Decrease In Population Size Research Articles

Some considerations on care of the elderly, using evolutionary genetic models

Some evolutionary genetic models that assume pleiotropic constraints among care for old parents and care for infants are developed, in order to examine the evolution of care for the elderly within a population, in which population aging coupled with a tendency toward a decrease in population size is in progress. Not only does this study suggest that high levels of care for old parents could evolve within the population if the cost of care of the elderly is not too heavy, but it also suggests that, if younger generations experience a high cost of elderly care, this behavior might be eliminated from the population, resulting in the loss of high levels of care for infants. It is also suggested that the benefit of the help from the elderly is essential, not only for the behavior of care for old parents to be maintained within the population, but also for population growth, even though there may be a high cost of elderly care. Based on the results obtained, some social issues that some countries, such as Japan, are now, or will be, faced with are discussed.

Some considerations on care of the elderly, using evolutionary genetic models

Some evolutionary genetic models that assume pleiotropic constraints among care for old parents and care for infants are developed, in order to examine the evolution of care for the elderly within a population, in which population aging coupled with a tendency toward a decrease in population size is in progress. Not only does this study suggest that high levels of care for old parents could evolve within the population if the cost of care of the elderly is not too heavy, but it also suggests that, if younger generations experience a high cost of elderly care, this behavior might be eliminated from the population, resulting in the loss of high levels of care for infants. It is also suggested that the benefit of the help from the elderly is essential, not only for the behavior of care for old parents to be maintained within the population, but also for population growth, even though there may be a high cost of elderly care. Based on the results obtained, some social issues that some countries, such as Japan, are now, or will be, faced with are discussed.

PSX-18 High-density genomic description of Russian native sheep breed of the Republic of Tyva

Abstract Tuva breed is the oldest native sheep breed in Russia with more than 2000 year-history and comes in third place by population size among coarse wool sheep. Tuva sheep produce high-quality meat as well as coarse wool to make traditional clothing in the Republic of Tyva. In present study, we aimed to evaluate genetic diversity and to establish genetic links of the Tuva breed with the other Russian coarse wool sheep to understand the origin and current status of this valuable livestock species. Twenty samples of Tuva were genotyped using Ovine Infinium® HD SNP BeadChip (Illumina, CA, USA). SNP-data were processed in PLINKv1.9, R package ‘diveRsity’ and SneP software. High-density SNP-genotypes of 10 coarse wool sheep breeds were used as comparison groups. Observed heterozygosity (Ho) and allelic richness (Ar) in Tuva breed were 0.336 and 1.884, respectively, and were practically equal to mean values estimated across all analyzed sheep breeds (Ho=0.335, Ar=1.884). All coarse wool breeds showed moderate heterozygote excess which was the highest in Tuva breed (1.6%). Effective population sizes estimated for three and five generations ago for Tuva breed (Ne3 =118 and Ne5 =179) were less than those in other breeds (Ne3 = 314 and Ne5 = 441 for Edilbai or Ne3 = 300 and Ne5 = 450 for Kalmyk) but not the lowest (Ne3 = 49 and Ne5 = 72 for Buubei). Values of historical effective population size estimated for 60 generations ago for Tuva breed was 1457 that was compatible with those obtained for other breeds (Ne60 from 586 for Buubei to 2634 for Kalmyk). Despite the obvious decrease in effective population size, levels of genetic diversity are not critical that would allow to develop programs to ensure preservation and sustainable development of Tuva breed. The study was funded by RSF No. 19-16-00070.

Slow breeding rates and low population connectivity indicate Australian palm cockatoos are in severe decline

Dispersal dynamics can determine whether animal populations recover or become extinct following decline or disturbance, especially for species with slow life-histories that cannot replenish quickly. Palm cockatoos (Probosciger aterrimus) have one of the slowest known reproductive rates of any parrot, and they face steep decline in at least one of three populations comprising the meta-population for the species in Australia. Consequently, we estimated demographic rates and population connectivity using data from published field studies, population genetics, and vocal dialects. We then used these parameters in a population viability analysis (PVA) to predict the trajectories of the three regional populations, together with the trajectory of the meta-population. We incorporated dispersal between populations using genetic and vocal data modified by landscape permeability, whereby dispersal is limited by a major topographical barrier and non-uniform habitat. Our PVA models suggest that, while dispersal between palm cockatoo populations can reduce local population decline, this is not enough to buffer steep decline in one population with very low breeding success. The small population size and likely decrease in the meta-population of greater than 50% over three generations (49 years) supports a change of conservation status for Australian palm cockatoos from ‘Vulnerable’ to ‘Endangered’ under IUCN criteria. Our research provides an important demonstration of how PVA can be used to assess the influence of complex meta-population scale processes on the population trajectory of species that are challenging to monitor.

