نتایج جستجو برای: evolutionary pattern
تعداد نتایج: 462879 فیلتر نتایج به سال:
An important goal in evolutionary biology is to understand the genetic changes underlying novel morphological structures. We investigated the origins of a complex wing pattern found among Amazonian Heliconius butterflies. Genome sequence data from 142 individuals across 17 species identified narrow regions associated with two distinct red colour pattern elements, dennis and ray. We hypothesise ...
background: stearoyl-coa desaturase (scd) is a key enzyme that converts saturated fatty acids (sfas) to monounsaturated fatty acids (mufas) in fat biosynthesis. despite being crucial for interpreting scds’ roles across species, the evolutionary relationship of scd proteins across species has yet to be elucidated. this study aims to present this evolutionary relationship based on amino acid sequ...
Spiking Neural Networks are considered as the third generation of Artificial Neural Networks, these neural networks naturally process spatio-temporal information. Spiking Neural Networks have been used in several fields and application areas; pattern recognition among them. For dealing with supervised pattern recognition task a gradientdescent based learning rule (Spike-prop) has been developed...
The recent evidence that extant cycads are not living fossils triggered a renewed search for a better understanding of their evolutionary history. In this study, we investigated the evolutionary diversification history of the genus Encephalartos, a monophyletic cycad endemic to Africa. We found an antisigmoidal pattern with a plateau and punctual explosive radiation. This pattern is typical of ...
Eye stalks and their scaling relationship with body size are important features in the mating system of many diopsid species, and sexual selection is a critical force influencing the evolution of this exaggerated morphology. Interspecific variation in eye span suggests there has been significant evolutionary change in this trait, but a robust phylogenetic hypothesis is required to determine its...
ABSTRACT In this paper we are analyzing the performance of feedforward neural networks with hybrid evolutionary algorithms for the recognition of hand written English alphabets after their scaling and rotation in the test pattern set whereas in the training set straight handwritten alphabets have used. In this performance analysis the neural network is trained with hybrid evolutionary algorithm...
The Acoustic Adaptation Hypothesis (AAH) predicts that acoustic signals emitted at sites with greater vegetation density should have spectral and temporal characteristics increase signal transmission, but there is a pleiotropism related to body size: large animals produce lower frequency. We used 238 advertisement calls of 34 populations Amazonian nurse frogs from two rainforests different test...
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