toggle visibility Search & Display Options

Select All    Deselect All
 |   | 
Details
   print
  Records Links
Author Weisbecker, V.; Goswami, A. url  doi
openurl 
  Title Brain size, life history, and metabolism at the marsupial/placental dichotomy Type Journal Article
  Year 2010 Publication (down) Proceedings of the National Academy of Sciences of the United States of America Abbreviated Journal Proc. Natl. Acad. Sci. U.S.A.  
  Volume 107 Issue 37 Pages 16216-16221  
  Keywords  
  Abstract The evolution of mammalian brain size is directly linked with the evolution of the brain's unique structure and performance. Both maternal life history investment traits and basal metabolic rate (BMR) correlate with relative brain size, but current hypotheses regarding the details of these relationships are based largely on placental mammals. Using encephalization quotients, partial correlation analyses, and bivariate regressions relating brain size to maternal investment times and BMR, we provide a direct quantitative comparison of brain size evolution in marsupials and placentals, whose reproduction and metabolism differ extensively. Our results show that the misconception that marsupials are systematically smaller-brained than placentals is driven by the inclusion of one large-brained placental clade, Primates. Marsupial and placental brain size partial correlations differ in that marsupials lack a partial correlation of BMR with brain size. This contradicts hypotheses stating that the maintenance of relatively larger brains requires higher BMRs. We suggest that a positive BMR–brain size correlation is a placental trait related to the intimate physiological contact between mother and offspring during gestation. Marsupials instead achieve brain sizes comparable to placentals through extended lactation. Comparison with avian brain evolution suggests that placental brain size should be constrained due to placentals’ relative precociality, as has been hypothesized for precocial bird hatchlings. We propose that placentals circumvent this constraint because of their focus on gestation, as opposed to the marsupial emphasis on lactation. Marsupials represent a less constrained condition, demonstrating that hypotheses regarding placental brain size evolution cannot be generalized to all mammals.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 5338  
Permanent link to this record
 

 
Author Lee, R.D. doi  openurl
  Title Rethinking the evolutionary theory of aging: transfers, not births, shape senescence in social species Type Journal Article
  Year 2003 Publication (down) Proceedings of the National Academy of Sciences of the United States of America Abbreviated Journal Proc Natl Acad Sci U S A  
  Volume 100 Issue 16 Pages 9637-9642  
  Keywords Adaptation, Physiological; *Aging; Animals; *Biological Evolution; Demography; Economics; Environment; Fertility; Humans; Life Expectancy; Longevity; Models, Theoretical; Parturition; Population Dynamics; Population Growth; Reproduction  
  Abstract The classic evolutionary theory of aging explains why mortality rises with age: as individuals grow older, less lifetime fertility remains, so continued survival contributes less to reproductive fitness. However, successful reproduction often involves intergenerational transfers as well as fertility. In the formal theory offered here, age-specific selective pressure on mortality depends on a weighted average of remaining fertility (the classic effect) and remaining intergenerational transfers to be made to others. For species at the optimal quantity-investment tradeoff for offspring, only the transfer effect shapes mortality, explaining postreproductive survival and why juvenile mortality declines with age. It also explains the evolution of lower fertility, longer life, and increased investments in offspring.  
  Address Department of Demography, University of California, 2232 Piedmont Avenue, Berkeley, CA 94720-2120, USA. rlee@demog.berkeley.edu  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0027-8424 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:12878733 Approved no  
  Call Number Equine Behaviour @ team @ Serial 5465  
Permanent link to this record
 

 
Author Liker, A.; Bókony, V. url  doi
openurl 
  Title Larger groups are more successful in innovative problem solving in house sparrows Type Journal Article
  Year 2009 Publication (down) Proceedings of the National Academy of Sciences of the United States of America Abbreviated Journal Proc Natl Acad Sci USA  
  Volume 106 Issue 19 Pages 7893-7898  
  Keywords  
  Abstract Group living offers well-known benefits to animals, such as better predator avoidance and increased foraging success. An important additional, but so far neglected, advantage is that groups may cope more effectively with unfamiliar situations through faster innovations of new solutions by some group members. We tested this hypothesis experimentally by presenting a new foraging task of opening a familiar feeder in an unfamiliar way to house sparrows in small and large groups (2 versus 6 birds). Group size had strong effects on problem solving: sparrows performed 4 times more and 11 times faster openings in large than in small groups, and all members of large groups profited by getting food sooner (7 times on average). Independently from group size, urban groups were more successful than rural groups. The disproportionately higher success in large groups was not a mere consequence of higher number of attempts, but was also related to a higher effectiveness of problem solving (3 times higher proportion of successful birds). The analyses of the birds' behavior suggest that the latter was not explained by either reduced investment in antipredator vigilance or reduced neophobia in large groups. Instead, larger groups may contain more diverse individuals with different skills and experiences, which may increase the chance of solving the task by some group members. Increased success in problem solving may promote group living in animals and may help them to adapt quickly to new situations in rapidly-changing environments.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 6538  
Permanent link to this record
 

