1,412 research outputs found
Condition dependence in biosynthesized chemical defenses of an aposematic and mimetic Heliconius butterfly
Aposematic animals advertise their toxicity or unpalatability with bright warning coloration. However, acquiring and maintaining chemical defenses can be energetically costly, and consequent associations with other important traits could shape chemical defense evolution. Here, we have tested whether chemical defenses are involved in energetic trade-offs with other traits, or whether the levels of chemical defenses are condition dependent, by studying associations between biosynthesized cyanogenic toxicity and a suite of key life-history and fitness traits in a Heliconius butterfly under a controlled laboratory setting. Heliconius butterflies are well known for the diversity of their warning color patterns and widespread mimicry and can both sequester the cyanogenic glucosides of their Passiflora host plants and biosynthesize these toxins de novo. We find energetically costly life-history traits to be either unassociated or to show a general positive association with biosynthesized cyanogenic toxicity. More toxic individuals developed faster and had higher mass as adults and a tendency for increased lifespan and fecundity. These results thus indicate that toxicity level of adult butterflies may be dependent on individual condition, influenced by genetic background or earlier conditions, with maternal effects as one strong candidate mechanism. Additionally, toxicity was higher in older individuals, consistent with previous studies indicating accumulation of toxins with age. As toxicity level at death was independent of lifespan, cyanogenic glucoside compounds may have been recycled to release resources relevant for longevity in these long-living butterflies. Understanding the origins and maintenance of variation in defenses is necessary in building a more complete picture of factors shaping the evolution of aposematic and mimetic systems.Peer reviewe
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Conservation and flexibility in the gene regulatory landscape of heliconiine butterfly wings
Funder: Wellcome Trust; doi: http://dx.doi.org/10.13039/100004440Abstract: Background: Many traits evolve by cis-regulatory modification, by which changes to noncoding sequences affect the binding affinity for available transcription factors and thus modify the expression profile of genes. Multiple examples of cis-regulatory evolution have been described at pattern switch genes responsible for butterfly wing pattern polymorphism, including in the diverse neotropical genus Heliconius, but the identities of the factors that can regulate these switch genes have not been identified. Results: We investigated the spatial transcriptomic landscape across the wings of three closely related butterfly species, two of which have a convergently evolved co-mimetic pattern and the other having a divergent pattern. We identified candidate factors for regulating the expression of wing patterning genes, including transcription factors with a conserved expression profile in all three species, and others, including both transcription factors and Wnt pathway genes, with markedly different profiles in each of the three species. We verified the conserved expression profile of the transcription factor homothorax by immunofluorescence and showed that its expression profile strongly correlates with that of the selector gene optix in butterflies with the Amazonian forewing pattern element ‘dennis.’ Conclusion: Here we show that, in addition to factors with conserved expression profiles like homothorax, there are also a variety of transcription factors and signaling pathway components that appear to vary in their expression profiles between closely related butterfly species, highlighting the importance of genome-wide regulatory evolution between species
Diversity and Evolution of Butterfly Wing Patterns: An Integrative Approach
nymphalid; ecology; evolution; genetics; mimicr
Novel Applications Of Music And Digital Media In Global Health Intervention And Education Initiatives During The Covid-19 Pandemic: A Case Study Of Bts And Army
The Korean musical group BTS (full name Bangtan Seoyeondan/방탄소년단) is one of the world’s most commercially and artistically successful entertainment acts. BTS is primarily known for their domination of both Western and Korean musical markets, impressive digital media presence, major role in supporting the South Korean economy, and highly mobilized 400,000 member fandom known as ARMY. BTS and their parent company HYBE’s artistic creation and marketing model has long focused on creating “Music and Artists for Healing,” or using music and various forms of primarily digital content to connect with and improve health outcomes for fans. In response, ARMY have developed significant grassroots public health organizing to improve health of other fans and general populations. Both BTS and ARMY’s intervention work regularly reaches global audiences of millions through primarily digital media delivery mechanisms.This interdisciplinary, mixed methods study uses qualitative analysis of BTS’ digital content (n = 478) and an introductory exploration of ARMY public health organizations to demonstrate that BTS’ music, HYBE’s digital content production and dissemination strategies, and ARMY’s community grassroots organizing produced one of the largest-reaching public health interventions in response to the early COVID-19 pandemic (March 2020- December 2021). Major intervention strategies included mitigating negative mental health outcomes, distributing health information, modeling safe behaviors, and engaging in both mutual aid and anti-racist health equity work. This exploratory research illuminates new directions in effective, novel public health intervention and education practices and posits that critical, nuanced study of BTS and ARMY’s impact on public health may hold important keys to re-imagining digitally delivered health interventions and their subsequent economic profitability
Insects
In this thematic series, engineers and scientists come together to address two interesting interdisciplinary questions in functional morphology and biomechanics: How do the structure and material determine the function of insect body parts? How can insects inspire engineering innovations
Maps for the lost: A collection of short fiction And Human / nature ecotones: Climate change and the ecological imagination: A critical essay
The thesis comprises a collection of short fiction, Maps for the Lost, and a critical essay, “Human / Nature Ecotones: Climate Change and the Ecological Imagination.” In ecological terms, areas of interaction between adjacent ecosystems are known as ecotones. Sites of relationship between biotic communities, they are charged with fertility and evolutionary possibility. While postcolonial scholarship is concerned with borders as points of cross-cultural contact, ecocritical thought focuses upon the ecotone that occurs at the interface between human and non-human nature.
In their occupation of the liminal zones between human and natural realms, the characters and narratives of Maps for the Lost reveal and nurture the porosity of conventional demarcations. In the title story, a Czech artist maps the globe by night in order to find his lover. The buried geographies of human landscapes coalesce with those of the non-human realm: the territories of wolves and the scent-trails of a fox mingle imperceptibly with nocturnal Prague and the ransacked villages of post-war Croatia. In “Seeds,” a narrative structured around the process of biological growth, the lost memories of an elderly woman are returned to her by her garden. “The Skin of the Ocean” traces the obsession of a diver who sinks his yacht under the weight of coral and fish, while in “Drift,” an Iranian refugee writes letters along the tide-line of a Tasmanian beach.
The essay identifies the inadequacy of literature and literary scholarship’s response to the threat of climate change as a failure of the imagination, reflecting the transgressive dimension of the crisis itself, and the dualistic legacy which still informs Western discourse on non-human nature. In order to redress this shortfall, which I argue the current generations of writers have an urgent moral responsibility to do, it is critical that we learn to understand the natural world of which we are a part, in ways that cast off the limitations of conventional representation. Paradoxically, it is the profoundly disruptive (apocalyptic?) nature of the climate crisis itself, which may create the imaginative traction for that shift in comprehension, forcing us, through loss, to interpret the world in ways that have been forgotten, or are fundamentally new. By analysing Alexis Wright’s The Swan Book, and Les Murray’s “Presence” sequence, the essay explores the correlation between imaginative and ecological processes, and the role of voice, embodiment, patterning and story in negotiations of nature and place. In the context of the asymptotical essence of the relation between text and world, and the paradox of phenomenological representation, it calls for a deeper cultural engagement with scientific discourse and indigenous philosophy, in order to illuminate the multiplicity and complexity of human connections to the non-human natural worl
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