Human Evolution

1984 ◽  
Vol 8 ◽  
pp. 182-198
Author(s):  
Catherine Badgley
Keyword(s):  
Human Evolution ◽  
Evolutionary History ◽  
Pan Paniscus ◽  
Homo Sapiens ◽  
Great Apes ◽  
Sister Group ◽  
The Family ◽  
History Of ◽  
Living Species ◽  
Single Living

The evolutionary history of humans is well understood in outline, compared to that of many other groups of mammals. But human evolution remains enigmatic in its details, and these are compelling both scientifically and personally because they relate to the biological uniqueness of humans. Humans are placed in the primate family Hominidae, which, in traditional classifications, contains a single living species, Homo sapiens. The closest living relatives of humans are great apes: the chimpanzees Pan paniscus and Pan troglodytes, the gorilla Gorilla gorilla, and the orangutan Pongo pygmaeus. These apes have traditionally been placed in the family Pongidae as the sister group of Hominidae. Living Hominidae and Pongidae, together with Hylobatidae (gibbons) comprise the modern representatives of the primate suborder Hominoidea.

scholarly journals Ancient origins and multiple appearances of carotenoid-pigmented feathers in birds

2014 ◽  
Vol 281 (1788) ◽  
pp. 20140806 ◽  
Author(s):  
Daniel B. Thomas ◽  
Kevin J. McGraw ◽  
Michael W. Butler ◽  
Matthew T. Carrano ◽  
Odile Madden ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
High Performance ◽  
Evolutionary History ◽  
Carotenoid Pigments ◽  
Biological Functions ◽  
The Family ◽  
Family Level ◽  
History Of ◽  
Living Species ◽  
Insight Into

The broad palette of feather colours displayed by birds serves diverse biological functions, including communication and camouflage. Fossil feathers provide evidence that some avian colours, like black and brown melanins, have existed for at least 160 million years (Myr), but no traces of bright carotenoid pigments in ancient feathers have been reported. Insight into the evolutionary history of plumage carotenoids may instead be gained from living species. We visually surveyed modern birds for carotenoid-consistent plumage colours (present in 2956 of 9993 species). We then used high-performance liquid chromatography and Raman spectroscopy to chemically assess the family-level distribution of plumage carotenoids, confirming their presence in 95 of 236 extant bird families (only 36 family-level occurrences had been confirmed previously). Using our data for all modern birds, we modelled the evolutionary history of carotenoid-consistent plumage colours on recent supertrees. Results support multiple independent origins of carotenoid plumage pigmentation in 13 orders, including six orders without previous reports of plumage carotenoids. Based on time calibrations from the supertree, the number of avian families displaying plumage carotenoids increased throughout the Cenozoic, and most plumage carotenoid originations occurred after the Miocene Epoch (23 Myr). The earliest origination of plumage carotenoids was reconstructed within Passeriformes, during the Palaeocene Epoch (66–56 Myr), and not at the base of crown-lineage birds.

scholarly journals Monophyly, Taxon Sampling, and the Nature of Ranks in the Classification of Orb-Weaving Spiders (Araneae: Araneoidea)

2019 ◽  
Author(s):  
Robert J Kallal ◽  
Dimitar Dimitrov ◽  
Miquel A Arnedo ◽  
Gonzalo Giribet ◽  
Gustavo Hormiga
Keyword(s):  
Evolutionary History ◽  
Sexual Size Dimorphism ◽  
Sister Group ◽  
Taxon Sampling ◽  
Sexually Dimorphic ◽  
The Family ◽  
History Of ◽  
Dated Phylogeny ◽  
Fundamental Requirement

Abstract We address some of the taxonomic and classification changes proposed by Kuntner et al. (2019) in a comparative study on the evolution of sexual size dimorphism in nephiline spiders. Their proposal to recircumscribe araneids and to rank the subfamily Nephilinae as a family is fundamentally flawed as it renders the family Araneidae paraphyletic. We discuss the importance of monophyly, outgroup selection, and taxon sampling, the subjectivity of ranks, and the implications of the age of origin criterion to assign categorical ranks in biological classifications. We explore the outcome of applying the approach of Kuntner et al. (2019) to the classification of spiders with emphasis on the ecribellate orb-weavers (Araneoidea) using a recently published dated phylogeny. We discuss the implications of including the putative sister group of Nephilinae (the sexually dimorphic genus Paraplectanoides) and the putative sister group of Araneidae (the miniature, monomorphic family Theridiosomatidae). We propose continuation of the phylogenetic classification put forth by Dimitrov et al. (2017), and we formally rank Nephilinae and Phonognathinae as subfamilies of Araneidae. Our classification better reflects the understanding of the phylogenetic placement and evolutionary history of nephilines and phonognathines while maintaining the diagnosability of Nephilinae. It also fulfills the fundamental requirement that taxa must be monophyletic, and thus avoids the paraphyly of Araneidae implied by Kuntner et al. (2019).

