Petite bodies of the “robust” australopithecines

The “robust” australopithecines are often depicted as having large and powerfully built bodies to match their massive masticatory apparatus, but until 1988 the sample of postcranial remains attributed with certainty to this group was very limited. Almost nothing was known about the body of the East African “robust” australopithecine because taxonomic attribution of the postcrania was so uncertain. The body of the South African “robust” australopithecine had to be reconstructed from about a dozen isolated fragments of postcrania. Now a partial skeleton is attributed with confidence to the East African “robust” group along with several isolated bones. The South African sample has more than tripled. Analyses of this vastly expanded sample reveal that a large portion of postcrania attributed to “robust” australopithecines from Swartkrans Member 1 (35%) are from extraordinarily small-bodied individuals similar in size to a modern Pygmy weighing as little as 28 kg. These small elements include parts from the forelimb, spine, and hindlimb. About 22% of these Swartkrans 1 “robust” australopithecines are about the same size as a modern human weighing about 43 kgs and about 43% are larger than this standard but less than or equal to a 54 kg modern human. Approximately the same pattern is true for the Swartkrans 2 hominids, but taxonomic attribution is less certain. All of the Member 3 specimens are similar in size to the 45 kg standard. The partial skeleton of the East African “robust” australopithecine (KNM-ER 1500) has hindlimb joints that would correspond to a modern human of 34 kgs although the actual weight may be 5 to 10 kgs greater judging from shaft robusticity and forelimb size. The largest postcranial element attributed with some certainty to the East African “robust” australopithecine group (the talus, KNM-ER 1464) is about the same overall size as a modern human of 54 kgs, although its tibial facet is slightly smaller. Although many previous studies have hinted at the possibility that “robust” australopithecines had relatively small bodies, the new fossils provide substantial evidence that these creatures ranged from quite small to only moderate in body size relative to modern humans. These were the petite-bodied vegetarian cousins of our ancestors. Sexual dimorphism in body size appears to be greater than that in modern humans, similar to that in Pan, and less than that in Gorilla or Pongo, although such comparisons are of limited value given the small samples, poorly known body proportions, time averaging, and many other problems.     

Ape-like endocast of “ape-man” Taung

I have identified and illustrated a spherical “dimple” or “depression” on the Taung endocast as indicating the most likely position of the medial end of the lunate sulcus but have not drawn an actual lunate sulcus on Taung because one is not visible. In a recent paper, R.L. Holloway (Am. J. Phys. Anthropol. 77:27–33, 1988) drew a lunate sulcus on his copy of the Taung endocast, incorrectly attributed this sulcus to me, and used it to obtain a ratio of 0.254 to describe “Falk's” position of the lunate sulcus. My published ratio of 0.242 for Taung (Falk: Am. J. Phys. Anthropol. 67:313–315, 1985a) was not considered, although the focus of Holloway's paper was my assessment of the position of the lunate sulcus. Holloway also excluded published ratios for a chimpanzee in my collection from his statistical analysis but, even so, my published ratio for Taung is still only 1.5 standard deviations from his chimpanzee mean. If my chimpanzee brain is included in the sample, the ratio for Taung is 1.2 standard deviations from the mean. Furthermore, one of Holloway's own chimpanzees (B60–7) has a ratio of 0.241, just 0.001 below my ratio for Taung. There is no sulcus where Holloway has drawn one on Taung, his “F(LS)” is not mine, his 2 mm error is not mine, and the correct ratio for my measurement of Tuang is the one that I published, not the one that Holloway attributes to me. Assessment of Holloway's chimpanzee data supports my claim that the dimple on the Taung endocast is within the chimpanzee range for the medial end of the lunate sulcus.     

