Adaptive Radiation Genomics of Two Ecologically Divergent Hawai‘ian Honeycreepers: The ‘akiapōlā‘au and the Hawai‘i ‘amakihi

2019 ◽  
Author(s):  
Michael G Campana ◽  
André Corvelo ◽  
Jennifer Shelton ◽  
Taylor E Callicrate ◽  
Karen L Bunting ◽  
...  
Keyword(s):  
Adaptive Radiation ◽  
De Novo ◽  
Demographic History ◽  
Genomic Islands ◽  
Genomic Diversity ◽  
Morphology Evolution ◽  
Effective Population ◽  
Island Endemic ◽  
Wide Range ◽  
Bill Morphology

Abstract The Hawai‘ian honeycreepers (drepanids) are a classic example of adaptive radiation: they adapted to a variety of novel dietary niches, evolving a wide range of bill morphologies. Here we investigated genomic diversity, demographic history, and genes involved in bill morphology phenotypes in 2 honeycreepers: the ‘akiapōlā‘au (Hemignathus wilsoni) and the Hawai‘i ‘amakihi (Chlorodrepanis virens). The ‘akiapōlā‘au is an endangered island endemic, filling the “woodpecker” niche by using a unique bill morphology, while the Hawai‘i ‘amakihi is a dietary generalist common on the islands of Hawai‘i and Maui. We de novo sequenced the ‘akiapōlā‘au genome and compared it to the previously sequenced ‘amakihi genome. The ‘akiapōlā‘au is far less heterozygous and has a smaller effective population size than the ‘amakihi, which matches expectations due to its smaller census population and restricted ecological niche. Our investigation revealed genomic islands of divergence, which may be involved in the honeycreeper radiation. Within these islands of divergence, we identified candidate genes (including DLK1, FOXB1, KIF6, MAML3, PHF20, RBP1, and TIMM17A) that may play a role in honeycreeper adaptations. The gene DLK1, previously shown to influence Darwin’s finch bill size, may be related to honeycreeper bill morphology evolution, while the functions of the other candidates remain unknown.

scholarly journals The onset of ecological diversification 50 years after colonization of a crater lake by haplochromine cichlid fishes

2018 ◽  
Vol 285 (1884) ◽  
pp. 20180171 ◽  
Author(s):  
Florian N. Moser ◽  
Jacco C. van Rijssel ◽  
Salome Mwaiko ◽  
Joana I. Meier ◽  
Benjamin Ngatunga ◽  
...  
Keyword(s):  
Adaptive Radiation ◽  
Lake Victoria ◽  
Demographic History ◽  
Genomic Diversity ◽  
Radiation Process ◽  
Haplochromine Cichlids ◽  
Ecological Diversification ◽  
Cichlid Fishes ◽  
Wide Range ◽  
Phenotypic Fitness

Adaptive radiation research typically relies on the study of evolution in retrospective, leaving the predictive value of the concept hard to evaluate. Several radiations, including the cichlid fishes in the East African Great Lakes, have been studied extensively, yet no study has investigated the onset of the intraspecific processes of niche expansion and differentiation shortly after colonization of an adaptive zone by cichlids. Haplochromine cichlids of one of the two lineages that seeded the Lake Victoria radiation recently arrived in Lake Chala, a lake perfectly suited for within-lake cichlid speciation. Here, we infer the colonization and demographic history, quantify phenotypic, ecological and genomic diversity and diversification, and investigate the selection regime to ask if the population shows signs of diversification resembling the onset of adaptive radiation. We find that since their arrival in the lake, haplochromines have colonized a wide range of depth habitats associated with ecological and morphological expansion and the beginning of phenotypic differentiation and potentially nascent speciation, consistent with the very early onset of an adaptive radiation process. Moreover, we demonstrate evidence of rugged phenotypic fitness surfaces, indicating that current ecological selection may contribute to the phenotypic diversification.

