Phylogenetic prediction of the maximum
            per capita
            rate of population growth

The maximum per capita rate of population growth, r , is a central measure of population biology. However, researchers can only directly calculate r when adequate time series, life tables and similar datasets are available. We instead view r as an evolvable, synthetic life-history trait and use comparative phylogenetic approaches to predict r for poorly known species. Combining molecular phylogenies, life-history trait data and stochastic macroevolutionary models, we predicted r for mammals of the Caniformia and Cervidae. Cross-validation analyses demonstrated that, even with sparse life-history data, comparative methods estimated r well and outperformed models based on body mass. Values of r predicted via comparative methods were in strong rank agreement with observed values and reduced mean prediction errors by approximately 68 per cent compared with two null models. We demonstrate the utility of our method by estimating r for 102 extant species in these mammal groups with unknown life-history traits.

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Aspects of the population biology, life history and threats to Aloe ortholopha Christian and Milne-Redh.: A serpentine endemic from the northern Great Dyke of Zimbabwe

Bothalia ◽

10.4102/abc.v49i1.2396 ◽

2019 ◽

Vol 49 (1) ◽

Cited By ~ 1

Author(s):

Ngoni I. Kunonga ◽

Tamuka Nhiwatiwa ◽

Mduduzi Tembani ◽

Shakkie Kativu

Keyword(s):

Life History ◽

Population Size ◽

Population Biology ◽

Reproductive Output ◽

Seed Set ◽

Size Class ◽

Great Dyke ◽

Size Class Distribution ◽

Class Distribution ◽

Per Capita

Background: Aloe ortholopha is a rare endemic confined to serpentine soils of the Great Dyke of Zimbabwe. Its International Union for Conservation of Nature (IUCN) status is listed as Vulnerable; however, its population biology and life history are poorly documented.Objectives: The aim of this article is to provide information on the population biology and life history of A. ortholopha through assessment of its size-class distribution, population size and density, reproductive output and fitness, and threats related to fire and mining.Method: Circumference of A. ortholopha leaf rosette was used to ascertain size-class distribution. Population size and density were determined by enumerating flowering individuals. Per-capita reproductive output was determined as mean number of flowers per plant, fruit set and mean number of seeds per fruit. Fitness was determined from seed germination capacity. Impact of fire and mining were recorded photographically.Results: Determination of size-class distribution of A. ortholopha from three study sites (southern region [SR], central region [CR] and northern region [NR]) revealed a bell-shaped curve dominated by intermediate size classes. Population size (number of flowering individuals) ranged from 36 to 66 per site. This translated to a density of 4.0–7.3 flowering plants per hectare. Per-capita reproductive output, measured as mean number of flowers per plant, was significantly different in SR and CR compared to that in the NR region. Mean number of fruits per plant did not significantly differ across the three regions. Mean seed set per plant in CR and NR was significantly different to that in the SR region. Species fitness, as determined from in vitro germination assays, showed that seeds harvested from fire-damaged capsules have the lowest cumulative germination percentage. It was also observed that leaf rosettes curled up to form a ball that protects the apical centre of plants from fire damage.Conclusion: A. ortholopha occurs in small population clusters of low density. The species has a low per-capita reproductive output characterised by production of many flowers, but with very low percentage fruit and seed set. The species has low fitness as evidenced by nominal recruitment of saplings and juveniles. Conspecific mates are frequently lost owing to fire and mining activities.

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Estimating the per Capita Rate of Population Change: How Well Do Life-History Surrogates Perform?

Annals of the Entomological Society of America ◽

10.1603/an09162 ◽

2010 ◽

Vol 103 (5) ◽

pp. 734-741 ◽

Cited By ~ 9

Author(s):

M. W. Chmielewski ◽

C. Khatchikian ◽

T. Livdahl

Keyword(s):

Life History ◽

Population Change ◽

Capita Rate ◽

Per Capita

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Legislation: Proposition 9 may increase per capita rate for school districts

PsycEXTRA Dataset ◽

10.1037/e363312004-003 ◽

2003 ◽

Author(s):

Keyword(s):

School Districts ◽

Capita Rate ◽

Per Capita

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A Successful Population Policy: Potentials and Constraints (Distinguishedl Lecture)

The Pakistan Development Review ◽

10.30541/v32i4ipp.411-431 ◽

1993 ◽

Vol 32 (4I) ◽

pp. 411-431

Author(s):

Hans-Rimbert Hemmer

Keyword(s):

