Skip to content
Login Register

#dispersal

2 public questions tagged with this topic.

Population Ecology

In a metapopulation, subpopulations are interconnected through:

“Dispersal of individuals” for in a metapopulation, subpopulations are interconnected through. This relationship follows from the ecological mechanism represented by the terms in the item, not merely from an association between their names. Population ecology links individual births, deaths, immigration, and emigration to changes in abundance. Per-capita rates determine the direction of change, while density dependence creates feedback when crowding alters survival or reproduction. The remaining alternatives—“Genetic drift”, “Resource partitioning”, “Competitive exclusion”—refer to different states, processes, or scales and therefore do not express the same causal relationship. Interpretation must distinguish absolute population change from a per-capita rate and must state the time interval and population boundary. Age structure, dispersal, environmental variation, and delayed responses can all make observed trajectories depart from a simple model. Linking the wording to measurable consequences for fitness, abundance, or flux gives the conclusion its scientific meaning and prevents a purely mnemonic interpretation.

Ref: Campbell Biology, Urry et al., 12th Ed., Unit 8 Ecology

View Details
Population Ecology

Fragmented populations linked through dispersal constitute:

“A metapopulation” for fragmented populations linked through dispersal constitute. This relationship follows from the ecological mechanism represented by the terms in the item, not merely from an association between their names. Interpretation must distinguish absolute population change from a per-capita rate and must state the time interval and population boundary. Age structure, dispersal, environmental variation, and delayed responses can all make observed trajectories depart from a simple model. The remaining alternatives—“A deme”, “A single large population”, “An isolated group”—refer to different states, processes, or scales and therefore do not express the same causal relationship. Mechanistic support comes from showing how resource limitation, enemies, mate availability, or physiological stress changes demographic performance. A descriptive association alone does not establish regulation or causation. This distinction matters because similar surface patterns can arise through different mechanisms, whereas ecological prediction depends on identifying the mechanism that actually changes rates. The cited framing is therefore most useful when treated as a conditional biological claim, with assumptions about scale and environmental context kept explicit.

Ref: Campbell Biology, Urry et al., 12th Ed., Unit 8 Ecology

View Details