Determinism of Temporal Variability in Size at Maturation of Sardine Sardina pilchardus in the Bay of Biscay

Age and size at maturation appear as key parameters governing the dynamics of a population as they affect growth rate, fecundity, and survival. The expression of such life history traits is determined by genetic make-up and modulated by environmental factors mainly through phenotypic plasticity. Moreover, fishing, besides decreasing population size and changing demographic composition can alter allelic frequencies through fisheries-induced evolution by selecting for some particular traits. In the Bay of Biscay, a decreasing trend in both sardine body condition and size-at-age has recently been pointed out at the population level. The Probabilistic Maturation Reaction Norm (PMRN) approach was applied to help disentangle phenotypic plasticity and genetic changes. Based on the analysis of sardine spawning seasonality, PMRN was estimated by considering body condition as additional life-history state variable to predict the onset of maturation. The resulting PMRN was then used to investigate temporal trends in reaction norm midpoints to test whether changes in length at maturation can be explained by plastic and/or evolutionary adaptive change. Overall, our results emphasize for the first time that including sardine body condition as explanatory variable improves predictions of maturation probability. We found that better individual condition increases maturation probability. The assessment of temporal changes in length at maturation confirms the low plasticity in this trait for a species maturing mostly at age-1 and advocates for the use of a monthly time scale when investigating PMRNs for this species. Beside environmental variables included in this analysis (water temperature, chlorophyll-a, and population biomass) that only show a weak correlation with PMRN midpoints, our results reveal no evidence for recent fisheries-induced evolution in the sardine stock of the Bay of Biscay. They suggest that the short-term variability in length at maturation is strongly dependent upon individual growth which is likely driven by environmental factors. For sardine fisheries management, our study highlights the need to consider both the length-composition data and the seasonality within a stock assessment model. Finally, we discuss the fact that considering individual growth trajectories should improve our understanding of the relationship between environmental variability and changes in maturation for sardine.

Low genetic diversity indicating the threatened status of Rhizophora apiculata (Rhizophoraceae) in Malaysia: declined evolution meets habitat destruction

Worldwide, many mangrove species are experiencing significant population declines, including Rhizophora apiculata, which is one of the most widespread and economically important species in tropical Asia. In Malaysia, there has been an alarming decline in R. apiculata populations driven primarily by anthropogenic activities. However, the lack of genetic and demographic information on this species has hampered local efforts to conserve it. To address these gaps, we generated novel genetic information for R. apiculata, based on 1,120 samples collected from 39 natural populations in Peninsular Malaysia. We investigated its genetic diversity and genetic structure with 19 transcriptome and three nuclear microsatellite markers. Our analyses revealed a low genetic diversity (mean He: 0.352) with significant genetic differentiation (FST: 0.315) among populations of R. apiculata. Approximately two-third of the populations showed significant excess of homozygotes, indicating persistent inbreeding which might be due to the decrease in population size or fragmentation. From the cluster analyses, the populations investigated were divided into two distinct clusters, comprising the west and east coasts of Peninsular Malaysia. The western cluster was further divided into two sub-clusters with one of the sub-clusters showing strong admixture pattern that harbours high levels of genetic diversity, thus deserving high priority for conservation.

Population structure and point pattern analysis of rare and endangered plant Helianthemum soongoricum in Ningxia, China

Helianthemum songaricum is a second-class protected plant in China, threatened by decreased population size and fragmentation of distribution area. It is a new record species in Ningxia. We analyzed population structure, spatial distribution, and relationship of different age classes of H. songaricum living in sandy and gravel habitats. The results showed that majority of H. songaricum individuals were belonged to age-class Ⅲ. The age structure of the population was inverted triangle. The population was at a declining stage. The spatial pattern and spatial association between different age class of H. songaricum were greatly affected by habitat condition, with strong dependence on spatial scale. Compared with sandy habitat, H. songaricum population in gravel habitat tended to be clustered distribution, with a more obvious positive correlation among different age classes. The difference between two habitats was related to environmental condition and plant community structure. H. songaricum from age-class Ⅰ and Ⅱ had mutually dependent ecological relationships.

