A new manuscript I wrote with my long-term colleagues Marc Mangel, Dusan Jesensek, Carlos Garza, and Alain Crivelli has just been accepted by the Proceedings of the Royal Society B.
This is the cover letter, in which I explain the high-level picture and some details of the analyses (it may help some junior scientists still struggling with cover letters, too much, too little, too many details or not enough etc.).
Santa Cruz, 09/26/2016
We are pleased to submit our manuscript “Genetic and life-history consequences of extreme climate events” to PRSB.
The climate change-induced increased frequency and intensity of extreme climate events is one the major threats to the persistence of species. However, when dealing with extreme events, finding the right model system, posing and testing tractable hypotheses on their demographic, genetic, and life-history consequences, and developing an overarching predictive framework is very challenging. First, climate extremes are rare events, and as a consequence most of the empirical studies on their effects have been opportunistic and anecdotal. Then, the demographic, genetic, and life-history effects of extreme climate events are not easily predictable or generalizable across species or habitats, especially when the investigations are not guided by ecological and evolutionary biology theory.
In this work, we test – to our knowledge for the first time - theoretical predictions on the demographic, genetic, and life-history effects of extreme climate events on two populations of a fish species. The two populations have been drastically reduced in size by flash floods that occurred in 2007 and 2009. We used a statistically sophisticated approach that included reconstruction of pedigrees using long-term tag-recapture data (1995 to 2014 from one population, 2006 to 2014 for the other) and genotypes of more than 1,800 unique fish. In particular, we tested for faster life histories, higher variance in reproductive success, and loss of genetic variation after the extreme climate events.
We are confident that our study significantly advances our understanding of the demographic, genetic, and life-history effects of extreme climate events on natural populations and would be of great interest to a broad audience of biologists.
And here below is the abstract (I will soon post the pdf in the Publications page of the website).
Climate change is predicted to increase the frequency and intensity of extreme climate events. Tests on empirical data of theory-based predictions on the consequences of extreme climate events are thus necessary to understand the adaptive potential of species and the overarching risks associated with all aspects of climate change. We tested predictions on the genetic and life-history consequences of extreme climate events in two populations of marble trout Salmo marmoratus that have experienced severe demographic bottlenecks due to flash floods. We combined long-term field and genotyping data, and pedigree reconstruction in a theory-based framework. Our results show that after flash floods, reproduction occurred at a younger age in one population. In both populations, we found the highest reproductive variance in the first cohort born after the floods due to a combination of fewer parents and higher early survival of offspring. A small number of parents allowed for demographic recovery after the floods, but the genetic bottleneck further reduced genetic diversity in both populations. Our results also elucidate some of the mechanism responsible for a greater prevalence of faster life histories after the extreme event.
Further considerations (some self-congratulatory)
These are some thoughts that I shared with one of my colleagues via email before submitting a revised version of the manuscript.
"Brief thoughts. This paper is an example of interdisciplinary work. There is solid life-history theory, we built up from previous work thus giving the sense of solid foundations and a on-going narrative, some hard tests as envisioned by Platt (age at reproduction decreases or not after the floods), demography, classic genetics, and state-of-the-art pedigree reconstruction.
Let's hope it gets accepted as is and we can then congratulate ourselves on an excellent, original work I am very proud of."