach coming generations of freshwater ecologists procedures for fish and plankton sampling and processing, water chemistry, and then at the end of a long day sit around the fire with a beer and watch the northern lights together. These moments will be deeply missed.

A good friend and incredibly generous and knowledgeable colleague has passed away, much too early. I had looked forward to further collaborations, and not the least more Christmas parties where he as usual was supposed to be responsible for the gløgg (mulled wine), and being the last one to leave the party. That did not happen. Instead, we will enjoy the good memories he has given us, and those are many! Ole continues to live on in the hearts of collaborators and students. My deepest condolences go to the family which has lost an amazing husband, father and grandfather.

Thomas Quinn

Ole (left) and Tom (right) in Alaska

Like all others who knew Ole Kristian Berg, I was shocked and saddened to hear of his passing, and extend my deepest sympathy to his family and friends. As sometimes happens in our profession, we became acquainted when I got an unexpected communication from him, indicating an interest in coming to meet and collaborate with me. Thankfully, I encouraged him. One thing led to another and 30 years ago, in the summer of 1993, he visited Seattle, stayed with me, and joined our field operations on Lake Aleknagik and Iliamna Lake, Alaska. The attached photo is from that year. I was immediately taken with his personal openness and friendly attitude, breadth of scientific ideas, and exceptional work ethic. Then, in 1995 and 1996 he came again, with his wife, children, and field technician, to work with Andrew Hendry, who was then my doctoral student. I was fortunate that a house across the street, owned by our neighbors and friends, Jim and Maxine Hinze, was vacant at the exact period when the Berg’s needed a place to stay. Otherwise, I am sure I would have squeezed them into my house, somehow! As always, he was lively, funny, kind, generous, and full of energy, but also full of mischief and tricks. Ole kindly invited us to a barbeque but then shocked us by revealing that he had smuggled minke whale meat into the US and that was what we were eating! Watching them all repacking their great volume of field gear among their bags to meet the weight requirements for luggage at the Seattle airport was something I will never forget.

Ole’s collaboration with Andrew Hendry resulted in a several important papers and a great boost to Andrew’s career, but it also provided an endless series of stories. The field camp where the Berg’s and Andrew were working, on Lake Nerka, was a long distance from the main field camp on Lake Aleknagik, which was accessible to stores for food, fuel, and other supplies. The Lake Nerka camp had what seemed like more than adequate food but in short order the unreliable old radio phone crackled with the news that they were running short of essentials. How could this be? Well, it seems that they ate in a week the supply of potatoes that would normally support a crew of that size for the whole season! Over on Iliamna Lake, the largest lake in Alaska, I will never forget wallowing in big waves in the middle of the night as we towed nets between two boats to sample juvenile sockeye salmon and sticklebacks. We barely escaped with our lives from the experience, but enjoyed a drink at 3 AM to celebrate our brush with death on the lake.

I raise a glass to a wonderful man – lively, loyal, experienced, wise, and kind.

Thrond Amundsen

Memories of Ole Kristian

It was so sad to hear that Ole Kristian had passed away so all too early. I’ve known Ole as an always supportive and friendly colleague ever since I started my job at NTNU, not so long after Ole was appointed himself, in the early 90s. I first and foremost think of Ole as a kind man, always interested, always supportive, always positive. These are qualities that don’t always thrive in modern academia but they mean a lot, and Ole’s kindness meant a lot to me.

For many years, up to Ole’s retirement and for longer than I can remember, I worked closely with Ole on our first-year course in Ecology, Behaviour and Evolution (BI1003). This is a special – and especially important – course for our department: it’s the first course for new NTNU students of biology, including lots of teachers and teaching assistants, and a large range of pedagogical tools and activities. In short, a cool course but a logistic nightmare to manage, requiring dedication ‘way beyond normal’. Ole put in enormous efforts and managed the course successfully for several years until his retirement two years back, to make it an enjoyable and successful course for students and teachers alike. Being the two old-timers of the course, Ole and I had many interesting chats on the smaller and bigger challenges of getting the course to work. I always felt that Ole appreciated my input and that of others and did his very best to make it a great course. Ole would have deserved much more praise for these efforts than he got. Last year, the course and its teachers were awarded the Teaching Excellence Award of the Faculty of Natural Sciences. Ole would truly have deserved to be part of the award-winning team – we who took over built the course on the foundation he laid down.

Ole was a true ‘fish person’, with a huge knowledge of fish biology and fish management. Other ‘fish people’ closer to his research can tell more about that then me. For me, who started dabbling with fish from a bird background, he was a rich source of knowledge and advice. And more importantly, he always showed a genuine interest and appreciation – he always had a kind and supportive word. I’m sure others can tell the same. To me, that meant more than he probably realized himself.

