Search results for "evolutionary"
showing 10 items of 4392 documents
Rapid parameter estimation of discrete decaying signals using autoencoder networks
2021
Machine learning: science and technology 2(4), 045024 (2021). doi:10.1088/2632-2153/ac1eea
Diplopod hemocyanin sequence and the phylogenetic position of the Myriapoda
2001
Hemocyanins are copper-containing respiratory proteins of the Arthropoda that have so far been thoroughly investigated only in the Chelicerata and the Crustacea but have remained unstudied until now in the Myriapoda. Here we report the first sequence of a myriapod hemocyanin. The hemocyanin of Spirostreptus sp. (Diplopoda: Spirostreptidae) is composed of two distinct subunits that are arranged in a 6 x 6 native molecule. The cloned hemocyanin subunit cDNA codes of for a polypeptide of 653 amino acids (75.5 kDa) that includes a signal peptide of 18 amino acids. The sequence closely resembles that of the chelicerate hemocyanins. Molecular phylogenetic analyses reject with high statistical con…
Paradox lost: variable colour-pattern geometry is associated with differences in movement in aposematic frogs
2014
Aposematic signal variation is a paradox: predators are better at learning and retaining the association between conspicuousness and unprofitability when signal variation is low. Movement patterns and variable colour patterns are linked in non-aposematic species: striped patterns generate illusions of altered speed and direction when moving linearly, affecting predators' tracking ability; blotched patterns benefit instead from unpredictable pauses and random movement. We tested whether the extensive colour-pattern variation in an aposematic frog is linked to movement, and found that individuals moving directionally and faster have more elongated patterns than individuals moving randomly and…
Sponges (Porifera) as living metazoan witnesses from the Neoproterozoic: biomineralization and the concept of their evolutionary success
2010
Terra Nova, 22, 1–11, 2010 Abstract The emergence of the Metazoa can be dated back to the Neoproterozoic Era which comprises the Cryogenian Period during which two major glaciations occurred, the Sturtian and the Varanger-Marinoan. At that time, the phylum Porifera (sponges) evolved as the first animals and developed a hard skeleton. The two classes of siliceous sponges, the Hexactinellida and the Demospongiae, are already provided with the major genetic repertoire and gene regulatory networks that also exist in modern multicellular animals. Besides these metazoan innovations, the siliceous sponges display one autapomorphic character, silicatein, an enzyme which mediates bio-silica formatio…
Isolation and characterization of two T-box genes from sponges, the phylogenetically oldest metazoan taxon
2003
It is now well established that all metazoan phyla derived from one common ancestor, the hypothetical Urmetazoa. Due to the basal position of Porifera (Demospongiae) in the phylogenetic tree of Metazoa, studies on the mechanisms controlling the development of these animals can provide clues on the understanding of the origin of multicellular animals and on how the first organization of the body plan evolved. In this report we describe the isolation and genomic characterization of two T-box genes from the siliceous sponge Suberites domuncula. The phylogenetic analysis classifies one into the subfamily of Brachyury, Sd-Bra, and the second into the Tbx2 subfamily, Sd-Tbx2. Analyses of the Sd-B…
Contrasting Automatic and Manual Group Formation: A Case Study in a Software Engineering Postgraduate Course
2021
This paper proposes the comparison of a group formation approach based on an evolutionary algorithm with a manual approach performed by an instructor with ten years of experience on this task. The groups were created based on the professional, psychological, and experience profile of each student. The results obtained demonstrated the algorithm’s potential, reaching an average similarity of \(83.46\%\) with the groups formed manually by the instructor.
Spiralian phylogenomics supports the resurrection of Bryozoa comprising Ectoprocta and Entoprocta.
2007
Phylogenetic analyses based on 79 ribosomal proteins of 38 metazoans, partly derived from 6 new expressed sequence tag projects for Ectoprocta, Entoprocta, Sipuncula, Annelida, and Acanthocephala, indicate the monophyly of Bryozoa comprising Ectoprocta and Entoprocta, 2 taxa that have been separated for more than a century based on seemingly profound morphological differences. Our results also show that bryozoans are more closely related to Neotrochozoa, including molluscs and annelids, than to Syndermata, the latter comprising Rotifera and Acanthocephala. Furthermore, we find evidence for the position of Sipuncula within Annelida. These findings suggest that classical developmental and mor…
From Dating to Mating and Relating: Predictors of Initial and Long–Term Outcomes of Speed–Dating in a Community Sample
2011
We studied initial and long–term outcomes of speed–dating over a period of 1 year in a community sample involving 382 participants aged 18–54 years. They were followed from their initial choices of dating partners up to later mating (sexual intercourse) and relating (romantic relationship). Using Social Relations Model analyses, we examined evolutionarily informed hypotheses on both individual and dyadic effects of participants’ physical characteristics, personality, education and income on their dating, mating and relating. Both men and women based their choices mainly on the dating partners’ physical attractiveness, and women additionally on men's sociosexuality, openness to experience, …
Why Mate Choices are not as Reciprocal as we Assume: The Role of Personality, Flirting and Physical Attractiveness
2011
Based on a social relations perspective on mating, the actual and assumed reciprocity of mate choices was studied in a real–life speed–dating context. A community sample involving 382 singles aged 18–54 years filled out a questionnaire for the measurement of self–perceived mate value, sociosexuality, extraversion, and shyness and participated in free speed–dating sessions. Immediately after each date, choices and assumed choices were recorded. Measures of physical attractiveness and flirting behaviour were obtained by independent observers. Results show that actual mate choices are not reciprocal although people strongly expect their choices to be reciprocated and flirting behaviour is ind…
Brain, Sociobiology, and Evolution in Primates
1981
Socialization in primates can be understood essentially as a function of the information processing ability of the CNS, which can be roughly measured in terms of relative brain size in closely related species groups. Both the cephalization constant (Hemmer 1971, 1974) and the extra neuron number (Jerison 1964, 1973) may be used for relevant quantification, as there is a highly significant correlation of both parameters in primates (7 ape species: r = 0.97, 20 Old World monkey species: r = 0.99; Hemmer 1978). The author has shown in a previous paper (Hemmer 1979) close negative correlations of relative brain size and the social organization as expressed in troop size (r = −0.92) and of relat…