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Basic Prediction (basic + prediction)

Distribution by Scientific Domains
Life Sciences50%

Selected Abstracts

Experimental evolution of dispersal in spatiotemporally variable microcosms

ECOLOGY LETTERS, Issue 10 2003
Nicholas A. Friedenberg
Abstract The world is an uncertain place. Individuals' fates vary from place to place and from time to time. Natural selection in unpredictable environments should favour individuals that hedge their bets by dispersing offspring. I confirm this basic prediction using Caenorhabditis elegans in experimental microcosms. My results agree with evolutionary models and correlations found previously between habitat stability and individual dispersal propensity in nature. However, I also find that environmental variation that triggers conditional dispersal behaviour may not impose selection on baseline dispersal rates. These findings imply that an increased rate of disturbance in natural systems has the potential to cause an evolutionary response in the life history of impacted organisms. [source]

Scramble or contest competition over food in solitarily foraging mouse lemurs (Microcebus spp.): New insights from stable isotopes

AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 2 2010
Melanie Dammhahn
Abstract The relationships between resource distribution, type of competition, and consequences for social organization have been formalized in the socioecological model (SEM) which predicts that ecological factors are the main determinants of female distribution. We tested this basic prediction in two solitary primates (Microcebus berthae and M. murinus) which differ in female association patterns. Using stable nitrogen and carbon isotope data of hair samples and food sources we quantified inter-specific differences in diet. ,13C in M. berthae reflected a diet composed mainly of insect secretions. Higher within-species as well as seasonal variation in ,13C of M. murinus indicated a wider trophic niche including plant and animal source food. Constantly elevated ,15N in M. murinus most likely reflected extended torpor during the lean season. This energy-saving strategy together with a wider, more opportunistic feeding niche might reduce female competition in this species, facilitating smaller female ranges, and a higher association potential. In contrast, ,15N fluctuated seasonally in M. berthae, most likely indicating varying amounts of arthropod food in the diet. Intense scramble competition over small and seasonally limited resources might lead to female spatial avoidance and a reduced association potential in M. berthae. Thus, differences in female association patterns between these two solitary foragers are due to different types of competition and overall intensities of intra-specific competition. Am J Phys Anthropol, 2010. © 2009 Wiley-Liss, Inc. [source]

The evolution of substructure in galaxy, group and cluster haloes , II.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 2 2005
Global properties
ABSTRACT In a previous paper, we described a new method for including detailed information about substructure in semi-analytic models of dark matter halo formation based on merger trees. In this paper, we present the basic predictions of our full model of halo formation. We first describe the overall properties of substructure in galaxy, group or cluster haloes at the present day. We then discuss the evolution of substructure, and the effect of the mass-accretion history of an individual halo on the mass function and orbital grouping of its subhalo population. We show, in particular, that the shape of the subhalo mass function is strongly correlated with the formation epoch of the halo. In a third paper in this series, we will compare the results of our semi-analytic method with the results of self-consistent numerical simulations of halo formation. [source]

On the interaction of ongoing cognitive activity and the nature of an event-based intention

APPLIED COGNITIVE PSYCHOLOGY, Issue 7 2000
Richard L. Marsh
Three experiments were conducted to explore the interaction between the nature of an event-based prospective intention and the ongoing activity in which it was embedded. Following the basic predictions of E. A. Maylor's (1996, 1998) task appropriate processing framework, we orthogonally crossed semantic and structural ongoing activities with intentions to respond to semantic and structural event-based cues. In Experiments 1 and 2, we found a cross-over interaction in which the match of the ongoing task and the nature of the intention resulted in better event-based performance than a mismatch between the two. Experiment 3 attempted to define boundary conditions for these effects by demonstrating that the task appropriate processing effect will not occur when event-based cues are particularly salient. The implications of the results and suggestions for further investigations are discussed. Copyright © 2000 John Wiley & Sons, Ltd. [source]