Maternal malnutrition during gestation and lactation is known to have adverse effects on offspring. We evaluate the impact of maternal diet on offspring bony labyrinth morphology. The bony labyrinth ...develops early and is thought to be stable to protect vital sensory organs within. For these reasons, bony labyrinth morphology has been used extensively to assess locomotion, hearing function, and phylogeny in primates and numerous other taxa. While variation related to these parameters has been documented, there is still a component of intraspecific variation that is unexplained. Although the labyrinthine developmental window is small, it may provide the opportunity for developmental instability to produce corresponding shape differences, as measured by fluctuating asymmetry (FA). We hypothesized that (a) offspring with poor maternal diet would exhibit increased FA, but (b) no unilateral shape difference. To test these hypotheses, we used two groups of rats (Rattus norvegicus; Crl:WIHan strain), one control group and one group exposed to a isocaloric, protein‐restricted maternal diet during gestation and suckling. Individuals were sampled at weaning, sexual maturity, and old age. A Procrustes analysis of variance identified statistically significant FA in all diet‐age subgroups. No differences in level of FA were identified among the subgroups, rejecting our first hypothesis. A principal components analysis identified no unilateral shape differences, supporting our second hypothesis. These results indicate that bony labyrinth morphology is remarkably stable and likely protected from a poor maternal diet during development. In light of this result, other factors must be explored to explain intraspecific variation in labyrinthine shape.
•Labyrinthine shape did not correspond with assessed sex in archaeological groups.•Cultural and dietary differences in archaeological groups had no effect.•Use of a previously-published equation or ...of raw measurements had no effect.•Bony labyrinth shape variation within humans is present, but not fully explored.
Osipov and colleagues American Journal of Physical Anthropology, 2(151) 2013 previously posited that the dimensions of the bony labyrinth exhibit sexual dimorphism. Using a recent sample of known sex, they produced an age-independent, multivariate equation to predict biological sex using several of these dimensions. We aim to test the applicability of this equation to archaeological samples, where the method could prove useful with poorly preserved remains. Using µCT data, we collected a standard set of linear dimensions from the bony labyrinth in two groups from the ancient Nile Valley that show body size differences associated with diet and disease. We determined the biological sex of these individuals using established skeletal features and with Osipov and colleagues’ (2013) equation. Results of each were compared with McNemar tests, and raw measurements were examined within each group for dimorphism with a Discriminant Function Analysis. Biological sex predicted by labyrinthine dimensions overidentified individuals from both groups as female. Adjustments to the equation constant balanced predicted sex numbers and increased consistency both on an individual level (31.3% to 67.4%) and model level (χ2 < critical value). Discriminant function analysis consistently classified 60% of el-Badari and 50% of Kerma individuals. Absolute bony labyrinth dimensions and the results of Osipov and colleagues’ (2013) equation did not produce sex estimations consistent with those made from assessment of pelvic and cranial features. As these assessments also have error, further exploration of sexual dimorphism in the labyrinth should be undertaken in collections with known sex.
Objectives
Intraspecific shape variation in the recent Homo sapiens bony labyrinth has been assessed for association with sexual dimorphism, body size, and genetic differences, but has not been fully ...assessed for association with extrinsic factors, such as subsistence strategy and climate. While the skull overall is known to vary with these variables, the bony labyrinth develops in utero and exhibits microstructural stability through adulthood. Therefore, labyrinthine morphology may be resistant to extrinsic variables.
Materials and methods
We collected labyrinthine shape data using computed tomography from 262 individuals associated with archeological or contemporary collections used for dissection in North America, Europe, Africa, and Southeast Asia. We assessed the data for observer error and asymmetry. Shape variation is examined between subsistence strategy groups and climate type groups with Principal Components Analyses and Procrustes ANOVA's, and shape variation was correlated with specific climate data (precipitation, temperature, altitude) with a two‐block partial least squares analysis.
Results
Both inter‐ and intra‐observer error as well as asymmetry minimally affected labyrinthine shape variation. We found that both subsistence strategy and climate each account for a statistically significant 7% of overall shape variation, and that specific climate variables have statistically significant correlation with labyrinthine shape variation (RV 0.52527).
Discussion
Morphological variation in this sample indicates that the labyrinth is not entirely resistant to extrinsic factors associated with subsistence strategy and climate. Shape differences are not localized to specific regions of the labyrinth, but may contribute to the complicated variation seen in recent human evolution and warrants further exploration.
The recent human bony labyrinth within the cranium (A) and segmented from the cranium (B) using computed tomography.
A fossil hominid tooth was discovered during survey at Galili, Somali region, Ethiopia. The geological and faunal context indicate an Early Pliocene age. The specimen (GLL 33) consists of an almost ...complete lower right third molar likely representing a male individual of advanced age-at-death. Its comparative metrical, morphological and (micro)structural analysis (supported by a microtomographic record) suggests a tentative taxonomic allocation to Australopithecus cf A. afarensis.
