Browsing by Subject "evoluutio"
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(2021)Education research has for decades acknowledged that prior knowledge is a strong predictor of academic success. This idea is largely based on constructivist theory of learning which postulates that all learning occurs by actively building on existing knowledge. When this prior knowledge conflicts with the normative scientific understanding, students are dealing with incompatible knowledge structures, or misconceptions. Misconceptions need to be revised and sometimes even replaced through a learning process called conceptual change. Research shows that the level of prior knowledge can determine students’ academic success and performance. Undergraduate biology students enrol to university with diverse levels of prior knowledge and concepts regarding topics such as photosynthesis, cellular respiration, primary production in ecosystems, and Darwinian evolution. These topics present challenges for learning because of their complexity. At the same time, a robust understanding of them is essential. These topics are at the heart of mitigating and resolving the climate crisis and other global natural threats. This study explored the level of prior knowledge and the nature of misconceptions held by undergraduate biology students at the beginning of their academic degree in fall of 2019, and further sought to describe how their conceptual understanding developed during the first academic year. Students (N = 41) completed a questionnaire consisting of eight open-ended questions that were designed to assess declarative knowledge of facts and meaning, and procedural integration and application of knowledge. This pre-test measurement was conducted in September 2019. In the post-test measurement, the same questionnaire was repeated a year later. The data were analysed with a mixed methods approach where the answers were quantitatively scored as well as qualitatively analysed for misconceptions. The qualitative content analysis of the answers relied both on existing literature and on the content of the answers themselves. Results showed that the students’ prior knowledge was relatively poor in the beginning of their studies. Most students performed well in tasks measuring knowledge of facts and meaning but struggled in tasks measuring integration and application of knowledge. During the first academic year, the students’ understanding generally improved as demonstrated by the improvement in mean scores of the tasks. Misconceptions were robust and pervasive. The most pervasive misconceptions reflected difficulties in understanding emergent properties and processes. Misconceptions related to the process of Darwinian evolution became more prominent in the post-test. Persistent misconceptions became integrated with the new conceptual frameworks that the students acquired during the first academic year. If students held no misconceptions in the post-test, they performed significantly better in both tests than those with misconceptions. During this first academic year learning seemed to be mainly additive as conceptual change turned out to be rare. The need for more encompassing biology teaching at least in the University of Helsinki became evident. Introductory courses should acknowledge the large degree of variation in students’ prior knowledge and assess the most common and serious misconceptions even over course theme disciplines to ensure more equal learning outcomes.
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(2020)Insects (Insecta) are the most species-rich class of organisms on earth. Due to their vast biodiversity, insects are found in almost every environment. However, approximately 90 % of the over 1 000 000 insect species described are terrestrial. The ocean covers over 70 % of the earths surface, but less than 2 000 marine insect species are known. The purpose of this thesis is to give the reader a comprehensive understanding of marine insect biodiversity and what has caused its sparceness in the seas. Such a multi-faceted review of the topic has not previously been written. The first aim of this review is to catalogue all insect taxons containing marine species, and to examine the habitat choices and ecology of these species. For this purpose, marine insect species have been researched using the World Register of Marine Species (WoRMS) and reference literature, as well as reviews and other articles. Based mostly on WoRMS, the number of marine insect species is determined to be 1 318, divided between 10 insect orders. In addition, seven insect orders are noted to include an unknown number of marine species. As well as examining marine insect biodiversity order-by-order, this work considers the littoral and pelagic habitats in which marine insects live, and the adaptations that are required of insects living in these environments. The second aim of this review is to investigate the lack of insects in marine environments as a phenomenon. The groundwork is laid at the beginning of the review with an examination of why and how insects have diversified so successfully. Later on, possible factors to prevent a similarily successful diversification in marine environments are presented, such as issues with osmoregulation and breathing systems, the typical features of insect reproduction and life cycles, and the fact that transitions between physically contrasting habitats are rare. Pertaining to this the evolutionary history of insects, which has produced the aforementioned features impeding radiation to the seas is also explored. Ultimately insect species in the oceans are few, because insects are a terrestrial evolutionary branch of Pancrustacea. Even though marine habits are uncommon among insects, they are not unheard of. Marine species have emerged in several insect clades and these species have adapted to their environment in numerous ways. For the purposes of further analyses and research on the radiation and biodiversity of marine insects, further surveying of the species and their habits and adaptations is recommended. This work will hopefully offer a point of reference for more detailed future studies and reviews of marine insect biodiversity and the factors that have led to the near-exclusion of insects from the seas.
