March Mammal Madness and the power of narrative in science outreach.

March Mammal Madness is a science outreach project that, over the course of several weeks in March, reaches hundreds of thousands of people in the United States every year. We combine four approaches to science outreach - gamification, social media platforms, community event(s), and creative products - to run a simulated tournament in which 64 animals compete to become the tournament champion. While the encounters between the animals are hypothetical, the outcomes rely on empirical evidence from the scientific literature. Players select their favored combatants beforehand, and during the tournament scientists translate the academic literature into gripping "play-by-play" narration on social media. To date ~1100 scholarly works, covering almost 400 taxa, have been transformed into science stories. March Mammal Madness is most typically used by high-school educators teaching life sciences, and we estimate that our materials reached ~1% of high-school students in the United States in 2019. Here we document the intentional design, public engagement, and magnitude of reach of the project. We further explain how human psychological and cognitive adaptations for shared experiences, social learning, narrative, and imagery contribute to the widespread use of March Mammal Madness

The effects of captive versus wild rearing environments on long bone articular surfaces in common chimpanzees (Pan troglodytes)

The physical environments of captive and wild animals frequently differ in substrate types and compliance. As a result, there is an assumption that differences in rearing environments between captive and wild individuals produce differences in skeletal morphology. Here, this hypothesis is tested using a sample of 42 captive and wild common chimpanzees (Pan troglodytes). Articular surface areas of the humerus, radius, ulna, femur, and tibia were calculated from linear breadth measurements, adjusted for size differences using Mosimann shape variables, and compared across sex and environmental groups using two-way ANOVA. Results indicate that the articular surfaces of the wrist and knee differ between captive and wild chimpanzees; captive individuals have significantly larger distal ulna and tibial plateau articular surfaces. In both captive and wild chimpanzees, males have significantly larger femoral condyles and distal radius surfaces than females. Finally, there is an interaction effect between sex and rearing in the articular surfaces of the femoral condyles and distal radius in which captive males have significantly larger surface areas than all other sex-rearing groups. These data suggest that long bone articular surfaces may be sensitive to differences experienced by captive and wild individuals, such as differences in diet, body mass, positional behaviors, and presumed loading environments. Importantly, these results only find differences due to rearing environment in some long bone articular surfaces. Thus, future work on skeletal morphology could cautiously incorporate data from captive individuals, but should first investigate potential intraspecific differences between captive and wild individuals

AMERICAN ANTHROPOLOGIST Biological Anthropology Complexity in Biological Anthropology in 2011: Species, Reproduction, and Sociality

ABSTRACT In 2011, the research of biological anthropologists contributed to the emergence of increasingly complex explanations of biological phenomena from previous, simpler interpretations. Major subjects of bioanthropological research in 2011 include new developments in understanding ancient hominin species and archaic Homo population histories; the physiological, neurological, and social effects of mating and reproducing in both humans and nonhuman primates; and the evolution of primate sociality and human cooperation. This review considers these topics of research from a perspective of complexity using conference proceedings, published articles, and social media. In closing, this article demonstrates the natural extension of our scholarly research to modern social networks and illustrates how they may act as a platform by which to increase intradisciplinary engagement and to highlight the complex, wide-reaching, and innovative research that our field contributes to society. [sociality, Denisovans, Australopithecus sediba, biological anthropology, annual review] I t is a testament to the strength of our discipline that our research questions are so many and wide ranging. This year, bioanthropologists made discoveries about extant and extinct species, added to the growing literature on human sociality, proposed a model for the evolution of primate sociality, tested the hormonal and neurological effects of mating and parenthood on primates, and produced insights on the myriad facets of infant development-and this list barely skims the surface of what biologically inclined anthropologists were up to. Although these research topics cover a wide swath of bioanthropology, they share a unifying theme: complexity. These trending topics both focused on inherently complex systems (e.g., social systems, the interaction between physiology and behavior) and also advanced our understanding of complexity within each. The year's research encompasses many levels of biological organization and complexity. At the population and species level, our understanding of hominin species diversity, phylogeny, and population histories continues to grow through contributions from new genetic data on modern humans, Denisovans, and Neanderthals. At the level of the individual, recent work on the physiological and neurological effects of mating, reproduction, and raising offspring has resulted in an evolving view of primate parental ecology. And, our understanding of the evolution of primate (incl. human) social systems has been advanced by ancestral stat