My last meeting with Ole was by accident, last fall, just outside the Natural Sciences building. I had only occasionally seen him since his retirement. Ole was in a good mood as always, and curious to hear about my stuff, including how things had worked out with my own group’s field work last summer (fortunately, for once, quite well!). On my part, I was curious how things were for him, and what he was up to at campus. Turned out he was on his way to talk to BI1003 students about how to present the projects they were about to complete, contributing as a ‘volunteer’. That’s typical of him – he loved that course, he loved engaging with students, and he was a very unselfish man, happy to help out when asked. On the private side, he told that he and his wife had spent the whole summer traveling Iceland, enjoying its splendid nature – and I believe culture, too. It sounded like they had had a great time up there, and we shared memories of Iceland’s natural riches.

When Ole has now so sadly passed away, that last meeting stands fresh in my memory, as typical of Ole – friendly, supportive, with a true love for nature and for educating the next generation about the value of nature. It makes me think that Ole lived his life to the full as a biologist, teacher, nature lover and family man until the very end. Even if that end came all too early.

Ole (left) was always happy - but never more so than when up to his wrists in fish guts.

Gunnbjørn Bremset, Jan Grimsrud Davidsen, Tor G. Heggberget, Sten Karlsson, Line Elisabeth Sundt-Hansen, and Eva Marita Ulvan

It is with great sadness we learned of Ole Kristian Berg's untimely passing. Most of us knew Ole Kristian from his time at the Zoological Institute at Rosenborg campus, where he devoted much of his research on the landlocked salmon (småblank) in River Namsen and River Mellingselva. It is especially our research collaboration on the småblank population in Upper Namsen that brought us together, where we mapped the status and distribution of småblank, as well as its unique genetical  and habitat use. Småblank was a natural study subject since Ole Kristian's father, Magnus Berg, was the first to describe the special salmon variant only found in the upper parts of the Namsen watercourse. Ole Kristian was very keen on preserving the original name of the landlocked salmon in Namsen, and it was therefore a great academic victory when "småblank" finally became the official nomenclature a few years back. Although småblank had a special place in his heart, there were many other areas of research that Ole Kristian worked on. Already in the 1980s, he focused on juvenile salmon that resided in atypical habitats, and together with graduate students, investigations were made in lakes on the west coast and in Namdalen, before later focusing on deeper lotic habitats in rivers in Nordmøre and Trøndelag. Ole Kristian was a pioneer in using modern analytical methods and was the first in Norway to conduct energetic analyses of juvenile salmonids in rivers such as River Homla and River Stjørdalselva. Many Norwegian fish researchers became interested in fish biology after Ole Kristian's lectures, and the number of students who have had him as a supervisor has gradually become extensive. In terms of personal qualities, we will especially highlight his good humor, infectious laughter, and unyielding optimism, and that he was very caring and generous towards his students and colleagues. His many antics during festive events at Rosenborg and the Natural Science Building are still being talked about, and we will never forget his performances with specially made dentures and glasses with special lenses. Ole Kristian will be deeply missed as a professional, colleague, and friend - and we will forever keep the memory of him in our hearts.

Ole's Most Cited Papers

Cuentos-Contos Week 3

For the final week of Cuentos/Contos, I present Dr. Bryan Juarez, Dr. Stepfanie Aguillon, Dr. Raul Diaz, Kiersten Formoso and a special interview with Dr. Melissa Guzman. 

Southeast LA and San Bernadino born and raised, Bryan, describes how his low-income background drove him to design novel mathematical approximations to tackle complex science problems (jumping in frogs), as an alternative to using expensive equipment that may have been financially inaccessible. He also explains how his Latinx background prepared him to spot genuine mentors and allies, which have now blossomed into solid friendship. Finally, Bryan touches on experiencing culture shock as a Latino in academia and how EEB departments can support their fellow Latinx academics. 

Stepfanie, a Texas-born, but Arizona-raised evolutionary biologist, tells us about how her immigrant roots influenced her work and school ethic. The importance of building community is discussed, especially with allies that understand DEI issues and the type of mentor she strives to be. Lastly, Stepfanie offers three important recommendations for making academic cultures more inclusive for Latinx students. 

Fervent herpetologist, Raul, remembers reading books on amphibians and reptiles at the local public library and knowing from childhood that her has going to pursue a career in herpetology. He also explains how his parents paved the way for success and supported him, despite not understanding his research interests. Lastly, Rauul argues that a diverse faculty team is th best way to attract Latinx students. 

Kiersten, a New York born but Jersey-raised vertebrate paleontologist passionately describes her reserach exploring land to sea [not sea to land!] evolutionary transformations. She tells us how she shakes off heightened self-awareness (as one of the few Latinx in academic spaces) and addresses barriers that keep Latinx from pursuing science careers. Despites these setbacks, Kiersten has also had many positive expereinces and ramains inspires to pursue a career as a tenure-track professor. 