“Stepping-sticks” and “seat-sticks”: New types of tools used by wild chimpanzees (Pan troglodytes) in Sierra Leone

In Tenkere, Sierra Leone, a community of wild chimpanzees (Pan troglodytes verus) spent long hours eating the fruits and flowers of the Kapok (Ceiba pentandra) tree. The branches of this species are covered in sharp thorns which make movement in their high canopies problematic for the chimpanzees. In an apparent attempt to increase their mobility and to ease the discomfort of lengthy bouts of eating in these trees, some of the Tenkere chimpanzees have been observed using stick tools as foot (“stepping-sticks”) and body (“seat-sticks”) protection against the painful thorns. This form of tool-using is culturally unique to the Tenkere chimpanzees, as at other sites where these apes have been observed eating parts of kapok trees, there are no published records of this tool technology. In three of the stepping-stick tool use incidents, the chimpanzee used the tool(s), held between their greater and lesser toes, in locomotion. This form of tool use is the first recorded case of habitually used tools that can be justifiably categorized as being “worn” by any known wild population of Pan troglodytes. Am J Primatol 41:45–52, 1997. © 1997 Wiley-Liss, Inc.     

Dietary Restraint and Control Over “Wanting” Following Consumption of “Forbidden” Food

Eating behavior can be influenced by the rewarding value of food, i.e., “liking” and “wanting.” The objective of this study was to assess in normal‐weight dietary restrained (NR) vs. unrestrained (NU) eaters how rewarding value of food is affected by satiety, and by eating a nonhealthy perceived, dessert‐specific food vs. a healthy perceived, neutral food (chocolate mousse vs. cottage cheese). Subjects (24NR age = 25.0 ± 8.2 years, BMI = 22.3 ± 2.1 kg/m²; 26NU age = 24.8 ± 8.0 years, BMI = 22.1 ± 1.7 kg/m²) came to the university twice, fasted (randomized crossover design). Per test‐session “liking” and “wanting” for 72 items divided in six categories (bread, filling, drinks, dessert, sweets, stationery (placebo)) was measured, before and after consumption of chocolate mousse/cottage cheese, matched for energy content (5.6 kJ/g) and individual daily energy requirements (10%). Chocolate mousse was liked more than cottage cheese (P < 0.05). After consumption of chocolate mousse or cottage cheese, appetite and “liking” vs. placebo were decreased in NR and NU (P < 0.03), whereas “wanting” was only decreased in NR vs. NU (P ≤ 0.01). In NR vs. NU “wanting” was specifically decreased after chocolate mousse vs. cottage cheese; this decrease concerned especially “wanting” for bread and filling (P < 0.05). To conclude, despite similar decreases in appetite and “liking” after a meal in NR and NU, NR decrease “wanting” in contrast to NU. NR decrease “wanting” specifically for a nonhealthy perceived, “delicious,” dessert‐specific food vs. a nutritional identical, yet healthy perceived, slightly less “delicious,” “neutral” food. A healthy perceived food may thus impose greater risk for control of energy intake in NR.     

Kronröhrenentstehung bei Solanum dulcamara L. und “kongenitale Verwachsung”

