Backyard evolutionary biology: Investigating local flowers brings learning to life.

Inquiry-based learning allows students to actively engage in and appreciate the process of science. As college courses transition to online instruction in response to COVID-19, incorporating inquiry-based learning is all the more essential for student engagement. However, with the cancelation of in-person laboratory courses, implementing inquiry can prove challenging for instructors.

Rotation of sex combs in Drosophila melanogaster requires precise and coordinated spatio-temporal dynamics from forces generated by epithelial cells.

The morphogenesis of sex combs (SCs), a male trait in many species of fruit flies, is an excellent system in which to study the cell biology, genetics and evolution of a trait. In Drosophila melanogaster, where the incipient SC rotates from horizontal to a vertical position, three signal comb properties have been documented: length, final angle and shape (linearity). During SC rotation, in which many cellular processes are occurring both spatially and temporally, it is difficult to distinguish which processes are crucial for which attributes of the comb.

Evolutionary Consequences of Male Driven Sexual Selection and Sex-Biased Fitness Modifications in Drosophila melanogaster and Members of the simulans Clade.

Males have evolved a variety of behavioral, morphological, and physiological traits to manipulate their mates in order to maximize their chances of success. These traits are bound to influence how females respond to male behaviors and influence the nature of sexual selection/conflict. A common consequence of aggressive male mating strategies in Drosophila melanogaster is the reduction of female lifespan.

Evolution of Drosophila sex comb length illustrates the inextricable interplay between selection and variation.

In spite of the diversity of possible biological forms observed in nature, a limited range of morphospace is frequently occupied for a given trait. Several mechanisms have been proposed to explain this bias in the distribution of phenotypes including selection, drift, and developmental constraints. Despite extensive work on phenotypic bias, the underlying developmental mechanisms explaining why particular regions of morphological space remain unoccupied are poorly understood.

Patterns of molecular evolution of the germ line specification gene oskar suggest that a novel domain may contribute to functional divergence in Drosophila.

In several metazoans including flies of the genus Drosophila, germ line specification occurs through the inheritance of maternally deposited cytoplasmic determinants, collectively called germ plasm. The novel insect gene oskar is at the top of the Drosophila germ line specification pathway, and also plays an important role in posterior patterning. A novel N-terminal domain of oskar (the Long Oskar domain) evolved in Drosophilids, but the role of this domain in oskar functional evolution is unknown.

The roles of cell size and cell number in determining ovariole number in Drosophila.

All insect ovaries are composed of functional units called ovarioles, which contain sequentially developing egg chambers. The number of ovarioles varies between and within species. Ovariole number is an important determinant of fecundity and thus affects individual fitness.

Condition dependence and the nature of genetic variation for male sex comb bristle number in Drosophila melanogaster.

Genetic architecture of variation underlying male sex comb bristle number, a rapidly evolving secondary sexual character of Drosophila, was examined. First, in order to test for condition dependence, diet was manipulated in a set of ten Drosophila melanogaster full-sib families. We confirmed heightened condition dependent expression of sex comb bristle number and its female homologue (distal transverse row bristles) as compared to non-sex sternopleural bristles.

Variation and evolution of male sex combs in Drosophila: nature of selection response and theories of genetic variation for sexual traits.

We investigated the genetic architecture of variation in male sex comb bristle number, a rapidly evolving secondary sexual character of Drosophila. Twenty-four generations of divergent artificial selection for sex comb bristle number in a heterogeneous population of Drosophila melanogaster resulted in a significant response that was more pronounced in the direction of low bristle numbers. We observed a strong positive correlated response to selection in the corresponding female transverse bristle row.

Coiling versus clipping for the treatment of aneurysmal subarachnoid hemorrhage: a longitudinal investigation into cognitive outcome.

Objective: Endovascular coiling has been used increasingly as an alternative to neurosurgical clipping for treating subarachnoid hemorrhage secondary to aneurysm rupture. The aim of the present study was to provide a prospective, longitudinal investigation into cognitive function in patients with aneurysmal subarachnoid hemorrhage treated with either neurosurgical clipping or endovascular coiling.

Methods: Twenty-three patients who were treated for aneurysmal subarachnoid hemorrhage at the National Hospital for Neurology and Neurosurgery in London, England, were recruited prospectively.