Question

Based on Schoener and Spiller's studies of spider densities in the Bahamas, what is the correct ranking (from highest to lowest) of the probability of spiders going extinct according to three different conditions: islands on which lizards are absent from the islands, islands on which lizards have been introduced to the islands, and islands on which lizards are present naturally?

Answer 1

The highest probability of spider extinction occurs on islands with introduced lizards, followed by islands with native lizard populations, and the lowest probability on islands where lizards are absent.

Step-by-step explanation:

Based on Schoener and Spiller's studies of spider densities in the Bahamas, the correct ranking of the probability of spiders going extinct from highest to lowest, under three different conditions are as follows:

1. Islands on which lizards have been introduced
2. Islands on which lizards are present naturally
3. Islands on which lizards are absent

Introduced predators, such as lizards, have been known to increase the risk of extinction for local species due to lack of co-evolved defenses of the prey. On islands where lizards are present naturally, the system may be more balanced, with prey species having adaptations to coexist with these predators. Islands without lizards would naturally show the lowest extinction rates for spiders as the primary predatory pressures would be absent.