Bei Solanum dulcamara werden die fünf Petalen als getrennte Primordien angelegt. Während ihres Heranwachsens werden Randmeristeme unterscheidbar. Diese Randmeristeme dehnen sich in die Regionen zwischen benachbarten Kronblattprimordien aus und vereinigen sich dort. Auf diese Weise wird die Kronröhre durch einen Vorgang der Randmeristemfusion angelegt. Sowohl die Randmeristeme als auch ihre Fusion wurden quantitativ durch Unterschiede im mitotischen Index bestimmt. Lebende Blütenknospen wurden mit Colchicin behandelt, um genügend Metaphasen für eine signifikante Berechnung des mitotischen Index anzuhäufen. Im Hinblick auf “kongenitale Verwachsung” kann man verschiedene Folgerungen ziehen. 1. Man kann argumentieren, daß Meristemfusion keine “kongenitale Verwachsung” ist, da erstere ontogenetisch beobachtbar ist, während letztere per Definition ontogenetisch als Verwachsung nicht beobachtbar ist. 2. Man kann “kongenitale Verwachsung” so definieren, daß sie beobachtbare Vorgänge wie Meristemfusion und nicht beobachtbare Verwachsungen einschließt. Ein solcher Begriff der “kongenitalen Verwachsung” würde ontogenetische, phylogenetische und metaphysische Verwachsungen charakterisieren. Um diese Heterogenität und die metaphysischen Aspekte zu eliminieren, wird als allgemeiner Oberbegriff der Begriff der relativen “Kontinuität” vorgeschlagen. Kontinuität kann das Ergebnis von “Oberflächenverwachsung” (traditionell als “postgenitale Verwachsung” bezeichnet), “Heterotopic” und/oder “interprimordialem Wachstum” sein. Extremfälle interprimordialen Wachstums sind verursacht durch Vorgänge wie Meristemfusion (Abb. 2 b, c, e), Entstehung gemeinsamer Meristeme (Abb. 2 d, f, g) und Meristemausdehnung (Abb. 2 i). Einige dieser Modi können als ontogenetische (Abb. 2 b, c, e) oder phylogenetische Verwachsungen (Abb. 2 a, a', d, f) bezeichnet werden, während andere mit Verwachsung überhaupt nichts zu tun haben (Abb. 2 g, h, i). Aus diesem Grunde ist “interprimordiales Wachstum” ein wesentlich allgemeinerer Begriff als die ontogenetischen und phylogenetischen Bedeutungen der “kongenitalen Verwachsung”. Da man Übergangsformen zwischen den Modi der Abbildung 2 in Betracht ziehen muß, kann sich die Unterscheidung von Fusionen und nicht-Fusionsprozessen verwischen. Es ist deshalb angemessener, Fälle des interprimordialen Wachstums als das Ergebnis kontinuierlicher oder diskontinuierlicher Änderungen der räumlichen und zeitlichen Wachstumsverteilung anzusehen. Selbst ein wissenschaftlicher Begriff der “kongenitalen Verwachsung” oder der “phylogenetischen Verwachsung” kann dann bestenfalls einen sehr beschränkten Anwendungsbereich haben, falls man ihn überhaupt verwenden will.     

Possible “atavistic” structures in human aneuploids

Comprehensive dissections of aneuploid (trisomy 18 and 13) neonates have revealed numerous supernumerary muscles that, although present in rare individuals, do not regularly occur in the human. These supernumerary muscles include: “platysma occipitalis,” “rhomboideus occipitalis,” “deltopectoral” complex, “latissimocondyloideus,” “pectorodorsalis,” “chondrohumeralis,” and “peroneus digiti quinti”; a few muscles, e.g., palmaris longus and brevis are lacking altogether. One specimen exhibited a “linguofacial trunk” arising from the external carotid artery. The supernumerary muscles found in these aneuploid specimens are regularly found in monkeys and sometimes in the great apes. It is suggested that these supernumerary muscles may be “atavistic” structures. Problems in establishing homologies between these muscles among primates are discussed, and mechanisms leading to the development of these muscles in human aneuploids are proposed.     

Constraints on the Structure of Combinatorial “Chick-a-dee” Calls

“Chick-a-dee” calls of the black-capped chickadee (Parus atricapillus) constitute a combinatorial system of animal communication, apparently the only such system yet described. Four note-types, which may be omitted or repeated a variable number of times, occur in a fixed sequence (A–B–C–D) to constitute calls. Quantitative analyses determining the nature of departures from first-order transitional probabilities between successive notes revealed a variety of results that point consistently to two underlying features of calls. (1) Some constraint operates to limit the length of calls, as manifest in shortening of repetition-strings and omitting of note-types expected to follow. (2) There is an opposing tendency to include at least one or two D-notes at the end of a call, regardless of the overall length. The second feature suggests important semantic properties of D-notes, especially the ratio of D s to other note-types and the flock-specific acoustical structure of D-notes. The constraint on length of call does not appear intimately related to semantic causes, but may instead be determined by the maximum duration of continuous phonation, in parallel with the fundamental breath-group of human speech. In this respect, a “chick-a-dee” call resembles an entire “natural sentence” of spoken human language.     