Long‐term trends in the survival rates of adult female Common EiderSomateria mollissimaat three colonies in Iceland

Identifying temporal and spatial patterns in demography is critical to understanding long‐term fluctuations in population size. Common EiderSomateria mollissimanumbers have shown a long‐term decline, resulting in the species being uplisted in 2015 to ‘Endangered’ within European Union countries. Obtaining improved estimates of survival rates of Common Eiders (and other seaducks) has been identified as a priority to improve our understanding of the demographic causes of the observed global decreases in population size and to inform conservation efforts. In this study, we used long‐term (1982–2017) mark–recovery data on 3018 individuals from three breeding colonies in Iceland to quantify the spatial and temporal variation in the annual true survival rates of adult female Common Eider. Model comparison using an information‐theoretic approach indicated that true survival and recovery rates varied between years and colonies but showed no consistent temporal pattern across the three colonies. Geometric mean (± se) annual true survival across our three breeding colonies was 0.916 ± 0.017 (95% confidence interval (CI) = 0.819–0.961), with a mean life expectancy of 11.8 years (95% CI 5.4–25.2). Our survival estimates were relatively high compared with those reported previously for many other Common Eider populations, which may reflect their protected status, low predation pressure and high food availability on Iceland and its surrounding waters. Our findings provide spatially and temporally explicit demographic information needed to help conservationists understand the local and global declines in Common Eider populations.

Mapping spatial distribution of genetic resources of kola (Cola nitida (Vent.) Schott & Endl.) in Ghana and collection of germplasm for conservation, characterization and development of improved varieties

Kola (Cola nitida (Vent.) Schott & Endl.) is a tree crop of great economic and socio-cultural importance. Available genetic resources of kola are increasingly vulnerable to genetic erosion due to decreased population sizes resulting from land use changes and cutting of trees for timber and firewood production. There is therefore an urgent need to conserve genetic resources of kola in Ghana. The objective of this research was to map distribution, ascertain status of collection and conservation of kola in Ghana and to collect germplasm from mapped provenances for characterization and breeding of improved varieties. Mapping of distribution of kola was carried out by undertaking trips to kola growing areas in Ghana. Transects were constructed and an inventory of C. nitida was carried out using GPS. The geo-references were interpolated into the map of Ghana using ArcGIS software. The spatial analysis showed Jasikan, Akaa, Ahamasu, Ampeyo, Pampawie, Oyoko, Akwadum, Jejeti, Atwedie, Kwahu, Asuom, Tweapease, Kade, Twifo Praso, Assin Fosu, Ntafrewaso, Hemang, Jamasi, Kona, Bipoa, Offinso, Akumadan and Aframcho as the areas with a dense natural populations of C. nitida. The current knowledge and understanding of distribution of kola resources provides opportunity to have a comprehensive collection of genetic resources of kola in Ghana. This aided in collection of 102 new accessions from 22 provenances in the Volta and Eastern regions of Ghana. This in addition to 226 earlier collections constitute 328 accessions of C. nitida in Ghana. The evaluation and understanding of diversity of these kola resources could offer yet-unknown traits of high economic value for further domestication and development of improved varieties.

Antarctic krill fishery effects over penguin populations under adverse climate conditions: Implications for the management of fishing practices.

Fast climate changes in the western Antarctic Peninsula are reducing krill density, which along with increased fishing activities in recent decades, may have had synergistic effects on penguin populations. We tested that assumption by crossing data on fishing activities and Southern Annular Mode (an indicator of climate change in Antarctica) with penguin population data. Increases in fishing catch during the non-breeding period were likely to result in impacts on both chinstrap (Pygoscelis antarcticus) and gentoo (P. papua) populations. Catches and climate change together elevated the probability of negative population growth rates: very high fishing catch on years with warm winters and low sea ice (associated with negative Southern Annular Mode values) implied a decrease in population size in the following year. The current management of krill fishery in the Southern Ocean takes into account an arbitrary and fixed catch limit that does not reflect the variability of the krill population under effects of climate change, therefore affecting penguin populations when the environmental conditions were not favorable.

When survival matters: is decreasing survival underlying the decline of common pochard in western Europe?