scholarly journals Fine-scale population structure and demographic history of British Pakistanis

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Elena Arciero ◽  
Sufyan A. Dogra ◽  
Daniel S. Malawsky ◽  
Massimo Mezzavilla ◽  
Theofanis Tsismentzoglou ◽  
...  
Keyword(s):  
Population Structure ◽  
Disease Risk ◽  
Demographic History ◽  
Population History ◽  
Genomic Diversity ◽  
Fine Scale ◽  
Effective Population ◽  
Scale Population ◽  
The Impact ◽  
British Pakistanis

AbstractPrevious genetic and public health research in the Pakistani population has focused on the role of consanguinity in increasing recessive disease risk, but little is known about its recent population history or the effects of endogamy. Here, we investigate fine-scale population structure, history and consanguinity patterns using genotype chip data from 2,200 British Pakistanis. We reveal strong recent population structure driven by the biraderi social stratification system. We find that all subgroups have had low recent effective population sizes (Ne), with some showing a decrease 15‒20 generations ago that has resulted in extensive identity-by-descent sharing and homozygosity, increasing the risk of recessive disorders. Our results from two orthogonal methods (one using machine learning and the other coalescent-based) suggest that the detailed reporting of parental relatedness for mothers in the cohort under-represents the true levels of consanguinity. These results demonstrate the impact of cultural practices on population structure and genomic diversity in Pakistanis, and have important implications for medical genetic studies.

scholarly journals Recent Demographic History Inferred by High-Resolution Analysis of Linkage Disequilibrium

2020 ◽  
Vol 37 (12) ◽  
pp. 3642-3653
Author(s):  
Enrique Santiago ◽  
Irene Novo ◽  
Antonio F Pardiñas ◽  
María Saura ◽  
Jinliang Wang ◽  
...  
Keyword(s):  
Linkage Disequilibrium ◽  
Demographic History ◽  
Sequencing Data ◽  
Effective Population ◽  
Recombination Rates ◽  
Animal Populations ◽  
Wide Range ◽  
Demographic Trajectories ◽  
Model Computer ◽  
Conservation Of Endangered Species

Abstract Inferring changes in effective population size (Ne) in the recent past is of special interest for conservation of endangered species and for human history research. Current methods for estimating the very recent historical Ne are unable to detect complex demographic trajectories involving multiple episodes of bottlenecks, drops, and expansions. We develop a theoretical and computational framework to infer the demographic history of a population within the past 100 generations from the observed spectrum of linkage disequilibrium (LD) of pairs of loci over a wide range of recombination rates in a sample of contemporary individuals. The cumulative contributions of all of the previous generations to the observed LD are included in our model, and a genetic algorithm is used to search for the sequence of historical Ne values that best explains the observed LD spectrum. The method can be applied from large samples to samples of fewer than ten individuals using a variety of genotyping and DNA sequencing data: haploid, diploid with phased or unphased genotypes and pseudohaploid data from low-coverage sequencing. The method was tested by computer simulation for sensitivity to genotyping errors, temporal heterogeneity of samples, population admixture, and structural division into subpopulations, showing high tolerance to deviations from the assumptions of the model. Computer simulations also show that the proposed method outperforms other leading approaches when the inference concerns recent timeframes. Analysis of data from a variety of human and animal populations gave results in agreement with previous estimations by other methods or with records of historical events.

scholarly journals Genome sequence and comparative analysis of reindeer (Rangifer tarandus) in northern Eurasia

2019 ◽  
Author(s):  
Melak Weldenegodguad ◽  
Kisun Pokharel ◽  
Yao Ming ◽  
Mervi Honkatukia ◽  
Jaana Peippo ◽  
...  
Keyword(s):  
Rangifer Tarandus ◽  
Population Genomics ◽  
De Novo ◽  
Demographic History ◽  
Mammalian Species ◽  
Genomic Research ◽  
Northern Eurasia ◽  
Effective Population ◽  
Vitamin D Metabolism ◽  
Genetic Lineages

