Quantitative Biology

1411 Submissions

[3] viXra:1411.0578 [pdf] submitted on 2014-11-27 07:38:16

Division of Labor in Hand Usage is Associated with Higher Hand Performance in Free-Ranging Bonnet Macaques, Macaca Radiata

Authors: Madhur Mangalam, Nisarg Desai, Mew Singh
Comments: 19 Pages.

A practical approach to understanding lateral asymmetries in body, brain, and cognition would be to examine the performance advantages/disadvantages associated with the corresponding functions and behavior. In the present study, we examined whether the division of labor in hand usage, marked by the preferential usage of the two hands across manual operations requiring maneuvering in three-dimensional space (e.g., reaching for food, grooming, and hitting an opponent) and those requiring physical strength (e.g., climbing), as described by Mangalam et al. [1], is associated with higher hand performance in free-ranging bonnet macaques, Macaca radiata. We determined the extent to which (a) the macaques exhibit laterality in hand usage in an experimental unimanual and a bimanual food-reaching task, and (b) manual laterality is associated with hand performance in an experimental hand-performance-differentiation task. We found strong negative relationships between (a) the performance of the preferred hand in the hand-performance-differentiation task (measured as the latency in food extraction; lower latency = higher performance), the preferred hand determined using the bimanual food-reaching task, and the normalized difference in the performance between the two hands (measured as the difference in the latency in food extraction between them normalized by the latency in food extraction using the preferred hand), and (b) the normalized difference in the performance between the two hands and the manual specialization (measured as the absolute difference in the laterality in hand usage between the unimanual and the bimanual food-reaching tasks; lesser difference = higher manual specialization). These observations demonstrate that the division of labor between the two hands is associated with higher hand performance.
Category: Quantitative Biology

[2] viXra:1411.0577 [pdf] submitted on 2014-11-27 07:41:38

Division of Labor: A Democratic Approach to Understanding Manual Asymmetries in Non-Human Primates

Authors: Madhur Mangalam, Nisarg Desai, Mewa Singh
Comments: 37 Pages.

A consequence of the ‘gold rush’ like hunch for human-like handedness in non-human primates has been that researchers have been continually analyzing observations at the level of the population, ignoring the analysis at the level of an individual and, consequently, have potentially missed revelations on the forms and functions of manual asymmetries. Recently, consecutive studies on manual asymmetries in bonnet macaques, Macaca radiata [Mangalam et al., 2014a; Mangalam et al., 2014b] revealed both the functional and the adaptive significance of manual asymmetries respectively, and pointed towards the division of labor as being the general principle underlying the observed hand-usage patterns. We review the studies on manual asymmetries in capuchin monkeys, Cebus spp. and argue that the observed hand-usage patterns might reflect specialization of the two hands for accomplishing tasks that require different dexterity types (i.e., maneuvering in three dimensional space or physical strength). To this end, we do a step-by-step analysis of the various tasks used in the studies on manual asymmetries in capuchin monkeys, wherein we: (a) analyze the different manual tasks that have been used to study manual asymmetries in non-human primates on the basis of the attributes such as the number of hands required to solve a given task (i.e., unimanual, pseudo unimanual, or bimanual) and the spatiotemporal progression of manual actions (i.e., sequential or concurrent). (b) Determine the forms and functions of manual asymmetries that these tasks can potentially elicit within the broader scope of the behavioral repertoire of an individual, a population, or a species. (c) Qualify the scope of the inter-individual, -population, or -species comparisons. We then describe the division of labor as a general principle underlying manual asymmetries in non-human primates, and propose experimental designs that would elaborate the forms and functions of manual asymmetries in non-human primates, and the associated adaptive value.
Category: Quantitative Biology

[1] viXra:1411.0036 [pdf] replaced on 2014-12-16 03:49:17

The Enigma of Darwin Diagram

Authors: Miloje M. Rakocevic
Comments: 96 Pages. This is a pre-print form for a booklet with the same title; the suggestions are welcome! As new, in relation to V3, here are Appendices H & K, and Remark 4.2.

According to my best knowledge, for the first time here is presented a hypothesis, that the one and only accompanying diagram in Darwin famous book On the Origin of Species contains, may be, a hidden code. Direct inspection reveals that the Diagram, viewed as built of four parts [(two upper and two lower / two left and two right); (two with more and two with less branches / two with multiple and two with single branches)], corresponds to the logical square of the genetic code. When, however, viewed as built of two parts (upper and lower), then it corresponds with Shcherbak diagram (Shcherbak, 1993, 1994) of four-codon and non-four-codon amino acids; not only by the form but also by the number of elementary quantities. The number of nucleons in the upper part of Shcherbak diagram (four-codon amino acids) is determined by the Pythagorean law, meaning that the total number of nucleons makes the product of the number 25 and Prime quantum 037 (925); and the number of branches in the lower part of Darwin diagram is determined by the law of Plato, meaning that the total number of branches makes the product of the number 216 and First quantum 01 (216). On the other hand, in the lower part of the Shcherbak diagram there are 60 of Prime quantum 037 (2220), while in the upper part of the Darwin diagram there are 60 of First quantum 01 (60). There are 216 + 60 = 276 branches (in total), and this number is also the number taken from a specific and unique arithmetical system. Furthermore, it is shown that Darwin, starting from the basic structure of the Diagram, formed a sophisticated structure which strictly corresponds to the arithmetical and /or algebraic structures that also appear to be the key determinants of the genetic code.
Category: Quantitative Biology