Primate origins,human origins,and the end of higher taxa

When people learn that I study human evolution and we start talking about it, they sometimes ask me, “How long ago did the first humans live?” My answer is usually another question: “What do you mean by 'humans'?” That response seems as baffling and wrong‐headed to them as their question seems to me, and it usually takes us a while to straighten things out. © 2012 Wiley Periodicals, Inc.     

Timing and plasticity of shoaling behaviour in the zebrafish, Danio rerio

The zebrafish has become a major model system for biomedical research and is an emerging model for the study of behaviour. While adult zebrafish express a visually mediated shoaling preference, the onset of shoaling behaviour and of this preference is unknown. To assess the onset of these behaviours, we first manipulated the early social environment of larval zebrafish subjects, giving them three model shoaling partners of the same pigment phenotype. We then assayed the subjects' preferences using binary preference tests in which we presented subjects with two shoals, one shoal of fish exhibiting the same pigment pattern phenotype as their models and another shoal with a radically different pigment pattern. To determine whether or not the visually mediated preference could be altered once it was established, we further manipulated the social environment of a number of subjects, rearing them with one model shoal and testing them, then changing their social consorts and retesting them. Our results demonstrate that larval zebrafish shoal early in their development, but do not exhibit a shoaling preference until they are juveniles. Moreover, we find that the shoaling preference is stable, as changing the social environment of fish after they had acquired a preference did not change their preference. These data will facilitate investigations into the mechanisms underlying social behaviour in this vertebrate model system.     

Function of the type 11 microtrich sensilla on the lotic amphipod,Gammarus pseudolimnaeus Bousfield

The type II microtrich sensilla on the lotic amphipod Gammarus pseudolimnaeus Bousfield enable it to control body orientation while swimming, as animals with their sensilla masked spent significantly more time swimming on their sides. These sensilla appear to be involved in the behavioural process that allows the animal to orient into the current (positive rheotaxis), as significantly fewer masked animals were able to turn into novel current flows compared with controls. The sensilla do not appear to play a role in detecting gravity. Results suggest that the sensilla transmit hydromechanical sensory information to the animal, and it is thought that the individual sensilla act in unison as a kinetic sensory organ. The sensilla are well adapted for such a hydromechanical role, as they would likely only be stimulated by currents hitting them broadside on. The sensilla are grouped, with each sensillum facing in a different direction, and the groups are located at appropriate positions for detecting current flows. The sensilla do not play a role in the detection of vibrations. Nor do they play a chemosensory role in the detection of food or predators; however, a role in conspecific chemodetection cannot be ruled out.     

Design, Development and Decisions

Evolutionary ideas and modern biological knowledge have important roles to play in the understanding of human behaviour. Nevertheless, it is deeply misleading to regard humans as robots in the grip of their genes. A well designed brain should respond to the consequences of behaviour; if an understanding of the likely consequences can be achieved without actually performing the act, then a person who knows that they will be rewarded or punished for certain acts is bound to be influenced by that knowledge. A brain designed in that way facilitates the evolution of societies with explicit social approval of certain activities and explicit disapproval of others. The evolutionary approach to psychology does not imply that individuals do not make free choices. Individuals clearly do make a big difference to what happens in their lives through their decisions. They may be surprised by the consequences of their own actions. A well designed brain should be able to anticipate the consequences of various courses of action and choose between them on the basis of their likely costs and benefits. Planning before doing is clearly of great advantage. People do make well considered decisions and they benefit from doing so.     

Aquatic animals, cognitive ethology, and ethics: questions about sentience and other troubling issues that lurk in turbid water

In this general, strongly pro-animal, and somewhat utopian and personal essay, I argue that we owe aquatic animals respect and moral consideration just as we owe respect and moral consideration to all other animal beings, regardless of the taxonomic group to which they belong. In many ways it is more difficult to convince some people of our ethical obligations to numerous aquatic animals because we do not identify or empathize with them as we do with animals with whom we are more familiar or to whom we are more closely related, including those species (usually terrestrial) to whom we refer as charismatic megafauna. Many of my examples come from animals that are more well studied but they can be used as models for aquatic animals. I follow Darwinian notions of evolutionary continuity to argue that if we feel pain, then so too do many other animals, including those that live in aquatic environs. Recent scientific data ('science sense') show clearly that many aquatic organisms, much to some people's surprise, likely suffer at our hands and feel their own sorts of pain. Throughout I discuss how cognitive ethology (the study of animal minds) is the unifying science for understanding the subjective, emotional, empathic, and moral lives of animals because it is essential to know what animals do, think, and feel as they go about their daily routines. Lastly, I argue that when we are uncertain if we are inflicting pain due to our incessant, annoying, and frequently unnecessary intrusions into the lives of other animals as we go about 'redecorating nature' (removing animals or moving them from place to place), we should err on the side of the animals and stop engaging in activities that cause pain and suffering.     