The story of a largely unknown evolution – Germ theory hoax

The Piltdown Man debacle provides us with the most infamous forgery in science. However, another equally intriguing story exists concerning a document by a Bostonian called George Sleeper, which purported to be a pre-Darwin–Wallace anticipation of evolution and an equally convincing account of the germ theory published before Louis Pasteur’s famous studies on this subject. The story involves two giants in the world of evolutionary theory, Alfred Russel Wallace and E.B. Poulton. While Wallace was convinced that the Sleeper document was genuine, Poulton’s detailed investigations showed that it was a fake and a hoax. Despite this conclusion, doubts still exist about the authenticity of the Sleeper document.     

150 Jahre “Biogenetisches Grundgesetz”

150 years “Biogenetic Law” The zoologist Ernst Haeckel is one of the most well‐known, but also one of the most controversial scientists of the late 19th and early 20th centuries. He was one of the earliest Darwinists and a forceful advocate of evolutionary theory. Together with “Darwin's Bulldog” Thomas Henry Huxley, Haeckel was a central figure in the early history and popularization of Darwinism. But his name is not only a symbol for the disputes about the theory of evolution and its popularization, but also for a campaign for monism, a world‐view or philosophy created by Haeckel himself. Together with Fritz Müller, Ernst Haeckel was one of the first to formulate a “Biogenetic Law”. He also created several concepts and terms still in use in biology today, such as “ontogeny”, “phylogeny”, “ecology”, “cholorogy” and “phylum” in his first, and maybe most important book “General Morphology of Organism”, which was published in 1866, 150 years ago.     

Ultrastructure of the “Cyst-like Bodies” of Trypanosoma conorhini*

SYNOPSIS. An electron microscope study was made of the “cyst-like bodies” (CLBs) previously described in cultures of Trypanosoma conorhini. It is again suggested that CLBs are a process of reproduction which involves fusion of epimastigotes, repeated divisions of DNA-containing organelles and organization of daughter epimastigotes that, after being completely formed, may be found free within the large central “vacuole” of the CLB. This “vacuole,” it is now evident, results from the fused and muchdilated flagellar reservoirs of parent epimastigotes. Our interpretation of the CLBs and their possible genetic significance are discussed.     

Transcriptome analysis reveals the difference between “healthy” and “common” aging and their connection with age‐related diseases

A key goal of aging research was to understand mechanisms underlying healthy aging and develop methods to promote the human healthspan. One approach is to identify gene regulations unique to healthy aging compared with aging in the general population (i.e., “common” aging). Here, we leveraged Genotype‐Tissue Expression (GTEx) project data to investigate “healthy” and “common” aging gene expression regulations at a tissue level in humans and their interconnection with diseases. Using GTEx donors' disease annotations, we defined a “healthy” aging cohort for each tissue. We then compared the age‐associated genes derived from this cohort with age‐associated genes from the “common” aging cohort which included all GTEx donors; we also compared the “healthy” and “common” aging gene expressions with various disease‐associated gene expressions to elucidate the relationships among “healthy,” “common” aging and disease. Our analyses showed that 1. GTEx “healthy” and “common” aging shared a large number of gene regulations; 2. Despite the substantial commonality, “healthy” and “common” aging genes also showed distinct function enrichment, and “common” aging genes had a higher enrichment for disease genes; 3. Disease‐associated gene regulations were overall different from aging gene regulations. However, for genes regulated by both, their regulation directions were largely consistent, implying some aging processes could increase the susceptibility to disease development; and 4. Possible protective mechanisms were associated with some “healthy” aging gene regulations. In summary, our work highlights several unique features of GTEx “healthy” aging program. This new knowledge could potentially be used to develop interventions to promote the human healthspan.     

