|Title / Titel||Habitat deterioration, population structure, genetic diversity and infectious disease: A holistic view on population declines|
|Abstract (PDF, 14 KB)|
|Summary / Zusammenfassung||This study will address an important question in conservation biology: Can genetic factors and an emerging infectious disease interact to cause population declines and local extinctions? Can these factors, alone or acting in concert, be more important than habitat loss and/or deterioration?
Many studies have addressed the effect of habitat loss and degradation on extinction but only a handful of studies asked whether genetic deterioration caused extinctions (e.g. Smith et al. 2006). Even fewer studies explored the role of emerging infectious diseases on extinction (but see Spielman et al. 2004b, but see Frankham 2005). None has asked whether there is an interaction between genetics and disease on the risk of extinction. This is surprising given the fact that it is well known that genetics strongly affect disease prevalence in many species (Keller and Waller 2002) and that interactions between stressors causing extinctions are the rule rather than the exception (Blaustein and Kiesecker 2002).
I will study a likely interaction between genetic diversity and an emerging infectious disease as the cause of declines in an amphibian, a group of vertebrates that is undergoing dramatic declines globally. An amphibian model system is well suited for such a project because (i) emerging infectious diseases (e.g. chytridiomycosis) contribute to global amphibian declines (e.g. Berger et al. 1998, Briggs et al. 2005, Lips et al. 2006, Pounds et al. 2006) and (ii) (molecular) genetic diversity is known to correlate to susceptibility to disease (Pearman and Garner 2005).
The goals of this project are
1) to determine the habitat-related factors and metapopulation factors that control the distribution and decline of the midwife toad;
2) to determine whether habitat-related factors and metapopulation factors affect the genetic diversity of the midwife toad;
3) to determine whether genetic diversity affects population viability through enhanced fitness; and
4) to determine the interplay between habitat factors, metapopulation factors, genetic structure and an emerging disease on the extinction probability of local populations of the midwife toad.
Alytes obstetricans, the common midwife toad, represents an ideal study system to address the question how genetic diversity is linked to population structure and whether genetic diversity affects disease prevalence and ultimately local extinction. Firstly, Alytes obstetricans in Switzerland is supposed to feature metapopulation structure that may be disrupted in intensively exploited areas (Hanski and Ovaskainen 2000, Kraaijeveld-Smit et al. 2005). Secondly, it faces two range edges, an altitudinal and a longitudinal one, where genetic variation is often lower (Garner et al. 2004). Thirdly, Alytes obstetricans is highly susceptible to chytridiomycosis (Bosch et al. 2001).
|Keywords / Suchbegriffe||amphibians, global amphibian decline, Alytes obstetricans, chytridiomycosis, habitat loss, fragmentation, population structure, conservation|
|Project leadership and contacts /
Projektleitung und Kontakte
|Other links to external web pages||http://www.karch.ch
|Funding source(s) /
|Universität Zürich (position pursuing an academic career), Forschungskredit der Universität Zürich, Others
Janggen-Pöhn Stiftung, St.Gallen; Basler Stiftung für biologische Forschung, Basel; Zoo Zürich; Grün Stadt Zürich; De Giacomi Stiftung, Chur; Zürcher Tierschutz; EUAC (European Union of Aquarium Curators); Vontobel-Stiftung, Zürich
|In collaboration with /
In Zusammenarbeit mit
|Duration of Project / Projektdauer||Jan 2007 to Jan 2011|