Cranial capacity in hominid evolution

We present an analysis of cranial capacity of 118 hominid crania available from the literature. The crania belong to both the genusAustralopithecus andHomo and provide a clear outline of hominid cranial evolution starting at more than 3 million years ago. Beginning withA. afarensis there is a clear increase in both absolute and relative brain size with every successive time period.H.s. neandertal has an absolutely and relatively smaller brain size (1412cc, E.Q.=5.6) than fossil modernH.s. sapiens (1487cc, E.Q.=5.9). Three evolutionary models of hominid brain evolution were tested: gradualism, punctuated equilibrium, and a mixed model using both gradualism and punctuated equilibrium. Both parametric and non-parametric analyses show a clear trend toward increasing brain size withH. erectus and a possible relationship within archaicH. sapiens. An evolutionary stasis in cranial capacity could not be refuted for all other taxa. Consequently, the mixed model appears to more fully explain hominid cranial capacity evolution. However, taxonomic decisions could directly compromise the possibility of testing the evolutionary mechanisms hypothesized to be operating in hominid brain expansion.     

Cranial capacity estimates for Olduvai Hominid 7

Estimation of cranial capacity for Olduvai Hominid (OH) 7 is determined from external parietal dimensions using multiple regressions calculated from an australopithecine grade sample. Capacity estimates for OH 7 (580–600 cc) are much lower than usually claimed. While differences in reconstruction may account for the varying estimates, a regression based only on undistorted and unreconstructed values, as well as a direct comparison of dimensions with other Homo habilis specimens, supports the smaller capacity determination.     

Cranial capacity/cranial base relationships and prediction of vault form: A canonical correlation analysis

Canonical correlation analysis was used to test an hypothesized morphological relationship between vault form and cranial capacity relative to length of the chondrocranium. Ninety-five adult male Czech skulls were measured for vault form expressed as length, width and height of the brain case; the chondrocranium was represented by nasion-basion and basion-opisthion lengths. In terms of explained variation, the first and most important dimension of covariation between vault and chondrocranial variables was size. The second most significant dimension of covariation expressed the hypothesized shape relationships—i.e., overall size being equal, the shorter the chondrocranial base relative to cranial capacity, the shorter and wider the vault. Furthermore, the competing hypothesis that vault form is determined by facial length proved untenable since facial length was predictive of vault shape only when measured as prosthion-basion, a measure that incorporates basal length. When corrected for basal length, facial length is unrelated to vault form. The results are consistent with the assumption that phylogenetic and microevolutionary trends toward brachycephaly in man stem from changes in the relationship between two components of skull growth, the chondrocranial base and the brain.     

Cranial capacity estimations of the FrankfurtPan troglodytes verus collection

Cranial capacity measurements of 18 individuals (9 ♂, 9 ♀) of a total collection of 277Pan troglodytes verus skulls were taken using four different methods:- two conventional filling methods and two mathematical methods. The two mathematical analyses normally used in hominids, were for the first time specifically modified forPan. The results probably present a more accurate estimation of total cranial capacity inPan and specifically inPan troglodytes verus (352 cm³) than previously available. Sexual differences related to this trait were also measured. Regardles of the methods used,Pan troglodytes verus seems to manifest the smallest cranial capacity of all subspecies ofPan.     

Ruse's Darwinian meta-ethics: A critique

Michael Ruse, in Taking Darwin Seriously seeks to establish that taking Darwin seriously requires us to treat morality as subjective and naturalistic. I argue that, if morality is not objective, then we have no good reason for being moral if we can avoid detection and punishment. As a consequence, we will only continue to behave morally as long as we remain ignorant of Ruse's theory, that is, as long as the cat is not let out of the bag. Ruse offers a number of arguments to show that his theory can overcome such problems. I argue that they all fail. Ruse also argues that he can offer a naturalistic account of ethics which steps around the naturalistic fallacy and avoids the confusion of reasons with causes. His principal argument for this view is an analogy between spiritualism and morality. I argue that this analogy fails.     

