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The methods used to study human growth and development (auxology) have not previously been applied within the setting of hominin maturation (ontogeny). Ontogeny is defined here as the pattern of biological change into an adult form, both at the individual and species level. The hominin fossil record has a lack of recovered immature materials, due to such factors as taphonomic processes that destroy pre-adults; the fragility of immature compared to adult bone; and the lower mortality rates of juveniles compared to adults. The recent discovery of pre-adult hominin skeletal material from a single, homogeneous Homo naledi species from the Rising Star cave system in South Africa provides the opportunity for a broader application of auxology methods and thus the need to understand their use in a modern context. Human auxology studies benefit from a robust database, across multiple populations, and with longitudinal studies in order to assess the patterns and variations in typical growth, development and life history stages. Here, we review the approach, vocabulary, and methods of these human studies, investigate commonalities in data with the fossil record, and then advance the reconstruction of ontogeny for the extinct hominin species H. naledi. To this end, we apply an auxology model into the paleontological context to broadly predict H. naledi birthweight of the offspring at 2.06 kg with a range (±1 SD) of 1.89 to 2.24 kg, with a length at birth 45.5 cm. We estimate a H. naledi juvenile partial skeleton DH7 to be a height of 111–125 cm at death. 相似文献
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C. H. Siven 《International Journal of Anthropology》1991,6(2):111-117
It is shown how the sex and age distribution of the (once) living population can be calculated from estimated mortalities. Fertility calculations and estimations of the number of children per woman are provided as well. The method is applied to two materials from the Middle Ages: Westerhus and Helgeandsholmen. 相似文献
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Efforts are underway to return the American chestnut (Castanea dentata) to eastern forests of North America following its decline due to the introduction of the chestnut blight (Cryphonectria parasitica). Approaches include developing blight‐resistant chestnut lines through breeding programs and via genetic engineering. Reestablishment of resistant chestnut to eastern forests would produce one of the most extensive ecological restoration transformations ever attempted. However, this undertaking is costly and optimization of reintroduction methods is needed. We used the computer program NEWGARDEN to model whether some patterns of founder placement (regular vs. random spacing at differing densities) produce more rapidly expanding populations across a range of gene dispersal distance conditions (via both offspring and pollen). For a simulated introduction project employing 169 founders, placing founders randomly in a square of side 0.85 km produced higher rates of predicted population growth compared with larger or smaller squares under near gene dispersal conditions; this side distance was 1.0 km under far gene dispersal conditions. After 100 population bouts of mating and under near gene dispersal conditions, the trial with founder placement producing the greatest population expansion rate exhibited a 314% increase in census size compared with the founder pattern yielding the slowest expansion. Neither loss of alleles nor inbreeding or subdivision was significantly increased under the founder placement patterns yielding the most descendants. Exploring different numerical and geometrical founding scenarios using NEWGARDEN can provide first estimates of founding patterns or stand manipulations that will return the most descendants produced per founder planted in restoration projects. 相似文献
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NICOLA PATRICIA SANGER STEPHEN WAITE 《Botanical journal of the Linnean Society. Linnean Society of London》1998,126(1-2):75-81
Ophrys sphegodes is a rare species in the United Kingdom. The largest extant population of the species, at Castle Hill National Nature Reserve in Sussex, has been monitored each year since 1975. At each annual census, which is conducted during the peak period of flowering (May), the co-ordinates of each plant are recorded, allowing the fate of individuals to be followed from one census to the next. In the present study the population was monitored throughout one complete year. The data collected allow the phenology of the species to be described and the effectiveness of the annual census to be assessed. The study shows that a substantial number of Ophrys sphegodes plants emerge above ground and re-enter the below ground phase before the census date. These results suggest that reliance on annual census records alone may result in the size of the population being underestimated and incorrect life-histories being ascribed to individual plants. True counts of the population may be obtained only if 'dormant' plants are retrospectively added to the population. 相似文献
