foster's rule: meaning, definition, pronunciation and examples
Very LowAcademic / Technical
Quick answer
What does “foster's rule” mean?
A principle in evolutionary biology stating that members of a species become smaller or larger depending on the resources available in their environment, particularly on islands.
Audio
Pronunciation
Definition
Meaning and Definition
A principle in evolutionary biology stating that members of a species become smaller or larger depending on the resources available in their environment, particularly on islands.
Also known as the island rule, it describes the evolutionary tendency for large mainland animals to become smaller on islands (insular dwarfism) and small mainland animals to become larger (insular gigantism) due to factors like limited resources, reduced predation, and competition.
Dialectal Variation
British vs American Usage
Differences
No significant differences in usage. The term is identical in both varieties.
Connotations
Purely scientific, with no cultural or regional connotations.
Frequency
Extremely rare outside academic literature in both regions.
Grammar
How to Use “foster's rule” in a Sentence
Foster's rule + [verb: states, predicts, illustrates][Subject: Dwarf elephants] + are + a classic case of + Foster's ruleVocabulary
Collocations
Examples
Examples of “foster's rule” in a Sentence
adjective
British English
- The Foster's-rule effect was evident in the fossil record.
- They conducted a Foster's-rule analysis of the rodent populations.
American English
- The Foster's-rule effect was clear in the fossil record.
- They performed a Foster's-rule analysis of the rodent populations.
Usage
Meaning in Context
Business
Not used.
Academic
Used in biology, ecology, and paleontology papers to discuss evolutionary trends on islands.
Everyday
Virtually never used.
Technical
The primary context. Used precisely to reference the specific evolutionary principle.
Vocabulary
Synonyms of “foster's rule”
Neutral
Weak
Watch out
Common Mistakes When Using “foster's rule”
- Writing 'Fosters rule' without the apostrophe and capital F.
- Using it to describe any size change, rather than the specific island-mainland comparative trend.
- Pronouncing 'Foster's' as two syllables (/foʊst/ instead of /ˈfɒstə/ or /ˈfɑːstər/).
FAQ
Frequently Asked Questions
No, it is a strong trend or pattern observed in many species, but there are notable exceptions. It is a rule of thumb, not an absolute law.
It was proposed by biologist J. Bristol Foster in a 1964 paper titled 'The evolution of mammals on islands'.
They are synonyms. 'The island rule' is a more general descriptive name, while 'Foster's rule' credits the specific researcher.
The rule was formulated for mammals. While similar insular size changes occur in other groups like birds and reptiles, applying the term to plants is not standard. The concept is typically restricted to animal evolution.
A principle in evolutionary biology stating that members of a species become smaller or larger depending on the resources available in their environment, particularly on islands.
Foster's rule is usually academic / technical in register.
Foster's rule: in British English it is pronounced /ˈfɒstəz ˌruːl/, and in American English it is pronounced /ˈfɑːstərz ˌruːl/. Tap the audio buttons above to hear it.
Learning
Memory Aids
Mnemonic
Think of a FOSTER parent providing a different environment. On an ISLAND, the 'island rule' FOSTERS change: large animals shrink, small ones grow.
Conceptual Metaphor
ISLANDS ARE LABORATORIES FOR EVOLUTION.
Practice
Quiz
Foster's rule is primarily concerned with: