scholarly journals Morphological variation of the deciduous second molars in the Baka Pygmies

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Petra G. Šimková ◽  
Gerhard W. Weber ◽  
Fernando V. Ramirez Rozzi ◽  
Lotfi Slimani ◽  
Jérémy Sadoine ◽  
...  
Keyword(s):  
Growth Rate ◽  
Morphological Variation ◽  
Growth Pattern ◽  
Distal Region ◽  
Dental Morphology ◽  
Human Sample ◽  
Different Populations ◽  
Dental Traits ◽  
South Americans ◽  
Range Of Variation

AbstractThe Baka Pygmies are known for their short stature resulting from a reduced growth rate during infancy. They are peculiar also for their teeth erupt earlier than in any other African population, and their posterior dentition is larger than in non-Pygmy populations. However, the Baka’s dental morphology, like several other aspects of their biology, is still understudied. Here, we explore the variation of the Baka’s deciduous upper and lower second molars (dm2s) in comparison to a geographically heterogeneous human sample by means of 3D geometric morphometrics and analysis of dental traits. Our results show that the different populations largely overlap based on the shape of their dm2s, especially the lower ones. Their distal region and the height of the dentinal crown differ the most, with the Baka showing the most extreme range of variation. Upper and lower dm2s covary to a great extent (RV = 0.82). The Baka’s and South Americans’ dm2s were confirmed among the largest in our sample. Despite the Baka’s unique growth pattern, long-lasting isolation, and extreme dental variation, it is not possible to distinguish them from other populations based on their dm2s’ morphology only.

scholarly journals Morphological Variation of the Deciduous Second Molars in the Baka Pygmies

2021 ◽  
Author(s):  
Petra G. Šimková ◽  
Gerhard W. Weber ◽  
Fernando V. Ramirez Rozzi ◽  
Lotfi Slimani ◽  
Jérémy Sadoine ◽  
...  
Keyword(s):  
Growth Rate ◽  
Morphological Variation ◽  
Growth Pattern ◽  
Distal Region ◽  
Dental Morphology ◽  
Human Sample ◽  
Different Populations ◽  
Dental Traits ◽  
South Americans ◽  
Range Of Variation

Abstract The Baka Pygmies are known for their short stature resulting from a reduced growth rate during infancy. They are peculiar also for their teeth erupt earlier than in any other African population, and their posterior dentition is larger than in non-Pygmy populations. However, the Baka’s dental morphology, like several other aspects of their biology, is still understudied. Here, we explore the variation of the Baka’s deciduous upper and lower second molars (dm2s) in comparison to a geographically heterogeneous human sample by means of 3D geometric morphometrics and analysis of dental traits. Our results show that the different populations largely overlap based on the shape of their dm2s, especially the lower ones. Their distal region and the height of the dentinal crown differ the most, with the Baka showing the most extreme range of variation. Upper and lower dm2s covary to a great extent (RV=0.82). The Baka’s and South Americans’ dm2s were confirmed among the largest in our sample. Despite the Baka’s unique growth pattern, long-lasting isolation, and extreme dental variation, it is not possible to distinguish them from other populations based on their dm2s’ morphology only.

Morphological Variation of the Baka Pygmies’ Deciduous Second Molars 

2021 ◽  
Author(s):  
Petra G. Šimková ◽  
Gerhard W. Weber ◽  
Fernando Ramirez-Rozzi ◽  
Lotfi Slimani ◽  
Jérémy Sadoine ◽  
...  
Keyword(s):  
Distal Region ◽  
Dental Morphology ◽  
Second Molar ◽  
Natural Logarithm ◽  
Dental Crowns ◽  
Human Sample ◽  
Molar Morphology ◽  
South Americans ◽  
Deciduous Molars ◽  
General Size

Abstract The Baka pygmies are known for their short stature resulting from a reduced growth rate during infancy. They are peculiar also for their teeth erupt earlier than in any other African population, and their posterior dentition is larger than in non-pygmies. However, the Baka’s dental morphology, as several other aspects of their biology, is still understudied. In this study we explore the Baka’s upper and lower second deciduous molars variation in comparison to a human sample including Africans, Asians, Europeans, and South Americans by means of 3D geometric morphometrics. We analyzed both the outer and inner aspect of the dental crowns, as well as their general size based on the natural logarithm of centroid sizes. Our results show largely overlapping morphologies between populations, especially for the lower molars. The distal region of the second molars is the most variable, with the Baka’s lower second molars showing the most extreme range of variation for this aspect and in terms of crown height. Upper and lower second molars showed high morphological covariation (RV=0.82). The Baka and South Americans’ second molars were confirmed among the largest in our sample. Despite of the Baka’s particular growth pattern, long-lasting isolation and extreme dental variation, it is not possible to distinguish them from other populations on the basis of their second molar morphology only.

scholarly journals Dental morphology of deciduous molars from late Neolithic Caves of the Meuse River Basin of Belgium

2018 ◽  
Vol 31 (2) ◽  
pp. 18-26
Author(s):  
Frank L'Engle Williams ◽  
Rebecca L George ◽  
Caroline Polet
Keyword(s):  
River Basin ◽  
Dental Morphology ◽  
Late Neolithic ◽  
Potential Relationship ◽  
Dental Traits ◽  
Deciduous Molars ◽  
Range Of Variation ◽  
Dental Casts ◽  
Meuse River

Nearly 200 karstic caves of the Meuse River Basin of Belgium preserve collective burials dated to the Late Neolithic. The gnathic remains from five well preserved sites provide an opportunity to explore potential relationship among these cave burials. The cave burials of Hastière Caverne M, Hastière Trou Garçon C, Maurenne Caverne de la Cave, Sclaigneaux and Bois Madame are dated to circa 4,635 to 3,830 years BP. Dental casts from mandibular and maxillary deciduous molars are scored using the ASUDAS. Carabelli’s trait varies from a small, Y-shaped depression to a full cusp, and the largest ones are found at Hastière Caverne M. The mandibular first molars have three to five cusps and the second molars have five, with one instance of six cusps at Bois Madame, which exceeds the range of variation for other dental traits.  The hypoconulid ranges from small to very large. A metaconulid is absent or small.           Although the results are contingent on idiosyncratic preservation, differences in the frequencies of traits exist between the earlier cave burial from Hastière Caverne M and the late/final Neolithic burials of Sclaigneaux and Bois Madame, the latter of which is the most variable in the expression of dental traits.   

THE GROWTH OF IQ AMONG ESTONIAN SCHOOLCHILDREN FROM AGES 7 TO 19

2004 ◽  
Vol 36 (6) ◽  
pp. 735-740 ◽  
Author(s):  
HELLE PULLMANN ◽  
JÜRI ALLIK ◽  
RICHARD LYNN
Keyword(s):  
Secondary School ◽  
School Children ◽  
Growth Pattern ◽  
Representative Sample ◽  
Sampling Error ◽  
First Grade ◽  
Maturation Process ◽  
Different Populations ◽  
The Mean ◽  
The Difference

The Standard Progressive Matrices test was standardized in Estonia on a representative sample of 4874 schoolchildren aged from 7 to 19 years. When the IQ of Estonian children was expressed in relation to British and Icelandic norms, both demonstrated a similar sigmoid relationship. The youngest Estonian group scored higher than the British and Icelandic norms: after first grade, the score fell below 100 and remained lower until age 12, and after that age it increased above the mean level of these two comparison countries. The difference between the junior school children and the secondary school children may be due to schooling, sampling error or different trajectories of intellectual maturation in different populations. Systematic differences in the growth pattern suggest that the development of intellectual capacities proceeds at different rates and the maturation process can take longer in some populations than in others.