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The pathogenic effects of Pratylenchus coffeae on growth and yield of tangelo (Citrus paradisi × C. reticulata) scions grafted on rough lemon (C jambhiri), sour orange (C. aurantium) and ''Cleopatra'' mandarin (C. reticulata) rootstocks were evaluated under field conditions for 4 years. Pratylenchus coffeae on inoculated trees increased to significantly damaging population densities on rough lemon rootstock the second year, on sour orange the third and on Cleopatra mandarin the fourth year after planting. Mean growth reduction of P. coffeae-infected trees after 4 years was 80, 77 and 49%, respectively, for the three rootstocks. Noninoculated trees on rough lemon and sour orange rootstocks yielded significantly more fruit than comparable inoculated trees. Natural migration of P. coffeae occurred horizontally on roots for a distance of 4.5 m. 相似文献
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Raquel García-Vernet Berta Martín Miguel A. Peinado Gísli Víkingsson Marta Riutort Alex Aguilar 《Marine Mammal Science》2021,37(4):1230-1244
Recovery rates for baleen whales that were decimated by exploitation vary between species and populations. Age determination is critical for the understanding of recovery trends and population structure, but determining age in free-ranging individuals remains challenging. Recent research has suggested that the methylation level of some genes in skin samples may provide age determinations with accuracy. We selected nine CpG sites from three genes (TET2, CDKN2A, and GRIA2) and analyzed them in 40 skin samples from known-age individuals pertaining to two different populations of fin whales from the North Atlantic. We observed significant correlations with age in five CpG sites. We used three of these CpG sites to perform an epigenetic age estimation. Predictions had a standard deviation of 2.94, but regression between observed and predicted ages showed a clear underestimation for older fin whales. For further development, we suggest: (1) screening for new CpG sites associated with age that exhibit higher variability between individuals, and (2) including older animals whenever the sampling allows it. We also observed subtle, but significant differences between the two populations studied in one of the CpG sites (TET2_CpG + 21). We attributed these differences to genetic differences or to the dissimilar environments that affect both populations. 相似文献
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在 2 0℃、2 5℃、2 8℃、30℃、32℃、35℃及 75 %rh下 ,采用绿豆作饲料 ,研究比较重庆绿豆象及西昌绿豆象生物学生态学特性差异。结果表明温度对两地绿豆象发育历期、存活率及繁殖力影响显著 (ANOVA ,P <0 0 5 )。t测验表明两地理种的整个未成熟期在 2 5℃、32℃下差异显著 (P <0 0 5 )。在 30℃、75 %rh条件下 ,研究绿豆、饭豆、蚕豆、爬山豆及大豆对绿豆象两地理种群生长发育和繁殖的影响。结果表明食物对产卵量的影响显著 (P <0 0 5 ) ,同一食物两地理种群产卵量之间差异显著 (P <0 0 5 )。本研究还测定了新羽化成虫体重及危害豆类后造成的羽化孔内径。由于地理隔离和豆类栽培制度的不同 ,在长期的进化过程中 ,绿豆象两地理种群生长发育、繁殖及危害特性上已明显达到分化程度 ,形成了两个不同的地理种群。 相似文献
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The differences of bionomics and ecologies of the two populations of Callosobruchus chinensis on mung bean (Vigna radiatus) at six constant temperatures (20, 25, 28, 30, 32, 35°C) and 75% r. h. were researched. ANOVA showed that temperature affected the developmental period and fertility significantly (P < 0.05). T‐test indicated there was significant difference of the combined immature stages between the two geographical populations at 25 and 32°C (P < 0.05). The average oviposition between the two geographical populations differed significantly at the same temperature (P < 0.05). At 30°C and 75% r. h., effects of 5 commercially grown legume seeds on development and reproduction of the two geographical populations of Callosobruchus chinensis (L.) were researched. The results showed that broad bean and soybean were more suitable for increase for Xichang population in terms of rm values. The adult weight and diameter of emergency hole of the two populations were also compared. According to the differences in the characteristics of development, reproduction, and damage to host seeds between the two geographical populations, conclusion can be drawn that both are different geographical populations. 相似文献
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病原菌在自然植物种群中普遍存在,其对寄主植物的生长发育,对寄主植物种群的大小、结构、动态、遗传和进化等都有重要影响。本文着重论述：１）病原菌对寄主植物个体的影响;２）病原菌对寄主植物种群生物学的影响;３）菌病发生的空间格局;４）病原菌感染的种群模型。 相似文献
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Kitty F. Emery 《Human ecology: an interdisciplinary journal》2008,36(5):617-634
Zooarchaeological analyses of animal remains from the Petexbatun sites in the Guatemalan lowlands provide proxy evidence to
test a hypothesis of dietary insufficiency during the Maya “collapse.” Ecological foraging theory and resource depression
models are used to interpret animal use patterns before and after the disintegration of the Petexbatun polity at the end of
the Late Classic period (around a.d. 800). Environmental failure models of the Maya “collapse” at the end of the Late Classic imply that a dietary insufficiency,
and particularly a lack of animal resources, was associated with the political and social transitions of this period. However,
the results of this zooarchaeological study do not support this hypothesis and point instead to very limited early reductions
of only highest-ranked dietary species. The lack of evidence for specific resource depression associated directly with the
period of political collapse does not support a model of environmental failure during political disintegration in the Petexbatun.
