Drivers of spider body plans: time, geography or climate?
thesisposted on 2022-03-28, 20:22 authored by Thomas Clarke
Spiders are a highly diverse order that are present across practically all terrestrial environments. Many aspects of their morphological characteristics have been studied, but what is not as well-known is the impact that climate has on their body-plan diversity and body plan overall. Spiders from differing climates or continents could have differing morphological variation. Spiders from five sites across climates, geographies and slices of geological time were measured and mapped on a two-dimensional representation of morphological space. One modern and one fossil site were specifically matched for climate, the two modern sites were matched for geography and two fossil sites were matched for geological epoch. From the analysis, it was shown that neither climate nor geography played any role in separating the sites in morphological space. The sites from the same epoch (Eocene for fossil, and modern) were identical to one another across the critical axis of the morphospace, which separated spiders by the ratio between their body length and leg length. Based on the family composition in sites and how well-constrained morphology was within a family, it seems most likely that phylogenetics or ecology dictate a spiders body plan. However close examination of a single family could yet yield other interesting results.