Mothers, not fathers, determine the delayed onset of male carrying in Goeldi's monkey (Callimico goeldii)

In biparental species, females are thought to accept and even to seek male assistance in rearing of the young. In this study, we present data that suggests that Goeldi's monkey females (Callimico goeldii) actually reject male parental care for a certain period. In Callimico, which have biparental care, mothers carry the infant exclusively for the first three weeks despite the fact that fathers are interested in their infants directly after birth. Fathers initiated significantly more body contact with their mates when newborn infants were present and retrieved one-day-old infants that were experimentally presented to them. The onset of paternal carrying in our colony was 27.5 days compared to 11.5 days (medians) observed in the field. However, presentation of a live potential predator induced earlier onset of paternal carrying by about 10 days. Additional costs to maternal carrying such as foraging and predator avoidance are likely factors influencing the decision of the mother as to when to share the cost of infant carrying with the father. We conclude that Goeldi's monkey fathers start carrying their infants so late because they do not get them earlier from the mother. We suggest that one ultimate explanation for that delay might be increased infant mortality when infant transfer starts at an earlier stage.     

Standing Up: Violin Performance Technique and Ethnic Resurgence in Saraguro,Ecuador

With greater participation in formal education and increased occupational diversity and mobility, young, cosmopolitan Saraguro musicians in the southern highlands of Ecuador are working to reconstitute their Saraguro Quichua ethnicity in a creative and selective process by which they discard, amplify, and reinvent the aspects of what they perceive to be authentic Saraguro musical culture. Young Saraguro violinists use the bodily movement of performance technique as a key resource with which to reconstitute their ethnicity. Through visual analysis of performance technique and theories of ethnic renewal and bodily movement, I argue that, though older Saraguro violinists sit down low to play their violins, these young Saraguro violinists break from tradition and stand up when they play not only to index their aspirations to do something with their lives other than what tradition and stereotypes dictate for them, but also to index their real opportunities to do so as Saraguros.     

Natal Attraction in Adult Female Baboons (Papio cynocephalus ursinus) in the Moremi Reserve, Botswana

Mammalian females are strongly attracted to infants and interact regularly with them. Female baboons make persistent attempts to touch, nuzzle, smell and inspect other females’ infants, but do not hold them for long periods, carry them, or provide other kinds of care for them. Mothers generally tolerate these interactions, but never initiate them. The function of these brief alloparental interactions is not well understood. Infant handling might be a form of reproductive competition if females’ interest in infants causes distress to mothers or harm to their infants. Alternatively, infant handling might be the product of selection for appropriate maternal care if females who are highly responsive to infants are the most successful mothers. We test several predictions derived from these hypotheses with data collected in a free‐ranging group of baboons (Papio cynocephalus ursinus) in the Moremi Reserve of Botswana. Infants were most attractive when they were very young. Mothers of young infants were approached by other adult females on average once every 6 min, and other females attempted to handle their infants approximately once every 9 min. By the time infants were a year old, their mothers were being approached only once every 30 min and infants were being handled only once every 5 h. Females were more strongly attracted to other females’ infants when they had young infants of their own, and their interest in other females’ infants declined as their own infants matured. Females seemed to be equally attracted to all infants, but had greater access to offspring of their relatives and subordinate females. Females nearly always grunted as they handled infants. As in other contexts grunts are a reliable predictive signal that non‐aggressive behavior will follow, the use of grunts before handling suggests that these interactions were not a form of deliberate harassment.     

Coronary heart disease in relation to age,sex, and the menopause.

Examination of the Registrar General''s mortality data suggested that women do not lose protection from coronary heart disease (CHD) after the menopause. Apparently, at around the age of 50 men begin to lose a factor that had previously put them at increased risk of developing CHD compared with women. Male sex hormones may be risk factors for CHD, and further studies are needed to clarify their role in the aetiology of CHD in men.     

Carnivorous Cats,Vegetarian Dogs,and the Resolution of the Vegetarian's Dilemma

The present research sought to further clarify the vegetarian's dilemma, the conflict that pits feeding one's pet an animal-based diet that may be perceived as best promoting their well-being with concerns over animal welfare and environmental degradation threatened by such diets. It specifically examined whether non-meat eaters would distinguish between pet dogs and cats in the percentage of their diet derived from animal products, guilt experienced from such diets, and perceived appropriateness of non-vegetarian diets. Survey responses from 290 vegans and vegetarians indicated that participants fed their pet dogs a diet significantly more vegetarian than they fed their pet cats, and reported experiencing less guilt feeding their cats a diet derived highly from animals than in feeding their dogs such a diet. This lack of guilt largely arose from greater endorsement that vegetarian diets were more inappropriate for cats than dogs. For dogs, then, the vegetarian's dilemma was resolved primarily through feeding them diets reduced in meat/fish. For cats, the primary attempt at resolving the dilemma was not behavioral but perceptual in that vegetarian diets were deemed inappropriate. As discussed, this latter strategy was met with mixed success. Overall, the reaction of participants reflected prevailing medical wisdom that vegetarian diets are somewhat acceptable for dogs but problematic for cats.     

