genetic drift: meaning, definition, pronunciation and examples

C2
UK/dʒɪˌnetɪk ˈdrɪft/US/dʒəˌnetɪk ˈdrɪft/

Technical, Academic

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Quick answer

What does “genetic drift” mean?

A mechanism of evolution where allele frequencies in a population change over generations due to random sampling.

Audio

Pronunciation

Definition

Meaning and Definition

A mechanism of evolution where allele frequencies in a population change over generations due to random sampling.

The process by which gene variants (alleles) become more or less common in a population purely by chance, rather than due to natural selection, leading to changes in traits over time. This effect is more pronounced in small populations.

Dialectal Variation

British vs American Usage

Differences

No lexical or spelling differences. The term is standard in international scientific English.

Connotations

Identical technical, neutral connotations.

Frequency

Usage frequency is identical and confined to scientific discourse in both varieties.

Grammar

How to Use “genetic drift” in a Sentence

Genetic drift [VERB: occurs, happens, operates] in small populations.[NOUN: Population size] influences the strength of genetic drift.The [NOUN: change] was due to genetic drift.

Vocabulary

Collocations

strong
randomallelefrequencypopulationevolutionsampling errorfounder effectbottleneck effect
medium
significantneutralobservecontribute tomeasurerate of
weak
strongpowerfulexplainstudymodel

Examples

Examples of “genetic drift” in a Sentence

verb

British English

  • The rare allele drifted to fixation over several centuries.
  • Genetic variation can drift considerably in isolated communities.

American English

  • The allele drifted out of the population entirely.
  • Researchers modeled how traits would drift under different conditions.

adverb

British English

  • The population changed driftily, not adaptively. (Rare, non-standard)
  • N/A

American English

  • N/A
  • N/A

adjective

British English

  • The drift process is neutral with respect to fitness.
  • They studied the drift dynamics in a simulated population.

American English

  • Genetic drift effects are strongest right after a bottleneck.
  • The drift component of evolutionary change was significant.

Usage

Meaning in Context

Business

Not used.

Academic

Primary context. Used in biology, genetics, and anthropology lectures, papers, and textbooks.

Everyday

Virtually never used in everyday conversation.

Technical

The exclusive domain of use. Precise meaning in evolutionary biology and population genetics.

Vocabulary

Synonyms of “genetic drift”

Strong

allele frequency drift

Neutral

random genetic driftSewall Wright effect

Weak

sampling errorstochastic change

Vocabulary

Antonyms of “genetic drift”

natural selectiondirected evolutionadaptive evolution

Watch out

Common Mistakes When Using “genetic drift”

  • Using 'genetic drift' to describe changes caused by natural selection.
  • Confusing it with 'gene flow' (migration of alleles).
  • Misspelling as 'genetic shift'.
  • Assuming it only reduces diversity (it can also increase it locally).

FAQ

Frequently Asked Questions

Genetic drift is one mechanism that can cause evolution (change in allele frequencies). Evolution can also be caused by natural selection, gene flow, and mutation.

It tends to reduce variation within a single population over the long term, but it can increase differences between separate populations (divergence).

Genetic drift is a random, non-adaptive process. Natural selection is a non-random process where traits that improve survival and reproduction become more common.

The effect of random sampling error is stronger in smaller populations. In large populations, random fluctuations in allele frequencies tend to average out.

A mechanism of evolution where allele frequencies in a population change over generations due to random sampling.

Genetic drift is usually technical, academic in register.

Genetic drift: in British English it is pronounced /dʒɪˌnetɪk ˈdrɪft/, and in American English it is pronounced /dʒəˌnetɪk ˈdrɪft/. Tap the audio buttons above to hear it.

Phrases

Idioms & Phrases

  • A victim of drift
  • To drift to fixation
  • Driven by drift

Learning

Memory Aids

Mnemonic

Think of a small boat (small population) drifting randomly on the ocean (over generations), its position (allele frequency) changing by chance, not by steering (selection).

Conceptual Metaphor

EVOLUTION IS A RIVER; GENETIC DRIFT IS RANDOM CURRENTS/EDDIES. / CHANGE IS MOVEMENT; GENETIC DRIFT IS RANDOM DRIFTING.

Practice

Quiz

Fill in the gap
In a very small population, can cause an allele to become completely lost or fixed, even if it is neither harmful nor beneficial.
Multiple Choice

Which scenario best illustrates genetic drift?