Interphase chromosome order: A proposal

A model for the arrangement of chromosomes in interphase nuclei is proposed. The model assumes that interphase chromosomes have a Rabl orientation (a relic telophase arrangement). During interphase and prophase telomeres are attached to the nuclear envelope often in pairs. The association of telomeres, homologous or nonhomologous, is based on similarity of arm lengths and occurs at the time the nuclear envelope reforms. At this stage arm lengths will vary to some extent due to the amount of uncoiling etc. The sequence of chromosomes resulting from telomere-telomere pairing may vary among cells, but the number of arrangements will be restricted by arm length similarities.The ramifications of this model on melotic pairing, the constant attachment of chromosomes to some structure throughout the cell cycle, the distribution of genes within nuclei, and chromosome evolution are raised.     

Developing manufacturing control software: A survey and critique

The complexity and diversity of manufacturing software and the need to adapt this software to the frequent changes in the production requirements necessitate the use of a systematic approach to developing this software. The software life-cycle model (Royce, 1970) that consists of specifying the requirements of a software system, designing, implementing, testing, and evolving this software can be followed when developing large portions of manufacturing software. However, the presence of hardware devices in these systems and the high costs of acquiring and operating hardware devices further complicate the manufacturing software development process and require that the functionality of this software be extended to incorporate simulation and prototyping. This paper reviews recent methods for planning, scheduling, simulating, and monitoring the operation of manufacturing systems. A synopsis of the approaches to designing and implementing the real-time control software of these systems is presented. It is concluded that current methodologies support, in a very restricted sense, these planning, scheduling, and monitoring activities, and that enhanced performance can be achieved via an integrated approach.     

Gaits of monkeys and horses: A methodological critique

In a previous paper it was shown that the traditional methodology used to analyze quadrupedal gaits is inadequate when applied to the gaits of monkeys. The traditional methods were modified for use with the monkey sample (Prost, '65). Was the modification a general improvement of the traditional approach or was it dictated by peculiarities of monkey locomotion? The traditional analysis receives its support primarily from its usefulness in handling horse gaits. If it can be shown that the modified methods improve the analysis for horses, then it can be claimed that the system is not a special case designed uniquely for use with monkeys. Motion pictures were taken of an American Saddle Bred, five-gaited horse performing several classic gaits. The films were analyzed using the modified methods developed to analyze monkey gaits. The analysis was superior to the traditional approach. All of the organizing principles which structure horse gaits were found to be identical to those which structure monkey gaits.     

A critique for phytosociology

Abstract. Phytosociology is a subdiscipline of plant ecology that describes the co‐occurrence of plant species in communities. Gradient analysis and classification are its complementary tools. Various peculiarities and anachronisms of Central European phytosociology conceal its similarity with Anglo‐American approaches. Phytosociology deserves to be updated as a part of modern vegetation science that can build on a vast heritage of high‐quality data and the tools to store and analyse them in ways that go beyond syntaxonomy. By providing a context to more specialized pure and applied research, it has a crucial role to play in understanding community structure, ecosystem functioning and biological evolution.     

