Description                                             

The Faculty of Health Science and Technology has an opening for one full-time post-doctoral research fellow in Biology at the Department of Environmental and Life Sciences in the field of quantitative aquatic ecology, with a focus on fish movement behaviour and machine learning techniques to predict how an eel will move in a river as a function of the surroundings.

The River Ecology and Management Research Group (RivEM), a research environment within the Department of Environmental and Life Sciences at Karlstad University, conducts both basic and applied research in and along rivers and lakes and their surrounding landscapes. The research group is interested in the sustainable use of natural resources in watersheds, working for solutions to environmental problems that benefit both society and nature. Areas of research addressed by RivEM include river connectivity and the effects of hydropower, aquatic- terrestrial interactions and habitats, winter ecology under global climate change, endangered species such as unionid mussels, conservation biology and social-ecological research relating to river regulation and recreational fishing (www.kau.se/biologyhttp://www.nrrv.se). Within many of these topics, research is conducted in collaboration with stakeholders from industry, administrative agencies, interest organizations and landowners. You will be employed as a post-doc in Biology and the employment is a temporary full-time position for two years, with a possible one-year-extension, and may include teaching or other academic duties in the Department.

Duties

Hydropower dams impact riverine connectivity, deteriorating life-cycle performance of many species as they obstruct the migration routes for organisms between areas used for feeding, reproduction and survival. To prevent further global declines in fish biodiversity, identifying and understanding key fish-environment interactions is crucial for successful conservation strategies. This is especially so for the European eel (Anguilla anguilla) whose population has declined 95% in the last 25 years and is currently categorized as critically threatened. The exact reasons for the decline in the eel population are not known, but a combination of effects from over-exploitation, new pathogens, climatic changes, and habitat degradation including fragmentation are believed to be the most probable causes. Adult seaward-migrating eels are more vulnerable to passage through hydropower installations than many other fish species due to their elongated body length. The need for mitigation and effective strategies for increasing survival of out-migrating eels in regulated rivers is thus obvious.

Concurrently, inferences of cost-effectiveness and relevance of mitigation and restoration efforts demand detailed knowledge of the specific processes that result in elevated migrating fish mortalities. In the case of eels and power plant-induced mortality, there is a very simple solution: prevent the eels from entering the turbines and restore river connectivity. This solution demands knowledge-based development of optimized solutions that should be rooted in in-depth knowledge about eel behaviour and ecology. However, at present there is a lack of detailed knowledge on how to create sustainable solutions to do this and at the same time prevent loss of hydropower electricity production. The reason being a lack of a fundamental understanding on how the eel behaves as a function of the hydrological environment.

Our project aims at developing a statistical framework that provides an understanding of how different key hydrological variables affect eel swimming behavior, and machine learning techniques to predict how an eel will move in a river as a function of the surroundings. The statistical model framework will be developed based on existing models for smolt behaviour, developed by members of the proposed project. This will provide a generic and general understanding of the correlation between hydrological variables and the swimming behavior of eels during downstream migration. This result will then be used in a machine learning model to predict eel downstream migratory routes. The results of this project are expected to help in the development of mitigation solutions for eels to strengthen the European eel population and consequently contribute to the restoration of the ecological dynamics of freshwater aquatic systems.

The successful candidate will work within RivEM, in close collaboration with experts from the Norwegian Institute for Nature Research (NINA) and Vattenfall R&D, with end-to-end data science projects which require leveraging state-of-the-art machine learning techniques, statistical methods, and other advanced analytics tools so as to deliver solutions for fish conservation. Through this role, you will have the opportunity to collaborate and develop your career together with experts within biology and other experienced data scientists in the project. In addition, silver eel telemetry studies in the field to study eel swimming behaviour and hydrodynamics can come into question. The applicant is expected to be active at the university and participate in the research environment.

