| 1. |
- Lindholm, Anna K., et al.
(author)
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The Ecology and Evolutionary Dynamics of Meiotic Drive
- 2016
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In: Trends in Ecology & Evolution. - : Elsevier BV. - 0169-5347 .- 1872-8383. ; 31:4, s. 315-326
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Research review (peer-reviewed)abstract
- Meiotic drivers are genetic variants that selfishly manipulate the production of gametes to increase their own rate of transmission, often to the detriment of the rest of the genome and the individual that carries them. This genomic conflict potentially occurs whenever a diploid organism produces a haploid stage, and can have profound evolutionary impacts on gametogenesis, fertility, individual behaviour, mating system, population survival, and reproductive isolation. Multiple research teams are developing artificial drive systems for pest control, utilising the transmission advantage of drive to alter or exterminate target species. Here, we review current knowledge of how natural drive systems function, how drivers spread through natural populations, and the factors that limit their invasion.
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| 2. |
- Kokko, Hanna, et al.
(author)
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Can Evolution Supply What Ecology Demands?
- 2017
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In: Trends in Ecology & Evolution. - : ELSEVIER SCIENCE. - 0169-5347 .- 1872-8383. ; 32:3, s. 187-197
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Research review (peer-reviewed)abstract
- A simplistic view of the adaptive process pictures a hillside along which a population can climb: when ecological 'demands' change, evolution 'supplies' the variation needed for the population to climb to a new peak. Evolutionary ecologists point out that this simplistic view can be incomplete because the fitness landscape changes dynamically as the population evolves. Geneticists meanwhile have identified complexities relating to the nature of genetic varia-tion and its architecture, and the importance of epigenetic variation is under debate. In this review, we highlight how complexity in both ecological 'demands' and the evolutionary 'supply' influences organisms' ability to climb fitness landscapes that themselves change dynamically as evolution proceeds, and encourage new synthetic effort across research disciplines towards eco-logically realistic studies of adaptation.
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| 3. |
- Kristensen, Nadiah Pardede, et al.
(author)
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Carryover effects from natal habitat type upon competitive ability lead to trait divergence or source–sink dynamics
- 2018
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In: Ecology Letters. - : Wiley. - 1461-023X. ; 21:9, s. 1341-1352
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Journal article (peer-reviewed)abstract
- Local adaptation to rare habitats is difficult due to gene flow, but can occur if the habitat has higher productivity. Differences in offspring phenotypes have attracted little attention in this context. We model a scenario where the rarer habitat improves offspring's later competitive ability – a carryover effect that operates on top of local adaptation to one or the other habitat type. Assuming localised dispersal, so the offspring tend to settle in similar habitat to the natal type, the superior competitive ability of offspring remaining in the rarer habitat hampers immigration from the majority habitat. This initiates a positive feedback between local adaptation and trait divergence, which can thereafter be reinforced by coevolution with dispersal traits that match ecotype to habitat type. Rarity strengthens selection on dispersal traits and promotes linkage disequilibrium between locally adapted traits and ecotype-habitat matching dispersal. We propose that carryover effects may initiate isolation by ecology.
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| 4. |
- Lindström, Jan, et al.
(author)
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From arctic lemmings to adaptive dynamics: Charles Elton's legacy in population ecology
- 2001
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In: Biological Reviews. - 1469-185X. ; 76:1, s. 129-158
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Research review (peer-reviewed)abstract
- We shall examine the impact of Charles S. Eltons 1924 article on periodic fluctuations in animal populations on the development of modern population ecology. We argue that his impact has been substantial and that during the past 75 years of research on multi-annual periodic fluctuations in numbers of voles, lemmings, hares, lynx and game animals he has contributed much to the contemporary understanding of the causes and consequences of population regulation. Elton was convinced that the cause of the regular fluctuations was climatic variation. To support this conclusion, he examined long-term population data then available. Despite his firm belief in a climatic cause of the self-repeating periodic dynamics which many species display, Elton was insightful and far-sighted enough to outline many of the other hypotheses since put forward as an explanation for the enigmatic long-term dynamics of some animal populations. An interesting, but largely neglected aspect in Eltons paper is that it ends with speculation regarding the evolutionary consequences of periodic population fluctuations. The modern understanding of these issues will also be scrutinised here. In population ecology, Eltons 1924 paper has spawned a whole industry of research on populations displaying multi-annual periodicity. Despite the efforts of numerous research teams and individuals focusing on the origins of multi-annual population cycles, and despite the early availability of different explanatory hypotheses, we are still lacking rigorous tests of some of these hypotheses and, consequently, a consensus of the causes of periodic fluctuations in animal populations. Although Elton would have been happy to see so much effort spent on cyclic populations, we also argue that it is unfortunate if this focus on a special case of population dynamics should distract our attention from more general problems in population and community dynamics.