Body weight prediction in early fossil hominids: Towards a taxon-“independent” approach

The choice of a model taxon is crucial when investigating fossil hominids that clearly do not resemble any extant species (such as Australopithecus) or show significant differences from modern human proportions (such as Homo habilis OH 62). An “interhominoid” combination is not adequate either, as scaling with body weight is strongly divergent in African apes and humans for most skeletal predictors investigated here. Therefore, in relation to a study of seven long bone dimensions, a new taxon-“independent” approach is suggested. For a given predictor, its taxonomic “independence” is restricted to the size range over which the body weight-predictor relationship for African apes and humans converges. Different predictors produce converging body weight estimates (BWEs) for different size ranges: taxon-“independent” estimates can be calculated for small- and medium-sized hominids (e. g., for weights below 50 kg) using femoral and tibial dimensions, whereas upper limb bones provide converging results for large hominids (above 50 kg). If the remains of Australopithecus afarensis really belong to one species, the relationship of male (above 60 kg) to female body weight (approximately 30 kg) does not fall within the observed range of modern hominoids. Considering Sts 14 (22 kg) to represent a small-sized Australopithecus africanus, the level of encephalization lies well above that of extant apes. If OH 62 (approximately 25 kg), with limb proportions less human-like than those of australopithecines, indeed represents Homo habilis (which has been questioned previously), an increase in relative brain size would have occurred well before full bipedality, an assumption running counter to current assumptions concerning early human evolution. © 1993 Wiley-Liss, Inc.     

“Reverse” sexual dichromatism in a Neotropical frog

Sexual dichromatism is widespread among animals, but examples of “reverse” sexual dichromatism, in which females are more brightly colored than males, are extremely rare. We discovered a unique case of reverse sexual dichromatism in the golden rocket frog (Anomaloglossus beebei), a diurnal Neotropical frog. Females are bright “golden” in color, and males are drab tan with brown pigmentation that darkens when they are calling. Here, we document this color variation with calibrated digital photography and further show that there is no evidence for sex‐specific habitat matching; both sexes live in the same well‐lit habitat on green bromeliad leaves. Our results suggest that color variation in this species is an intraspecific signal and provide an important exception to the general expectation that males are more visually conspicuous in species with conventional sex roles.     

Adoption by captive parturient rhesus macaques: Biological vs. adopted infants and the cost of being a “twin” and rearing “twins”

Four rhesus macaque (Macaca mulatta) mothers each spontaneously adopted and reared an abandoned, unrelated neonate in addition to their own neonate. Data on relative time spent in maternal contact and who maintained proximity were collected for the biological and adopted “twins” and singleton control infants using focal animal sampling. Infant weight gain and the subsequent conception history for each mother were obtained for the following year. Biological infants spent more time in maternal contact than their adopted “twin” siblings. When in contact with their mothers, biological “twins” spent more time in the ventro-ventral position and more ventral time alone than adoptees. Mothers initiated more contacts with their biological infants than their adopted infants, suggesting these differences may be due to differential maternal behavior. “Twins” gained weight at a slower rate than singletons, and mothers rearing “twins” produced significantly fewer offspring the following season. Am. J. Primatol. 43:259–264, 1997. © 1997 Wiley-Liss, Inc.     

