List of top Ecology and Evolution Questions

Which one or more of the following reasons has/have been invoked to explain high species diversity in the tropics?
The table shows the relative abundance of three potential prey species in the environment and in the diet of a bat predator.
Some lizard species show positive allometry in head width, with larger individuals investing disproportionately more in musculature leading to wider heads. To test for positive allometry in a study population, a researcher measures body size and head width for 100 individuals and fits a straight line to a log-log plot of these two traits. Which one of the following estimated values of the slope indicates support for positive allometry?
A team of ecologists laid 100 plots of 50 m \(\times\) 50 m in a forest and counted the number of individuals of a tree species in each plot. They then calculated the mean and variance of the number of individuals per plot. If trees are randomly distributed, then which one of the following relationships between the variance and mean is expected?
\(\beta\)-diversity quantifies the difference in species composition between two ecological communities. Which one of the following statements is correct about \(\beta\)-diversity?
S1 and S2 are two strains of bacteria. The results of a bacterial growth experiment on these strains measured after 24 hours are shown. Black and white bars represent S1 and S2, respectively.
The Bateman gradient is a popular explanation for why the strength of sexual selection is typically stronger on males than on females. Which one of the following figures is the correct representation of the Bateman gradient? In all figures, the dotted line represents males and the solid line females.
Sparrows use two foraging tactics to obtain food. They either search for grains themselves (Producer tactic P) or follow other individuals and steal grains from them (Scrounger tactic S). The following graphs show how the fitness of each tactic (P : dashed line and S : solid line) varies as a function of the relative frequency of S. Which one of the graphs shows the correct representation of these tactics if they were maintained through negative frequency dependence?
Excess fertilizers used in agriculture commonly end up as runoff and cause phytoplankton blooms in rivers. To figure out whether these blooms were driven by ammonium or phosphate fertilizers, researchers cultured a phytoplankton species in multiple samples of unpolluted river water. The samples were divided equally among three treatments: ammonium fertilizer added, phosphate fertilizer added, and no fertilizer added. They then measured phytoplankton density in each of the samples after a week. Phytoplankton densities (in thousands of cells/ml) are reported in the table shown.
The term “living fossil” applies to which one or more of the following organisms?
A behavioural ecologist records the number of times a kingfisher succeeds in catching fish over multiple five-minute intervals. Which one of the following distributions best describes these data?
Which one or more of the following options represent(s) life history trade-offs?
Which one or more of the following reasons has/have been invoked to explain island gigantism?
Which one or more of the following is/are not an example of a zoonotic disease(s)?
Which one of the following does not help maintain genetic diversity at a given locus?
Which one of the following is potentially explained by the mid-domain effect?
Small islands tend to have fewer species than nearby large islands. Which one or more of the following reasons explain(s) this outcome?
Which one of the following is not an expected impact of global warming?
Which one of the following represents the chemical energy available to herbivores in an ecosystem?
Which one of the following major mass extinctions is the most recent?
Which one of the following sets of characteristics is most likely to cause population extinction via demographic stochasticity?
A gene coding for a particular protein exhibits 2% DNA sequence divergence between humans and chimpanzees. However, protein sequences encoded by them are identical. Which one of the following processes explains this?
A cross between a pure-bred plant with red flowers and a pure-bred plant with white flowers produced F1 generation with pink flowers. If the plants with pink flowers are selfed, what is the proportion of white : pink : red flowers expected in the next generation?
Which one of the following processes is not likely to lead to the stable coexistence of two species at the same trophic level within an ecological community?
Moth caterpillars that mimic bird droppings are an example of which one of the following phenomena?