scholarly journals Developing demographic toxicity data: optimizing effort for predicting population outcomes

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2067 ◽  
Author(s):  
John D. Stark ◽  
John E. Banks
Keyword(s):  
Life Cycle ◽  
Population Growth ◽  
Growth Rates ◽  
Life Tables ◽  
Demographic Parameters ◽  
Toxicity Data ◽  
Population Growth Rates ◽  
Full Life Cycle ◽  
Cutoff Points ◽  
Full Life

Mounting evidence suggests that population endpoints in risk assessment are far more accurate than static assessments. Complete demographic toxicity data based on full life tables are eminently useful in predicting population outcomes in many applications because they capture both lethal and sublethal effects; however, developing these life tables is extremely costly. In this study we investigated the efficiency of partial life cycle tests as a substitute for full life cycles in parameterizing population models. Life table data were developed for three species of Daphniids,Ceriodaphnia dubia,Daphnia magna, andD. pulex, weekly throughout the life span of these species. Population growth rates (λ) and a series of other demographic parameters generated from the complete life cycle were compared to those calculated from cumulative weeks of the life cycle in order to determine the minimum number of weeks needed to generate an accurate population projection. Results showed that forC. dubiaandD. pulex,λvalues developed at >4 weeks (44.4% of the life cycle) were not significantly different fromλdeveloped for the full life cycle (9 weeks) of each species. ForD. magna,λvalues developed at >7 weeks (70% of the life cycle) were not significantly different fromλdeveloped for the full life cycle (10 weeks). Furthermore, these cutoff points forλwere not the same for other demographic parameters, with no clear pattern emerging. Our results indicate that forC. dubia, D. magna, andD. pulex, partial life tables can be used to generate population growth rates in lieu of full life tables. However, the implications of differences in cutoff points for different demographic parameters need to be investigated further.

scholarly journals Founder effects drive the genetic structure of passively dispersed aquatic invertebrates

2018 ◽  
Author(s):  
Javier Montero-Pau ◽  
Africa Gomez ◽  
Manuel Serra
Keyword(s):  
Life Cycle ◽  
Genetic Structure ◽  
Population Growth ◽  
Local Adaptation ◽  
Growth Rates ◽  
High Population ◽  
Founder Effects ◽  
Population Growth Rates ◽  
High Population Growth ◽  
The Impact

Populations of passively dispersed organisms in continental aquatic habitats typically show high levels of neutral genetic differentiation, despite their high dispersal capabilities. Several evolutionary factors, including founder events and local adaptation, and life cycle features such as high population growth rates and the presence of propagule banks, have been proposed to be responsible for this paradox. Here, we have modeled the colonization process in these organisms to assess the impact of migration rate, growth rate, population size, local adaptation and life-cycle features on their population genetic structure. Our simulation results show that the strongest effect on population structure is caused by persistent founder effects, resulting from the interaction of a few population founders, high population growth rates, large population sizes and the presence of diapausing egg banks. In contrast, the role of local adaptation, genetic hitchhiking and migration is limited to small populations in these organisms. Our results indicate that local adaptation could have different impact on genetic structure in different groups of zooplankters.

scholarly journals Founder effects drive the genetic structure of passively dispersed aquatic invertebrates

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e6094 ◽  
Author(s):  
Javier Montero-Pau ◽  
Africa Gómez ◽  
Manuel Serra
Keyword(s):  
Life Cycle ◽  
Genetic Structure ◽  
Population Growth ◽  
Local Adaptation ◽  
Growth Rates ◽  
High Population ◽  
Founder Effects ◽  
Population Growth Rates ◽  
High Population Growth ◽  
The Impact

Populations of passively dispersed organisms in continental aquatic habitats typically show high levels of neutral genetic differentiation despite their high dispersal capabilities. Several evolutionary factors, including founder events, local adaptation, and life cycle features such as high population growth rates and the presence of propagule banks, have been proposed to be responsible for this paradox. Here, we have modeled the colonization process to assess the impact of migration rate, population growth rate, population size, local adaptation and life-cycle features on the population genetic structure in these organisms. Our simulations show that the strongest effect on population structure are persistent founder effects, resulting from the interaction of a few population founders, high population growth rates, large population sizes and the presence of diapausing egg banks. In contrast, the role of local adaptation, genetic hitchhiking and migration is limited to small populations in these organisms. Our results indicate that local adaptation could have different impact on genetic structure in different groups of zooplankters.

scholarly journals Founder effects drive the genetic structure of passively dispersed aquatic invertebrates

2018 ◽  
Author(s):  
Javier Montero-Pau ◽  
Africa Gomez ◽  
Manuel Serra
Keyword(s):  
Life Cycle ◽  
Genetic Structure ◽  
Population Growth ◽  
Local Adaptation ◽  
Growth Rates ◽  
High Population ◽  
Founder Effects ◽  
Population Growth Rates ◽  
High Population Growth ◽  
The Impact