Molting, enzymes and new targets for chemotherapy of Onchocerca volvulus

Parasitic nematodes do not multiply in definitive hosts, but they do molt, grow and mature for a certain period after infection, after which they devote their energies almost entirely to egg production. In this review, Sara Lustigman describes key metabolic enzymes that are essential to the development of the larval stages of Onchocerca volvulus in the host, making them potential therapeutic targets.     

Socializing with the neighbors: stem cells and their niche

The potential of stem cells in regenerative medicine relies upon removing them from their natural habitat, propagating them in culture, and placing them into a foreign tissue environment. To do so, it is essential to understand how stem cells interact with their microenvironment, the so-called stem cell niche, to establish and maintain their properties. In this review, we examine adult stem cell niches and their impact on stem cell biology.     

Comparative marker analysis of the ependymocytes of the subcommissural organ in four different mammalian species

Summary The subcommissural organ (SCO), classified as one of the circumventricular organs, is composed mainly of modified ependymal cells, attributable to a glial lineage. Nevertheless, in the rat, these cells do not possess glial markers such as glial fibrillary acidic protein (GFAP), protein S100, or the enzyme glutamine synthetase (GS). They receive a synaptic 5-HT input and show pharmacological properties for uptake of GABA resembling the uptake mechanism of neurons. In this study, we examine the phenotype of several mammalian SCO (cat, mouse, rabbit) and compare them with the corresponding features of the rat SCO. In all these species, the SCO ependymocytes possess vimentin as an intermediate filament, but never express GFAP or neurofilament proteins. They do not contain GS as do glial cells involved in GABA metabolism, and when they contain protein S100 (rabbit, mouse), its rate is low in comparison to classical glial or ependymal cells. Thus, these ependymocytes display characteristics that differentiate them from other types of glial cells (astrocytes, epithelial ependymocytes and tanycytes). Striking interspecies differences in the capacity of SCO-ependymocytes for uptake of GABA might be related to their innervation and suggest a species-dependent plasticity in their function.     

Egg attendance and brooding by males of the giant water bugLethocerus medius (Guerin) in the field (Heteroptera: Belostomatidae)

Males of the giant water bug Lethocerus medius(Guerin) typify their monobasic subfamily, the Lethocerinae, in that they do not brood eggs attached to their backs as do males of all members of the subfamily Belostomatinae. Exclusive male parental investment as expressed in the Belostomatinae is extremely rare behavior among animals, and evolution of the trait is obscure. Lethocerus mediusmales apparently remain with their mates through oviposition and are consistently found in attendance of eggs after the female has departed. This behavior may enhance paternity assurance at no cost in opportunity for polygyny. Two double clutches of eggs were found, from which we infer the potential for polygynous matings and shared parental investment. Male L. mediusbrood attended egg clutches above the surface of the water, where they may moisten them, shade them, and defend them against predation. Egg attendance/brooding by L. mediusand other Lethocerusspecies may represent a plesiomorphic state from which paternal back- brooding evolved in the Belostomatinae.     

Epidermal structure of the scleractinian coral Mycetophyllia ferox: light-induced vesicles,copious mucocytes,and sporadic tentacles

Three colony fragments of the scleractinian coral Mycetophyllia ferox Wells from Florida were observed in flow-through seawater aquaria under light and dark conditions. The colonies were then anesthetized and fixed for microscopic examination. Small vesicles formed across the epidermis in response to light as gastrodermis containing approximately 1.9 × 10⁶ zooxanthellae cm⁻² migrated into them. The vesicles flattened in the dark and the gastrodermis retreated to a clumped position. The epidermis is dominated by mucus cells with more than 6300 per mm². In contrast, there are very few epidermal cnidae. The polyps lack tentacles entirely, though small tentacles do occur, albeit sporadically, along the colline walls. Colline tentacles are expanded both day and night, and there is considerable intracolonial variability in the number of cnidae within them, ranging from as few as 316 to more than 3200 per mm² tentacle. There may be several small cnidocyst batteries containing both spirocysts and nematocysts (all microbasic p-mastigophores), but the principal battery is at the tentacle tip where cnidae are much more densely packed. There is considerable variation in the ratio of the two cnidae among tentacles in the same colony. Since the tentacles occur inconsistently and do not appear to expand, their functional role is unclear. Comparisons of epidermal characters are made with other members of the genus Mycetophyllia.     

