<p dir="ltr">Spiders (order <i>Araneae</i>) are the most diverse and densely distributed predators in tropical ecosystems, serving critical ecological functions and services. The diversity and abundance of these organisms are highly influenced by environmental conditions. These characteristics can be significantly influenced by changes in habitat quality resulting from fragmentation and alterations to trophic webs.</p><p dir="ltr">Forest habitats serve as reservoirs of biodiversity, facilitating species dispersal and are therefore expected to harbour high biodiversity. While modern urbanisation is transforming natural habitats into cities, it introduces various environmental challenges, such as the urban heat island effect (UHI). These changes result in drastically altered conditions in urban environments, which are expected to impact the diversity and abundance of the spider community. Previous studies conducted in temperate cities indicate that urban thermal patterns shape the distribution of spider species and shift the spider community structures. However, there is limited research on the urban diversity of tropical spiders, and a knowledge gap remains on their adaptation to urban environments.</p><p dir="ltr">In my work, I test the theoretical framework exploring the role of environmental backgrounds in the structure and physiology of spider communities. For this, I contrasted the diversity of spiders in rural and urban areas, testing the hypothesis of the heat island effect as the main driver of differences in spider communities. In addition, I assessed the thermal plasticity of spiders from different habitats and evolutionary histories, evaluating the effects of ecological and evolutionary backgrounds on their physiological potentials.</p>