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| 5. |
- Malmgren, Jan C.
(author)
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Evolutionary ecology of newts
- 2001
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Doctoral thesis (other academic/artistic)abstract
- Sexual dimorphism, predator avoidance and migratory behaviour are adaptive traits that show variation at the population and species level. Such features respond to the environment in the broad sense, that is, when both abiotic and biotic components are included. Newts of the genus Triturus have several unique features and therefore make interesting model organisms. I use multivariate methods to test predictions about the evolution of sex differences in morphological traits. There was no evidence for dimorphism due to diverging feeding niche specialisation between the sexes in great crested and smooth newts (Triturus cristatus and T. vulgaris, respectively). The sexes, on the other hand, diverged in traits related to female fecundity and male reproductive success. Within the genus Triturus, there was no overall allometry for sexual size dimorphism (SSD), but subgenus Triturus, a lineage comprised by medium- to large-bodied species, were significantly allometric, and SSD decreased with increasing body size for male-biased taxa and increased with size for female-biased taxa. Species in the marmoratus-cristatus species group were almost perfectly isometric, but female-biased. With respect to an ancestral state, I suggest that differences in mating system have caused medium- and small-bodied species (subgenus Palaeotriton) to decrease SSD with smaller body size, whereas subgenus Triturus have evolved larger body size with a reversal from male- to female-biased SSD. Several peculiar traits are common to the latter group. I argue, and present a conceptual model, that the reversal is an adaptation to genetic constraints posed by a balanced lethal system (the developmental arrest syndrome). Several life history traits, as well as morphological and reproductive traits, may be interpreted as evidence for the scenario. Predictions from the model are presented and future research to test the validity of the model is encouraged. Newts are threatened by the introduction of fish and predictions from a predator-prey model on the evolution of predator avoidance behaviour, are tested. The results suggest that the great crested newt may be able to detect chemical cues from the ninespined stickleback, Pungitius pungitius, and adjust its behaviour accordingly. The response could be a predator avoidance response that enables adults to increase reproductive success by eliminating predation risk. I also studied migration behaviour in response to surrounding landscape elements after breeding and metamorphosis in great crested and smooth newts. Fragmentation effects reduce the chance for newts to disperse to suitable habitat patches in the landscape. I demonstrate that newts appear to orientate towards forest non-randomly, regardless of age-class or species, and their responses may be used to predict where critical elements for population persistence are located, in relation to a breeding pond. Overall, the results from my studies suggest that the great crested newt may be more prone to local extinction than previously believed, much due to genetic constraints and possible habitat specialisation. I use the results to present avenues for future research and discuss implications from my studies for management and conservation of newts and newt-friendly landscapes.
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| 6. |
- Saastamoinen, Marjo, et al.