Experiments on the elimination of symbionts from the tsetse fly,Glossina morsitans morsitans (Diptera: Glossinidae), by antibiotics and lysozyme

One sulfonamide and ten antibiotics were tested for symbiont elimination in Glossina morsitans morsitans. Only tetracycline, penicillin, and kanamycin could be used in concentrations which destroyed the symbionts and impeded host reproduction, but did not affect host longevity. The later the treatment with penicillin and kanamycin began, the smaller was the damage to symbionts from these two antibiotics. Small doses damaged the symbionts to an extent that flies could produce offspring, but these were free of symbionts. Lysozyme was used as an alternative to antibiotics. After both injection and oral administration of lysozyme the symbionts were damaged, and host reproduction ceased, although host longevity remained unaffected. It can be concluded from the results of these experiments that tsetse flies do not require their symbionts for survival but probably do need them for reproduction.     

Sleepwalking, Violence and Desire in the Middle Ages

This study discusses the phenomenon of medieval sleepwalking as a disorder of body and soul. In the thirteenth and early fourteenth centuries, medical and natural philosophical writers began to identify the category of the sleepwalker with unusual precision: the most common example of the disorder involved an aristocrat who rose, armed himself, and mounted his horse, all the while imagining that he was fighting enemies or hunting deer. Explanations for this extraordinary behaviour involved the physiology of sleep and the functioning of the brain. In particular, theorists believed that the imagination, a storehouse of images located towards the front of the brain, took control because reason and sensation had been disabled during sleep. As a consequence, daytime fears and traumas could come to the fore for some sleepers, causing them to act and react in their sleep in ways they could not, or were not willing to do, in their waking, rational state. As such, medieval medical writers viewed sleepwalking as a dangerous, disordered state which called into question the Aristotelian divide between waking and sleeping as well as the categories of reason, sensation and voluntary motion.     

The Role of Learning in the Aggressive and Reproductive Behavior of Blue Gouramis, Trichogaster trichopterus

Like countless other vertebrates and even many invertebrates, blue gouramis, Trichogaster trichopterus, a freshwater tropical fish, can learn to associate environmental cues with the appearance of biologically important events. Research with blue gouramis reveals that this capacity for learning, which psychologists call Pavlovian conditioning, provides the means to enhance their territorial defense as well as reap large reproductive benefits. That is, males are able to defend their territories more efficiently when the appearance of a rival is signaled than when territorial invasion is less predictable. Not only does signaling enable Pavlovian-conditioned males to mount a more aggressive defense of their territories than males that do not have the benefit of signaling, but it helps them to concentrate their efforts at times when, or places where, the territory is most vulnerable. In addition, both males and females can learn to anticipate the appearance of a mate. Signaling of female accessibility enables Pavlovian-conditioned males to attenuate their initial aggressive response to arriving females without compromising their territorial defense. More important, when the arrival of a potential mate is signaled, Pavlovian-conditioned males are able to spawn with females sooner, clasp females more often, and produce more young than males that do not have the benefit of a signal. The ability of blue gouramis, among many other fish, to anticipate the appearance of such different biologically important events suggests that Pavlovian conditioning may play a significant role in their behavioral ecology. In addition, conditioning may provide a useful tool in several practical domains, including animal husbandry, zoological management, and conservation biology.     

Towards a concept of thrombosis in accelerated flow: rheology, fluid dynamics, and biochemistry

The predilection sites of arterial thrombosis are characterized by local increase in wall shear stress, flow separation with eddy formation and stagnation point flow. The defenders of high shear, as well as those of low shear theory of thrombogenesis, point to correlations of predilection sites and the respective flow abnormalities. Experimental evidence is provided, that high shear rates can damage both red cells and platelets, that lysed red cells constitute a potent platelet stimulant, due to their content of adenine nucleotides, and that platelets do not adhere to surfaces unless transported onto them by convective motion, the effectiveness of the platelet-wall interaction being enhanced by platelet activation. Based on these facts, a resolution of the contrast between high and low shear theory of thrombosis is attempted in a way, that the different flow regimens, with blood cells sequentially passing them, are each considered important and interdependent steps on the way to thrombosis.     

Ultrastructural aspects of oogenesis and oocyte primary growth in Serrasalmus spilopleura (Teleostei, Characiformes, Characidae)

The ultrastructural characteristics of the organelles present in Serrasalmus spilopleura oogonia and oocytes undergoing primary growth were described in detail, considering its role in the nuclear and cytoplasmic metabolic processes that occur in these cell types. Even though these cells do not significantly differ from those similar to them that are found in other teleost groups, the analysis of their ultrastructure makes available new data on the reproductive biology of Characiformes.