When a Fly Has to Fly to Reproduce: Selection against Conditional Recessive Lethals in Drosophila

Abstract

We propose an experimental model suitable for demonstrating allele frequency change in Drosophila melanogaster populations caused by selection against an easily scorable conditional lethal, namely recessive flightless alleles such as apterous and vestigial. Homozygotes for these alleles are excluded from reproduction because the food source used to establish each generation is accessible only by flight. The observed dynamics of flightless-allele frequencies generally follows the theoretically predicted pattern, with slight deviation toward less intense selection. We also suggest observing selection against flight-independent visible marker alleles in the same population as a meaningful comparison. The proposed experiments can easily be scheduled within one semester, and the expected data provide ample opportunities for discussion of quantitative evolutionary patterns.

Experimental evolution

“…If time permits, students could then compete the evolved and ancestral strains in the absence of antibiotic to test for tradeoffs. Using Drosophila, students can, over a semester, observe selection against alleles that are readily scored, such as those that disrupt wing morphology [102]. (Of course, such experiments in classrooms require suitable facilities and appropriately trained teachers, and they must comply with institutional policies and local regulations on biological experiments.)…”

Predator Escape: An Ecologically Realistic Scenario for the Evolutionary Origins of Multicellularity

“…Most labs exploring macroevolutionary change have relied on comparisons with living lineages, fossils, or computer simulations (Dubowsky and Hartman 1986;Rodrígues et al Rodríguez et al 2006;Soderberg and Price 2003). While these are valuable teaching materials, inquiry based exercises that utilize living organisms can be more transparent, and offer a direct connection to the ecological theater in which evolutionary processes play out (Delpech 2009;Green et al 2011;Olson and Loucks-Horsley 2000;Plunkett and Yampolsky 2010).…”

Effectiveness of Virtual Laboratories in Teaching and Learning Biology: A Review of Literature

“…Moreover, various studies have shown that virtual labs are adequate for improving understanding of biology topics that are difficult to observe directly in the classroom context (Collier et al, 2012;Pope et al, 2017;Radhamani et al, 2014). For example, evolution by natural selection has been shown to be notoriously difficult for students to understand, and its processes have been described as not directly observable (Krist & Showsh, 2007;Nehm & Schonfeld, 2008;Plunkett & Yampolsky, 2010). However, Pope et al (2017) clearly showed that simulations of natural phenomena are effective tools that support an active teaching approach to help students overcome natural selection misconceptions.…”