Question

Populations that are clearly isolated geographically and/or socially from other population groups are known as __________ isolates.
 

• A. Breeding
• B. Ostracized
• C. Geographical
• D. Reproductive

Hint:

Think about the consequences of isolation. Both geographic and social barriers lead to a population that primarily breeds within itself. Therefore, "breeding isolate" is the most fitting and comprehensive technical term.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
In population genetics, an isolate is a population with limited or no gene flow with other populations. This isolation can be caused by geographical barriers (e.g., mountains, oceans) or social/cultural factors (e.g., rules of endogamy based on religion, caste, or language). The question asks for the best term to describe such a group.
Step 2: Detailed Explanation:
- Breeding isolate: This is a population within which mating is largely confined to members of the group. This confinement can be due to either geographical or social barriers. The consequence of this isolation is the formation of a distinct breeding population. This term accurately encompasses both conditions mentioned in the question.
- Ostracized isolate: "Ostracized" is a social term meaning shunned or excluded. While an ostracized group might become a social isolate, it is not a standard scientific term in population genetics.
- Geographical isolate: This term only refers to populations isolated by physical barriers, which is only one part of the question's definition ("geographically and/or socially").
- Reproductive isolate: This term typically refers to a more extreme form of isolation where populations have evolved to a point where they can no longer interbreed to produce fertile offspring (i.e., they are different species). The question implies reduced gene flow, not necessarily a complete biological barrier to reproduction.
Step 3: Final Answer:
The term "breeding isolate" best describes a population that is isolated either geographically or socially, as it focuses on the outcome of that isolation: the creation of a distinct mating group.