 
Author Morand-Ferron, J.; Quinn, J.L. url  doi
openurl 
  Title Larger groups of passerines are more efficient problem solvers in the wild Type Journal Article
  Year 2011 Publication (down) Proceedings of the National Academy of Sciences of the United States of America Abbreviated Journal Proc Natl Acad Sci USA  
  Volume 108 Issue 38 Pages 15898-15903  
  Keywords  
  Abstract Group living commonly helps organisms face challenging environmental conditions. Although a known phenomenon in humans, recent findings suggest that a benefit of group living in animals generally might be increased innovative problem-solving efficiency. This benefit has never been demonstrated in a natural context, however, and the mechanisms underlying improved efficiency are largely unknown. We examined the problem-solving performance of great and blue tits at automated devices and found that efficiency increased with flock size. This relationship held when restricting the analysis to naive individuals, demonstrating that larger groups increased innovation efficiency. In addition to this effect of naive flock size, the presence of at least one experienced bird increased the frequency of solving, and larger flocks were more likely to contain experienced birds. These findings provide empirical evidence for the “pool of competence” hypothesis in nonhuman animals. The probability of success also differed consistently between individuals, a necessary condition for the pool of competence hypothesis. Solvers had a higher probability of success when foraging with a larger number of companions and when using devices located near rather than further from protective tree cover, suggesting a role for reduced predation risk on problem-solving efficiency. In contrast to traditional group living theory, individuals joining larger flocks benefited from a higher seed intake, suggesting that group living facilitated exploitation of a novel food source through improved problem-solving efficiency. Together our results suggest that both ecological and social factors, through reduced predation risk and increased pool of competence, mediate innovation in natural populations.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 6539  
Permanent link to this record
 

 
Author Young, H.P. url  openurl
  Title The dynamics of social innovation Type Journal Article
  Year 2011 Publication (down) Proceedings of the National Academy of Sciences Abbreviated Journal Proc. Natl. Acad. Sci. U.S.A.  
  Volume 108 Issue Supplement 4 Pages 21285-21291  
  Keywords  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes 10.1073/pnas.1100973108 Approved no  
  Call Number Equine Behaviour @ team @ Serial 5940  
Permanent link to this record
 

 
Author Gorodnichenko, Y.; Roland, G. url  openurl
  Title Individualism, innovation, and long-run growth Type Journal Article
  Year 2011 Publication (down) Proceedings of the National Academy of Sciences Abbreviated Journal Proc. Natl. Acad. Sci. U.S.A.  
  Volume 108 Issue Supplement 4 Pages 21316-21319  
  Keywords  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes 10.1073/pnas.1101933108 Approved no  
  Call Number Equine Behaviour @ team @ Serial 5941  
Permanent link to this record
 

 
Author Harvey, P.H.; Clutton-Brock, T.H.; Mace, G.M. url  openurl
  Title Brain size and ecology in small mammals and primates Type Journal Article
  Year 1980 Publication (down) Proceedings of the National Academy of Sciences Abbreviated Journal PNAS  
  Volume 77 Issue 7 Pages 4387-4389  
  Keywords  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 5456  
Permanent link to this record
 

 
Author Noy, L.; Dekel, E.; Alon, U. url  openurl
  Title The mirror game as a paradigm for studying the dynamics of two people improvising motion together Type Journal Article
  Year 2011 Publication (down) Proceedings of the National Academy of Sciences Abbreviated Journal  
  Volume Issue Pages  
  Keywords  
  Abstract Joint improvisation is the creative action of two or more people without a script or designated leader. Examples include improvisational theater and music, and day-to-day activities such as conversations. In joint improvisation, novel action is created, emerging from the interaction between people. Although central to creative processes and social interaction, joint improvisation remains largely unexplored due to the lack of experimental paradigms. Here we introduce a paradigm based on a theater practice called the mirror game. We measured the hand motions of two people mirroring each other at high temporal and spatial resolution. We focused on expert actors and musicians skilled in joint improvisation. We found that players can jointly create novel complex motion without a designated leader, synchronized to less than 40 ms. In contrast, we found that designating one player as leader deteriorated performance: The follower showed 2–3 Hz oscillation around the leader's smooth trajectory, decreasing synchrony and reducing the range of velocities reached. A mathematical model suggests a mechanism for these observations based on mutual agreement on future motion in mirrored reactive–predictive controllers. This is a step toward understanding the human ability to create novelty by improvising together.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes 10.1073/pnas.1108155108 Approved no  
  Call Number Equine Behaviour @ team @ Serial 5493  
Permanent link to this record
 

