Journal of Experimental Biology - Latest Issue

• Environmentally dependent developmental induction as a potential driver of heart evolution

  ABSTRACT

  Developmental biology and evolutionary theory have traditionally emphasized gene mutations as the primary drivers of new traits, with natural selection shaping the resulting variation. However, recent insights highlight the role of environmental factors during development in shaping trait evolution. In this Commentary, I introduce the ‘environmentally dependent developmental induction’ (EDDI) model, which proposes that phenotypic evolution is driven not only by genetic changes but also by environmentally induced modifications to the core developmental program. Using cardiogenesis as an example, I argue that environmental triggers such as oxygen levels and mechanical forces expand the genotypic toolkit available to heart development, activating new pathways that lead to the emergence of novel cardiac structures. These lineage-specific environmental changes might thus influence the differentiation of cardiac progenitor cells, resulting in modifications to the cardiac building plan. The EDDI model provides a novel explanation for how the basic cardiac plan was expanded during evolution while simultaneously explaining why cardiogenesis is vulnerable to malformations, even in the absence of genetic defects.

• Visual learning performance of non-pollen and pollen foragers in Bombus pauloensis bumblebees

  ABSTRACT

  Despite its economic and ecological importance, little is known about the learning abilities of the South American bumblebee Bombus pauloensis. To date, no studies have explored the visual learning capacity of its foragers, potential differences between non-pollen and pollen foragers, the effect of body size on learning, or male learning abilities. Here, we investigated the visual learning performance of workers, taking into account forager type (pollen versus non-pollen foragers) and body size. As a complementary analysis, we assessed the same variables in males. Our results show that both female foragers and males of this South American bumblebee can learn to associate a specific color with a sugar reward and do not exhibit color bias for the tested colors (blue and yellow). We found no significant differences in color learning ability or body size between pollen and non-pollen foragers. Additionally, body size significantly influenced visual learning performance during the testing phase. This study provides new insights into the visual learning abilities of both foragers and males in the South American bumblebee Bombus pauloensis, enriching the understanding of cognition of native pollinators.

• ECR Spotlight – Erik Etzler

  ECR Spotlight is a series of interviews with early-career authors from a selection of papers published in Journal of Experimental Biology and aims to promote not only the diversity of early-career researchers (ECRs) working in experimental biology but also the huge variety of animals and physiological systems that are essential for the ‘comparative’ approach. Erik Etzler is an author on ‘ Rivers and roads, silence and songs: female crickets respond similarly to conspecific male song in natural and anthropogenic soundscapes’, published in JEB. Erik is a Postdoc in the lab of John Ratcliffe at the University of Toronto Mississauga, Canada, investigating selective pressures on singing insects.

• Rivers and roads, silence and songs: female crickets respond similarly to conspecific male song in natural and anthropogenic soundscapes

  ABSTRACT

  Many studies have demonstrated that anthropogenic noise affects animals' auditory perception of salient stimuli. Few have tested whether these effects are different from those experienced in nature. We tested the ability of female field crickets, Teleogryllus oceanicus, to phonotactically locate a speaker playing conspecific male song in four acoustic backgrounds: silence, road noise, river noise and heterospecific song. Crickets approaching conspecific song paused more frequently in river noise and heterospecific song treatments compared with silence or road noise. We also recorded auditory interneuron (AN1 and AN2) activity under the first three acoustic background treatments to construct and compare treatment-specific audiograms and interneuron responses to conspecific song. We found little difference in activity, other than that AN2 thresholds for 6 kHz sounds (the tested frequency closest to male song) were highest in river noise, while heterospecific song increased baseline AN2 activity and reduced AN2 activity to conspecific song onset. Our results suggest road noise is not necessarily a greater disturbance than river noise.

• ECR Spotlight – Reshma Menon

  ECR Spotlight is a series of interviews with early-career authors from a selection of papers published in Journal of Experimental Biology and aims to promote not only the diversity of early-career researchers (ECRs) working in experimental biology but also the huge variety of animals and physiological systems that are essential for the ‘comparative’ approach. Reshma Menon is an author on ‘ Moderate nutritional stress reprogrammes insulin responses to drive enhanced starvation tolerance in Drosophila melanogaster’, published in JEB. Reshma is a PhD student in the lab of Dr Jishy Varghese at School of Biology, IISER TVM, investigating the intricate relationship between stress and stress responses, particularly focusing on the physiological rewiring that occurs under stress and the mechanisms that drive anticipatory adaptive stress responses.