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1.
D. Grimaud-Hervé 《Human Evolution》1986,1(2):167-181
A comparative study of Indonesian parietal bones from Sangiran, Sambungmachan 1 and Ngandong has been undertaken. This study
comprises a morphological and metrical analysis of the individual parietal bones, followed by consideration of the biparietal
vault. The results are compared with other hominids from earlier and later periods. These hominids were found in China (Sinanthropus
II, III, X, XI and XII), in Africa (ER 3733, OH 9, Ternifine, Broken Hill and Saldanha) and in Europe (Arago XLVII, Petralona,
Swanscombe, Steinheim, Le Lazaret, La Chaise (Abri Suard) and Cova Negra). These European Middle Pleistocene hominids are
attributed toHomo erectus by various authors (Lumley 1973;Hemmer 1972;Spitery 1982;Lumley andFournier 1982) and to an early Neanderthal group, pre-Neanderthal orHomo sapiens sensu lato (Neanderthals+modern humans) by others (Stringer 1980, 1981, 1983, 1984,Wolpoff 1980,Holloway 1982). The discussion about the classification of those hominids is not closed, but it is not the subject of this paper and
not our intention to solve it here. So we have chosen to call this fossil material ‘Anteneandertals’ (Lumley 1973).
It appears that some morphological metrical features allow us to separate the Sangiran and Ngandong samples. Sambungmachan
1, whose chronological age is not well established, appears to be closer to Ngandong men. 相似文献
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M. E. Leegwater-van der Linden E. P. M. Tiggelman 《Entomologia Experimentalis et Applicata》1984,35(3):283-294
In the tsetse fly Glossina pallidipes Austen multiple mating of females and the inseminating capacity of males was investigated with the aim of economizing on the number of males in mass rearing. Forty five percent of mated but uninseminated females and 9% of inseminated females remated.Virgin males inseminated four times in succession and remained eager to copulate thereafter. Restoration of the inseminating ability took 2 h rest. Experienced and virgin males were equally successful at mating. Insemination occurred during the last 30 s of the copulation and one male inseminated nine females on the average. Females mated in a 1:1 or a 1:3 / ratio were equally productive. The females that were mated in a 1:3 ratio survived better.Series of three successive matings, alternated with periods of rest, showed that the males did not regain their original inseminating capacity. In the first series all three mates were inseminated, but in subsequent series only the first and the second. An efficacious reduction of the number of males to 20% of the number of females to be mated may be possible by using the males first in a 1:3 and subsequently in a 1:2 / ratio.
Résumé Afin d'économiser le nombre de mâles à maintenir dans des élevages de masse pour des études sur les méthodes de protection contre Glossina pallidipes, les accouplements multiples des mâles et des femelles ont été étudiés au laboratoire.7 à 9 jours après leur émergence, les femelles ont eu pour la première fois la possibilité de s'accoupler avec des mâles vierges ou non. La réceptivité lors des accouplements ultérieurs a été testée immédiatement après le premier accouplement. 45% des femelles non inséminées se réaccouplent. Parmi les femelles inséminées, seulement 9% copulent à nouveau dans les 6 h qui suivent le premier accouplement.Les mâles présentés à une succession de femelles restaient avides de copuler, mais la majorité était incapable de les inséminer après la 4ème copulation; la restauration du pouvoir fertilisant demandait une période de repos de 2 h.En laboratoire, les mâles vierges ou expérimentés ne présentaient aucun avantage sexuel les uns par rapport aux autres. Les femelles semblaient avoir été inséminées dans les 30 dernières secondes de la copulation.Aucune différence de productivité n'a été observée quand les accouplements ont eu lieu avec 1 mâle pour 1 ou 3 femelles.Des séries de 3 accouplements successifs, alternant avec des periodes de repos, ont montré que le pouvoir fertilisant ne retrouvait pas son niveau initial. Dans les premières séries, toutes les 3 femelles ont été inséminées, mais dans les séries ultérieures seulement la 1ère et la 2nde. En moyenne, un maximum de 9 femelles était inséminé, marqué par un remplissage de la spermathèque de plus de 50% ou une fécondité supérieure à 0,8. Une réduction efficace du nombre de mâles, au cinquième de celui des femelles à accoupler, est possible en utilisant d'abord 1 mâle pour 3 femelles et ensuite 1 mâle pour 2 femelles.相似文献
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The finer control of mating activity by testosterone in male sheep was investigated using the castrated ram (wether) as an experimental model. Adult wethers that had been castrated before puberty were injected with graded doses of testosterone propionate (TP) and mating behavior was assessed in standardized libido trials at various times during treatment. Doses of 1 to 2 mg TP/day elicited mounting behavior in wethers but did not result in intromission or ejaculation. On the other hand, TP doses of 4 mg/day or greater stimulated the complete mating response which included intromission and the ejaculatory reflex. The threshold dose of TP required for complete mating activity (4 mg/day) produced plasma testosterone levels which were lower than those normally observed in intact rams. The results of this study indicate that the behavioral aspects (arousal mechanisms) of mating in rams have a lower testosterone threshold than intromission and ejaculation (consummatory mechanisms). Also, since complete mating activity was stimulated in wethers having relatively low plasma testosterone levels, this may explain why there is no apparent relationship between plasma testosterone and mating drive in intact rams. 相似文献
