scholarly journals Evolutionary Patterns in the Genus Homo

2021 ◽  
Vol 21 (01) ◽  
Author(s):  
Nisar A. Shar

ABSTRACT The demographic history of Homo sapiens is complex; it involves a wide range of migrations and genetic adaptations. One of the closely related species to Homo sapiens is Neanderthals, which became extinct about 30,000 years ago. The aim of this research is to compare Homo sapiens with Neanderthals and chimpanzees to understand the patterns of inheritance and survival instincts of Homo sapiens. Results show that out of all selected groups of genes in this study, metabolism, and language genes are found to be the most evolving group of genes. This shows that these most evolving genes are contributing to the advancement of Homo sapiens. However, after comparing human intelligence genes with the primates, it is found that exonic regions are contributing more to the evolution of human intelligence hence, making Homo sapiens unique in terms of intelligence.

2002 ◽  
Vol 16 (6) ◽  
pp. 893 ◽  
Author(s):  
I. Beveridge

The monotypic nematode genus Coronostrongylus Johnston & Mawson, 1939 from the stomachs of macropodid marsupials was reviewed and was found to consist of a least seven closely related species. Coronostrongylus coronatus Johnston & Mawson, 1939 is found most commonly in Macropus rufogriseus, but occurs occasionally in M. dorsalis, M. parryi and Petrogale inornata. Coronostrongylus johnsoni, sp. nov. is most commonly found in M. dorsalis, but occurs also in M. rufogriseus, M. parma, Thylogale stigmatica, Petrogale godmani and P. brachyotis. Coronostrongylus barkeri, sp. nov. is most prevalent in Onychogalea unguifera, but occurs also in M. rufus, M. robustus and P. brachyotis. Coronostrongylus closei, sp. nov. is restricted to Petrogale persephone. Coronostrongylus sharmani, sp. nov. occurs only in rock wallabies from eastern Australia: P.�coenensis, P. godmani and P. mareeba; C. spratti, sp. nov. occurs in P. inornata and P. assimilis. Coronostrongylus spearei, sp. nov. is restricted to Papua New Guinea where it is found in Dorcopsulus vanhearni, Dorcopsis hageni and D. muelleri. Although all of the nematode species occur in one principal host species or a series of closely related host species, occurrences in geographically disjunct areas and in phylogenetically distant hosts are features of C. coronatus, C. barkeri, sp. nov. and C. johnsoni, sp. nov. The occurrence of seven closely related nematode species found in a wide range of macropodid host species is more readily accounted for by a hypothesis involving multiple colonisations of hosts than by the hypothesis of co-speciation.


Parasitology ◽  
1959 ◽  
Vol 49 (3-4) ◽  
pp. 374-386 ◽  
Author(s):  
R. J. Thomas

1. The life history of N. battus is described, and a comparative description of the life history of N. filicollis is given.2. The life histories of these two species are compared with those of N. spathiger and N. helvetianus, two closely related species, and are shown to follow the same basic pattern, with minor variations in timing which appear to be specific in nature, and not related to differences in culture methods or host species.3. The pathogenesis of Nematodirus species is discussed and related to the migration of larvae into the intestinal mucosa during development.


2019 ◽  
Vol 24 (5) ◽  
pp. 866
Author(s):  
Jerzy Błoszyk ◽  
Katarzyna Buczkowska ◽  
Anna Maria Bobowicz ◽  
Alina Bączkiewicz ◽  
Zbigniew Adamski ◽  
...  

The study presented in this research paper is the first taxonomic investigation focusing on Uropodina (Acari: Mesostigmata) mites with a brief discussion of the genetic differences of two very closely related species from the genus Oodinychus Berlese, 1917, i.e. O. ovalis (C.L. Koch, 1839) and O. karawaiewi (Berlese, 1903). These two morphologically similar species are quite common and they have a wide range of occurrence in Europe. They also live in almost the same types of habitat. However, O. ovalis usually exhibits higher abundance and frequency of occurrence. The major aim of the study was to carry out a comparative analysis of the systematic position, morphological and biological differences, as well as habitat preferences and distribution of O. ovalis and O. karawaiewi. The next aim was to ascertain whether the differences in number and frequency of these species may stem from the genetic differences at the molecular level (16S rDNA and COI). The study shows that O. ovalis, which is a more abundant species than O. karawaiewi, turned out to be genetically more polymorphic.