AbstractReindeer are semi-domesticated ruminants that have adapted to the challenging northern Eurasian environment characterized by long winters and marked annual fluctuations in daylight. We explored the genetic makeup behind their unique characteristics by de novo sequencing the genome of a male reindeer and conducted gene family analyses with nine other mammalian species. We performed a population genomics study of 23 additional reindeer representing both domestic and wild populations and several ecotypes from various geographic locations. We assembled 2.66 Gb (N50 scaffold of 5 Mb) of the estimated 2.92 Gb reindeer genome, comprising 27,332 genes. The results from the demographic history analysis suggested marked changes in the effective population size of reindeer during the Pleistocene period. We detected 160 reindeer-specific and expanded genes, of which zinc finger proteins (n=42) and olfactory receptors (n=13) were the most abundant. Comparative genome analyses revealed several genes that may have promoted the adaptation of reindeer, such as those involved in recombination and speciation (PRDM9), vitamin D metabolism (TRPV5, TRPV6), retinal development (PRDM1, OPN4B), circadian rhythm (GRIA1), immunity (CXCR1, CXCR2, CXCR4, IFNW1), tolerance to cold-triggered pain (SCN11A) and antler development (SILT2). The majority of these characteristic reindeer genes have been reported for the first time here. Moreover, our population genomics analysis suggested at least two independent reindeer domestication events with genetic lineages originating from different refugial regions after the Last Glacial Maximum. Taken together, our study has provided new insights into the domestication, evolution and adaptation of reindeer and has promoted novel genomic research of reindeer.

scholarly journals Impact of past climate warming on genomic diversity and demographic history of collared lemmings across the Eurasian Arctic

2020 ◽  
Vol 117 (6) ◽  
pp. 3026-3033 ◽  
Author(s):  
Vadim B. Fedorov ◽  
Emiliano Trucchi ◽  
Anna V. Goropashnaya ◽  
Eric Waltari ◽  
Susan Erin Whidden ◽  
...  
Keyword(s):  
Climate Warming ◽  
Demographic History ◽  
Genomic Diversity ◽  
Northern Eurasia ◽  
Last Interglacial ◽  
Effective Population ◽  
The West ◽  
Past Climate ◽  
History Of ◽  
Late Pleistocene To Holocene

The Arctic climate was warmer than today at the last interglacial and the Holocene thermal optimum. To reveal the impact of past climate-warming events on the demographic history of an Arctic specialist, we examined both mitochondrial and nuclear genomic variation in the collared lemming (Dicrostonyx torquatus, Pallas), a keystone species in tundra communities, across its entire distribution in northern Eurasia. The ancestral phylogenetic position of the West Beringian group and divergence time estimates support the hypothesis of continental range contraction to a single refugial area located in West Beringia during high-magnitude warming of the last interglacial, followed by westward recolonization of northern Eurasia in the last glacial period. The West Beringian group harbors the highest mitogenome diversity and its inferred demography indicates a constantly large effective population size over the Late Pleistocene to Holocene. This suggests that northward forest expansion during recent warming of the Holocene thermal optimum did not affect the gene pool of the collared lemming in West Beringia but reduced genomic diversity and effective population size in all other regions of the Eurasian Arctic. Demographic inference from genomic diversity was corroborated by species distribution modeling showing reduction in species distribution during past climate warming. These conclusions are supported by recent paleoecological evidence suggesting smaller temperature increases and moderate northward forest advances in the extreme northeast of Eurasia during the Late Pleistocene-to-Holocene warming events. This study emphasizes the importance of West Beringia as a potential refugium for cold-adapted Arctic species under ongoing climate warming.

scholarly journals Fine-scale population structure and demographic history of British Pakistanis