Populations of passively dispersed organisms in continental aquatic habitats typically show high levels of neutral genetic differentiation, despite their high dispersal capabilities. Several evolutionary factors, including founder events and local adaptation, and life cycle features such as high population growth rates and the presence of propagule banks, have been proposed to be responsible for this paradox. Here, we have modeled the colonization process in these organisms to assess the impact of migration rate, growth rate, population size, local adaptation and life-cycle features on their population genetic structure. Our simulation results show that the strongest effect on population structure is caused by persistent founder effects, resulting from the interaction of a few population founders, high population growth rates, large population sizes and the presence of diapausing egg banks. In contrast, the role of local adaptation, genetic hitchhiking and migration is limited to small populations in these organisms. Our results indicate that local adaptation could have different impact on genetic structure in different groups of zooplankters.

scholarly journals Founder effects drive the genetic structure of passively dispersed aquatic invertebrates

2017 ◽  
Author(s):  
Javier Montero-Pau ◽  
Africa Gomez ◽  
Manuel Serra
Keyword(s):  
Life Cycle ◽  
Genetic Structure ◽  
Population Growth ◽  
Local Adaptation ◽  
Growth Rates ◽  
High Population ◽  
Founder Effects ◽  
Population Growth Rates ◽  
High Population Growth ◽  
The Impact

Populations of passively dispersed organisms in continental aquatic habitats typically show high levels of neutral genetic differentiation, despite their high dispersal capabilities. Several evolutionary factors, including founder events and local adaptation, and life cycle features such as high population growth rates and the presence of propagule banks, have been proposed to be responsible for this paradox. Here, we have modeled the colonization process in these organisms to assess the impact of migration rate, growth rate, population size, local adaptation and life-cycle features on their population genetic structure. Our simulation results show that the strongest effect on population structure is caused by persistent founder effects, resulting from the interaction of a few population founders, high population growth rates, large population sizes and the presence of diapausing egg banks. In contrast, the role of local adaptation, genetic hitchhiking and migration is limited to small populations in these organisms. Our results indicate that local adaptation could have different impact on genetic structure in different groups of zooplankters.

scholarly journals Full life-cycle models from ring-recovery data: estimating fecundity from age ratios at capture

2018 ◽  
Author(s):  
Todd. W. Arnold
Keyword(s):  
Growth Rate ◽  
Life Cycle ◽  
Population Growth ◽  
Population Growth Rate ◽  
Large Scale ◽  
Adult Survival ◽  
List Type ◽  
Vital Rates ◽  
Full Life Cycle ◽  
Full Life

AbstractTag-recovery data from organisms captured and marked post breeding are commonly used to estimate juvenile and adult survival. If annual fecundity could also be estimated, tagging studies such as European and North American bird-ringing schemes could provide all parameters needed for building full life-cycle projection models.I modified existing tag-recovery models to allow estimation of annual fecundity using age composition and recapture probabilities obtained during routine banding operations of northern pintails (Anas acuta) and dark-eyed juncos (Junco hyemalis), and I conducted simulations to assess estimator performance in relation to sample size.For pintails, population growth rate from band-recovery data (λ = 0.929, SD 0.060) was similar but less precise than count-based estimates from the Waterfowl Breeding Pair and Habitat Survey (λ 0.945, SE 0.001). Models with temporal variation in vital rates indicated that annual population growth in pintails was driven primarily by variation in fecundity. Juncos had lower survival but greater fecundity, and their estimated population growth rate (λ 1.01, SD 0.19) was consistent with count-based surveys (λ 0.986).Simulations indicated that reliable (CV < 0.10) estimates of fecundity could be obtained with >1000 same-season live encounters. Although precision of survival estimates depended primarily on numbers of adult recoveries, estimates of population growth rate were most sensitive to total number of live encounters.Synthesis and applications: Large-scale ring-recovery programmes could be used to estimate annual fecundity in many species of birds, but the approach requires better data curation, including accurate assessment of age, better reporting of banding totals and greater emphasis on obtaining and reporting same-season live encounters.

scholarly journals Full life-cycle monitoring and earlier warning for bolt joint loosening using modified vibro-acoustic modulation

2022 ◽  
Vol 162 ◽  
pp. 108054
Author(s):  
Xiaoshu Qin ◽  
Chang Peng ◽  
Gaozheng Zhao ◽  
Zengye Ju ◽  
Shanshan Lv ◽  
...  
Keyword(s):  
Life Cycle ◽  
Full Life Cycle ◽  
Full Life ◽  
Acoustic Modulation ◽  
Cycle Monitoring

scholarly journals Estimates of regional annual abundance and population growth rates of white sharks off central California

2021 ◽  
Vol 257 ◽  
pp. 109104
Author(s):  
Paul E. Kanive ◽  
Jay J. Rotella ◽  
Taylor K. Chapple ◽  
Scot D. Anderson ◽  
Timothy D. White ◽  
...  
Keyword(s):  
Population Growth ◽  
Growth Rates ◽  
Central California ◽  
Population Growth Rates
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