Search results for "ympäristö"
showing 10 items of 1346 documents
Global urban environmental change drives adaptation in white clover
2022
Made available in DSpace on 2022-04-28T19:52:06Z (GMT). No. of bitstreams: 0 Previous issue date: 2022-03-18 Urbanization transforms environments in ways that alter biological evolution. We examined whether urban environmental change drives parallel evolution by sampling 110,019 white clover plants from 6169 populations in 160 cities globally. Plants were assayed for a Mendelian antiherbivore defense that also affects tolerance to abiotic stressors. Urban-rural gradients were associated with the evolution of clines in defense in 47% of cities throughout the world. Variation in the strength of clines was explained by environmental changes in drought stress and vegetation cover that varied am…
Tadpole Responses to Environments With Limited Visibility: What We (Don’t) Know and Perspectives for a Sharper Future
2022
Amphibian larvae typically inhabit relatively shallow freshwater environments, and within these boundaries there is considerable diversity in the structure of the habitats exploited by different species. This diversity in habitat structure is usually taken into account in relation to aspects such as locomotion and feeding, and plays a fundamental role in the classification of tadpoles into ecomorphological guilds. However, its impact in shaping the sensory worlds of different species is rarely addressed, including the optical qualities of each of these types of water bodies and the challenges and limitations that they impose on the repertoire of visual abilities available for a typical vert…
Kaupungista maalle : miten lapset kokevat maallemuuton
2005
Biological adaptation in light of the Lewontin–Williams (a)symmetry
2022
Neo-Darwinism characterises biological adaptation as a one-sided process, in which organisms adapt to their environment but not vice versa. This asymmetric relationship – here called Williams’ asymmetry – is called into question by Niche Construction Theory, which emphasises that organisms and their environments often mutually affect each other. Here we clarify that Williams’ asymmetry is specifically concerned with (quasi-) directed modifications towards phenotypes that increase individual fitness. This directedness – which drives the adaptive fit between organism and environment – entails far more than the mere presence of cause-effect relationships. We argue that difficulties with invoki…
The evolution of temperature tolerance and invasiveness in a fluctuating thermal environment
2016
The consequences of the climate change on species are still uncertain, despite of intensive research. Currently, rising temperature is not the only concern, since the climate change scenarios also predict increases in the amount of disturbances, such as storms, floods, and thermal fluctuations. Disturbances have also been shown to affect species’ evolution, for example by selecting for traits that are advantageous in fluctuating environments but are also facilitating invasiveness. In this thesis, I study the consequences of evolving in a fluctuating thermal environment by utilizing bacterial microcosms. First I tested the effects of fluctuating vs. constant temperature on the evolution of t…
Intergenerational fitness effects of the early life environment in a wild rodent
2019
The early life environment can have profound, long‐lasting effects on an individual's fitness. For example, early life quality might (a) positively associate with fitness (a silver spoon effect), (b) stimulate a predictive adaptive response (by adjusting the phenotype to the quality of the environment to maximize fitness) or (c) be obscured by subsequent plasticity. Potentially, the effects of the early life environment can persist beyond one generation, though the intergenerational plasticity on fitness traits of a subsequent generation is unclear. To study both intra‐ and intergenerational effects of the early life environment, we exposed a first generation of bank voles to two early life…
Early life of fathers affects offspring fitness in a wild rodent
2019
Intergenerational fitness effects on offspring due to the early life of the parent are well studied from the standpoint of the maternal environment, but intergenerational effects owing to the paternal early life environment are often overlooked. Nonetheless, recent laboratory studies in mammals and ecologically relevant studies in invertebrates predict that paternal effects can have a major impact on the offspring's phenotype. These non‐genetic, environment‐dependent paternal effects provide a mechanism for fathers to transmit environmental information to their offspring, and could allow rapid adaptation. We used the bank vole Myodes glareolus, a wild rodent species with no paternal care, t…
The role of adolescents' peer groups in the school context
2008
Nuoruusvuosina ikätovereiden merkitys kasvaa ja ikätoverisuhteet muuttuvat aikaisempaa läheisemmiksi. Nuorilla on erityinen huoli siitä, mitä muut ihmiset itsestä ajattelevat. He alkavat myös yhä enemmän ajatella tulevaisuuttaan, esimerkiksi koulutustaan ja ammatin valintaa.Noona Kiuru tutki toveriryhmien merkitystä nuorten koulutussuunnitelmissa ja koulutuspoluissa sekä koulusopeutumisessa siirtymävaiheessa toisen asteen koulutukseen.- Toveriryhmillä on suuri merkitys nuorten koulutussuunnitelmissa ja koulusopeutumisessa. Samaan toveriryhmään kuuluvat nuoret muistuttavat toisiaan useiden asioiden kuten koulumenestyksen, koulutussuunnitelmien, koulutuspolkujen, sosiaalisen taustan ja koulus…