Ape femoral-humeral rigidities and arboreal locomotion

ObjectivesThis study investigates patterns of bone functional adaptations in extant apes through comparing hindlimb to forelimb bone rigidity ratios in groups with varying levels of arboreality.Materials and MethodsUsing CT scans, bone rigidity (J) was calculated at three regions of interest (ROI) along femoral and humeral diaphyses in Homo, Pongo, Pan, and Gorilla with further comparisons made between species and subspecies divisions within Pan and Gorilla.ResultsConsistent with previous work on extant hominoids, species exhibited differences in midshaft femoral to humeral (F/H) rigidity ratios. Results of the present study confirm that these midshaft differences extend to 35% and 65% diaphyseal ROIs. Modern humans, exhibiting larger ratios, and orangutans, exhibiting smaller ratios, bracketed the intermediate African apes in comparisons. Within some African apes, limb rigidity ratios varied significantly between taxonomic groups. Eastern gorillas exhibited the highest mean ratios and chimpanzees the lowest at all three ROIs. In posthoc comparisons, chimpanzees and bonobos did not differ in relative limb rigidity ratios at any of the three ROIs. However, western gorillas were more similar to bonobos than eastern gorillas at 50% and 35% ROIs, but not at the 65% ROI.ConclusionSpecies, and to a lesser extent subspecies, can be distinguished by F/H limb rigidity ratios according to broad positional behavior patterns at multiple regions of interest along the diaphyses. Similarity of bonobos and western gorillas is in line with behavioral data of bonobos being the most terrestrial of Pan species, and western gorillas the most arboreal of the Gorilla groups.Hominoid species can be distinguished by F/H limb rigidity ratios according to levels of arboreality at multiple regions of interest along the diaphyses.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/175237/1/ajpa24632.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/175237/2/ajpa24632_am.pd

A Wider Pelvis Does Not Increase Locomotor Cost in Humans, with Implications for the Evolution of Childbirth

The shape of the human female pelvis is thought to reflect an evolutionary trade-off between two competing demands: a pelvis wide enough to permit the birth of large-brained infants, and narrow enough for efficient bipedal locomotion. This trade-off, known as the obstetrical dilemma, is invoked to explain the relative difficulty of human childbirth and differences in locomotor performance between men and women. The basis for the obstetrical dilemma is a standard static biomechanical model that predicts wider pelves in females increase the metabolic cost of locomotion by decreasing the effective mechanical advantage of the hip abductor muscles for pelvic stabilization during the single-leg support phase of walking and running, requiring these muscles to produce more force. Here we experimentally test this model against a more accurate dynamic model of hip abductor mechanics in men and women. The results show that pelvic width does not predict hip abductor mechanics or locomotor cost in either women or men, and that women and men are equally efficient at both walking and running. Since a wider birth canal does not increase a woman’s locomotor cost, and because selection for successful birthing must be strong, other factors affecting maternal pelvic and fetal size should be investigated in order to help explain the prevalence of birth complications caused by a neonate too large to fit through the birth canal

The effects of phylogeny, body size, and locomotor behavior on the three-dimensional shape of the pelvis in extant carnivorans

The mammalian pelvis is thought to exhibit adaptations to the functional demands of locomotor behaviors. Previous work in primates has identified form-function relationships between pelvic shape and locomotor behavior; few studies have documented such relationships in carnivorans, instead focusing on long bones. Most work on the functional morphology of the carnivoran pelvis, in particular, has used univariate measures, with only a few previous studies incorporating a three-dimensional (3D) analysis. Here we test the hypothesis that carnivoran taxa that are characterized by different locomotor modes also differ in 3D shape of the os coxae. Using 3D geometric morphometrics and phylogenetic comparative methods, we evaluate the phylogenetic, functional, and size-related effects on 3D pelvis shape in a sample of 33 species of carnivorans. Using surface models derived from laser scans, we collected a suite of landmarks (N = 24) and curve semilandmarks (N = 147). Principal component analysis on Procrustes coordinates demonstrates patterns of shape change in the ischiopubis and ilium likely related to allometry. Phylogenetic generalized least squares analysis on principal component scores demonstrates that phylogeny and body size have greater effects on pelvic shape than locomotor function. Our results corroborate recent research finding little evidence of locomotor specialization in the pelvis of carnivorans. More research on pelvic morphological integration and evolvability is necessary to understand the factors driving pelvic evolution in carnivorans

Hip abductor mechanics and cost comparisons in males and females.

