Question

South African plant species Senecio pterophorus (Asteraceae) was introduced into Australia 70-100 years ago) and Europe 30 years ago). Insect seed predation (measured as the proportion of damaged seed heads) was evaluated across the native and invaded ranges. In South Africa 25% of the seed heads of sampled plants were damaged, in Australia 15 % of seed heads were damaged, and in Europe 0.2% of seed heads were damaged. The insect communities feeding on S. pterophorus in Australia and Europe differed from each other and from those found in South Africa Which hypothesis most likely explains the pattern of seed predation observed in South Africa, Australia, and Europe? Australian Seed Predation Hypothesis Evolution of increased Competitive Ability Hypothesis Darwin's Naturalization Hypothesis O Enemy Release Hypothesis Hybridization Hypothesis

Answer 1

Answer – Option D – Enemy release hypothesis.

The enemy release hypothesis is most often applied to invasive plants, but there is evidence for its usefulness in other systems also. This hypothesis assume that seed predation suppress plant population growth, these seed predator attack on native plants more than immigrating non-native species, and non-native plants are able to leverage this advantage into more rapid population growth. As in the case of question where South African plant in South Africa were more damaged than in Australia and Europe with non-native plant.