scholarly journals Different Stages of Evolution of Humankind

2017 ◽  
pp. 46-77
Author(s):  
Slaven Jozic
Keyword(s):  
Human Evolution ◽  
Homo Sapiens ◽  
Evolutionary Process ◽  
Great Apes ◽  
Distinct Species ◽  
Scientific Disciplines ◽  
Late Cretaceous Period ◽  
Anatomically Modern Humans ◽  
Gradual Development ◽  
History Of

Human evolution is the evolutionary process that led to the emergence of anatomically modern humans, beginning with the evolutionary history of primates—in particular genus Homo—and leading to the emergence of Homo sapiens as a distinct species of the hominid family, the great apes. This process involved the gradual development of traits such as human bipedalism and language, as well as interbreeding with other hominines, which indicate that human evolution was not linear but a web. The study of human evolution involves several scientific disciplines, including physical anthropology, primatology, archaeology, paleontology, neurobiology, ethology, linguistics, evolutionary psychology, embryology and genetics. Genetic studies show that primates diverged from other mammals about 85 million years ago, in the Late Cretaceous period, and the earliest fossils appear in the Paleocene, around 55 million years ago. Within the Hominoidea (apes) superfamily, the Hominidae family diverged from the Hylobatidae (gibbon) family some 15–20 million years ago; African great apes (subfamily Homininae) diverged from orangutans (Ponginae) about 14 million years ago; the Hominini tribe (humans, Australopithecines and other extinct biped genera, and chimpanzee) parted from the Gorillini tribe (gorillas) between 8–9 million years ago; and, in turn, the subtribes Hominina (humans and biped ancestors) and Panina (chimps) separated 4–7.5 million years ago.

scholarly journals A theory about the evolutionary history of Lachnidae and comments on the results of some molecular phylogenetic studies of aphids (Hemiptera: Aphidoidea)

2015 ◽  
Vol 84 (4) ◽  
pp. 275-287 ◽  
Author(s):  
Ole E. Heie
Keyword(s):  
Evolutionary History ◽  
Sister Group ◽  
Compound Eyes ◽  
Host Alternation ◽  
Phylogenetic Studies ◽  
The Family ◽  
Molecular Phylogenetic ◽  
History Of

Abstract Several characters of the Lachnidae are discussed, and it is explained why some of them are not plesiomorphies as previously believed, but apomorphies. This applies e.g. to the absence of host alternation in the extant genera, to the short cauda and to the presence of compound eyes in the nymphs and the apterous adults. Some characters are adaptations to attention by ants or ways of feeding. It is concluded that many characters show that the family is relatively young and probably originally had host alternation of the same kind as Aphididae, which is regarded as the sister group. The results of some molecular phylogenetic studies are discussed.

Systematic evidence from gene duplication and regulation

1990 ◽  
Vol 3 (1) ◽  
pp. 145
Author(s):  
DJ Colgan
Keyword(s):  
Gene Duplication ◽  
Evolutionary History ◽  
Tandem Duplication ◽  
Fragment Length Polymorphism ◽  
Duplicate Genes ◽  
Polymorphism Analysis ◽  
Multiple Origins ◽  
The Family ◽  
History Of ◽  
Phylogenetic Hypotheses

This paper is a review of the use of information regarding the presence of duplicate genes and their regulation in systematics. The review concentrates on data derived from protein electrophoresis and restriction fragment length polymorphism analysis. The appearance of a duplication in a subset of a group of species implies that the members of the subset belong to the same clade. Suppression of the duplication may render this clade apparently paraphyletic, but may itself be informative of relations within the lineage through patterns of loss of expression in all, or some tissues, or through restrictions of the formation of functional heteropolymers in polymeric enzymes. Examples are given of studies which have used such information to establish phylogenetic hypotheses at the family level, to identify an auto- or allo-polyploid origin of polyploid species and to determine whether there have been single or multiple origins of such species. The likelihood of homoplasy in the patterns of appearance and regulation of duplicates depends on the molecular basis of the duplication. In particular, the contrast between the expected consequences of tandem duplication and the expression of pseudogenes emphasises the value of determining the mechanism of the original duplication. Many instances of sporadic gene duplication are now known, and polyploidisation is a common event in the evolutionary history of both plants and animals. So the opportunities to discover duplicationrelated characters will arise in many systematic studies. A program is presented to increase the chances that such useful information will be recognisable during the studies.