Developing Countries ◽

Economic Development ◽

Population Growth ◽

Capita Income ◽

Population Policy ◽

Mortality Rates ◽

Per Capita Income ◽

Access To Health Services ◽

Industrial Countries ◽

Per Capita

The current rapid population growth in many developing countries is the result of an historical process in the course of which mortality rates have fallen significantly but birthrates have remained constant or fallen only slightly. Whereas, in industrial countries, the drop in mortality rates, triggered by improvements in nutrition and progress in medicine and hygiene, was a reaction to economic development, which ensured that despite the concomitant growth in population no economic difficulties arose (the gross national product (GNP) grew faster than the population so that per capita income (PCI) continued to rise), the drop in mortality rates to be observed in developing countries over the last 60 years has been the result of exogenous influences: to a large degree the developing countries have imported the advances made in industrial countries in the fields of medicine and hygiene. Thus, the drop in mortality rates has not been the product of economic development; rather, it has occurred in isolation from it, thereby leading to a rise in population unaccompanied by economic growth. Growth in GNP has not kept pace with population growth: as a result, per capita income in many developing countries has stagnated or fallen. Mortality rates in developing countries are still higher than those in industrial countries, but the gap is closing appreciably. Ultimately, this gap is not due to differences in medical or hygienic know-how but to economic bottlenecks (e.g. malnutrition, access to health services)

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Mapping the adaptive landscape of a major agricultural pathogen reveals evolutionary constraints across heterogeneous environments

The ISME Journal ◽

10.1038/s41396-020-00859-w ◽

2021 ◽

Author(s):

Anik Dutta ◽

Fanny E. Hartmann ◽

Carolina Sardinha Francisco ◽

Bruce A. McDonald ◽

Daniel Croll

Keyword(s):

Life History ◽

Large Scale ◽

Life History Traits ◽

Genetic Correlations ◽

Stress Factors ◽

Life History Trait ◽

Adaptive Landscape ◽

Heterogeneous Environments ◽

Growth Responses ◽

Trade Offs

AbstractThe adaptive potential of pathogens in novel or heterogeneous environments underpins the risk of disease epidemics. Antagonistic pleiotropy or differential resource allocation among life-history traits can constrain pathogen adaptation. However, we lack understanding of how the genetic architecture of individual traits can generate trade-offs. Here, we report a large-scale study based on 145 global strains of the fungal wheat pathogen Zymoseptoria tritici from four continents. We measured 50 life-history traits, including virulence and reproduction on 12 different wheat hosts and growth responses to several abiotic stressors. To elucidate the genetic basis of adaptation, we used genome-wide association mapping coupled with genetic correlation analyses. We show that most traits are governed by polygenic architectures and are highly heritable suggesting that adaptation proceeds mainly through allele frequency shifts at many loci. We identified negative genetic correlations among traits related to host colonization and survival in stressful environments. Such genetic constraints indicate that pleiotropic effects could limit the pathogen’s ability to cause host damage. In contrast, adaptation to abiotic stress factors was likely facilitated by synergistic pleiotropy. Our study illustrates how comprehensive mapping of life-history trait architectures across diverse environments allows to predict evolutionary trajectories of pathogens confronted with environmental perturbations.

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Toward a Dualistic Growth? Population Increase and Land-Use Change in Rome, Italy

Land ◽

10.3390/land10070749 ◽

2021 ◽

Vol 10 (7) ◽

pp. 749

Author(s):

Leonardo Bianchini ◽

Gianluca Egidi ◽

Ahmed Alhuseen ◽

Adele Sateriano ◽

Sirio Cividino ◽

...

Keyword(s):

Land Use ◽

Land Use Change ◽

Population Growth ◽

Mediterranean Basin ◽

Urban Expansion ◽

Arable Land ◽

Central Italy ◽

Agricultural Landscapes ◽

Population Increase ◽

Per Capita

The spatial mismatch between population growth and settlement expansion is at the base of current models of urban growth. Empirical evidence is increasingly required to inform planning measures promoting urban containment in the context of a stable (or declining) population. In these regards, per-capita indicators of land-use change can be adopted with the aim at evaluating long-term sustainability of urbanization processes. The present study assesses spatial variations in per-capita indicators of land-use change in Rome, Central Italy, at five years (1949, 1974, 1999, 2008, and 2016) with the final objective of quantifying the mismatch between urban expansion and population growth. Originally specialized in agricultural productions, Rome’s metropolitan area is a paradigmatic example of dispersed urban expansion in the Mediterranean basin. By considering multiple land-use dynamics, per-capita indicators of landscape change delineated three distinctive waves of growth corresponding with urbanization, suburbanization, and a more mixed stage with counter-urbanization and re-urbanization impulses. By reflecting different socioeconomic contexts on a local scale, urban fabric and forests were identified as the ‘winner’ classes, expanding homogeneously over time at the expense of cropland. Agricultural landscapes experienced a more heterogeneous trend with arable land and pastures declining systematically and more fragmented land classes (e.g., vineyards and olive groves) displaying stable (or slightly increasing) trends. The continuous reduction of per-capita surface area of cropland that’s supports a reduced production base, which is now insufficient to satisfy the rising demand for fresh food at the metropolitan scale, indicates the unsustainability of the current development in Rome and more generally in the whole Mediterranean basin, a region specialized traditionally in (proximity) agricultural productions.