Check out this special interview with Dr. Melissa Guzman!

To learn more about the featured scientists reach out via their emails or websites,

Bryan - Bryan H Juarez (bhjuarez.github.io) 

Stepfanie - Stepfanie M. Aguillon, PhD – Stanford Science Fellow (stepfanieaguillon.com)

Raul - The Diaz Laboratory – "We Study Weird" – Evolutionary Developmental Morphology of Reptiles (reptile-embryos.com)

Kiersten - Home & Blog | Formorphology

Dr. Melissa Guzman - Melissa Guzman |Ecological Data Science Lab (edslab.org)

To check out the full versions of all the Cuentos-Contos, follow this link. 

I hope you all can take away something from reading the cuentos/contos of so many brilliant scholars and people. Although I only shared the cuentos/contos of 13 Latino/a/x scholars, remember to share your own and tell your cuento/conto. You never know who is reading, and who will be the next, Ecologist, Developmental Biologist, Evolutionary Biologist, Astrobiologist, Microbiologist, Marine Biologist, Paleontologist, etc inspired by your cuento/conto. 

Cuentos-Contos Week 2

In week 2 of the Cuentos/Contos, I am pleased to share the cuentos of Daisy Flores, Eduardo Tassoni Tsuchida, Alonso Delgado and Maya Yanez. 

Daisy Flores, a San Diego local and marine biologist, tells us how her Latinx identity has influenced the way she approaches education in the US and abroad. Additionally, Daisy emphasizes how a strong support system encourages her to preserve in academia, even during tough times. Lastly, she provides a few suggestions to increase inclusivity in universities and departments. 

Eduardo, a biologist studying cell response to stress, reflects on how his Brazilian background has shaped his grad school experience. He touches on the importance of therapy and keeping up with family during the COVID-19 pandemic. Eduardo believes he is doing his part to increase Latinx representation by mentoring Latinx student and working in various programs and committers to promote inclusivity and community. 

Alonso (originally hailing from the San Fernando Valley), shares his academic evolution: from pursuing an aviation adminstration degree in community college to obtaining a BSc. to currently researching venom changes in off-sea anemones! He also discusses the hidden curriculum, mentorship in academia and why he started organization, "Latinx in Marine Sciences".

Geobiologist and Los Angeles local, Maya Yanez, recounts navigating academia as a first-generation scholar, including the terrifying moments when she found out her loans were denied and how the problem was resolved! She explains how acknowledging and embracing her identity as a Latina has shaped her academic career. Maya candidly addresses her plans for the future, the reasons why she is not considering a career in academia and suggestions on welcoming and retaining Latin students. 

To learn more about the featured scientists reach out via their emails or websites, Eduardo Tassoni Tsuchida - etassoni@stanford.edu, Maya Yanez - Mdyanez@usc.edu, Daisy Flores - dmflores@utexas.edu, and Alonso Delgado - Home | Alonso Delgado (delgado73.wixsite.com).

To check out the full versions of all the Cuentos-Contos, follow this link. Don't forget to view last week's cuentos/contos. 

And for now, Hasta luego! 

Cuentos-Contos Week 1

 In the Fall of 2021, I sought out to highlight the stories of Latino/a/x researchers generally in "Ecology and Evolution". With the support of Dr. Carly Kenkel, Dr. Oliver Rizk and Emily Aguirre, we were able to put on a series titled "Cuentos-Contos" (short stories in Spanish and Portuguese) to be shared to our Marine and Environmental Biology section at the University of Southern California. Now I am sharing these short stories to Ecoevoevoevo to share with a wider research community as I believe it is important to highlight researchers from similar backgrounds in academia as this space is often isolating. Throughout the next couple of weeks, I hope you feel inspiration, empathy and joy as every person details how their career, passion and aspirations intersect with their culture and identity. To start off, I highlight several talented scientists: Emily Aguirre, Ivan Moreno, Melody Aleman, and Dr. Suzana Leles.

Angeleno microbial ecologist, Emily, studies algal-bacterial symbiosis in the emerging cnidarian system, Aiptasia pallida, using genomic, culturing and microscopy techniques. In this cuento, she highlights her support system as a "non-traditional" student and discusses inefficient, outdated and harmful academic structures. Emily concludes by suggesting solutions for improving the academy, and transforming it into a space that truly supports talent, ingenuity and diversity. 

 Long Beach raised microbial ecologist, Ivan, studies microbes in extreme environments via genomics. He discusses the importance of a work-life balance as an underrepresented student (soccer and video games!) and how this keeps him grounded. Ultimately, Ivan believes that if he strives to be the best scientist and researcher now, he will be able to provide those same opportunities for others once he's an established academic.