Requirements

To be eligible for the position, applicants are required to hold a PhD (or to be completed before the decision about the employment is taken) in quantitative ecology, statistics, computational ecology, or related fields. The candidate must have completed the degree no more than three years before the last date for applications unless special grounds exist. Older PhD degrees can be taken into account when there are special reasons, such as leave due to sick leave, parental leave, clinical service, positions of trust within unions or other similar circumstances. Excellent oral and written communication skills in English are required.

To apply for this role, visit, https://kau.varbi.com/en/what:job/jobID:674172/

Felix Eissenhauer, a PhD student at the University of New Brunswick, will be giving a seminar entitled “Ecology of the American eel (Anguilla rostrata) in a large tidal and hydropower-regulated river” over Zoom  https://kau-se.zoom.us/j/65816884688 at 13:15 CET on December 5, 2023.

Felix’s work focuses on the ecology of the American eel in the Wolastoq River, a large tidal and hydropower-regulated river in Canada. He is studying how a hydropower dam affects the recruitment of eel elvers and using mark-recapture methods to assess their population size and demographics. Further, Felix uses acoustic telemetry to study the depth and thermal habitat use and the seasonal migration behaviour of yellow eels in the Wolastoq River.

You are welcome to join this seminar

Louis Addo, a doctoral student from the Department of Environmental and Life Science, biology, will give a 50 percent seminar on his doctoral research work. The opponent will be Paul Hart, Professor Emeritus, from the University of Leicester, UK. Date: November 16 at 13.15 CET. Location: 5F423  and Zoom: https://kau-se.zoom.us/s/65816884688. You are warmly welcome!

Stephen De Lisle (Associate Senior Lecturer)

Stephen’s research focuses on understanding the causes and consequences of natural selection, specifically in sexually reproducing populations. In this seminar, he will argue the following points: sexual dimorphism, or within species differences between the sexes, are a pervasive form of biodiversity, often with ecological importance. He will then present a series of experiments from salamanders and flies that test for a role of direct ecological causes of sexual dimorphism – that is, ecological character displacement between the sexes. He will then go on to explore the theoretical and realized consequences of sexual dimorphism for the assembly of ecological communities. 

Tuesday 31 October 2023, kl. 13.15 Room 5F322 (https://kau-se.zoom.us/j/3552606964). You are welcome!

Satu Ramula (PhD, adjunct Professor)

Satu Ramula, an Adjunct Professor in Ecology and Evolutionary Biology from University of Turku, Finland will give a seminar entitled ” The role of soil microbes in plant invasions“. Satu’s areas of expertise are Demographic methods, invasive species, plant ecology, population ecology, and structured population models.

Time and Date: Friday 13th October 2023 from 09:00 to 9:50 CET over zoom (https://kau-se.zoom.us/j/63791052457). You are cordially welcome to join this seminar.

Raviv Gal, PhD Student

Raviv Gal, PhD student at NRRV, will give a seminar about freshwater mussels as ecosystem engineers. Freshwater mussels are a highly endangered group with a fascinating life history and an important role in the ecosystem. Raviv will tell us about what we know about the role of mussels in freshwaters, with a focus on his own research into their interactions with the rest of the benthic macroinvertebrate community and decomposition processes. Date and Time: Tuesday 19 September 2023 at 13:15 CET. You can join this seminar live on Zoom (https://kau-se.zoom.us/j/63110430909) or in Room 5D306 at Karlstad University campus. You are all invited.

This post covers chapters 21 & 22 from Futuyma and Kirkpatrick’s book on Evolution (2018). The author of this post is Sam Shry.

Evolution and Homo sapiens; the birds and bees of where we come from

We now turn our attention to the evolution of our own species and how we came to be this unique, evolutionary phenomenon. Of course, we have already learned that we arose from a last universal common ancestor (LUCA), but closer in evolutionary time we arose from the group called great apes, more specifically our closest relatives are the chimpanzee (Pan troglodytes) and the bonobo (Pan paniscus). The lineage hominin (us) diverged from the chimpanzee lineage around 7 Mya, with Homo sapiens becoming the only species from this lineage not to go extinct. With genetic similarities in our protein-coding genes of more than 98% between chimpanzee and humans, it’s no wonder that there are such close similarities between these two species in terms of morphological, social, and cognitive features. We, however, differ in many aspects too, for example, we have evolved the ability to live upright on two feet (bipedal), adapting to a changing climate during this time via movement and migration. We also evolved reduced body hair to probably aid in making sweating and evaporative cooling more efficient. We also have many differences in our hand morphology, teeth, and our larger brain. What is interesting to me is that our potential growth rate is so much higher than for other ape species, as human females can become pregnant even when they have dependent children, in contrast to chimpanzees that cannot.