In western Europe, common pochard populations have experienced a sharp decline over the last two decades, together with an increasing proportion of males. Both of these changes were suggested to result from decreasing survival of nesting females (i.e. survival of adult females) owing to increasing predation pressure. To test this hypothesis, we used capture–mark–recapture/recovery data of common pochard ringed during autumn–winter (October–February) in three countries of western Europe (Switzerland, United Kingdom and France). We found no evidence for decreasing survival of individuals ringed in the United Kingdom or in Switzerland over the long term (1977–2011). In France, adult males and juvenile females experienced significant decreasing survival over a shorter interval (2004–2017). Overall, females displayed lower survival than males, although this was only weakly supported by the French dataset. In contrast, only sex differences and no age differences in survival rates were recorded in the UK and Switzerland (females 0.67 ± 0.03 and 0.69 ± 0.03; males: 0.81 ± 0.01 and 0.75 ± 0.01, respectively), while both age and sex differences were recorded for France (adult females 0.62 ± 0.07, adult males 0.66 ± 0.07, juvenile females 0.49 ± 0.08, juvenile males 0.54 ± 0.08). Therefore, decreasing survival of adult females was unlikely the underlying cause of the decline of common pochard populations in western Europe. Using an age‐structured two‐sex matrix population model, we show that when adult males experience higher survival than adult females (as it is the case for common pochards), decreasing survival of nests and/or juveniles can trigger decreasing population size and increasing proportions of males at the same time.

Gene conservation of six Hungarian local chicken breeds maintained in small populations over time.

Investigation into the genetic diversity of certain endangered native breeds of domestic animals has been in common practice for several decades. The primary objective of these investigations has been to reveal the exceptional genetic value of such breeds, both for their conservation and also to gain insight into their current genetic status, as they have been undergoing a progressive decrease in population size and general diversity; this has been compounded by the general lack of an optimal breeding scheme. In this study, we have investigated changes in the genetic diversity of six Hungarian local chicken breeds based on 29 microsatellite loci over a period of 15 years. In terms of the basic diversity measures, populations sampled in 2017 generally exhibited a lower heterozygosity and mean number of alleles and thus, experienced a higher degree of inbreeding. Although the effective population size increased, the estimates of populations sampled over different periods indicated comparatively low values, suggesting overall lower genetic variance. Pairwise FST estimates were higher in the populations sampled in 2017, showing a larger genetic distance between them. Considerable differences exist between the populations of the same breeds, which can most likely be attributed to genetic drift. STRUCTURE results have shown a clear separation between the Hungarian populations, which is in agreement with the principal coordinate analysis. The most likely clustering was found at K = 6, classifying the populations of the same breed as one group. No considerable allele loss was found in the Hungarian indigenous chicken breeds after 15 years of conservation. In general terms, after 15 years, the level of inbreeding within the populations was, in fact, higher, although this could be effectively reduced through the use of an improved mating system. Consequently, the breed management applied in the case of Hungarian local chicken breeds was found to be effective at adequately conserving their genetic variability.

Genetic structure and diversity in the freshwater gastropod Chilina dombeiana in the Biobío River, Chile

In river ecosystems, spatial complexity as well as anthropogenic factors operating at different temporal and spatial scales are shaping demography, connectivity and population genetic structure of species inhabiting these habitats. Chilina dombeiana is a freshwater gastropod with direct development (absence of a free larval phase) that inhabits the Biobio river basin in Chile (36°S). No studies have yet evaluated the spatial patterns of the genetic diversity of this species and the potential factors that influence these patterns. Consequently, in this study, we analyzed the population genetics of C. dombeiana based on 15 locations along the Biobio river. Eight microsatellite loci were genotyped. Also, at each sampling site, 40 environmental parameters were recorded to characterize them. Results showed that C. dombeiana has low genetic variability with high population structure. In addition, we detected signs of historical decreases in effective population sizes, unidirectional gene flow (upstream to downstream) and contemporary demographic bottleneck. Spatial subdivisions in populations showed a pattern of isolation by distance. The redundancy analysis and variance partitioning showed that spatial components and dissolved oxygen could explain 28% of the interpopulation genetic variation, while the Random Forest analysis identified significant effects of dissolved oxygen, nitrite and total coliforms on the genetic variability of populations (22%). Although C. dombeiana is widely distributed in Chilean rivers, its low dispersal and specific habitat requirements make this species very sensitive to the severe increase in anthropogenic disturbances affecting river ecosystems in recent decades. Long-term monitoring of genetic population conditions and environmental parameters are needed to implement robust management and conservation policies.

Mitochondrial DNA variation and phylogeography of Old World camels.

