Search results for "evolutionary"

Identification of subspecies and parentage relationship by means of DNA fingerprinting in two exemplary of Pan troglodytes (Blumenbach, 1775) (Mammal…

2018

Four chimpanzee subspecies (Mammalia Hominidae) are commonly recognised: the Western Chimpanzee, P. troglodytes verus (Schwarz, 1934), the Nigeria-Cameroon Chimpanzee, P. troglodytes ellioti, the Central Chimpanzee, P. troglodytes troglodytes (Blumenbach, 1799), and the Eastern Chimpanzee, P. troglodytes schweinfurthii (Giglioli, 1872). Recent studies on mitochondrial DNA show the incorporation of P. troglodytes schweinfurthii in P. troglodytes troglodytes, suggesting the existence of only two subspecies: P. troglodytes troglodytes in Central and Eastern Africa and P. troglodytes verus-P. troglodytes ellioti in West Africa. The aim of the present study is twofold: first, to identify the cor…

Memory-saving optimization algorithms for systems with limited hardware

2011

Optimization of Delayed-State Kalman-Filter-based Algorithm via Differential Evolution for Sensorless Control of Induction Motors

2010

This paper proposes the employment of the differential evolution (DE) to offline optimize the covariance matrices of a new reduced delayed-state Kalman-filter (DSKF)-based algorithm which estimates the stator-flux linkage components, in the stationary reference frame, to realize sensorless control of induction motors (IMs). The DSKF-based algorithm uses the derivatives of the stator-flux components as mathematical model and the stator-voltage equations as observation model so that only a vector of four variables has to be offline optimized. Numerical results, carried out using a low-speed training test, show that the proposed DE-based approach is very promising and clearly outperforms a cla…

Original data for article: Weak warning signals can persist in the absence of gene flow

2019

Aposematic organisms couple conspicuous warning signals with a secondary defense to deter predators from attacking. Novel signals of aposematic prey are expected to be selected against due to positive frequency-dependent selection. How, then, can novel phenotypes persist after they arise, and why do so many aposematic species exhibit intrapopulation signal variability? Using a polytypic poison frog (Dendrobates tinctorius), we explored the forces of selection on variable aposematic signals using two phenotypically distinct (white, yellow) populations. Contrary to expectations, local phenotype was not always better protected compared to novel phenotypes in either population; in the white pop…

Supplementary data for: Improved camouflage through ontogenetic colour change confers reduced detection risk in shore crabs

2019

Many animals change appearance with age but the reasons why are rarely tested. Common shore crabs (Carcinus maenas), for example, are known for their ability to change colour over time. Young crabs show remarkable variation in coloration and it has been suggested that their variable appearance may help them to hide from predators in the habitats they use. However, as crabs grow they become more mobile and adult crabs, in contrast, are known to possess a more uniform coloration. This creates a problem: how to remain hidden in habitats that are variable and very different in appearance? To answer this, we first reared young shore crabs of two shades, pale or dark, on two background types rese…

An evolutionary perspective on stress responses, damage and repair

2022

Variation in stress responses has been investigated in relation to environmental factors, species ecology, life history and fitness. Moreover, mechanistic studies have unravelled molecular mechanisms of how acute and chronic stress responses cause physiological impacts (‘damage’), and how this damage can be repaired. However, it is not yet understood how the fitness effects of damage and repair influence stress response evolution. Here we study the evolution of hormone levels as a function of stressor occurrence, damage and the efficiency of repair. We hypothesise that the evolution of stress responses depends on the fitness consequences of damage and the ability to repair that damage. To o…

Bateman gradients from first principles

2022

In 1948, Angus Bateman presented experiments and concepts that remain influential and debated in sexual selection. The Bateman gradient relates reproductive success to mate number, and Bateman presented this as the cause of intra-masculine selection. A deeper causal level was subsequently asserted: that the ultimate cause of sex differences in Bateman gradients is the sex difference in gamete numbers, an argument that remains controversial and without mathematical backup. Here I develop models showing how asymmetry in gamete numbers alone can generate steeper Bateman gradients in males. This conclusion remains when the further asymmetry of internal fertilisation is added to the model and fe…

External Changes and R&I Inter-Organizational Network Dynamics: The Case of EU R&I Policy Change

2022

The paper seeks to understand in what way changes in EU innovation policy incentives affect the EU R&I inter-organizational network dynamics. In particular, the study’s empirical settings are the two innovative inter-organizational networks that connect knowledge actors financed through two EU Framework Programs: the 7th Framework Program (or FP7), and the 8th Framework Program, named HORIZON 2020 (or H2020). Using a dataset of more than 22,228 unique projects in FP7 and 22,153 in H2020, we constructed two collaboration networks. We apply network analysis as a research instrument to identify and measure the fundamental structural properties and evolutionary dynamics of whole networks. I…

Marine food web perspective to fisheries-induced evolution

2021

Fisheries exploitation can cause genetic changes in heritable traits of targeted stocks. The direction of selective pressure forced by harvest acts typically in reverse to natural selection and selects for explicit life-histories, usually for younger and smaller spawners with deprived spawning potential. While the consequences that such selection might have on the populational dynamics of a single species are well emphasised, we are just beginning to perceive the variety and severity of its propagating effects within the entire marine food webs and ecosystems. Here, we highlight the potential pathways in which fishing-induced evolution, driven by size-selective fishing, might resonate throu…

Insular endemism in the Mediterranean vascular flora: the case of the Aeolian Islands (Sicily, Italy)

2012

The present paper briefly provides the state of the art of the knowledge on vascular plant endemism in the oceanic (“thalassogenous”) Aeolian Archipelago (Sicily). Preliminary analysis of distribution areas and review of recent literature on biosystematics of endemic species revealed that: (a) Aeolian strictly endemic taxa are just 6, i.e. about the 0.7 % of the local vascular flora; among them, just 4 can be considered (with doubt) derived from in situ evolution. (b) The other 18 endemics are taxa occurring in wider areas, so they cannot be generally considered “locally evolved” but relicts. This preliminary analysis confirms that not only continental (“chersogenous”) but all Mediterranean…