A biologist studying a desert ecosystem observes that the population of a lizard species increases following a particularly hot, dry period that causes a snake population to decline. What could the biologist hypothesize about the roles of these two species?
A.The lizard preys on the snake
B.The lizard is a parasite of the snake
C.The snake and lizard use the same limiting resource
D.The snake is a keystone species in the ecosystem
C.The snake and lizard use the same limiting resource
Since the snake preys on the lizard is not on the list
To answer this question, the biologist should make a hypothesis based on the observation that the lizard population increases following a decline in the snake population. Let's examine the different options:
A. The lizard preys on the snake: If the lizard is observed actively hunting and consuming snakes, this could be a viable hypothesis. However, the question does not provide any evidence to suggest this.
B. The lizard is a parasite of the snake: For this hypothesis to be plausible, there would need to be evidence that the lizard depends on the snake for its survival, perhaps by feeding on the snake's blood or utilizing the snake's resources in some way. However, this scenario is not mentioned in the question either.
C. The snake and lizard use the same limiting resource: This hypothesis suggests that both the snake and lizard rely on the same scarce resource in the ecosystem, such as food, shelter, or water. The hot, dry period may have caused a shortage of this limiting resource, leading to a decline in the snake population. Consequently, with fewer snakes, there may be less competition for the resource, allowing the lizard population to increase. This seems like a plausible explanation based on the provided information.
D. The snake is a keystone species in the ecosystem: A keystone species is one that plays a critical role in maintaining the structure and functioning of an ecosystem. While the decline in the snake population implies that it has an impact on the ecosystem, there is no evidence to suggest that it is a keystone species. Therefore, this hypothesis is less likely.
Based on the given information, the most reasonable hypothesis is that the snake and lizard species use the same limiting resource. So, option C is the most appropriate choice.