Search results for "SEM"
showing 10 items of 8949 documents
Evolution of signal diversity: predator-prey interactions and the maintenance of warning colour polymorphism in the wood tiger moth Arctia plantaginis
2017
Aposematic organisms avoid predation by advertising defences with warning signals. The theory of aposematism predicts warning signal uniformity, yet variation in warning coloration is widespread. The chemically defended wood tiger moth Arctia plantaginis shows both geographic variation and local polymorphism in warning coloration. In this thesis, I studied whether predation by local avian predators is driving the evolution of wood tiger moth warning colours. The close relatives of the wood tiger moth designated here to genus Arctia do not show similar colour polymorphism. The wood tiger moth is thus apparently under evolutionary radiation and provides a natural laboratory for observing curr…
The impact of life stage and pigment source on the evolution of novel warning signal traits
2021
Our understanding of how novel warning color traits evolve in natural populations is largely based on studies of reproductive stages and organisms with endogenously produced pigmentation. In these systems, genetic drift is often required for novel alleles to overcome strong purifying selection stemming from frequency-dependent predation and positive assortative mating. Here, we integrate data from field surveys, predation experiments, population genomics, and phenotypic correlations to explain the origin and maintenance of geographic variation in a diet-based larval pigmentation trait in the redheaded pine sawfly (Neodiprion lecontei), a pine-feeding hymenopteran. Although our experiments c…
Diversity in warning coloration: selective paradox or the norm?
2019
Aposematic theory has historically predicted that predators should select for warning signals to converge on a single form, as a result of frequency-dependent learning. However, widespread variation in warning signals is observed across closely related species, populations and, most problematically for evolutionary biologists, among individuals in the same population. Recent research has yielded an increased awareness of this diversity, challenging the paradigm of signal monomorphy in aposematic animals. Here we provide a comprehensive synthesis of these disparate lines of investigation, identifying within them three broad classes of explanation for variation in aposematic warning signals: …
Influence of colour, smell and taste on the survival of the wood tiger moth (Arctia plantaginis) adults during predation event
2021
Saalistajien torjumiseksi saalis voi käyttää erilaisia puolustusmekanismeja, jotka stimuloivat useita eri aisteja (ts. multimodaalista signalointia). Esimerkiksi aposemaattiset eliöt puolustautuvat varoitussignaalin lisäksi sekundaarisella puolustuksella. Tässä tutkimuksessa keskityttiin siihen, kuinka täpläsiilikkään (Arctia plantaginis) väritys (genotyypit WW, Wy ovat valkoisia ja yy keltaisia), haju (metoksipyratsiinista) ja maku (pyrrolitsidiinialkaloidista) toimivat puolustuksena lintusaalistajien hyökkäyksiä vastaan. Linnuille tarjottiin kummankin värisiä eläviä siilikkäitä, joita oli manipuloitu niin, että niillä oli joko hajua, makua tai molempia näistä. Näin pystyttiin tutkimaan ku…
Lapualaisaktivismia punamaakunnassa : työväentalojen sulkemiset ja kunnanvaltuustojen puhdistukset Pohjois-Savossa 1930
2000
Les équivalents de traduction dans 'Tintti Afrikassa' et 'Seitsemän kristallipalloa' par rapport aux albums originaux 'Tintin au Congo' et 'Les sept…
2007
Revegetation through hydroseeding in degraded Mediterranean areas
2012
Hydroseeding is a technique increasingly used to establish vegetation on degraded areas in order to perform environmental protection. The objective of this paper was to evaluate the effectiveness of four different hydroseeding methods on a degraded artificial slope in the southern Mediterranean area determining total vegetation cover, hydroseeding vegetation cover, hydroseeding success index (HSI), natural and hydroseeded vegetation height. The test area does not allow the use of any operating machine for soil and vegetation management, the only applicable technique is therefore hydroseeding. After hydroseeding was applied (December 2010), 21 checks were carried out every 15 days (from Janu…
Regional metacommunities in two coastal systems: spatial structure and drivers of plant assemblages
2014
Aim Biogeographical patterns in metacommunities are still poorly understood, and different processes are expected to occur in different habitats. We analysed the regional plant metacommunities of coastal habitats to test whether (1) the influence of space and climate differs between two habitats differentiated along the seashore–inland gradient, and (2) regional variation in species composition of these habitats can be ascribed to different metacommunity paradigms. Location The entire coast of the Iberian Peninsula, south-western Europe. Methods We collected data on the plant species composition of coastal sites on sand dunes across 3000 km of coastline. The sites were classified into two h…
Ravinnon vaikutuksia valikoituihin verimuuttujiin kansallisen tason miesjalkapalloilijoilla kilpailukaudella
2015
Johdanto. Jalkapalloilijoiden tulee ravitsemuksessaan kiinnittää erityisesti huomiota riittävään energian ja suojaravinteiden saantiin johtuen lajin harjoittelu- ja kilpailuvaatimuksista. Puutteellisella ravitsemuksella sen sijaan voi olla esimerkiksi elimistön immuunipuolustusjärjestelmän toimintaa heikentävä vaikutus ja näin ollen suurentunut riski sairastua infektioihin kauden aikana. Tämän tutkimuksen tarkoituksena oli selvittää mahdollisia muutoksia jalkapalloilijoiden valikoiduissa verimuuttujissa kilpailukauden aikana sekä heidän ravinnonsaantiaan. Menetelmät. Tutkimukseen osallistui 22 jyväskyläläistä miesjalkapalloilijaa iältään 24,9 ± 5,6 vuotta. Tutkimus toteutettiin kilpailukaud…