Learn Biogeography In This Quiz!

Isolated islands have steeper species-area curves than mainland habitats of the same size because isolated islands experience higher rates of species loss as they become smaller. This can be attributed to factors such as limited resources, increased vulnerability to disturbances, and reduced gene flow. As the size of an isolated island decreases, the available habitat shrinks, leading to a higher likelihood of species extinctions. In contrast, mainland habitats generally have larger and more stable populations, allowing for greater species persistence even as the area decreases. Therefore, the statement is true.

The Equilibrium Theory of Island Biogeography states that the number of species on an island is determined by a balance between the rates of extinction and immigration. This theory suggests that as the rate of extinction decreases and the rate of immigration increases, the number of species on the island will increase, and vice versa. Therefore, the statement that the ETIB is a 'dynamic' tradeoff between rates of extinction and immigration is true.

The correct answer is "Offers simple predictions of island species richness based on three very basic observations: isolation, size, turnover" and "Fairly easy to design tests of its prediction". These strengths indicate that ETIB provides straightforward predictions about the number of species on an island by considering only three basic factors: isolation, size, and turnover. Additionally, it is relatively easy to test the accuracy of these predictions, making it a practical and effective tool in studying island biodiversity.

The statement suggests that the major weakness of ETIB (presumably a model or theory) is that it is too oversimplified to accurately represent reality. It implies that there may be other factors that are important and not accounted for in ETIB. Therefore, the answer "True" is correct as it aligns with the given explanation.

The Great Basin is considered a non-equilibrium biota because the mountains in this region were isolated for a significant period of time after the Pleistocene era. This isolation likely led to unique evolutionary processes and adaptations in the species found there. The statement also mentions that small mammals had a steeper species-area curve compared to birds, which suggests that mammals had a higher number of species in a given area. This could be attributed to the fact that mammals have less dispersal ability, meaning they are less likely to move to new areas and establish new populations. Therefore, the given answer of "True" is correct.

The explanation for the given correct answer is that the graphical representations of endemism of insular biotas show a positive correlation between area and isolation from the mainland with the likelihood of endemism. This means that as the area of an island or isolated habitat increases, and as the distance from the mainland increases, there is a higher chance for unique species to evolve and become endemic to that specific location. This is because larger areas and greater isolation provide more opportunities for genetic divergence and speciation to occur, leading to a higher level of endemism.

The statement is true because isolated islands tend to have unique ecosystems and limited interactions with other land masses. This isolation leads to the evolution of distinct species that are found only on those islands. As a result, more isolated islands generally have a higher number of unique species compared to islands that are more connected or closer to mainland areas.

The disharmonic for insular biota refers to the lack of balance or imbalance in the composition of species on an island. This disharmony tends to increase with isolation, meaning that the more isolated an island is, the greater the disharmony in its biota. Therefore, the statement that the disharmonic for insular biota increases with isolation is true.

Diffuse competition refers to the competition between different species that possess different traits, which can potentially indicate which species are likely to compete with each other. This means that species with similar traits are more likely to compete for the same resources, while species with different traits may have less competition. Therefore, the statement that diffuse competition is how different species with different traits might predict which species might be competing with each other is true.

The explanation for the given correct answer is that the meadow vole, being a prey species, prefers to inhabit islands without shrews because shrews are predators that are more commonly found in grassland habitats. Therefore, the meadow voles have a higher density on islands without shrews, which are closer to forest habitats. Conversely, they are almost nonexistent on islands with shrews, which are closer to grassland habitats. This suggests that the presence or absence of shrews influences the distribution and density of meadow voles, supporting the statement that the answer is true.

The explanation for the given answer is that the short-tailed shrew has a high population on islands with voles because voles are a preferred food source for them. However, even on islands without voles, the shrew population is still present because they have dietary alternatives. This means that they can adapt and find other food sources to sustain their population, indicating that niche shifts can occur. Therefore, the statement is true.

Niches refer to the specific roles and positions that organisms occupy within an ecosystem. This statement suggests that niches can change based on the availability of predators and prey. This is true because the presence or absence of predators can influence the behavior and distribution of prey species, which in turn can affect the resources and habitats available to other organisms. Therefore, the availability of predators and prey can cause shifts in the niches of different species within an ecosystem.

The statement is true because on islands, there is often limited space and resources, which can lead to intense competition among species. In such environments, it is advantageous for plants to have seeds with less dispersal traits to prevent them from being carried away to less suitable habitats. This trend of reduced dispersal morphology is a common adaptation seen in many island species.