ObjectiveOld World camels are a valuable genetic resource for many countries around the world due to their adaptation to the desert environment. At present, Old World camels have encountered the challenge of unprecedented loss of genetic resources. Through our research, we would reveal the population structure and genetic variation in Old World camel populations, which provides a theoretical basis for understanding the germplasm resources and origin and evolution of different Old World camel populations.MethodsIn the present study, we assessed mtDNA control region sequences of 182 individuals from Old World camels to unravel genetic diversity, phylogeography, and demographic dynamics.ResultsThirty-two haplotypes confirmed by 54 polymorphic sites were identified in the 156 sequences, which included 129 domestic and 27 wild Bactrian camels. Meanwhile, 14 haplotypes were defined by 47 polymorphic sites from 26 sequences in the dromedaries. The wild Bactrian camel population showed the lowest haplotype and nucleotide diversity, while the dromedaries investigated had the highest. The phylogenetic analysis suggests that there are several shared haplotypes in different Bactrian camel populations, and that there has been genetic introgression between domestic Bactrian camels and dromedaries. In addition, positive values of Tajima’s D and Fu’s Fs test demonstrated a decrease in population size and/or balancing selection in the wild Bactrian camel population. In contrast, the negative values of Tajima’s D and Fu’s Fs test in East Asian Bactrian camel populations explained the demographic expansion and/or positive selection.ConclusionIn summary, we report novel information regarding the genetic diversity, population structure and demographic dynamics of Old World camels. The findings obtained from the present study reveal that abundant genetic diversity occurs in domestic Bactrian camel populations and dromedaries, while there are low levels of haplotype and nucleotide diversity in the wild Bactrian camel population.

Does Land Finance Contraction Accelerate Urban Shrinkage? A Study Based on 84 Key Cities in China

Abstract After approximately 30 years of sustained and rapid development, some Chinese cities have seen urban shrinkage marked by a decreasing population size. Land finance, which is the second pub...

Challenges in monitoring mobile populations: Applying bayesian multi‐site mark–recapture abundance estimation to the monitoring of a highly mobile coastal population of bottlenose dolphins

Abstract Monitoring the abundance of mobile and wide‐ranging cetacean populations for conservation management is challenging, especially when the management is focused on static protected areas. Where abundance estimates are derived from mark–recapture data, such as photo‐identification of naturally marked individuals, unpredictable movements of animals in and out of the survey area can reduce ‘capture’ probabilities and affect the precision and accuracy of resulting estimates. A Bayesian hierarchical log–linear model was applied to photo‐identification data collected in summer 2014 to derive a multi‐site abundance estimate for a population of bottlenose dolphins, Tursiops truncatus, ranging widely throughout the coastal waters of western Ireland. In addition, the effects of varying levels of sampling effort on the minimum detectable decrease in population size were examined. The abundance (median) of dolphins was estimated as 189 (coefficient of variation (standard deviation/mean), 0.11; 95% highest‐posterior density interval, 162–232). Over 50% of the well‐marked dolphins encountered throughout the study were sighted in more than one distinct coastal area, thus displaying high mobility. In addition, it was found that it would require biennial surveys to detect a 25% decline in abundance within the six‐year reporting period of the EU’s Habitats Directive. Given that the Special Area of Conservation designated for these dolphins consists of two separate areas covering a substantial portion of the west coast of Ireland, the multisite approach is appropriate for monitoring this population. It produces a more precise estimate and is well suited for sparse recapture data collected opportunistically at multiple sites, when the lack of resources prevents large‐scale surveys or when concentrating surveys on smaller localized areas fails to capture the broad range and unpredictable occurrence of the animals. The Bayesian multi‐site approach could be applied to the management of other wide‐ranging marine or terrestrial taxa.

Demography of <i>Attalea nucifera</i>: Sustainable management and conservation of a threatened species of Colombia

Attalea nucifera is an acaulescent palm native of Colombia that is in risk of extinction. Between 2016-2017 we evaluated the structure and density of populations in six localities of the Magdalena river valley, and studied the population dynamic in the locality of Guaduas, Cundinamarca (VC). Although the population structure differs among locations (X2 = 1819, gl = 25, P < 0.05), populations tend to group according to the degree of habitat perturbation. In four localities an inverted J population structure was observed. A matrix population model showed a finite growth rate (λ) of 0.979 (CI95 % = 0.962–0.997). The demographic processes of the permanence of seedlings, sub-adults and young adults show more elasticity. A transient dynamic simulation projected to 30 years shows that under the scenarios of paddock and cattle lopping the population size decrease drastically. The extinction threshold calculated for the population in the locality VC is of 145 years, but paddock and cattle lopping activities can reduce it to less than 40 years. Although Attalea nucifera persists in very disturbing locations in the Middle Magdalena Basin, the results of population dynamics in the locality VC suggest that it could be less tolerant of environmental disturbances. Thus, it is necessary to increase our knowledge of its population dynamics, as well as seed germination and seedling establishment in different disturbance conditions.