The divergence of hominins occurred in Africa, as Darwin predicted long before fossil evidence. Hominins split into several species, with all (except us) eventually dying out, giving an interesting insight into the evolution of our species. One of these (Ardipithecus ramidus) had apelike features like a chimpanzee’s brain size and climbing adaptations, but also had small canine teeth and a pelvis adapted for walking upright. The genus Homo dates back about 3 Mya, where the Homo habilis and Homo erectus are thought to be the ancestors of our own species. Homo habilis resembled modern humans closer than earlier species, with a flatter face, shorter tooth row, and greater cranial capacity than before. Homo erectus had a resemblance that was even closer to modern humans and was the first hominin to leave Africa around 2 Mya, spreading into the Middle East and eventually Asia. Our ancestors continued to slowly disperse across the world, with Homo heidelbergensis, a common ancestor to the well-known Neanderthals, dispersing throughout Europe and Asia around 600 Kya (figure 1). I like the analogy in the book that describes the phylogeny of hominins as a densely tangled bush, with humans only being a leaf on this bush. 

Figure 1. Migrations and colonization of Earth by humans. (Wikimedia Commons, User:Dbachmann)

We can map our ancestral dispersal across earth over time using our gene trees of mitochondrial DNA (mtDNA) sequences to complement and provide additional insight to fossil evidence and estimate the age of the most recent common ancestor of mtDNA in living humans. We also find that these different groups of hominins hybridized, for example, Neanderthals and Denisovans, contributing advantageous alleles to the human gene pool. In today’s human populations, we also find some genetic differentiation, but these differences are very low compared to other species, due probably to the very short amount of time we have evolved since colonization. What is surprising is how adapted some human populations are to their environments due to high selective pressure, for example, lighter skin color in Europeans and East Asians adapted to limited sunlight in northern latitudes.

One important characteristic of humans is our brain size. Our cognitive abilities far surpass other species, giving us the ability to reason, think, and understand. One hypothesis for this is ecological, in that we evolved cognition for dealing with complex environments. Another hypothesis is called the social brain hypothesis, where our complex social groups selected for large brains that would ultimately increase survival and the chance for reproduction (increasing fitness).  Social cooperation and accumulated knowledge via the use of language are key elements to the evolution of increased cognitive abilities in our species. The evolved modification of our vocal tract enables vocal versatility, enabling a wider range of sounds, but at the cost of possibly choking to death on food, so the advantages of spoken language must be strong in our evolution.

These somewhat strange evolutionary tradeoffs are further seen when looking at the costs of a larger brain, causing higher reproductive costs and requiring more energy to grow all the way up to 18 years, making human life history paradoxical. We do however have longer life spans than other primates, we evolved higher metabolic rates, higher reproductive rates, and a larger energy budget. We did this by switching diets to adding meats and tubers, and learning to hunt and gather. Agriculture was developed and animal domestication began to feed our growing population. Agriculture was double-sided, providing food stability, but changing human lifestyle, culture, and environment around us. Adapting to a new diet selected for specific genes, for example, the lactase persistence enzyme that allows for the digestion of lactose in milk. What is also interesting is how our ancestor dispersal from Africa left traces in our DNA sequence variation, where individuals that disperse furthest from Africa have the highest deleterious mutations, given they were small populations (founder effect), accumulating rare variants, less effective natural selection, and intense drift that fixed these mutations. 