2020 ◽  
Author(s):  
Elena Arciero ◽  
Sufyan A. Dogra ◽  
Massimo Mezzavilla ◽  
Theofanis Tsismentzoglou ◽  
Qin Qin Huang ◽  
...  
Keyword(s):  
Population Structure ◽  
Disease Risk ◽  
Demographic History ◽  
Population History ◽  
Genomic Diversity ◽  
Fine Scale ◽  
Effective Population ◽  
Scale Population ◽  
The Impact ◽  
British Pakistanis

AbstractPrevious genetic and public health research in the Pakistani population has focused on the role of consanguinity in increasing recessive disease risk, but little is known about its recent population history or the effects of endogamy. Here, we investigate fine-scale population structure, history and consanguinity patterns using genetic and questionnaire data from >4,000 British Pakistani individuals, mostly with roots in Azad Kashmir and Punjab. We reveal strong recent population structure driven by the biraderi social stratification system. We find that all subgroups have had low effective population sizes (Ne) over the last 50 generations, with some showing a decrease in Ne 15-20 generations ago that has resulted in extensive identity-by-descent sharing and increased homozygosity. Using new theory, we show that the footprint of regions of homozygosity in the two largest subgroups is about twice that expected naively based on the self-reported consanguinity rates and the inferred historical Ne trajectory. These results demonstrate the impact of the cultural practices of endogamy and consanguinity on population structure and genomic diversity in British Pakistanis, and have important implications for medical genetic studies.

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

Genes ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 599 ◽  
Author(s):  
Morteza Bitaraf Sani ◽  
Javad Zare Harofte ◽  
Ahmad Bitaraf ◽  
Saeid Esmaeilkhanian ◽  
Mohammad Hossein Banabazi ◽  
...  
Keyword(s):  
Population Structure ◽  
Population Size ◽  
Balancing Selection ◽  
Demographic History ◽  
Genomic Analysis ◽  
Genotyping By Sequencing ◽  
Genomic Diversity ◽  
Nucleotide Polymorphisms ◽  
Effective Population ◽  
Genome Wide

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.

scholarly journals De novo genome assembly of the marine teleost, Bluefin Trevally (Caranx melampygus)

2021 ◽  
Author(s):  
Brandon D Pickett ◽  
Jessica R Glass ◽  
Perry G Ridge ◽  
John S K Kauwe
Keyword(s):  
Genome Assembly ◽  
Large Scale ◽  
De Novo ◽  
Demographic History ◽  
Population Expansion ◽  
Marine Teleost ◽  
Population Demography ◽  
Population Declines ◽  
Effective Population ◽  
De Novo Genome Assembly

Abstract The bluefin trevally, Caranx melampygus, also known as the bluefin kingfish or bluefin jack, is known for its remarkable, bright-blue fins. This marine teleost is a widely-prized sportfish, but few resources have been devoted to the genomics and conservation of this species because it is not targeted by large-scale commercial fisheries. Population declines from recreational and artisanal overfishing have been observed in Hawai‘i, USA, resulting in both an interest in aquaculture and concerns about the long-term conservation of this species. Most research to-date has been performed in Hawai‘i, raising questions about the status of bluefin trevally populations across its Indo-Pacific range. Genomic resources allow for expanded research on stock status, genetic diversity, and population demography. We present a high-quality, 711Mbp nuclear genome assembly of a Hawaiian bluefin trevally from noisy long-reads with a contig NG50 of 1.2Mbp and longest contig length of 8.9Mbp. As measured by single-copy orthologs, the assembly was 95% complete, and the genome is comprised of 16.9% repetitive elements. The assembly was annotated with 33.1K protein-coding genes, 71.4% of which were assigned putative functions, using RNA-seq data from eight tissues from the same individual. This is the first whole-genome assembly published for the carangoid genus Caranx. Using this assembled genome, a multiple sequentially Markovian coalescent model was implemented to assess population demography. Estimates of effective population size suggest population expansion has occurred since the Late Pleistocene. This genome will be a valuable resource for comparative phylogenomic studies of carangoid fishes and will help elucidate demographic history and delineate stock structure for bluefin trevally populations throughout the Indo-Pacific.