Solving artificial ant problem using two artificial bee colony programming versions

Artificialant problem is considered as a sub-problem of robotic path planning. In this study, it is solved using two different methods: artificial bee colony programming and a new version of it called shrinking artificial bee colony programming. The former is a novel evolutionary computation based automatic programming method based on artificial bee colony algorithm and it was previously applied to this problem by the researchers. However, in this study, more comprehensive analyses and comparison study are provided. The shrinking artificial bee colony programming was developed in this study and its basic idea is to reduce the number of food sources, periodically, instead of a constant number used in the artificial bee colony programming. First, some parameter tuning studies were carried out for the shrinking artificial bee colony programming. Then, performances of the artificial bee colony programming, shrinking artificial bee colony programming and some other evolutionary computation based automatic programming methods were compared on Santa Fe and Los Altos Hills trails. Simulation results and the comparison study show that both of the algorithms can be used to solve the artificial ant problem effectively. Furthermore, the periodically decreasing population size property added to the artificial bee colony programming improves the performance of the algorithm on the artificial ant problem. While the proposed approach shows one of the superior performances among the considered methods, the results of the artificial bee colony programming are competitive to the methods in the comparison study.

A perfect storm of genetic drift and divergence may prevent the rebuilding of the gemfish (Rexea solandri) stock on the east Australian coast

The potentially negative effects of genetic drift are expected to be minor in fisheries species because they are numerically abundant, fecund and able to move freely in ecosystems that lack barriers to gene flow. Here we investigate the operation of genetic drift in a fisheries species that has experienced a dramatic decrease in population size. On the east coast of Australia between 1977–1988 the peak catch of gemfish (Rexea solandri) was approximately 5000 tonnes pa before a 95% decline with little subsequent recovery. To test for genetic drift on the east coast and to investigate population structure, individuals from six locations were genotyped with SNP (n = 2197) and microsatellite (n = 13) loci and were assayed for sequence variation in the mtDNA control region. Genetic divergence between the two populations (east and west) was high; FST for SNP loci was 0.439, G’’ST for microsatellite loci was 0.195 and mtDNA haplotypes were fixed. There was no evidence of interbreeding or gene flow between populations despite spatial overlap. The genetic diversity of the overexploited east population was 10% lower and allelic richness was 28% lower than the west population based on microsatellite loci, and there were significantly fewer SNP alleles in the east compared to the west population. Tajima’s D for SNP loci from the east population was high (1.826) providing support for a sudden population contraction. Genetic effective population size was 486 (95% CI; 278–1779) in the east compared to 1487 (95% CI; 592–infinite) for the west population. We conclude that genetic drift has occurred within the east population and speculate that this has disrupted adaptation, which may explain the resistance of the population to recovery from overharvesting and may indicate a reduced capacity to respond to environmental change. Similar combinations of genetic and genomic approaches may reveal the operation of genetic drift in other harvested species, emphasising the urgency to preserve naturally occurring animal populations which are essential for human food security.

Genome-Wide Diversity, Population Structure and Demographic History of Dromedaries in the Central Desert of Iran.

The development of camel husbandry for good production in a desert climate is very important, thus we need to understand the genetic basis of camels and give attention to genomic analysis. We assessed genome-wide diversity, linkage disequilibrium (LD), effective population size (Ne) and relatedness in 96 dromedaries originating from five different regions of the central desert of Iran using genotyping-by-sequencing (GBS). A total of 14,522 Single Nucleotide Polymorphisms (SNPs) with an average minor allele frequency (MAF) of 0.19 passed quality control and filtering steps. The average observed heterozygosity in the population was estimated at 0.25 ± 0.03. The mean of LD at distances shorter than 40 kb was low (r2 = 0.089 ± 0.234). The camels sampled from the central desert of Iran exhibited higher relatedness than Sudanese and lower than Arabian Peninsula dromedaries. Recent Ne of Iran’s camels was estimated to be 89. Predicted Tajima’s D (1.28) suggested a bottleneck or balancing selection in dromedary camels in the central desert of Iran. A general decrease in effective and census population size poses a threat for Iran’s dromedaries. This report is the first SNP calling report on nearly the chromosome level and a first step towards understanding genomic diversity, population structure and demography in Iranian dromedaries.