Pennsylvanian marine microbial ecologist, Melody, breaks down the racial, social and class obstacles she faced as a Latina, on her way to grad school. She addresses the importance of utilizing the university's mental health resources, and how this has helped her cope with the global pandemic and anxiety. Lastly, Melody gives a shout out to her former/current mentors and encourages departments to support their Latinx students through more funding opportunities and access to genuine mentorship.

Brazilian oceanographer, Suzana, discusses he academic trajectory across the globe, and how she ended up building mathematical querying microbial food webs in Los Angeles, California. She addresses the supporting factors (and discouraging aspects) that allowed her to succeed and become a Ph.D., despite enduring hurtful experiences and how she continued on an academic track. Finally, Suzana provides helpful tips on building welcoming spaces for non-native English speakers!

To learn more about the featured scientists reach out via their emails or websites. Ivan -  imoreno[at]ucsd.edu, Melody - maleman[at]usc.edu, Suzana -  suzanaleles[@]gmail.com, Emily - Emily Aguirre (weebly.com). 

To check out the full versions of all the Cuentos-Contos, follow this link. 

And for now, Hasta luego! 

Within, among, or between?

I was recently surprised to learn from my students (I really appreciate that they spoke up about it) that some phrases I had been using were confusing - most specifically among-population variation.* This led to a discussion of the meaning of within, among, and between and how these terms are used in ecology and evolution (a microcosm of how they are used more generally). As the confusion appears to be more common than I thought, perhaps it is worth explaining the situation here.

To make this explanation clear, first imagine that you are analyzing a number of separate populations (e.g., humans in different populations) and that you have measured a particular trait (let's say body size) in a number of individuals in each of those populations. Note: this is not a random example, it is precisely what we did in a paper some years ago - McKellar et al. (2009). Below is a figure from that paper providing compilation of within-population variation (y-axis) and among-population variation (x-axis) measures (here the "coefficient of variation" - CV) within a large number of animal populations.

Within 

If you report a descriptive statistic for each population separately, those measures are within-population summary statistics. Thus, within-population variation is a measure of variation within each of those populations - as might be indexed in a variance or standard deviation or coefficient of variation of body size for each of those populations separately. You can then also calculate the average or variation (across populations) of those within-populations measurements. In this case, you use the various within-population measures you have calculated (e.g., the variance within each population) as data to calculate another set of descriptive statistics, such as the mean (across populations) of the within-population variance. 

I should note that, in some cases, one wishes to assume that these within-population measures are all estimating the same global (that is, shared across populations) within-population variance (or mean or whatever). In such cases, it can be assumed that populations with larger sample sizes (more individuals measured) are providing better estimates of that shared (common across populations) within-population parameter - and so the estimated average (across populations) of the within-population parameter is calculated by weighting the within-population estimates by their sample sizes. This is precisely what is done when one calculates a "pooled standard deviation." Of course, variation among the within-population estimates of the parameter are a measure of how much variation might exist among populations in those within-population parameters.

Between and Among

If you next report a descriptive statistic that examines trait variation across the populations, then you are in the world of between-population (if across only two of the populations) or among-population (if across three or more populations) estimates.** Typically, these estimates do NOT include variation within those populations. That is, you don't simply pool all of the individuals across all of your populations and calculate a single mean or variance - because this approach mixes within and among population variation.***

So, instead, the simplest approach is to take the within-population parameter estimates, such as the within-population means and variances of trait values for each of populations you measured, and use them as data points to calculate a new mean and variance. The first of these (the mean of the means) was mentioned above as it is the mean of the within-population means - and thus the "best" estimate of the trait mean within populations (assuming they are the same - or near enough as to make no difference). The second of these (the variance of the means) is a measure of among-population variation - that is, it is the variance among population means. It is the among-population variance.

Of course, the within and between population contributions to variation can be estimated together from an appropriate statistical model (e.g., nested analysis of variance) that appropriate partitions the variance between the different levels. Further, uncertainty associated within lower levels of the hierarchy (e.g.. variance within populations) can be propagated in some models (e.g., Bayesian) up to higher levels of the analysis (e.g., variance among populations).

I above noted that estimates of among-population variance should not include within-population variance. However, some analysis are interested in scaling the among-population variation by the within-population variation. The simplest way to do this is to divide the among-population variance by the within-population variance - and versions of this are seen in the estimation of parameters such as FST, QST, and PST.

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* When used as an adjective preceding the noun, you want to use a hyphen (e.g., within-population variation) but, in other situations, you don't want to use a hyphen (e.g., the variation within populations). 

** The terms "between" and "among" are also used more generally in writing when you are discussing analyses that are contrasting only two populations (between) or when you are contrasting more than two populations (among).

*** As an aside, this is one of the issues encountered when performing PCA on data from multiple populations simultaneously. That is, PCA (as opposed to DFA) ignores population identity and thus generates axes that combine within-population and among-population variation, which can generate considerable biases. Note: I am not saying PCA can't be used in such instances - but rather that it should be used with caution.