Local Behavior of the Tumor: Growth Pattern and Growth Rate

1987 ◽  
pp. 39-58 ◽  
Author(s):  
Holger Pettersson ◽  
Dempsey S. Springfield ◽  
William F. Enneking
Keyword(s):  
Growth Rate ◽  
Tumor Growth ◽  
Growth Pattern ◽  
Local Behavior

scholarly journals Testing the utility of dental morphological trait combinations for inferring human neutral genetic variation

2020 ◽  
Vol 117 (20) ◽  
pp. 10769-10777 ◽  
Author(s):  
Hannes Rathmann ◽  
Hugo Reyes-Centeno
Keyword(s):  
Modern Human ◽  
Genomic Variation ◽  
Future Research ◽  
Human Populations ◽  
Dental Morphology ◽  
Genomic Signatures ◽  
Neutral Genetic Variation ◽  
Tooth Form ◽  
Dental Traits ◽  
Population Affinity

Researchers commonly rely on human dental morphological features in order to reconstruct genetic affinities among past individuals and populations, particularly since teeth are often the best preserved part of a human skeleton. Tooth form is considered to be highly heritable and selectively neutral and, therefore, to be an excellent proxy for DNA when none is available. However, until today, it remains poorly understood whether certain dental traits or trait combinations preserve neutral genomic signatures to a greater degree than others. Here, we address this long-standing research gap by systematically testing the utility of 27 common dental traits and >134 million possible trait combinations in reflecting neutral genomic variation in a worldwide sample of modern human populations. Our analyses reveal that not all traits are equally well-suited for reconstructing population affinities. Whereas some traits largely reflect neutral variation and therefore evolved primarily as a result of genetic drift, others can be linked to nonstochastic processes such as natural selection or hominin admixture. We also demonstrate that reconstructions of population affinity based on many traits are not necessarily more reliable than those based on only a few traits. Importantly, we find a set of highly diagnostic trait combinations that preserve neutral genetic signals best (up to x∼r = 0.580; 95% r range = 0.293 to 0.758; P = 0.001). We propose that these trait combinations should be prioritized in future research, as they allow for more accurate inferences about past human population dynamics when using dental morphology as a proxy for DNA.

Shoot morphology and growth pattern in seedlings of Pinusbrutia provenances

1988 ◽  
Vol 18 (2) ◽  
pp. 188-194 ◽  
Author(s):  
Roberto Calamassi ◽  
Mauro Falusi ◽  
Laura Mugnai
Keyword(s):  
Growth Rate ◽  
Growth Pattern ◽  
High Growth ◽  
Growing Season ◽  
Variable Number ◽  
Growth Potential ◽  
Academic Press ◽  
Shoot Morphology ◽  
Apical Bud ◽  
Total Growth

The process of primary growth in 2-year-old seedlings of six Pinusbrutia Ten. provenances is described. At the end of the first growing season, two types of shoot morphology were observed: type 1, a terminal winter bud, and type 2, a terminal rosette of primary needles protecting the meristematic apex. During the 2nd year the seedlings exhibited a succession of shoots (varying in number from one to five), each of which was due to the elongation of a new apical bud. Morphological observations along with an anatomical examination of the winter bud led to the conclusion that the growth pattern in juvenile P. brutia is monocyclic with a variable number of summer shoots (using the terminology proposed by Lanner (Lanner, R.M. 1976. In Tree physiology and yield improvement. Editedby M.G.R. Cannell and F.T. Last. Academic Press, London, pp. 223-243)). The provenances studied differed both in growth potential and in seasonal growth pattern (differences in number of shoots, ratio of spring shoot to total growth, growth rate). Two groups could be identified: (i) the provenances of the island of Crete, which had a low growth potential and short growing season, and (ii) the high-altitude provenances of inland Turkey, with high growth potential and a growth rate that peaked in summer.

A REASSESSMENT OF THE BROMUS MADRITENSIS COMPLEX (POACEAE): A MULTIVARIATE APPROACH

1994 ◽  
Vol 42 (3) ◽  
pp. 245-255 ◽  
Author(s):  
F. Sales
Keyword(s):  
Morphological Variation ◽  
Entire Range ◽  
Multivariate Approach ◽  
Bromus Madritensis ◽  
The Mediterranean ◽  
Range Of Variation

The morphological variation in the Mediterranean/SW Asia complex ofBromus madritensisL.,B. madritensisL. subsp.kunkeliiH. Scholz,B. rubensL.,B. haussknechtiiBoiss., andB.flabellatusBoiss. is analyzed by computer and the data discussed. The conclusion is that the entire range of variation falls in one species with two subspecies:B. madritensisL. subsp.madritensisandB. madritensisL. subsp.rubens(L.) Husnot.

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