Abstract
Delayed life history effects (DLHEs) occur when fitness in one life stage affects fitness in subsequent life stages. Given their biphasic life cycle, pond-breeding amphibians provide a natural system for studying DLHEs, although these effects are not restricted to species with biphasic life histories. In this study, we used multiple mark-recapture techniques enabled by a large trapping array to monitor components of fitness and resulting DLHEs in a population of the endangered California tiger salamander (Ambystoma californiense). We found that DLHEs are prominent across all life stage transitions and that there is variation in whether selection acts primarily at the individual or cohort level. We also demonstrated that there is more than an order of magnitude variation in mean cohort fitness, providing tremendous variation for DLHEs to act upon. We documented an evolutionary trade-off between mass at emergence and date of emergence, which may play a role in maintaining the variation in mass (fitness) at emergence. A literature review revealed that such high levels of intercohort variation occur in many other pond-breeding amphibians, and that appropriately documenting the magnitude of intercohort variation requires long-term studies (roughly two population turnovers). Given the profound effect that DLHEs can have on population dynamics, quantifying intercohort variation in mean fitness and the level(s) at which selection acts will be very important for developing accurate models of population dynamics. In general, when developing models of population dynamics, more attention should be paid to variation in mean fitness and not just variation in total numbers.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 68-77 |
| Number of pages | 10 |
| Journal | Ecology |
| Volume | 95 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jan 1 2014 |
| Externally published | Yes |
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Keywords
- Ambystoma californiense
- California
- California tiger salamander
- Contextual analysis
- Date of emergence
- Intercohort variation
- Jepson Prairie Preserve
- Mass at emergence
- Pondbreeding amphibian
- Population turnover
- Selection gradient
- USA
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics
Cite this
Delayed life history effects, multilevel selection, and evolutionary trade-offs in the California tiger salamander. / Searcy, Christopher; Gray, Levi N.; Trenham, Peter C.; Shaffer, H. Bradley.
In: Ecology, Vol. 95, No. 1, 01.01.2014, p. 68-77.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Delayed life history effects, multilevel selection, and evolutionary trade-offs in the California tiger salamander
AU - Searcy, Christopher
AU - Gray, Levi N.
AU - Trenham, Peter C.
AU - Shaffer, H. Bradley
PY - 2014/1/1
Y1 - 2014/1/1
N2 - Delayed life history effects (DLHEs) occur when fitness in one life stage affects fitness in subsequent life stages. Given their biphasic life cycle, pond-breeding amphibians provide a natural system for studying DLHEs, although these effects are not restricted to species with biphasic life histories. In this study, we used multiple mark-recapture techniques enabled by a large trapping array to monitor components of fitness and resulting DLHEs in a population of the endangered California tiger salamander (Ambystoma californiense). We found that DLHEs are prominent across all life stage transitions and that there is variation in whether selection acts primarily at the individual or cohort level. We also demonstrated that there is more than an order of magnitude variation in mean cohort fitness, providing tremendous variation for DLHEs to act upon. We documented an evolutionary trade-off between mass at emergence and date of emergence, which may play a role in maintaining the variation in mass (fitness) at emergence. A literature review revealed that such high levels of intercohort variation occur in many other pond-breeding amphibians, and that appropriately documenting the magnitude of intercohort variation requires long-term studies (roughly two population turnovers). Given the profound effect that DLHEs can have on population dynamics, quantifying intercohort variation in mean fitness and the level(s) at which selection acts will be very important for developing accurate models of population dynamics. In general, when developing models of population dynamics, more attention should be paid to variation in mean fitness and not just variation in total numbers.
AB - Delayed life history effects (DLHEs) occur when fitness in one life stage affects fitness in subsequent life stages. Given their biphasic life cycle, pond-breeding amphibians provide a natural system for studying DLHEs, although these effects are not restricted to species with biphasic life histories. In this study, we used multiple mark-recapture techniques enabled by a large trapping array to monitor components of fitness and resulting DLHEs in a population of the endangered California tiger salamander (Ambystoma californiense). We found that DLHEs are prominent across all life stage transitions and that there is variation in whether selection acts primarily at the individual or cohort level. We also demonstrated that there is more than an order of magnitude variation in mean cohort fitness, providing tremendous variation for DLHEs to act upon. We documented an evolutionary trade-off between mass at emergence and date of emergence, which may play a role in maintaining the variation in mass (fitness) at emergence. A literature review revealed that such high levels of intercohort variation occur in many other pond-breeding amphibians, and that appropriately documenting the magnitude of intercohort variation requires long-term studies (roughly two population turnovers). Given the profound effect that DLHEs can have on population dynamics, quantifying intercohort variation in mean fitness and the level(s) at which selection acts will be very important for developing accurate models of population dynamics. In general, when developing models of population dynamics, more attention should be paid to variation in mean fitness and not just variation in total numbers.
KW - Ambystoma californiense
KW - California
KW - California tiger salamander
KW - Contextual analysis
KW - Date of emergence
KW - Intercohort variation
KW - Jepson Prairie Preserve
KW - Mass at emergence
KW - Pondbreeding amphibian
KW - Population turnover
KW - Selection gradient
KW - USA
UR - http://www.scopus.com/inward/record.url?scp=84893285981&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84893285981&partnerID=8YFLogxK
U2 - 10.1890/13-0120.1
DO - 10.1890/13-0120.1
M3 - Article
VL - 95
SP - 68
EP - 77
JO - Ecology
JF - Ecology
SN - 0012-9658
IS - 1
ER -