Natural selection and evolution are still acting on our species, it’s just that the selection pressures have changed. We find modern hygiene and medicine alleviate the fitness differences, but still, we see selection occurring in some traits, such as cholesterol levels and height, due to our diet, lifestyle, and environmental factors. We also still see the effects of changing to an agricultural diet in our obesity crisis, with calorie-dense foods combined with our sedentary lifestyles. We also have the evolution of culture acting on our society, simultaneously driving cultural elements, innovation, and social interactions. The cumulation of cultural influences, human behavior, and biological tendencies guide, but do not limit our diversity as we continue to move forward in time.

Evolution and Society

The theory of evolution by natural selection has had a profound impact on our understanding of ourselves and the world around us, “unifying the realm of life, meaning and purpose with the realm of space and time, cause and effect, mechanism and physical law.” – Daniel Dennett

Although there is a long line of evidence behind this theory’s confirmation, there are still those that do not accept this theory as reality and cannot grip general reasoning. An extreme, sub-population have “beliefs” in creationism, that God directly created the human species. Certain, literal interpretations of the Bible and other religious documents have conflicting ideas of Earth’s creation and its life, for example in the book of Genesis and the literal interpretation of the creation of Earth and life in six days. Others believe evolution is the mechanism by which God enabled/s creation to proceed and now lets the Earth run on its own without further intervention. People can believe whatever they want, but issues arise when religion and beliefs are confused with science and education. For example, in the US, some schools are required to give equal teaching time to religious doctrine like intelligent design as they do to scientific theory such as evolution. The problem with this is that people do not understand how science works and how it is not comparable to religion. The process of science is to forever test our understanding of the world through the scientific method. Over time we have come up with our best understanding of the world and these denoted theories are “proven” beyond a reasonable doubt via scientific testing and evidence-based science. As this book has explained over the last 21 chapters, the theory of evolution is a highly complex system that we are continuing to understand better every day. Evidence for evolution has been already described throughout the book but we can just recap a few examples. The fossil record and the transitional fossils between species have given us physical evidence of evolution that often matches up, time-wise, with phylogenetic predicted sequences. The phylogenetic relationship between species via DNA analysis has opened a vast new world of understanding every species connection and diversity. Though this evidence does not waver for some true believers, the failed argument of intelligent design gives a baseless ground for these beliefs. The whole argument of a godly design is that these complex species are created perfectly. So, the vast number of failed, inferior designed traits or species in this world would indicate an unkind, incompetent designer.  Why would an ultimate designer create sickle-cell disease, saving some and killing everyone else that is homozygous for a gene? Intelligent design is unable to explain the selfish behaviors that natural selection can explain, like cannibalism, siblicide, and infanticide. We have also been able to use the information gleaned from the mechanisms governing the theory of evolution to understand the world around us and how it is changing. For example, understanding domesticated plants and animals, resistance to pesticides and antibiotics, and rapid adaptations to climate changes.  In short, the evidence behind evolutionary theory should never be compared to beliefs and even if they were to be, there is no evidence for these beliefs.

Understanding evolution and its mechanisms has shaped our understanding of the world today. It has formed the world we live in, ourselves, and every other species. The concept of natural selection can be applied to all aspects of our lives, such as culture, language, political science, and the overall human experience. The practical application of evolutionary mechanisms has helped us in advancing food production, managing natural resources, improving conservation, and human health. By having this understanding of how organisms evolve, we can make future predictions for our species, other species, and even understand how to develop new technologies and organisms to further benefit us or save our species. This work is vital to combating today’s challenges such as climate change, biodiversity loss, genetic diseases, cancer, infectious diseases, and general public health. One example is the current extinction crises, the global loss of species diversity. Due to rapid climate change, species are unable to genetically adapt to new climate conditions, causing species extinction. Evolution is a unifying theme throughout the biological and social sciences and is the backbone to understanding the world around us. It is, however, only knowledge, with no external meaning, morals, or ethics. It is important knowledge for our society, one species of the millions inhabiting this earth. It is always fun to think about how little evolutionary time our species has inhabited this earth and how/if we will endure or just become another species on the extinction list.