2011 ◽  
Vol 13 (7) ◽  
pp. 1687-1709 ◽  
Author(s):  
Ryan A. Thum ◽  
Matthew P. Zuellig ◽  
Robert L. Johnson ◽  
Michael L. Moody ◽  
Charles Vossbrinck

2017 ◽  
Author(s):  
Zhihao Ling ◽  
Thomas Brockmöller ◽  
Ian T. Baldwin ◽  
Shuqing Xu

AbstractAlternative pre-mRNA splicing (AS) is prevalent among all plants and is involved in many interactions with environmental stresses. However, the evolutionary patterns and underlying mechanisms of AS in plants remain unclear. By analyzing the transcriptomes of six plant species, we revealed that AS diverged rapidly among closely related species, largely due to the gains and losses of AS events among orthologous genes. Furthermore, AS that generates transcripts containing premature termination codons (PTC), although only representing a small fraction of the total AS, are more conserved than those that generate non-PTC containing transcripts, suggesting that AS coupled with nonsense-mediated decay (NMD) might play an important role in regulating mRNA levels post-transcriptionally. With a machine learning approach we analyzed the key determinants of AS to understand the mechanisms underlying its rapid divergence. Among the studied species, the presence/absence of alternative splicing site (SS) within the junction, the distance between the authentic SS and the nearest alternative SS, the size of exon-exon junctions were the major determinants for both alternative 5’ donor site and 3’acceptor site, suggesting a relatively conserved AS mechanism. Comparative analysis further demonstrated that variations of the identified AS determinants, mostly are located in introns, significantly contributed to the AS turnover among closely related species in both Solanaceae and Brassicaceae taxa. These new mechanistic insights into the evolution of AS in plants highlight the importance of post-transcriptional regulation in mediating plant-environment interactions.One sentence summaryChanges of intron located splicing regulators contributed to the rapid evolution of alternative splicing in plants.


2016 ◽  
Vol 2 (1) ◽  
Author(s):  
Ian Tattersall

The history of the hominid family, like that of other mammals, means diversification, competition, and, sometimes, extinction. Paleoanthropologist Ian Tattersall explains why we need a phylogeny-based definition of the genus Homo that includes our species Homo sapiens, and why we don’t have one.


2019 ◽  
Author(s):  
Наталья Борщик ◽  
Natal'ya Borschik ◽  
Артем Пархоменко ◽  
Artem Parhomenko

The monograph covers a wide range of issues related to the study of the mechanism of state registration of subjects of the Russian Empire. The causes of the transition to the poll tax form residents of the country in the early eighteenth century, traced the evolution of the census office, its complication and improvement. The audits were supplemented by numerous population surveys conducted at the initiative of individual ministries and departments, regional authorities, local governments, were associated with the beginning of registration of natural population movement by the Russian Orthodox Church, etc. The role of demographic information in the formation of the main directions of the internal policy of the state is shown. It is addressed to all readers interested in the demographic history of our country.


2017 ◽  
Vol 4 (8) ◽  
pp. 161029 ◽  
Author(s):  
Yoko Matsumura ◽  
Takuya Kubo

Some species of criocerine beetles have a hyper-elongated part of the intromittent organ called a flagellum. In resting position, the flagellum is stored in a specialized internal sac in the intromittent organ. This specialized state of the flagellum and internal sac is indispensable during copulation for flagellar insertion into the female spermathecal duct for sperm transfer. However, the morphogenesis of the flagellum does not generate the active state of the flagellum; rather, the flagellum is generated in an inactive and completely coiled state. After eclosion, males of Lema coronata evert and withdraw the internal sac multiple times before sexual maturation, without mounting a female. This behaviour serves to uncoil the flagellum and guide it into the active state with the aid of surface structures on the internal sac. A closely related species, Lema dilecta , also has a long flagellum and undergoes the same behaviour to place the flagellum in the active position. However, some other species of criocerine beetles with much shorter flagella can attain the active state without exhibiting this behaviour. Based on a previously proposed phylogenetic tree, we discuss the evolutionary history of the hyper-elongation of the flagellum and associated behaviour.


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