 
Author Warmuth, V.; Eriksson, A.; Bower, M.A.; Barker, G.; Barrett, E.; Hanks, B.K.; Li, S.; Lomitashvili, D.; Ochir-Goryaeva, M.; Sizonov, G.V.; Soyonov, V.; Manica, A. url  doi
openurl 
  Title Reconstructing the origin and spread of horse domestication in the Eurasian steppe Type Journal Article
  Year 2012 Publication (down) Proceedings of the National Academy of Sciences Abbreviated Journal Proc Natl Acad Sci U S A  
  Volume Issue Pages  
  Keywords  
  Abstract Despite decades of research across multiple disciplines, the early history of horse domestication remains poorly understood. On the basis of current evidence from archaeology, mitochondrial DNA, and Y-chromosomal sequencing, a number of different domestication scenarios have been proposed, ranging from the spread of domestic horses out of a restricted primary area of domestication to the domestication of numerous distinct wild horse populations. In this paper, we reconstruct both the population genetic structure of the extinct wild progenitor of domestic horses, Equus ferus, and the origin and spread of horse domestication in the Eurasian steppes by fitting a spatially explicit stepping-stone model to genotype data from >300 horses sampled across northern Eurasia. We find strong evidence for an expansion of E. ferus out of eastern Eurasia about 160 kya, likely reflecting the colonization of Eurasia by this species. Our best-fitting scenario further suggests that horse domestication originated in the western part of the Eurasian steppe and that domestic herds were repeatedly restocked with local wild horses as they spread out of this area. By showing that horse domestication was initiated in the western Eurasian steppe and that the spread of domestic herds across Eurasia involved extensive introgression from the wild, the scenario of horse domestication proposed here unites evidence from archaeology, mitochondrial DNA, and Y-chromosomal DNA.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 5612  
Permanent link to this record
 

 
Author Pruvost, M.; Bellone, R.; Benecke, N.; Sandoval-Castellanos, E.; Cieslak, M.; Kuznetsova, T.; Morales-Muñiz, A.; O'Connor, T.; Reissmann, M.; Hofreiter, M.; Ludwig, A. url  openurl
  Title Genotypes of predomestic horses match phenotypes painted in Paleolithic works of cave art Type Journal Article
  Year 2011 Publication (down) Proceedings of the National Academy of Sciences Abbreviated Journal  
  Volume 108 Issue 46 Pages 18626-18630  
  Keywords  
  Abstract Archaeologists often argue whether Paleolithic works of art, cave paintings in particular, constitute reflections of the natural environment of humans at the time. They also debate the extent to which these paintings actually contain creative artistic expression, reflect the phenotypic variation of the surrounding environment, or focus on rare phenotypes. The famous paintings “The Dappled Horses of Pech-Merle,” depicting spotted horses on the walls of a cave in Pech-Merle, France, date back ~25,000 y, but the coat pattern portrayed in these paintings is remarkably similar to a pattern known as “leopard” in modern horses. We have genotyped nine coat-color loci in 31 predomestic horses from Siberia, Eastern and Western Europe, and the Iberian Peninsula. Eighteen horses had bay coat color, seven were black, and six shared an allele associated with the leopard complex spotting (LP), representing the only spotted phenotype that has been discovered in wild, predomestic horses thus far. LP was detected in four Pleistocene and two Copper Age samples from Western and Eastern Europe, respectively. In contrast, this phenotype was absent from predomestic Siberian horses. Thus, all horse color phenotypes that seem to be distinguishable in cave paintings have now been found to exist in prehistoric horse populations, suggesting that cave paintings of this species represent remarkably realistic depictions of the animals shown. This finding lends support to hypotheses arguing that cave paintings might have contained less of a symbolic or transcendental connotation than often assumed.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes 10.1073/pnas.1108982108 Approved no  
  Call Number Equine Behaviour @ team @ Serial 5700  
Permanent link to this record
Select All    Deselect All
 |   | 
Details
   print