Molecular tools applied to study the evolution and adaptation of springtails to the extreme Antarctic terrestrial ecosystem

• Main Author: Leo, Chiara
• Other Authors: CARAPELLI, ANTONIO
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: Università degli Studi di Siena 2020
• Subjects: Antarctica; Collembola; species delimitation; microbiome; population genetic; phytogeography; evolution; mitochondrial genome; climate change; Settore BIO/05 - Zoologia; Antarctic; Antarctic Peninsula; South Pole; The Antarctic; Victoria Land; Antarc*; Antarctic Springtail; South pole; Springtail
• Online Access: http://hdl.handle.net/11365/1105154

Collembola (=springtails) is one of the most abundant, widespread and ancient lineages of basal hexapods. During their long evolutionary history, springtails have adapted to most damp environments on Earth, including those of South Pole. Antarctic springtails are endemic to the frozen Continent and among the few invertebrate taxa adapted to its strictly terrestrial ecosystem. These species have evolved when Antarctica was still linked to the Gondwanaland at lower latitudes and have adapted and survived to the cooling, isolation and southwards migration of the landmass. Antarctic springtails’ habitats are restricted to the few coastal areas, seasonally ice-free and accounting for less than the 0.5% of the entire continental area and off-shore islands. The niche fragmentation, together with springtails poor dispersal capability (due to the primary absence of wings), entail a severe degree of isolation among populations, with very low levels of gene flow. The Antarctic springtail species composition is limited without overlap among the two main Antarctic bioregions (i.e., the maritime and the continental Antarctica), with Friesea antarctica being the only species found both in the Antarctic Peninsula and Victoria Land (continental Antarctica). The high levels of endemism and fragmentation among populations, as well as the low invertebrate biodiversity and the complex and delicate array of physiological adaptation these species evolved, make Antarctic taxa particularly susceptible to anthropogenic climate changes, that we are all experiencing since the second industrial revolution in the XIXth century. In this respect, studying the molecular mechanisms underlying springtail adaptation to such a harsh environment, as well as the genetic structure of the populations and the way in which specimens may have been and can be influenced by the Antarctic terrestrial environment, may greatly assist the development of adequate and biogeographically-specific (thus, effective) conservational plans. In order to address these ...