Systematics and biogeography of the “Metacryphaeus group” Calmoniidae (Trilobita, Devonian), with comments on adaptive radiations and the geological history of the Malvinokaffric Realm

1993 ◽  
Vol 67 (4) ◽  
pp. 549-570 ◽  
Author(s):  
Bruce S. Lieberman
Keyword(s):  
New Species ◽  
South African ◽  
Evolutionary History ◽  
Geological History ◽  
Parsimony Analysis ◽  
Evolutionary Patterns ◽  
The Family ◽  
History Of ◽  
Adaptive Radiations ◽  
Rapid Diversification

Phylogenetic parsimony analysis was used to classify the Siegenian–Eifelian “Metacryphaeus group” of the family Calmoniidae. Thirty-eight exoskeletal characters for 16 taxa produced a shortest-length cladogram with a consistency index of 0.49. A classification based on retrieving the structure of this cladogram recognizes nine genera: Typhloniscus Salter, Plesioconvexa n. gen., Punillaspis Baldis and Longobucco, Eldredgeia n. gen., Clarkeaspis n. gen., Malvinocooperella n. gen., Wolfartaspis Cooper, Plesiomalvinella Lieberman, Edgecombe, and Eldredge (used to represent the malvinellid clade), and Metacryphaeus Reed. The malvinellid clade is most closely related to a revised monophyletic Metacryphaeus. Typhloniscus is the basal member of the “Metacryphaeus group,” and the monotypic Wolfartaspis is sister to the clade containing the malvinellids and Metacryphaeus. Six new species are diagnosed: Punillaspis n. sp. A, “Clarkeaspis” gouldi, Clarkeaspis padillaensis, Malvinocooperella pregiganteus, Metacryphaeus curvigena, and Metacryphaeus branisai. Primitively, this group has South African and Andean affinities, and its evolutionary history suggests rapid diversification. In addition, evolutionary patterns in this group, and the distribution of character reversals, call into question certain notions about the nature of adaptive radiations. The distributions of taxa may answer questions about the number of marine transgressive/regressive cycles in the Emsian–Eifelian of the Malvinokaffric Realm.

Wood anatomy of the Mascarene Dombeyoideae: Systematic and ecological implications

IAWA Journal ◽  
2011 ◽  
Vol 32 (4) ◽  
pp. 493-519 ◽  
Author(s):  
Anaïs Boura ◽  
Timothée Le Péchon ◽  
Romain Thomas
Keyword(s):  
Evolutionary History ◽  
Wood Anatomy ◽  
Sister Group ◽  
Biological Data ◽  
Sister Group Relationship ◽  
Anatomical Features ◽  
Ecological Implications ◽  
History Of ◽  
Mascarene Islands ◽  
Almost All

The Dombeyoideae (Malvaceae) are one of the most diversified groups of plants in the Mascarene Islands. Species of Dombeya Cav., Ruizia Cav. and Trochetia DC. are distributed in almost all parts of the archipelago and show a wide diversity in their growth forms. This study provides the first wood anatomical descriptions of 17 out of the 22 Mascarene species of Dombeyoideae. Their wood anatomy is similar to that of previously described species: wide vessels, presence of both apotracheal and paratracheal parenchyma, and storied structure. In addition, we also found a second wood anatomical pattern with narrower vessels, high vessel frequency and thick-walled fibres. The two aforementioned wood patterns are considered in a phylogenetic context and used to trace the evolutionary history of several wood anatomical features. For example, the pseudoscalariform pit arrangement supports a sister group relationship between Trochetia granulata Cordem. and T. blackburniana Bojer ex Baker and may be a new synapomorphy of the genus Trochetia. Finally, wood variability is evaluated in relation to geographic, climatic and biological data. Despite the juvenile nature of some of the specimens studied, we discuss how the habit, but also factors related to humidity, influence the variability observed in the Mascarene Dombeyoideae wood structure.