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C J Cook P D Gluckman B M Johnston C Williams 《Journal of developmental physiology》1987,9(5):441-455
Somatosensory evoked potentials were recorded in utero from 13 chronically instrumented fetal lambs (97 to 148 days of gestation) following electrical stimulation of the upper lip or upper limb. Several clear and reproducible peaks were observed. Following upper lip stimulation, peaks were seen with mean peak latencies of 9, 13.2, 17.8, 21.3, 33.8 and 206 ms at a gestational age of 125 days. Similar peaks, but of slightly later mean latencies, were seen following limb stimulation. These peaks demonstrated significant gestational age related falls in peak latencies (P less than 0.05). Several of the mid to late latency peaks, notably those occurring at 21.3, 33.8 and 206 ms, demonstrated changes (P less than 0.05) in both latency (longer in low voltage) and amplitude (reduced in low voltage) dependent on electrocorticographic state. Rate of stimulus presentation also had a significant effect on both amplitude and latency of several peaks (P less than 0.05) with this effect lessening with advancing gestational age. Evoked potentials can thus be successfully obtained from chronically instrumented fetal lambs and provide a useful indice for studies of neural maturation. 相似文献
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TETLEY JH 《Parasitology》1958,48(3-4):353-363
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Summary We investigated effects of plant density on floral phenology and potential mating in artificial populations of the outcrossing ornamental Nicotiana alata planted at three densities. Path analysis revealed that increasing plant density yielded significantly earlier peak flowering dates, significantly earlier last flowering dates, and significantly lower plant biomass. Direct effects of density on final flower number were not significant. Variation among replicate plots for first date of flowering was larger than variation among densities, indicating that factors other than density influence floral initiation.We did not record actual mating, but determined from phenological data the number and identity of potential mates. Increased density had several effects on potential mating patterns and on potential Ne, effective population number. At high density, fewer focal plants flowered for shorter durations. This led to less overlap in flowering time among plants, decreasing the number of potential parental combinations possible among the progeny. Two outcomes of high density, the lower total number of plants flowering and the lower number of plants flowering at most census dates, tended to reduce potential Ne. In contrast, it was low density, where variance in flower number was greatest, that was most likely to yield the greatest reduction in Ne due to variance in progeny number.At high density the potential for assortative mating among tall plants was much greater and occurred later than among large plants at low density. Much of the potential high density assortative mating occurred late in the phenology of individual plants, when there was likely to be lower fruit set.We discuss how ecological agents that alter flowering phenology can potentially alter the genetics of populations, the level and timing of assortative mating and, if genetic variation for response to such ecological agents exists, the potential selection regime. 相似文献
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Hiroshi Kuriyama Dudi Sastraatmadja Yoko Igosaki Kaoru Watanabe Atit Kanti Takema Fukatsu 《Mycoscience》1997,38(4):441-445
Yeast strains with amylolytic activity were isolated from cassavatapé and its precursor,ragi. they were divided into two groups based on their characteristics: group 1, possessing high amylolytic activity and low ethanol
yield; and group 2, possessing low amylolytic activity and high ethanol yield. The major strains of the group 1 were identified
asEndomyces fibuliger, and those of group 2 were identified asPichia anomala. Based on 18S rDNA analysis, an isolate fromragi that had a high amylolytic activity was thought to be an undescribed species that was related to the basidiomycetous genera. 相似文献
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Hair sheep ewes were used to evaluate the influence of various levels of mating stimuli on the duration and timing of estrus and LH concentrations around estrus. Ewes were treated with PGF2alpha (15 mg, im) 10 d apart. At the time of the second PGF2alpha treatment (Day 0) ewes were placed in groups and exposed to different types of mating stimuli. One group of ewes (n = 16) was exposed to an epididymectomized ram (RAM), a second group of ewes (n = 16) was exposed to an epididymectomized ram wearing an apron to prevent intromission (APRON) and a third group of ewes (n = 17) was exposed to an androgenized ovariectomized ewe (T-EWE). Jugular blood samples were collected from ewes at 6-h intervals through Day 5. Plasma was harvested and LH concentration was determined by RIA. The ewes were observed at 6-h intervals to detect estrus. A ewe was considered to be out of estrus when she no longer stood to be mounted by the teaser animal. There was no difference (P > 0.10) in the proportion of ewes expressing estrus (79.6%) or having an LH surge (85.7%) among the treatments. Neither the time to estrus nor the duration of estrus were different (P > 0.10) among APRON, RAM or T-EWE groups (41.6+/-3.8 vs 43.6+/-3.6 vs 46.1+/-3.6 h, respectively, and 26.5+/-2.2 vs 24.8+/-2.3 vs 30.5+/-2.2 h, respectively). The time to LH surge was similar (P > 0.10) among APRON, RAM and T-EWE groups (51.2+/-4.5 vs 51.2+/-4.7 vs 52.7+/-4.5 h, respectively). The magnitude of the LH surge was similar (P > 0.10) in the T-EWE, APRON and RAM ewes (99.7+/-4.9 vs 87.2+/-4.9 vs 85.8+/-5.0 ng/mL, respectively). The time from estrus to the LH surge was not different (P > 0.10) among APRON, RAM or T-EWE ewes (10.1+/-2.2 vs 9.8+/-2.3 vs 11.6+/-2.3 h, respectively). These results show that the expression and duration of estrus are not influenced by different types of mating stimuli in hair sheep ewes. In addition, the timing and the magnitude of LH release does not appear to be influenced by mating stimuli around the time of estrus. 相似文献