(author)
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Genetics of dispersal
- 2018
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In: Biological Reviews. - : Wiley. - 1464-7931 .- 1469-185X. ; 93:1, s. 574-599
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Research review (peer-reviewed)abstract
- Dispersal is a process of central importance for the ecological and evolutionary dynamics of populations and communities, because of its diverse consequences for gene flow and demography. It is subject to evolutionary change, which begs the question, what is the genetic basis of this potentially complex trait? To address this question, we (i) review the empirical literature on the genetic basis of dispersal, (ii) explore how theoretical investigations of the evolution of dispersal have represented the genetics of dispersal, and (iii) discuss how the genetic basis of dispersal influences theoretical predictions of the evolution of dispersal and potential consequences. Dispersal has a detectable genetic basis in many organisms, from bacteria to plants and animals. Generally, there is evidence for significant genetic variation for dispersal or dispersal-related phenotypes or evidence for the micro-evolution of dispersal in natural populations. Dispersal is typically the outcome of several interacting traits, and this complexity is reflected in its genetic architecture: while some genes of moderate to large effect can influence certain aspects of dispersal, dispersal traits are typically polygenic. Correlations among dispersal traits as well as between dispersal traits and other traits under selection are common, and the genetic basis of dispersal can be highly environment-dependent. By contrast, models have historically considered a highly simplified genetic architecture of dispersal. It is only recently that models have started to consider multiple loci influencing dispersal, as well as non-additive effects such as dominance and epistasis, showing that the genetic basis of dispersal can influence evolutionary rates and outcomes, especially under non-equilibrium conditions. For example, the number of loci controlling dispersal can influence projected rates of dispersal evolution during range shifts and corresponding demographic impacts. Incorporating more realism in the genetic architecture of dispersal is thus necessary to enable models to move beyond the purely theoretical towards making more useful predictions of evolutionary and ecological dynamics under current and future environmental conditions. To inform these advances, empirical studies need to answer outstanding questions concerning whether specific genes underlie dispersal variation, the genetic architecture of context-dependent dispersal phenotypes and behaviours, and correlations among dispersal and other traits.
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| 7. |
- Svensson, Catarina, et al.
(author)
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Veterinary herd health management-Experiences and perceptions among Swedish dairy cattle veterinarians
- 2022
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In: Journal of Dairy Science. - : American Dairy Science Association. - 0022-0302 .- 1525-3198. ; 105, s. 6820-6832
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Journal article (peer-reviewed)abstract
- Cattle veterinarians have long been encouraged to take on a role as proactive health consultants. How-ever, the process so far has been slow in Sweden and elsewhere, and only a rather small proportion of cattle work conducted by veterinarians involves vet-erinary herd health management (VHHM). The aims of this exploratory study were to explore Swedish cattle veterinarians' interpretation of VHHM services and to understand the factors that might affect the extent to which cattle veterinarians perform VHHM. Six focus group discussions with cattle veterinarians complemented with 5 individual telephone interviews with clinic managers were conducted in 2020. In total, 33 cattle veterinarians participated, all employed by the largest employer of Swedish cattle veterinarians: Distriktsveterinarerna (Swedish Board of Agriculture). Participants were chosen from 6 geographical regions with the aim to present variations in gender, age, coun-try of education, proportion of dairy cattle work at the clinic, experience in the veterinary profession, and ex-perience in work with dairy herds and in VHHM. The focus group discussions and interviews were recorded and these recordings were transcribed and analyzed thematically. Participants interpreted VHHM as work associated with the process of advising and included both ad hoc advising and more strategic forms of ser-vices. Prebooked visits per se were not seen as VHHM. We identified 4 different themes among the factors af-fecting the extent of VHHM services: (1) farmer trust and demand; (2) veterinary competence; (3) time avail-able for VHHM; and (4) the individual veterinarian's commitment and motivation. To gain farmers' trust and to create a demand for VHHM services, the results of VHHM work and the veterinarian's competence were deemed central by the participants. The veterinarians' skills in communication and relation building were considered especially important. Some farmers were perceived as having little interest in, or lacking deeper knowledge about, VHHM services. The promotion of VHHM services was mentioned as an important fac-tor to increase farmer demand. Participants described VHHM as work demanding high skills and continuous capacity development. Veterinarians' personal commit-ment and motivation were also described as important for the extent to which VHHM services were performed. This was in turn affected by the psychosocial work environment (e.g., workload, interest and recognition from farmers and managers, and acceptance, priority, and support by colleagues and managers). Clinic man-agers had a central role in the extent to which VHHM services are offered by an individual veterinarian due to their responsibility for staff scheduling, which highly affects the conditions for capacity development, inter-collegiate networking, and cooperation. Lack of time was a major barrier for VHHM. On-call duty time and subsequent compensatory leave affected the total time available, and participants described time conflicts between VHHM and emergency services; moreover, it was perceived as challenging to find sufficient time for capacity development in several different species for veterinarians working in mixed practice. The slow de-velopment toward more proactive approaches for cattle veterinarians can be explained by the numerous dif-ferent factors that together constrain the veterinarian to the traditional role of diagnosing and treating sick animals.
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