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Dating the Great Divergence

Journal of Global History ◽

10.1017/s1740022820000406 ◽

2021 ◽

Vol 16 (2) ◽

pp. 266-285

Author(s):

Jack A. Goldstone

Keyword(s):

Population Growth ◽

Industrial Revolution ◽

Income Growth ◽

Strong Growth ◽

Income Per Capita ◽

Great Divergence ◽

Per Capita

AbstractNew data on Dutch and British GDP/capita show that at no time prior to 1750, perhaps not before 1800, did the leading countries of northwestern Europe enjoy sustained strong growth in GDP/capita. Such growth in income per head as did occur was highly episodic, concentrated in a few decades and then followed by long periods of stagnation of income per head. Moreover, at no time before 1800 did the leading economies of northwestern Europe reach levels of income per capita much different from peak levels achieved hundreds of years earlier in the most developed regions of Italy and China. When the Industrial Revolution began in Britain, it was not preceded by patterns of pre-modern income growth that were in any way remarkable, neither by sustained prior growth in real incomes nor exceptional levels of income per head. The Great Divergence, seen as the onset of sustained increases in income per head despite strong population growth, and achievement of incomes beyond pre-modern peaks, was a late occurrence, arising only from 1800.

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Natural variation in fecundity is correlated with species-wide levels of divergence in Caenorhabditis elegans

G3 Genes|Genome|Genetics ◽

10.1093/g3journal/jkab168 ◽

2021 ◽

Author(s):

Gaotian Zhang ◽

Jake D Mostad ◽

Erik C Andersen

Keyword(s):

Life History ◽

Caenorhabditis Elegans ◽

Life History Traits ◽

Life History Trait ◽

Selective Sweeps ◽

C Elegans ◽

Genome Wide ◽

Genetic Complexity ◽

Genomic Regions ◽

Global Population

Abstract Life history traits underlie the fitness of organisms and are under strong natural selection. A new mutation that positively impacts a life history trait will likely increase in frequency and become fixed in a population (e.g. a selective sweep). The identification of the beneficial alleles that underlie selective sweeps provides insights into the mechanisms that occurred during the evolution of a species. In the global population of Caenorhabditis elegans, we previously identified selective sweeps that have drastically reduced chromosomal-scale genetic diversity in the species. Here, we measured the fecundity of 121 wild C. elegans strains, including many recently isolated divergent strains from the Hawaiian islands and found that strains with larger swept genomic regions have significantly higher fecundity than strains without evidence of the recent selective sweeps. We used genome-wide association (GWA) mapping to identify three quantitative trait loci (QTL) underlying the fecundity variation. Additionally, we mapped previous fecundity data from wild C. elegans strains and C. elegans recombinant inbred advanced intercross lines that were grown in various conditions and detected eight QTL using GWA and linkage mappings. These QTL show the genetic complexity of fecundity across this species. Moreover, the haplotype structure in each GWA QTL region revealed correlations with recent selective sweeps in the C. elegans population. North American and European strains had significantly higher fecundity than most strains from Hawaii, a hypothesized origin of the C. elegans species, suggesting that beneficial alleles that caused increased fecundity could underlie the selective sweeps during the worldwide expansion of C. elegans.

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Demography of Xenosaurus platyceps (Squamata: Xenosauridae): a comparison between tropical and temperate populations

Amphibia-Reptilia ◽

10.1163/156853808784124992 ◽

2008 ◽

Vol 29 (2) ◽

pp. 245-256 ◽

Cited By ~ 6

Author(s):

Carissa Jones ◽

Isaac Rojas-González ◽

Julio Lemos-Espinal ◽

Jaime Zúñiga-Vega

Keyword(s):

Life History ◽

Population Growth ◽

Adult Mortality ◽

Life History Strategies ◽

Relative Importance ◽

Theoretical Frameworks ◽

Population Growth Rates ◽

Relative Contribution ◽

Two Populations ◽

Average Fitness

Abstract There appears to be variation in life-history strategies even between populations of the same species. For ectothermic organisms such as lizards, it has been predicted that demographic and life-history traits should differ consistently between temperate and tropical populations. This study compares the demographic strategies of a temperate and a tropical population of the lizard Xenosaurus platyceps. Population growth rates in both types of environments indicated populations in numerical equilibrium. Of the two populations, we found that the temperate population experiences lower adult mortality. The relative importance (estimated as the relative contribution to population growth rate) of permanence and of the adult/reproductive size classes is higher in the temperate population. In contrast, the relative importance for average fitness of fecundity and growth is higher in the tropical population. These results are consistent with the theoretical frameworks about life-historical differences among tropical and temperate lizard populations.

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