scholarly journals Genetic variation in Pan species is shaped by demographic history and underlies lineage-specific functions

2018 ◽  
Author(s):  
Sojung Han ◽  
Aida M. Andrés ◽  
Tomas Marques-Bonet ◽  
Martin Kuhlwilm
Keyword(s):  
Genetic Variation ◽  
Pan Paniscus ◽  
Demographic History ◽  
Genomic Variation ◽  
Genomic Diversity ◽  
Age At Menarche ◽  
Rapid Decline ◽  
Female Reproduction ◽  
Effective Population ◽  
Physiological Differences

AbstractChimpanzees (Pan troglodytes) and bonobos (Pan paniscus) are the closest living relatives of humans, but they show distinct behavioral and physiological differences, particularly regarding female reproduction. Despite their recent rapid decline, the demographic histories of the two species have been different during the past one to two million years, likely having an impact on their genomic diversity. Here, we analyze the inferred functional consequences of genetic variation across 69 individuals, making use of the most complete dataset of genomic variation in the Pan clade to date. We test to which extent the demographic history influences the efficacy of purifying selection in these species. We find that small historical effective population sizes (Ne) correlate not only with small genetic diversity, but also with more homozygous deleterious alleles, and an increased proportion of deleterious changes at low frequencies. Furthermore, we exploit the catalog of deleterious protein-coding changes on each lineage to investigate the putative genetic basis for phenotypic differences between chimpanzees and bonobos. We show that bonobo-specific non-synonymous changes are enriched in genes related to age at menarche in humans, suggesting that the prominent physiological differences in the female reproductive system between chimpanzees and bonobos might be explained, in part, by putatively adaptive changes on the bonobo lineage.

scholarly journals An examination of genetic diversity and effective population size in Atlantic salmon populations

2009 ◽  
Vol 91 (6) ◽  
pp. 395-412 ◽  
Author(s):  
NATACHA NIKOLIC ◽  
JAMES R. A. BUTLER ◽  
JEAN-LUC BAGLINIÈRE ◽  
ROBERT LAUGHTON ◽  
IAIN A. G. McMYN ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Atlantic Salmon ◽  
Population Size ◽  
Effective Population Size ◽  
Demographic History ◽  
Effective Population ◽  
High Genetic Diversity ◽  
Historical Processes ◽  
Wide Range ◽  
Microsatellite Dna Markers

SummaryEffective population size (Ne) is an important parameter in the conservation of genetic diversity. Comparative studies of empirical data that gauge the relative accuracy of Ne methods are limited, and a better understanding of the limitations and potential of Ne estimators is needed. This paper investigates genetic diversity and Ne in four populations of wild anadromous Atlantic salmon (Salmo salar L.) in Europe, from the Rivers Oir and Scorff (France) and Spey and Shin (Scotland). We aimed to understand present diversity and historical processes influencing current population structure. Our results showed high genetic diversity for all populations studied, despite their wide range of current effective sizes. To improve understanding of high genetic diversity observed in the populations with low effective size, we developed a model predicting present diversity as a function of past demographic history. This suggested that high genetic diversity could be explained by a bottleneck occurring within recent centuries rather than by gene flow. Previous studies have demonstrated the efficiency of coalescence models to estimate Ne. Using nine subsets from 37 microsatellite DNA markers from the four salmon populations, we compared three coalescence estimators based on single and dual samples. Comparing Ne estimates confirmed the efficiency of increasing the number and variability of microsatellite markers. This efficiency was more accentuated for the smaller populations. Analysis with low numbers of neutral markers revealed uneven distributions of allelic frequencies and overestimated short-term Ne. In addition, we found evidence of artificial stock enhancement using native and non-native origin. We propose estimates of Ne for the four populations, and their applications for salmon conservation and management are discussed.

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