<p>Effective mechanical advantage (<i>EMA</i>), <i>R</i>, and hip abductor cost estimates determined at a walk (female n = 13, male n = 12) and a run (female n = 10, male n = 11) for subjects who participated in kinematics, metabolic and MRI trials. Net locomotor cost determined for a combined sample of subjects who participated in walking (female n = 19, male n = 20) and running (female n = 13, male n = 14) metabolic trials. Mean ± standard deviation. <b>Bold</b> values indicate statistical significance at the Holm-Bonferroni alpha level [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0118903#pone.0118903.ref038" target="_blank">38</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0118903#pone.0118903.ref039" target="_blank">39</a>].</p><p>Hip abductor mechanics and cost comparisons in males and females.</p

Summary statistics for anthropometric measurements.

<p>Mean ± standard deviation. <b>Bold</b> values indicate statistical significance at the Holm-Bonferroni alpha level [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0118903#pone.0118903.ref036" target="_blank">36</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0118903#pone.0118903.ref037" target="_blank">37</a>].</p><p>Summary statistics for anthropometric measurements.</p

Static and dynamic models of hip abductor force production.

<p>a. The standard static biomechanical model of hip abductor force production assumes the ground reaction force vector (<i>GRF</i>) passes nearly vertically through the body center of mass during locomotion. The effective mechanical advantage (<i>EMA</i>) of the hip abductor muscles is defined as <i>r</i>/<i>R</i>, where <i>r</i> is the abductor muscle moment arm and <i>R</i> is the moment arm of the <i>GRF</i> vector. Hip abductor force (<i>F</i>_<i>m</i>) is equal the multiple of <i>GRF</i> and 1/<i>EMA</i>. A narrow pelvis is thought to reduce locomotor cost by decreasing <i>R</i> and hip abductor force production, but this may increase the likelihood of cephalopelvic disproportion (CPD) by narrowing the maternal birth canal. b. Inverse dynamics models the lower extremity as a series of linked-segments in which the foot, shank and thigh each act as rigid bodies interacting at frictionless joints [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0118903#pone.0118903.ref023" target="_blank">23</a>,<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0118903#pone.0118903.ref024" target="_blank">24</a>]. The net internal hip moment is equal to the thigh moment of inertia times its angular acceleration, minus the distal thigh moment (<i>M</i>_{<i>thighD</i>}), minus the cross-product of the positional vector of hip relative to the thigh center of mass (<i>r</i>_{<i>hip-COM</i>}) and gravity (<i>g</i>), minus the external moment acting on the thigh defined as the cross product of the positional vector of the distal thigh segment relative to the hip (<i>r</i>_{<i>thighD-hip</i>}) and the force vector acting on the distal thigh (<i>F</i>_{<i>thighD</i>}). <i>R</i> can then be measured dynamically as the perpendicular distance from the hip joint center to <i>F</i>_{<i>thighD</i>} (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0118903#sec002" target="_blank">Methods</a>). If the predictions of the static model and the obstetrical dilemma hold, <i>R</i> measured dynamically will be nearly equal to half- biacetabular width.</p

Metabolic cost of hip abductor activation and net locomotor cost in men and women.

<p>a. Hip abductor mass-specific cost is higher in women at both a walk (<i>P</i> = 0.006) and a run (<i>P</i> = 0.006) due to lower EMA from shorter average abductor moment arm length (see text, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0118903#pone.0118903.t002" target="_blank">Table 2</a>) b. Net mass-specific locomotor cost does not differ between men and women at a walk or a run. Black bar indicates mean, box indicates mean±1SD and whiskers are mean±2SD.</p