List of top Behavioural Ecology Questions asked in GATE Ecology and Evolution

A phylogenetic tree for the evolution of two pigmentation traits in species of fish is shown for clades X, Y, and Z. Genes A and/or B, if mutated, can cause dark pigmentation in the body.
\includegraphics[width=0.5\linewidth]{57a.png}
Which one or more of the following statements is/are correct?

Grey langurs found in the southern Western Ghats (SWG) and grey langurs in Sri Lanka (SL) look very similar. Nilgiri langurs (found in SWG) and purple faced langurs (found in SL) also look similar. If allopatry played a role in the early diversification of this group (at point X in the tree), which one of the phylogenetic trees is most likely to be correct?
\includegraphics[width=0.5\linewidth]{52a.png}

Males of the swordtail fish \textit{Xiphophorus helleri possess long tails, while those of \textit{X. maculatus} do not. Females of \textit{X. helleri} prefer males with longer tails. Interestingly, experimental studies show that females of \textit{X. maculatus} prefer \textit{X. maculatus} males with attached artificial long tails over those without.} If the long-tailed \textit{Xiphophorus species evolved from ancestors that lacked a long tail, which one of the following processes best explains the evolution of the observed preference among \textit{X. maculatus} females?}

The figure shows the time-series of atmospheric CO\(_2\) concentration on Earth (graph not-to-scale).
\includegraphics[width=0.5\linewidth]{24.png}
Which one of the factors given is the primary reason for the sudden increase in atmospheric CO\(_2\) concentration after 1950?

Which one of the following theories is supported by the distribution patterns of extinct flora such as \textit{Glossopteris across South America, Africa, and Australia, and extant marsupial mammals across South America and Australia?}