Ontogenetic study of the skull in modern humans and the common chimpanzees: Neotenic hypothesis reconsidered with a tridimensional procrustes analysis

2002 ◽  
Vol 118 (1) ◽  
pp. 50-62 ◽  
Author(s):  
Xavier Penin ◽  
Christine Berge ◽  
Michel Baylac
Keyword(s):  
Procrustes Analysis ◽  
Modern Humans ◽  
Ontogenetic Study ◽  
The Common

scholarly journals The unidirectional phylogeny of Homo sapiens anchors the origin of modern humans in Eurasia

Hereditas ◽  
2021 ◽  
Vol 158 (1) ◽  
Author(s):  
Úlfur Árnason
Keyword(s):  
Nuclear Dna ◽  
Maternal Inheritance ◽  
Homo Sapiens ◽  
Human Populations ◽  
Before Present ◽  
Modern Humans ◽  
Origin Of Modern Humans ◽  
The Common ◽  
Out Of Africa ◽  
Mtdna Introgression

Abstract Background The Out of Africa hypothesis, OOAH, was challenged recently in an extended mtDNA analysis, PPA (Progressive Phylogenetic Analysis), that identified the African human populations as paraphyletic, a finding that contradicted the common OOAH understanding that Hss had originated in Africa and invaded Eurasia from there. The results were consistent with the molecular Out of Eurasia hypothesis, OOEH, and Eurasian palaeontology, a subject that has been largely disregarded in the discussion of OOAH. Results In the present study the mtDNA tree, a phylogeny based on maternal inheritance, was compared to the nuclear DNA tree of the paternally transmitted Y-chromosome haplotypes, Y-DNAs. The comparison showed full phylogenetic coherence between these two separate sets of data. The results were consistent with potentially four translocations of modern humans from Eurasia into Africa, the earliest taking place ≈ 250,000 years before present, YBP. The results were in accordance with the postulates behind OOEH at the same time as they lent no support to the OOAH. Conclusions The conformity between the mtDNA and Y-DNA phylogenies of Hss is consistent with the understanding that Eurasia was the donor and not the receiver in human evolution. The evolutionary problems related to OOAH became similarly exposed by the mtDNA introgression that took place from Hss into Neanderthals ≈ 500,000 YBP, a circumstance that demonstrated the early coexistence of the two lineages in Eurasia.

Exchanging Perspectives

2019 ◽  
Vol 25 (1-3) ◽  
pp. 21-42 ◽  
Author(s):  
Eduardo Viveiros de Castro
Keyword(s):  
Animal Species ◽  
Common Knowledge ◽  
Cultural Models ◽  
Human Soul ◽  
Modern Humans ◽  
Cognitive Capacities ◽  
Human Culture ◽  
Cultural Framework ◽  
The Common ◽  
Nonhuman Species

Originally published in 2004 in the Common Knowledge symposium “Talking Peace with Gods,” this article elaborates the nature and consequences of the perspectivist cosmologies of Amerindian societies. Contemporary Western cosmologies regard humans as ex-animals who became differentiated from other nonhuman species through the acquisition of advanced cognitive capacities. Amerindian cultures, by contrast, regard animals as ex-humans who became differentiated from both modern humans and other animal species via a series of physical adaptations. Underneath these physical differences, both humans and nonhumans retain a shared human soul; what is more, each species perceives its own kind as human and all other kinds—including humans—as animals. Viveiros de Castro distinguishes this “perspectivism” from relativism: whereas Western relativism assumes multiple valid cultural models, Amerindian perspectivism holds that human and nonhuman species possess a common values system and cultural framework. While this commonality is ordinarily obscured by biologically grounded, perceptual differences, the gap in perspective may be bridged by shamans, whose gift of adopting nonhuman subjectivities enables them to see other species as they see themselves—namely, as humans partaking in human culture. Perspectivism influences both the practices that Amerindian peoples adopt toward nonhuman species and their attitudes toward other human groups, especially in the context of warfare. The Amerindian warrior’s capacity to overcome an enemy ultimately depends on a shaman-like entry into the subjectivity of another: rather than denying the personhood of his enemy, the Amerindian warrior must acknowledge the affinity between them.

VESSEL MEMBERS IN THE STEM OF DIOSCOREA ALATA L.