Neanderthals and Denisovans are extinct groups of hominins that separated from each other more than 390,000 years ago
. Here we present the genome of 'Denisova 11', a bone fragment from Denisova Cave ...(Russia)
and show that it comes from an individual who had a Neanderthal mother and a Denisovan father. The father, whose genome bears traces of Neanderthal ancestry, came from a population related to a later Denisovan found in the cave
. The mother came from a population more closely related to Neanderthals who lived later in Europe
than to an earlier Neanderthal found in Denisova Cave
, suggesting that migrations of Neanderthals between eastern and western Eurasia occurred sometime after 120,000 years ago. The finding of a first-generation Neanderthal-Denisovan offspring among the small number of archaic specimens sequenced to date suggests that mixing between Late Pleistocene hominin groups was common when they met.
A high-coverage Neandertal genome from Chagyrskaya Cave Mafessoni, Fabrizio; Grote, Steffi; de Filippo, Cesare ...
Proceedings of the National Academy of Sciences - PNAS,
06/2020, Letnik:
117, Številka:
26
Journal Article
Recenzirano
Odprti dostop
We sequenced the genome of a Neandertal from Chagyrskaya Cave in the Altai Mountains, Russia, to 27-fold genomic coverage. We show that this Neandertal was a female and that she was more related to ...Neandertals in western Eurasia Prüfer et al., Science 358, 655–658 (2017); Hajdinjak et al., Nature 555, 652–656 (2018) than to Neandertals who lived earlier in Denisova Cave Prüfer et al., Nature 505, 43–49 (2014), which is located about 100 km away. About 12.9% of the Chagyrskaya genome is spanned by homozygous regions that are between 2.5 and 10 centiMorgans (cM) long. This is consistent with the fact that Siberian Neandertals lived in relatively isolated populations of less than 60 individuals. In contrast, a Neandertal from Europe, a Denisovan from the Altai Mountains, and ancient modern humans seem to have lived in populations of larger sizes. The availability of three Neandertal genomes of high quality allows a view of genetic features that were unique to Neandertals and that are likely to have been at high frequency among them. We find that genes highly expressed in the striatum in the basal ganglia of the brain carry more aminoacid- changing substitutions than genes expressed elsewhere in the brain, suggesting that the striatum may have evolved unique functions in Neandertals.
The last couple of decades have highlighted the importance of studying hybridization, particularly among primate species, as it allows us to better understand our own evolutionary trajectory. Here, ...we report on genetic ancestry estimates using dense, full genome data from 881 olive (Papio anubus), yellow (Papio cynocephalus), or olive-yellow crossed captive baboons from the Southwest National Primate Research Center. We calculated global and local ancestry information, imputed low coverage genomes (n = 830) to improve marker quality, and updated the genetic resources of baboons available to assist future studies. We found evidence of historical admixture in some putatively purebred animals and identified errors within the Southwest National Primate Research Center pedigree. We also compared the outputs between two different phasing and imputation pipelines along with two different global ancestry estimation software. There was good agreement between the global ancestry estimation software, with R.sup.2 > 0.88, while evidence of phase switch errors increased depending on what phasing and imputation pipeline was used. We also generated updated genetic maps and created a concise set of ancestry informative markers (n = 1,747) to accurately obtain global ancestry estimates.
Denisovans, a sister group of Neandertals, have been described on the basis of a nuclear genome sequence from a finger phalanx (Denisova 3) found in Denisova Cave in the Altai Mountains. The only ...other Denisovan specimen described to date is a molar (Denisova 4) found at the same site. This tooth carries a mtDNA sequence similar to that ofDenisova 3. Here we present nuclear DNA sequences fromDenisova 4and a morphological description, as well as mitochondrial and nuclear DNA sequence data, from another molar (Denisova 8) found in Denisova Cave in 2010. This new molar is similar toDenisova 4in being very large and lacking traits typical of Neandertals and modern humans. Nuclear DNA sequences from the two molars form a clade withDenisova 3. The mtDNA ofDenisova 8is more diverged and has accumulated fewer substitutions than the mtDNAs of the other two specimens, suggesting Denisovans were present in the region over an extended period. The nuclear DNA sequence diversity among the three Denisovans is comparable to that among six Neandertals, but lower than that among present-day humans.
With the exception of Neanderthals, from which DNA sequences of numerous individuals have now been determined, the number and genetic relationships of other hominin lineages are largely unknown. Here ...we report a complete mitochondrial (mt) DNA sequence retrieved from a bone excavated in 2008 in Denisova Cave in the Altai Mountains in southern Siberia. It represents a hitherto unknown type of hominin mtDNA that shares a common ancestor with anatomically modern human and Neanderthal mtDNAs about 1.0 million years ago. This indicates that it derives from a hominin migration out of Africa distinct from that of the ancestors of Neanderthals and of modern humans. The stratigraphy of the cave where the bone was found suggests that the Denisova hominin lived close in time and space with Neanderthals as well as with modern humans.
PDF