Adaptive convergent evolution of genome proofreading in SARS-CoV2: insights into the Eigen’s paradox

2021 ◽  
Author(s):  
Keerthic Aswin ◽  
Srinivasan Ramachandran ◽  
Vivek T Natarajan
Keyword(s):  
Convergent Evolution ◽  
Genome Stability ◽  
Evolutionary History ◽  
Rna Binding ◽  
Phylogenetic Analyses ◽  
Comparative Genome Analysis ◽  
The Family ◽  
History Of ◽  
Key Residues

AbstractEvolutionary history of coronaviruses holds the key to understand mutational behavior and prepare for possible future outbreaks. By performing comparative genome analysis of nidovirales that contain the family of coronaviruses, we traced the origin of proofreading, surprisingly to the eukaryotic antiviral component ZNFX1. This common recent ancestor contributes two zinc finger (ZnF) motifs that are unique to viral exonuclease, segregating them from DNA proof-readers. Phylogenetic analyses indicate that following acquisition, genomes of coronaviruses retained and further fine-tuned proofreading exonuclease, whereas related families harbor substitution of key residues in ZnF1 motif concomitant to a reduction in their genome sizes. Structural modelling followed by simulation suggests the role of ZnF in RNA binding. Key ZnF residues strongly coevolve with replicase, and the helicase involved in duplex RNA unwinding. Hence, fidelity of replication in coronaviruses is a result of convergent evolution, that enables maintenance of genome stability akin to cellular proofreading systems.

scholarly journals Evolution and taxonomy of nematode-associated entomopathogenic bacteria of the genera Xenorhabdus and Photorhabdus: an overview

Symbiosis ◽  
2020 ◽  
Vol 80 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Ewa Sajnaga ◽  
Waldemar Kazimierczak
Keyword(s):  
Evolutionary History ◽  
Entomopathogenic Nematode ◽  
Bacterial Species ◽  
Entomopathogenic Bacteria ◽  
Insecticidal Toxins ◽  
The Family ◽  
The World ◽  
History Of ◽  
Phylogenetic Origin ◽  
Animal Hosts

AbstractEntomopathogenic bacteria from the genera Photorhabdus and Xenorhabdus are closely related Gram-negative bacilli from the family Enterobacteriaceae (γ-Proteobacteria). They establish obligate mutualistic associations with soil nematodes from the genera Steinernema and Heterorhabditis to facilitate insect pathogenesis. The research of these two bacterial genera is focused mainly on their unique interactions with two different animal hosts, i.e. nematodes and insects. So far, studies of the mutualistic bacteria of nematodes collected from around the world have contributed to an increase in the number of the described Xenorhabdus and Photorhabdus species. Recently, the classification system of entomopatogenic nematode microsymbionts has undergone profound revision and now 26 species of the genus Xenorhabdus and 19 species of the genus Photorhabdus have been identified. Despite their similar life style and close phylogenetic origin, Photorhabdus and Xenorhabdus bacterial species differ significantly in e.g. the nematode host range, symbiotic strategies for parasite success, and arrays of released antibiotics and insecticidal toxins. As the knowledge of the diversity of entomopathogenic nematode microsymbionts helps to enable the use thereof, assessment of the phylogenetic relationships of these astounding bacterial genera is now a major challenge for researchers. The present article summarizes the main information on the taxonomy and evolutionary history of Xenorhabdus and Photorhabdus, entomopathogenic nematode symbionts.

XVI.—Quantitative Evolution. III. Dp-ages of Gramineæ

1938 ◽  
Vol 57 ◽  
pp. 221-227
Author(s):  
James Small
Keyword(s):  
Time Scale ◽  
Evolutionary History ◽  
Geological Time ◽  
Exponential Curve ◽  
The Family ◽  
History Of ◽  
Geological Origin ◽  
Fossil Records

Applying Udny Yule's formulæ (1924) to the Compositæ, Small (1937) found that the average ages in doubling periods (Dp-ages) of the tribes of Compositæ, when plotted against a time-scale, gave points on an exponential curve called the BAT curve. If this curve is characteristic of average families of Angiosperms it should be possible to place the Dp-ages of tribes within other families on this curve as plotted against geological time, and thus obtain an order of geological origin which is quite independent of actual fossil records and which can be checked against any facts known concerning the evolutionary history of the family.

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