The manchester school in Africa and Israel: A critique

Conclusion There is a fundamental continuity in the problems posed by the Manchester School in Africa and Israel: in brief, what is the actual strength of the dominant systems, respectively colonial Indirect Rule and post-statehood Zionism? Analyses of conflicts and cleavages (between White and Black, Westerners and Orientals) began either from the problem: how might conflicts contribute to broader integration, adaptation and adjustment, or: why are these conflicts and cleavages not disruptive to the general order.Whereas in the studies on Central Africa the strengths/weaknesses of the system were relatively opposed to the goodness/badness of the system, this is not the case in the studies of Israeli communities. These latter project a critical assessment of the viability and relevance of old ideals applied to new groups (e.g. Oriental Jews) under new circumstances (e.g. a high level of bureaucratization). Here the anthropologists implicitly test both the strength and the goodness (i.e. relevance) of Zionism as embodied in Israeli Jewish society. In fact, the works on Israel do not only elaborate on the principles that lie behind the supposed integration of the society (as in the studies on Africa), but also on the principles that might reconcile reality and ideology. Since values are explicitly introduce into the analyses, the forms of presentation, and generally the mode of discourse are changed: the distance between the anthropologist and his objects is minimized by the use of a literary style, sympathetic words, the introduction of the anthropologist himself into the account, the presentation of people as subjects who make their own history.Manchester forms of theory and presentation are not only deployed as explanatory devices, but may also be used to heighten the drama of the story itself: petty conflicts (human weaknesses) contrast with devotion to common ideals; minor social cleavages only accentuate broader cohesion. Moreover, people are not presented as role-performers, but as human beings striving and struggling toward a better life — within the broader status quo. This mode of discourse might be partly explained by referring to the fieldwork situation in which these Israeli anthropologists were involved. All authors shared to some extent in a common cultural enterprise with the people they studied. Aronoff felt himself a member of a pioneering community; Shokeid had to meet expectations concerning the fusion of exiles, while Deshen was involved in an election campaign. However, these anthropologists were not only committed to the people they studied, but also, out of their basically Zionist orientation, to the larger integration of Israeli society on western lines. Their analyses suggest ways in which these commitments can be reconciled on a theoretical level.As stated in my review of the works of the Manchester School on Africa, the fieldwork situation there was characterized firstly by some measure of suspicion from both the colonial administration and the Africans, and secondly by the psychological and political difficulties encountered by the anthropologists in their efforts to identify wholeheartedly either with the colonial system or with the Africans as a political group. The anthropologist thus became an observer who identified with academe or with individual persons during fieldwork. The distance between the anthropologist and the Africans was reflected in the analyses by the rather strict separation between science and values: the strength of the system was studied, not the viability of either the European or African communities. The anthropologist took plains to look neutral to his/her western academic audience [70], by means of his academic interests and formulations.However, these differences in modes of discourse are subordinate to the real continuities in the applications of the paradigm. Functionalist Manchester anthropology, as applied both in Africa and Israel, tests the strength of the dominant systems within the status quo. Far from being a critical test, the theory itself presupposes the answer by the choice of assumptions and concepts.T. van Teeffelen studies anthropology at the University of Amsterdam.     

Sexually dimorphic neuron number in lumbosacral dorsal root ganglia of the rat: Development and steroid regulation

Rats possess a sexually dimorphic neuromuscular system that controls penile reflexes critical for copulation. This system includes two motor nuclei in the lumbar cord and their target musculature in the perineum. The spinal nucleus of the bulbocavernosus (SNB) and the dorsolateral nucleus (DLN) motoneuron populations and their target perineal muscles are much larger in males than in females. The sex difference in motoneuron number develops via androgen-regulated differential cell death during the perinatal period; androgen also regulates retention of the target muscles. The developmental pattern and steroid sensitivity of peripheral afferents to the SNB/DLN motor nuclei were previously unknown. In order to characterize the peripheral sensory component of the dimorphic SNB/DLN system, the neurons of the relevant dorsal root ganglia (DRGs) were quantified in terms of number, size, and androgen sensitivity at various perinatal ages. DRG neuron number is greatest prenatally, then decreases in both sexes after birth; the timing and pattern of neuron number development are similar to those seen in the SNB and DLN. Postnatally, males have more DRG neurons than females, as a result of greater neuron death in the DRGs of females. Females treated with testosterone propionate during the perinatal period exhibit masculine development of DRG neuron number. Thus, the normal development of DRG neuron number parallels that of the SNB/DLN motor nuclei and target muscles in pattern and timing, is sexually dimorphic, and is regulated by androgen. © 1993 John Wiley & Sons, Inc.