1967 ◽  
Vol 45 (2) ◽  
pp. 155-167 ◽  
Author(s):  
J. J. Shah ◽  
K. Unnikrishnan ◽  
K. V. Poulose
Keyword(s):  
Vessel Element ◽  
Dioscorea Alata ◽  
Gujarat State ◽  
Perforation Plate ◽  
Vessel Elements ◽  
Ontogenetic Study ◽  
Final Length ◽  
The Common ◽  
Perforation Plates ◽  
Mother Nucleus

The internodal and nodal vessel elements and certain aspects of their ontogeny in the stem of Dioscorea alata L., the common cultivated yam of Gujarat State, India, are described. The internodal vessel elements are unusually long with foraminate, scalariform, reticulate, or rarely simple perforation plates. The nodal vessel elements are comparatively short with two to five perforation plates. They generally differ from internodal vessel elements in characters such as (i) size and shape and (ii) nature, number, inclination, and distribution of perforation plates. The ontogenetic study of the vessel element revealed that the coenocytic condition is a result of frequent mitotic divisions of the mother nucleus. The formation of the perforation plate occurs after the vessel element has reached final length. The protoplast persists after the formation of the perforation plate. In D. alata the cell wall in the region of the perforation shows primordial pits.

2. Finding our place

2019 ◽  
pp. 7-23
Author(s):  
Bernard Wood
Keyword(s):  
Molecular Biology ◽  
Human Evolution ◽  
Scientific Method ◽  
Common Ancestor ◽  
Natural World ◽  
Modern Human ◽  
Human Origins ◽  
Modern Humans ◽  
History Of ◽  
The Common

When did the process of using reason to try and understand human origins begin, and how did it develop? When was the scientific method first applied to the study of human evolution? ‘Finding our place’ begins by reviewing the history of how first philosophers and then scientists came to realize that modern humans are part of the natural world. It then explains why, using advances in molecular biology, scientists think chimpanzees and bonobos are more closely related to modern humans than they are to gorillas, and why they think the common ancestor of the chimpanzee/bonobo and modern human clades lived between six and eight million years ago.

scholarly journals Using the Neandertal and Denisova Genetic Data to Understand the Common MAPT 17q21 Inversion in Modern Humans

Human Biology ◽  
2012 ◽  
Vol 84 (6) ◽  
pp. 633-640 ◽  
Author(s):  
Núria Setó-Salvia ◽  
Federico Sánchez-Quinto ◽  
Eudald Carbonell ◽  
Carlos Lorenzo ◽  
David Comas ◽  
...  
Keyword(s):  
Genetic Data ◽  
Modern Humans ◽  
The Common

Catalogue reduction techniques

1978 ◽  
Vol 48 ◽  
pp. 389-390 ◽  
Author(s):  
Chr. de Vegt
Keyword(s):  
Adjustment Process ◽  
Proper Motions ◽  
Measuring Process ◽  
Aerial Photogrammetry ◽  
Reduction Techniques ◽  
Observational Technique ◽  
The Common ◽  
Astrometric Data

AbstractReduction techniques as applied to astrometric data material tend to split up traditionally into at least two different classes according to the observational technique used, namely transit circle observations and photographic observations. Although it is not realized fully in practice at present, the application of a blockadjustment technique for all kind of catalogue reductions is suggested. The term blockadjustment shall denote in this context the common adjustment of the principal unknowns which are the positions, proper motions and certain reduction parameters modelling the systematic properties of the observational process. Especially for old epoch catalogue data we frequently meet the situation that no independent detailed information on the telescope properties and other instrumental parameters, describing for example the measuring process, is available from special calibration observations or measurements; therefore the adjustment process should be highly self-calibrating, that means: all necessary information has to be extracted from the catalogue data themselves. Successful applications of this concept have been made already in the field of aerial photogrammetry.

Renilla Bioluminescence: A Morphologic Approach to the Location of Photocytes

1974 ◽  
Vol 32 ◽  
pp. 208-209
Author(s):  
Ben O. Spurlock ◽  
Milton J. Cormier
Keyword(s):  
Excited State ◽  
Ground State ◽  
Molecular Basis ◽  
Light Emission ◽  
Chemical Basis ◽  
Electronic Excited State ◽  
Colonial Form ◽  
The Common ◽  
Eighteenth And Nineteenth Centuries ◽  
Catalyzed Oxidation

The phenomenon of bioluminescence has fascinated layman and scientist alike for many centuries. During the eighteenth and nineteenth centuries a number of observations were reported on the physiology of bioluminescence in Renilla, the common sea pansy. More recently biochemists have directed their attention to the molecular basis of luminosity in this colonial form. These studies have centered primarily on defining the chemical basis for bioluminescence and its control. It is now established that bioluminescence in Renilla arises due to the luciferase-catalyzed oxidation of luciferin. This results in the creation of a product (oxyluciferin) in an electronic excited state. The transition of oxyluciferin from its excited state to the ground state leads to light emission.

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