Complete question:
Both species of garter snakes prey on the California newt. Taricha torso, small amphibian that produces a potent neurotoxin (TTX) in its skin. However, neither species of garter snake is affected by TTX. The resistance to TTX is associated with mutations in the SCN4A gene. which of the following best supports a claim that TTX resistance arose independently in T. atratus and T. sirtalis?
A. The stomach contents in fossils of both species include the remains of food items that contains TTX.
B. Both species of snakes possess the SCN4A gene.
C. The two species of snakes have different genetic mutations in the SCN4A gene.
D. T. atratus and T. sirtalis are sister species that share many of the same morphological features.
Answer:
C. The two species of snakes have different genetic mutations in the SCN4A gene.
Explanation:
These are two different species that feed on the same amphibian species and that developed resistance to TTX. Resistance to the toxic is associated with mutations in the SCN4A gene. So probably both species by separated developed different mutations in the gene that led them to be resistant to the toxin.
Supporting the fact that natural selection is not random, both species might have become resistant to TTX through different mutations in the same gene. Both species are feeding on the California newt that produces neurotoxin in the skin. Animals that feed on this amphibian need to be resistant to the toxin to avoid death and keep preying. TTX might be acting as a modeling pressure that led snakes to develop resistance to the toxin, favoring the same phenotype but independently.
A. The stomach contents in fossils of both species include the remains of food items that contain TTX. → Food items with TTX in the stomachs do not mean that species were resistant to the toxin. And if they were, it does not mean that species developed the resistance independently or not.
B. Both species of snakes possess the SCN4A gene. → The fact that both species have the gene does not mean that they have mutations in the gene
C. The two species of snakes have different genetic mutations in the SCN4A gene. → That both species have different mutations in the same gene means that they evolved independently from each other. They suffered different mutations in the same gene that led them to express the same resistance phenotype.
D. T. atratus and T. sirtalis are sister species that share many of the same morphological features. → Morphological features do not necessarily reflect molecular features. The fact that they are similar sister species does not say anything about the SCN4A gene.
The condition that best supports this experiment is the two species of snakes have different genetic mutations in the gene described above.
Mutations may be defined as sudden, stable, and inheritable changes in the genetic material of an organism.
Both species of snake have different mutations in the same gene means that they evolved independently from each other. They undergo different mutations in the same gene that led them to express the same resistance phenotype.
Therefore, the condition that best supports this experiment is the two species of snakes have different genetic mutations in the gene described above.
To learn more about Mutations, refer to the link:
https://brainly.com/question/17031191
