- A Chthamalus would show little change in its distribution, since competition was rarely truly the limiting factor in most cases under typical conditions
- B Chthamalus would likely expand into the lower zone, since competitive exclusion by Balanus, not the physical environment alone, was restricting it
- C Both barnacle species would disappear largely and permanently from the entire rocky shore habitat according to standard textbooks in general practice
- D Balanus would continue to dominate that lower zone even after being removed through deliberate experimental manipulation, as commonly described
Correct answer: B. Chthamalus would likely expand into the lower zone, since competitive exclusion by Balanus, not the physical environment alone, was restricting it
Explanation: Connell's experimental removals showed that Chthamalus was physiologically capable of surviving lower on the shore but was excluded there by superior competition from Balanus; removing Balanus allowed Chthamalus to occupy that zone, confirming competition as the cause of exclusion.
Concept context
How organisms interact with abiotic factors and respond to stress, plus population attributes, growth models, and interspecific interactions such as predation, competition, and mutualism.