A critique of the “ultra‐high risk” and “transition” paradigm

The transdiagnostic expression of psychotic experiences in common mental disorder (anxiety/depression/substance use disorder) is associated with a poorer prognosis, and a small minority of people may indeed develop a clinical picture that meets criteria for schizophrenia. However, it appears neither useful nor valid to observe early states of multidimensional psychopathology in young people through the “schizo”‐prism, and apply misleadingly simple, unnecessary and inefficient binary concepts of “risk” and “transition”. A review of the “ultra‐high risk” (UHR) or “clinical high risk” (CHR) literature indicates that UHR/CHR samples are highly heterogeneous and represent individuals diagnosed with common mental disorder (anxiety/depression/substance use disorder) and a degree of psychotic experiences. Epidemiological research has shown that psychotic experiences are a (possibly non‐causal) marker of the severity of multidimensional psychopathology, driving poor outcome, yet notions of “risk” and “transition” in UHR/CHR research are restrictively defined on the basis of positive psychotic phenomena alone, ignoring how baseline differences in multidimensional psychopathology may differentially impact course and outcome. The concepts of “risk” and “transition” in UHR/CHR research are measured on the same dimensional scale, yet are used to produce artificial diagnostic shifts. In fact, “transition” in UHR/CHR research occurs mainly as a function of variable sample enrichment strategies rather than the UHR/CHR “criteria” themselves. Furthermore, transition rates in UHR/CHR research are inflated as they do not exclude false positives associated with the natural fluctuation of dimensional expression of psychosis. Biological associations with “transition” thus likely represent false positive findings, as was the initial claim of strong effects of omega‐3 polyunsatured fatty acids in UHR samples. A large body of UHR/CHR intervention research has focused on the questionable outcome of “transition”, which shows lack of correlation with functional outcome. It may be more productive to consider the full range of person‐specific psychopathology in all young individuals who seek help for mental health problems, instead of “policing” youngsters for the transdiagnostic dimension of psychosis. Instead of the relatively inefficient medical high‐risk approach, a public health perspective, focusing on improved access to a low‐stigma, high‐hope, small scale and youth‐specific environment with acceptable language and interventions may represent a more useful and efficient strategy.     

The “Basqueness” of the Basques of Alava: A reappraisal from a multidisciplinary perspective

The genetic and linguistic peculiarity of the Basque population is well known. Analysis of the studies published to date on the Basque population reveals that these studies refer basically to the provinces of Vizcaya and Labourd, both in the Northern part of the Basque Country. Multidisciplinary information indicates that the landscape differences of the Basque Country could have conditioned differential population biodynamics in the Atlantic and Mediterranean parts of the Basque area. In order to evaluate this possibility, this study focuses on the genetic constitution of the Basque population of Alava (in the South of the Basque Country) through the analysis of several red-cell systems. The data obtained in this genetic study and those from archaeology, linguistics, ethnography, and skeletal biology suggest that within the “Basque population” there may be at least two distinct groups: an “Atlantic” group and a “Mediterranean” one, divided mainly by the watershed. This geographical feature could have led to a greater genetic isolation of the Northern slopes, with the South more open to population contact. This is reflected nowadays in the different cline distribution detected for most systems in the Alava Basques in comparison with other Basque and Iberian Peninsula series studied to date. © 1996 Wiley-Liss, Inc.     

Encapsulated fusion protein confers “sense and respond” activity to chitosan–alginate capsules to manipulate bacterial quorum sensing

We demonstrate that “nanofactory”‐loaded biopolymer capsules placed in the midst of a bacterial population can direct bacterial communication. Quorum sensing (QS) is a process by which bacteria communicate through small‐molecules, such as autoinducer‐2 (AI‐2), leading to collective behaviors such as virulence and biofilm formation. In our approach, a “nanofactory” construct is created, which comprises an antibody complexed with a fusion protein that produces AI‐2. These nanofactories are entrapped within capsules formed by electrostatic complexation of cationic (chitosan) and anionic (sodium alginate) biopolymers. The chitosan capsule shell is crosslinked by tripolyphosphate (TPP) to confer structural integrity. The capsule shell is impermeable to the encapsulated nanofactories, but freely permeable to small molecules. In turn, the capsules are able to take in substrates from the external medium via diffusion, and convert these via the nanofactories into AI‐2, which then diffuses out. The exported AI‐2 is shown to stimulate QS responses in vicinal Escherichia coli. Directing bacterial population behavior has potential applications in next‐generation antimicrobial therapy and pathogen detection. We also envision such capsules to be akin to artificial “cells” that can participate in native biological signaling and communicate in real‐time with the human microbiome. Through such interaction capabilities, these “cells” may sense the health of the microbiome, and direct its function in a desired, host‐friendly manner. Biotechnol. Bioeng. 2013; 110: 552–562. © 2012 Wiley Periodicals, Inc.