Search results for " comparative method"

Sexual selection and the chemical signal design of lacertid lizards

2018

Animal signals can differ considerably in complexity and composition, even among closely related species. Work on vocal and visual signals has revealed how sexual selection can elaborate signals relevant in mate choice or rival assessment, but few studies have investigated this process in chemical signals. In this study, we correlated chemical signalling diversity and richness with degree of sexual dimorphism in a data set of 60 species of the lizard family Lacertidae. The femoral glands of male lacertid lizards exude waxy secretions, of which the lipophilic fraction is known to function in chemical communication. We determined the composition of the gland secretions using gas chromatograph…

Fifteen species in one: deciphering the Brachionus plicatilis species complex (Rotifera, Monogononta) through DNA taxonomy

2016

Understanding patterns and processes in biological diversity is a critical task given current and rapid environmental change. Such knowledge is even more essential when the taxa under consideration are important ecological and evolutionary models. One of these cases is the monogonont rotifer cryptic species complex Brachionus plicatilis, which is by far the most extensively studied group of rotifers, is widely used in aquaculture, and is known to host a large amount of unresolved diversity. Here we collate a dataset of previously available and newly generated sequences of COI and ITS1 for 1273 isolates of the B. plicatilis complex and apply three approaches in DNA taxonomy (i.e. ABGD, PTP, …

2020

Understanding how and why rates of evolutionary diversification vary is a key issue in evolutionary biology, ecology, and biogeography. Evolutionary rates are the net result of interacting processes summarized under concepts such as adaptive radiation and evolutionary stasis. Here, we review the central concepts in the evolutionary diversification literature and synthesize these into a simple, general framework for studying rates of diversification and quantifying their underlying dynamics, which can be applied across clades and regions, and across spatial and temporal scales. Our framework describes the diversification rate (d) as a function of the abiotic environment (a), the biotic envir…

A comparative analysis of patch-leaving decision rules in a parasitoid family

2003

The proximate behavioural rules adopted by parasitoid females to manage their foraging time on patches of hosts were studied, under standardized laboratory conditions, in different species (and populations) of the Trichogrammatidae (Hymenoptera) family. Seventeen species/populations were compared and the behavioural mechanisms adopted by the females were identified by means of a Cox's proportional hazards model. On average, females increased their patch-leaving tendency each time a healthy host was attacked and each time a parasitized host was rejected. Strong variation was observed in these patch-leaving mechanisms among the different species. Moreover, the interspecific variation in these…

African Law(s)

2023

The book presents a critical rethinking of the study of law in Africa from a comparative law perspective and proposes a new approach on how to consider law in Africa. It highlights the inadequacies of current Western theoretical perspectives in comparative law, especially for studying African law, arguing that they are too eurocentric to fully catch the peculiarities and characteristics of the African “lawscape”. The common thread of the present work is that of consider law in Africa from a different perspective. The aim of the proposed approach is to demonstrate that the African legal culture can be considered at the same level of the Western one, so that – being deeply rooted in the cultu…

2015

Songs in passerine birds are important for territory defense and mating. Speciation rates in oscine passerines are so high, due to cultural evolution, that this bird lineage makes up half of the extant bird species. Leaf warblers are a speciose Old-World passerine family of limited morphological differentiation, so that songs are even more important for species delimitation. We took 16 sonographic traits from song recordings of 80 leaf warbler taxa and correlated them with 15 potentially explanatory variables, pairwise, and in linear models. Based on a well-resolved molecular phylogeny of the same taxa, all pairwise correlations were corrected for relatedness with phylogenetically independe…

Sexual conflict drives micro- and macroevolution of sexual dimorphism in immunity

2021

Abstract Background Sexual dimorphism in immunity is believed to reflect sex differences in reproductive strategies and trade-offs between competing life history demands. Sexual selection can have major effects on mating rates and sex-specific costs of mating and may thereby influence sex differences in immunity as well as associated host–pathogen dynamics. Yet, experimental evidence linking the mating system to evolved sexual dimorphism in immunity are scarce and the direct effects of mating rate on immunity are not well established. Here, we use transcriptomic analyses, experimental evolution and phylogenetic comparative methods to study the association between the mating system and sexua…

Firm survival: The role of incubators and business characteristics

2015

This paper analyzes the impact of business incubators on firm survival. Using a configurational comparative method, namely fuzzy-set qualitative comparative analysis (fsQCA), the article also examines whether degree of business innovation, size, sector, and export activity affects firm survival. Results show that, when combined with other variables (i.e. sector, technology), business size is a sufficient condition for firm survival. Likewise, incubators alone cannot affect survival. A combination between incubators and other factors is necessary to ensure firm survival. Sin financiación 2.129 JCR (2015) Q2, 40/120 Business UEV

COMPARING THE MARSHALL PLAN AND THE EUROPEAN NEXT GENERATION UE. Models and Legal Tools of International and Supernational Cooperation to Promote Eco…

2022

The article analyzes and compares the European Recovery Plan of 1948, commonly known as the Marshall Plan, for the reconstruction of Europe after the Second World War (paragraphs 2, 2.1, 2.2), and the Next Generation EU (paragraphs 3, 3.1) through the lens and methods of legal comparison and historical analysis. As the description of the law cannot ignore the historicization of the object of study, such comparison is carried out inductively, through the analysis of the legal mechanisms in their concrete attitudes and the construction of descriptive schemes of facts, having regard to the legal discipline, but also to the functional profiles and the context in which the rules are conceived. T…

Before and after Science. Radcliffe-Brown e la questione dei rapporti tra metodi di ricerca sul campo, etnografia e teoria

2020

Nella prima parte del capitolo, mi occupo del periodo iniziale della carriera di Radcliffe-Brown che precede la pubblicazione, nel 1922, del suo celebre scritto, di carattere programmatico, su I metodi dell’etnologia e dell’antropologia sociale. Questo periodo di formazione è segnato dal rapporto con Haddon e Rivers, dalle due esperienze di ricerca sul campo nelle isole Andamane e tra gli aborigeni australiani, e dalla riflessione critica sul modello di scienza sociale proposto da Durkheim, riguardante in particolare le teorie formulate da quest’ultimo a proposito dei tipi di morfologia sociale e del ruolo di integrazione sociale svolto dalle credenze e dai rituali religiosi nelle “società …