The island rule suggests that when a species colonizes an island, it tends to evolve into a larger size if it originated from a smaller mainland species, and into a smaller size if it originated from a larger mainland species. This phenomenon is believed to be a result of the different ecological conditions and resource availability on islands compared to the mainland. Therefore, the statement that the island rule states that a smaller mainland species gives rise to a larger island species and a larger mainland species gives rise to a smaller island species is true.

The statement is true because species richness tends to decrease in higher latitudes due to factors such as colder temperatures, shorter growing seasons, and lower overall productivity. These conditions make it more challenging for a wide variety of species to survive and thrive. On the other hand, range size tends to increase in higher latitudes because species have larger areas of suitable habitat available to them. This allows them to occupy larger ranges and have more space to move and adapt to different environmental conditions.

The given statement is true. The road to extinction typically starts with a species being classified as vulnerable, which means it is at risk of becoming endangered. If the threats continue and the population declines further, the species may be classified as endangered. If the decline persists and the species is at a very high risk of extinction, it may be classified as critically endangered. Finally, if the species cannot be found in the wild anymore, it is considered extinct. This progression from vulnerable to endangered to critically endangered to extinct reflects the increasing severity of the threat to the species' survival.

Islands are a topic of interest for several reasons. Firstly, their discrete boundaries and often small size make it possible to study the entire biota present on the island. This allows for a comprehensive understanding of the species and their interactions. Secondly, the presence of many islands allows for replication of studies, which increases the reliability of the findings. Additionally, the simplified community composition on islands, with fewer species and trophic levels, makes it easier to study species interactions and ecological processes. Islands also serve as experimental systems, where unintentional "experiments" or intentional manipulations can be conducted to understand ecological dynamics. Lastly, the limited number of islands makes it feasible to characterize all of them, providing a comprehensive understanding of island ecosystems.

The statement that the nature of immigration is random and nonselective is false. Immigration processes usually involve a selection process where individuals are chosen based on specific criteria such as skills, education, or family ties. This selection process allows countries to control and manage immigration based on their needs and priorities. Therefore, immigration is not random but rather a deliberate and selective process.

Volant (flying) species >> Terrestrial species with regards to immigration

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Other attributes of endangerment include: (1) Large mammals with small ranges (2) Large mammals with small ranges and slow reproduction

The assembly of island biota involves various factors. Competitive exclusion refers to the process where one species outcompetes and excludes another species from a particular habitat, leading to the formation of distinct biota on islands. Diffuse competition occurs when multiple species compete indirectly for resources, influencing the composition of island biota. Assembly rules are principles that determine the patterns of species composition and diversity in an ecosystem. Niche shifts occur when species adapt and occupy different ecological niches, affecting the assembly of island biota. Predator release refers to the absence or reduction of predation pressure on islands, leading to changes in species interactions and the assembly of biota.

The correct answer options all reflect evolutionary trends on islands. Adaptation refers to the process by which species change over time in response to their environment. Speciation occurs when new species arise due to isolation and genetic divergence. Random events, such as natural disasters, can have a significant impact on the evolution of island populations. Loss of flight is a common trend on islands, as flight is often unnecessary and energetically costly. Loss of dispersal morphology in plants refers to the reduction or loss of structures that aid in seed dispersal, as plants on islands may rely on other means of dispersal. Body size changes can occur on islands, with some species becoming larger or smaller depending on the available resources. Gain of flight and gain of dispersal morphology in plants are not evolutionary trends on islands, as they involve the acquisition of traits that are typically not present in island populations.

The given correct answer states that dwarfing is characteristic of species whose mainland source population is comprised of larger animals, while gigantism is characteristic of species whose mainland source population is comprised of smaller mammals. This suggests that when a species originates from a population of larger animals, it tends to become smaller in size over time, while when a species originates from a population of smaller mammals, it tends to become larger in size. This explanation highlights the relationship between mainland source population size and the resulting body size changes in species.

The fields of areography, ecogeography, and macroecology of continental and oceanic biotas involve characterizing the geographic range and explaining geographic variation in characteristics of individuals and populations. This includes studying the evolution, dispersal, and range shift of these biotas.

Bergmann's Rule states that body size increases with latitude. This can be explained by the possible reasons mentioned in the answer choices. Heat conservation is a possible reason because larger bodies have a smaller surface area-to-volume ratio, which helps to conserve heat in colder climates. Heat dissipation is another possible reason because smaller bodies have a larger surface area-to-volume ratio, allowing them to dissipate heat more efficiently in warmer climates. Endurance is a possible reason because larger bodies have a higher mass-to-surface area ratio, which helps them to retain heat and survive in colder environments. Dispersal is also a possible reason because larger bodies have a greater ability to disperse and migrate to new habitats.