Question

Which of the following may help to explain why there are no populations in which newts produce so much toxin that they kill all snakes, but there are several populations where snakes are completely unaffected by the toxicity of newts?

1) a change in a single amino acid can result in resistance against the toxin
2) a series of mutations are required to make newts more toxic
3) snakes can learn to avoid newts
4) a and b are correct
5) a, b, and c are correct

Answer 1

In the evolutionary relationship between snakes and newts, factors like genetic mutations conferring resistance, the complexity of evolving increased toxicity, and behavioral adaptations contribute to the observed dynamics. Option 5, encompassing all these aspects, is correct.

Step-by-step explanation:

The question explores the evolutionary dynamics between newts and snakes, focusing on why we don't observe populations of newts that produce enough toxin to kill all snakes, while some snake populations are completely immune to newt toxins. Several factors play a role in this evolutionary arms race:

• A change in a single amino acid can make snakes resistant to the toxins produced by newts.
• Multiple mutations might be required for newts to increase their toxicity, which is a complex process.
• Snakes can learn to avoid newts that are toxic.

The natural selection process works on existing genetic variation; thus, the presence of resistance genes in a population can lead to immunity in predators without necessitating the prey to become more toxic. Option 5, which includes a, b, and c, is correct because it combines the genetic potential for resistance in the predator, the complexities of increasing toxicity in the newt, and the behavioral adaptations of the snake.