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Spiromastix saturnispora, isolated from a soil sample collected from central Java in Indonesia, is described and illustrated as a new species. The new species was compared with the type ofSpiromastix, S. warcupii, and is similar in having brownish ascomata with a peridium of a loose network of delicate hyphae, peridial appendages which are curved in the manner of a scimitar and never completely coiled, and the absence of an anamorph. The ascospores ofS. saturnispora are characterized as large oblate, 3.2–4.8 × 2.5–3µm, punctate, and with an equatorial rim, which serves to distinguish the species fromS. warcupii and other known species. 相似文献
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Food availability is one of the basic factors affecting primate density and socioecology, but food availability is difficult
to assess. Two different ways to obtain accurate estimates of food availability have been proposed: using phenology data or
using the behaviour of animals. Phenology data can be refined by only including trees that are large enough to be used; including
(potential) tree species in which by the concerned primate species forage; or including (fruiting) trees of these species
that actually produce fruit. Alternatively, the sizes of the actually visited trees (foraging trees) give an estimate of fruit
availability. These measures are compared for three sympatric primate species at the Ketambe Research Station, Sumatra, Indonesia:
the Thomas langur, the long-tailed macaque and the orangutan. The sizes of fruiting trees and the foraging trees are larger
than the potential trees. The sizes of the potential trees and of the fruiting trees are similar for the three primate species.
This, however, is not reflected in the use of trees: the langurs forage on average in trees of similar size to those producing
fruit, whereas the macaques and orangutans forage in trees larger than those producing fruit. The use of trees does not necessitate
a different cut off point of included dbhs for the three compared primate species. The use of trees of different sizes, however,
may be regulated by food competition. This indicates that sympatric primates make different foraging decisions and that behavioural
measures of food availability will be less reliable. 相似文献
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M. C. Mansperger 《Human Evolution》1990,5(3):245-259
What was the precultural human mating system? This paper uses primate cross-species comparisons to arrive at a plausible answer which challenges many current theories. The results of this investigation suggest that (1) our precultural ancestors resided in multimale, multifemale communities; (2) the male-female consortships of our ancestors were genetically programmed to last for a short period, i.e., a few months or less; and, most importantly, (3) the precultural human mating system was a form of «selective promiscuity.» Also, it is suggested that our precultural mating system is a continuing fundamental tendency within us that is being suppressed and modified by culture. 相似文献
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Summary Illegitimate / diploids heterozygous for the dmt gene, described previously, have been created and analyzed with respect to auxotrophic markers on chromosome III. It has been shown that in a high proportion of these diploids, which were theoretically heterozygous for the chromosome III auxotrophic markers his4, leu2 and thr4, the expected dominant phenotype was not obtained. This non-expression of the dominant gene (NEDG) appears to be a result of modification of the chromosome III genes found in dmt containing strains. The dmt gene is thought to affect the mating type locus located 22 centermorgans from the centromere on chromosome III. Thus a closely linked antibiotic resistance marker for cryptopleurine was examined along with the auxotrophic markers located on other parts of chromosome III. Control experiments gave the expected expression of cryptopleurine resistance or sensitivity whereas / diploids heterozygous for the dmt gene once again showed non-expression of the dominant genotype for this mating type linked marker. A number of these diploids also showed the unexpected ability to sporulate and gave rise to either two or four viable spores per ascus. Our results are consistent with the idea that the dmt gene causes deletions on chromosome III, and this in turn alters the mating properties of the haploid cells. By observing the effects of various deletions in samples selected for mating dynfunction, it is possible to speculate on certain properties of mating regulation. 相似文献
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John Blamire 《Molecular genetics and genomics : MGG》1975,141(2):185-188
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