Biology subjects

Marjanovic, D.

Publications and source records attributed to Marjanovic, D..

6 recordsLinked to original sources

bioRxiv2022

Croatian Genetic Heritage: Renewed Y Chromosome Story a Decade Later

AimTo analyze an additional set of Y-Chromosome genetic markers to acquire a more detailed insight into the diversity of the Croatian population. MethodsThe total number of 518 Yfiler Plus profiles were genotyped. Allele, haplotype frequencies, and haplotype diversity were calculated using the STRAF software package v2.0.4. Genetic distances were quantified by Rst using AMOVA online tool from the YHRD. The evolutionary history was inferred using the neighbor-joining method of phylogenetic tree construction in MEGAX software. Whit Atheys Haplogroup Predictor v5 was used for additional comparison with available regional and other European populations. ResultsThe total of 507 haplotypes were used for genetic STR analysis. The interpopulation study on 17 Y-STR markers shows the lowest genetic diversity between the Croatian and Bosnian-Herzegovinian populations and the highest between the Croatian and Irish populations. Additional interpopulation comparison with the original 27 Y-STR markers (for the population with available data) was also performed. A total of 518 haplotypes were used in the determination of haplogroup diversity. Haplogroup I with its sublineage I2a expressed the highest prevalence. Haplogroup R, with its major sublineage R1a, is the second most abundant in the studied Croatian population, except for the subpopulation of Hvar, where E1b1b is the second most abundant haplogroup. Rare haplogroups also confirmed in this study are L, T, and Q. G1 is detected for the very first time in the Croatian population. ConclusionNew insight into differences between examined subpopulations of Croatia and their possible (dis)similarities with neighboring abroad populations was notified.

evolutionary biology↗

bioRxiv2021

The scratch-digging lifestyle of the Permian "microsaur" Batropetes as a model for the exaptative origin of jumping locomotion in frogs

Recent studies have shown that the Triassic stem-frog Triadobatrachus lacked the ability to jump off, but nonetheless had the forelimb strength to withstand the impact of landing from a jump. We propose a hypothesis to resolve this pseudoparadox: the strengthened forelimbs are former adaptations to forelimb-based digging that later made jumping possible by exaptation. Micro-CT data from a skeleton of Batropetes palatinus reveal thin cortical bone, confirming Batropetes as terrestrial. Combining adaptations to walking and digging, confirmed by statistical analyses, Batropetes is thought to have searched for food in leaf litter or topsoil. We interpret Batropetes as having used one forelimb at a time to shove leaf litter aside. Batropetes may thus represent an analog or possibly a homolog of the digging stage that preceded the origin of Salientia. We discuss the possibility of homology with the digging lifestyles of other "microsaurs" and other amphibians.

paleontology↗

bioRxiv2020

Phylogenetic pattern of SARS-CoV-2 from COVID-19 patients from Bosnia and Herzegovina: lessons learned to optimize future molecular and epidemiological approaches

Whole Genome Sequence of four samples from COVID-19 outbreaks was done in two laboratories in Bosnia and Herzegovina (Veterinary Faculty Sarajevo and Alea Genetic Center). All four BiH sequences cluster mainly with European ones (Italy, Austria, France, Sweden, Cyprus, England). The constructed phylogenetic tree indicates probable multiple independent introduction events. The success of future containment measures concernig new introductions will be highly challenging for country due to the significant proportion of BH population living abroad.

genetics↗

bioRxiv2019

Recalibrating the transcriptomic timetree of jawed vertebrates

Molecular divergence dating has the potential to overcome the incompleteness of the fossil record in inferring when cladogenetic events (splits, divergences) happened, but needs to be calibrated by the fossil record. Ideally but unrealistically, this would require practitioners to be specialists in molecular evolution, in the phylogeny and the fossil record of all sampled taxa, and in the chronostratigraphy of the sites the fossils were found in. Paleontologists have therefore tried to help by publishing compendia of recommended calibrations, and molecular biologists unfamiliar with the fossil record have made heavy use of such works (in addition to using scattered primary sources and copying from each other). Using a recent example of a large node-dated timetree inferred from molecular data, I reevaluate all thirty calibrations in detail, present the current state of knowledge on them with its various uncertainties, rerun the dating analysis, and conclude that calibration dates cannot be taken from published compendia or other secondary or tertiary sources without risking strong distortions to the results, because all such sources become outdated faster than they are published: 50 of the sources I cite to constrain calibrations were published in 2019, half of the total of 276 after mid-2016, and 90% after mid-2005. It follows that the present work cannot serve as such a compendium either; in the slightly longer term, it can only highlight known and overlooked problems. Future authors will need to solve each of these problems anew through a thorough search of the primary paleobiological and chronostratigraphic literature on each calibration date every time they infer a new timetree; and that literature is not optimized for that task, but largely has other objectives.

evolutionary biology↗

bioRxiv2019

The genomic impact of European colonization of the Americas

The human genetic diversity of the Americas has been shaped by several events of gene flow that have continued since the Colonial Era and the Atlantic slave trade. Moreover, multiple waves of migration followed by local admixture occurred in the last two centuries, the impact of which has been largely unexplored.\n\nHere we compiled a genome-wide dataset of [~]12,000 individuals from twelve American countries and [~]6,000 individuals from worldwide populations and applied haplotype-based methods to investigate how historical movements from outside the New World affected i) the genetic structure, ii) the admixture profile, iii) the demographic history and iv) sex-biased gene-flow dynamics, of the Americas.\n\nWe revealed a high degree of complexity underlying the genetic contribution of European and African populations in North and South America, from both geographic and temporal perspectives, identifying previously unreported sources related to Italy, the Middle East and to specific regions of Africa.

genomics↗

bioRxiv2018

What do ossification sequences tell us about the origin of extant amphibians?

ABSTRACTThe controversial origin of extant amphibians has been studied using several sources of data and methods, including phylogenetic analyses of morphological data, molecular dating, stratigraphic data, and integration of ossification sequence data, but a consensus has failed to emerge. We have compiled five datasets to assess the relative support for six competing hypotheses about the origin of extant amphibians: a monophyletic origin among temnospondyls, a monophyletic origin among lepospondyls, a diphyletic origin among both temnospondyls and lepospondyls, a diphyletic origin among temnospondyls alone, and two variants of a triphyletic origin, in which anurans and urodeles come from different temnospondyl taxa while caecilians come from lepospondyls and are either closer to anurans and urodeles or to amniotes. Our datasets comprise ossification sequences of up to 107 terminal taxa and up to eight cranial bones, and up to 65 terminal taxa and up to seven appendicular bones, respectively. Among extinct taxa, only two or three temnospondyl can be analyzed simultaneously for cranial data, but this is not an insuperable problem because each of the six tested hypotheses implies a different position of temnospondyls and caecilians relative to other sampled taxa. For appendicular data, more extinct taxa can be analyzed, including some lepospondyls and the finned tetrapodomorph Eusthenopteron, in addition to temnospondyls. The data are analyzed through maximum likelihood, and the AICc (corrected Akaike Information Criterion) weights of the six hypotheses allow us to assess their relative support. By an unexpectedly large margin, our analyses of the cranial data support a monophyletic origin among lepospondyls; a monophyletic origin among temnospondyls, the current near-consensus, is a distant second. All other hypotheses are exceedingly unlikely according to our data. Surprisingly, analysis of the appendicular data supports triphyly of extant amphibians within a clade that unites lepospondyls and temnospondyls, contrary to all molecular and recent paleontological phylogenies, but this conclusion is not very robust.View Full Text

paleontology↗