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(2021)Ympäristöön sopeutuminen on laaja käsite, joka pitää sisällään sekä pitkällä aikavälillä tapahtuvan evolutiivisen sopeutumisen että yksilöissä lyhyellä aikavälillä tapahtuvan fenotyypin sopeutumisen. Evolutiivisessa sopeutumisessa keskeisenä mekanismina toimivan luonnonvalinnan on havaittu olevan monille opiskelijoille haastava käsite ymmärtää, ja siihen tiedetään liittyvän paljon virhekäsityksiä. Kuitenkin suomalaisten opiskelijoiden virhekäsityksiä ja ymmärrystä aiheesta on tutkittu vain vähän. Tässä tutkimuksessa selvitettiin suomalaisten peruskoulun yhdeksäsluokkalaisten osaamista liittyen eläinten sopeutumiseen ja evoluution mekanismeihin. Lisäksi tutkimuksessa tarkasteltiin erilaisten tekijöiden, kuten oppikirjasarjan ja oppilaan luontoharrastuneisuuden, yhteyksiä aiheen osaamiseen. Tutkimusaineisto (N=90) kerättiin sähköisen kyselylomakkeen avulla. Tutkimukseen osallistui yhdeksäsluokkalaisia neljästä eri koulusta. Kyselylomake koostui sekä monivalintatehtävistä että avoimista kysymyksistä, ja aineisto analysoitiin kvantitatiivisia sekä kvalitatiivisia menetelmiä käyttäen. Kvantitatiivisessa analyysissä vastaajien kokonais- ja tehtäväkohtaisia pisteitä vertailtiin eri ryhmien, kuten eri sukupuolten ja eri kirjasarjoja käyttäneiden, välillä. Lisäksi tarkasteltiin mm. luontoharrastusten ja biologian arvosanan yhteyksiä kyselyssä menestymiseen. Kvalitatiivisessa analyysissä avoimen tehtävän vastauksista eriteltiin oppilaiden virhekäsityksiä luonnonvalinnasta, ja virhekäsitykset luokiteltiin vakavuuden perusteella eri tasoihin. Vain pieni osa yhdeksäsluokkalaisista menestyi evoluutiota ja sopeutumista koskevassa kyselyssä hyvin ja osasi vastata luonnonvalinnan mekanismeja koskevaan avoimeen kysymykseen tieteellisen käsityksen mukaisesti. Suurella osalla tutkittavista havaittiin vakavan tason virhekäsityksiä luonnonvalinnan mekanismeista. Luonnonvalinnan eri osa-alueista oppilaat ymmärsivät heikoiten populaation muutoksen, muuntelun alkuperän ja lajiutumisen. Fysiologiseen sopeutumiseen liittyvissä tehtävissä oppilaat suoriutuivat hieman paremmin kuin evolutiivista sopeutumista koskevissa tehtävissä. Oppilaan viimeisimmän biologian arvosanan ja kyselyssä menestymisen välillä havaittiin positiivinen riippuvuus. Tulosten perusteella opetussuunnitelman keskeiset, evoluutiota koskevat tavoitteet eivät näytä toteutuvan kuin harvojen oppilaiden kohdalla, ja siten peruskoulun evoluutio-opetusta olisi yhä syytä kehittää. Saatuja tietoja evoluution ymmärtämisen ongelmakohdista ja yleisimmistä virhekäsityksistä voidaan hyödyntää opetuksen kehittämisessä. Jatkossa olisi tärkeää kehittää evoluutio-opetukseen uusia, erilaisia opetusmenetelmiä sekä selvittää niiden toimivuutta tämän haastavan aiheen oppimisessa.
Now showing items 1-3 of 3