Correlations are found between animal use patterns and the specifics of site size and periods of peak political activity,
suggesting that small-scale resource depressions might have resulted at some sites during early periods of human population
growth, site expansion, and increasing political activity. 相似文献
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R. R. RAMEY II 《Molecular ecology》1995,4(4):429-440
In the south-western United States and Mexico, mountain sheep were found to have low levels of mtDNA sequence divergence among haplotypes and low overall nucleotide diversity. Potential causes for this low diversity are discussed. Significant differences in mtDNA haplotype distributions over short distances and high values of NST on a local scale appear to be a result of the tendency of female mountain sheep to disperse less frequently and over shorter distances than males. A lack of concordance between mtDNA haplotype distributions and assumed subspecies boundaries suggest that some taxonomic labels need to be revised. 相似文献
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The populations of tench from two gravel pit lakes of contrasting habitat type were studied. The population density of tench from St Peter's Lake, which has abundant aquatic vegetation was 176 individuals ha−1 (102.2 kg ha−1 ) compared to 0.3 individuals ha−1 (0.5 kg ha−1 ) in the Main Lake which has very little aquatic vegetation. The results of ageing tench by scales, opercular bones and otoliths were compared; all three structures gave similar results up to 9 years of age, but thereafter there were difficulties in ageing using scales and care was needed in counting annuli. The oldest tench caught was 15 years old. Growth of male and female tench was similar and fitted the von Bertalanffy model; for female tench L∞ = 573 mm, K =0.122 and for male tench L∞ = 586 mm, K =0.114. Recruitment was variable and strong year classes occurred in years with warm summers. 相似文献
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影响水稻纹枯病流行、危害的因子分析 总被引：8，自引：1，他引：7
以连作早稻为研究对象,对影响水稻纹枯病发生、危害有关的因子,即品种、施氮肥量、气象因素、为害损失、发病时间、病情程度及药剂等作了系统的定量研究.结果表明,品种间存在抗病性和危害损失程度上的差异;施氮肥量与发病程度关系密切;气象因素中以日均温和雨日频率与病害流行速率关系密切;发病时间与为害损失率相关性不明显,药剂防治效果与控病时间、病情基数有关. 相似文献
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Molly K. Burke Thomas T. Barter Larry G. Cabral James N. Kezos Mark A. Phillips Grant A. Rutledge Kevin H. Phung Richard H. Chen Huy D. Nguyen Laurence D. Mueller Michael R. Rose 《Evolution; international journal of organic evolution》2016,70(9):2085-2098
Laboratory selection experiments are alluring in their simplicity, power, and ability to inform us about how evolution works. A longstanding challenge facing evolution experiments with metazoans is that significant generational turnover takes a long time. In this work, we present data from a unique system of experimentally evolved laboratory populations of Drosophila melanogaster that have experienced three distinct life‐history selection regimes. The goal of our study was to determine how quickly populations of a certain selection regime diverge phenotypically from their ancestors, and how quickly they converge with independently derived populations that share a selection regime. Our results indicate that phenotypic divergence from an ancestral population occurs rapidly, within dozens of generations, regardless of that population's evolutionary history. Similarly, populations sharing a selection treatment converge on common phenotypes in this same time frame, regardless of selection pressures those populations may have experienced in the past. These patterns of convergence and divergence emerged much faster than expected, suggesting that intermediate evolutionary history has transient effects in this system. The results we draw from this system are applicable to other experimental evolution projects, and suggest that many relevant questions can be sufficiently tested on shorter timescales than previously thought. 相似文献
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Most evolutionary theory focuses on species that reproduce through sexual reproduction where both sexes have a diploid chromosome count. Yet a substantial proportion of multicellular species display complex life cycles, with both haploid and diploid life stages. A classic example is haplodiploidy, where females develop from fertilized eggs and are diploid, while males develop from unfertilized eggs and are haploid. Although haplodiploids make up about 15% of all animals (de la Filia et al. 2015 ), this type of reproduction is rarely considered in evolutionary theory. In this issue of Molecular Ecology, Patten et al. ( 2015 ) develop a theoretical model to compare the rate of nuclear and mitochondrial introgression in haplodiploid and diploid species. They show that when two haplodiploid species hybridize, nuclear genes are much less likely to cross the species barrier than if both species were to be diploids. The reason for this is that only half of the offspring resulting from matings between haplodiploid species are true hybrids: sons from such mating only inherit their mother genes and therefore only contain genes of the maternal species. Truly, hybrid males can only occur through backcrossing of a hybrid female to a male of one of the parental species. While this twist of haplodiploid transmission genetics limits nuclear introgression, mitochondrial genes, which are maternally inherited, are unaffected by the scarcity of hybrid males. In other words, the rate of mitochondrial introgression is the same for haplodiploid and diploid species. As a result, haplodiploid species on average show a bias of mitochondrial compared to nuclear introgression. 相似文献