Name: how microbes gain new traits
Uploaded: 2026-03-12T13:57:33.000Z
Duration: 1 min 26 s
Channel: JoVE

In microbes, short generation times and often large population sizes can support rapid evolution. They evolve through processes such as horizontal gene transfer, mutation, recombination, and genetic drift.Horizontal gene transfer through processes, like conjugation, allows genes to move between different strains or species.This gene flow introduces novel traits, such as antibiotic resistance, which can quickly spread in microbial populations.Genetic variation, often caused by random mutation, can enable beneficial adaptations, such as tolerating high temperatures or extreme pH levels.Recombination events, such as integration of external DNA into the bacterial genome, can produce new allele combinations.Finally, genetic drift refers to the random shifts in allele frequencies over generations, particularly when populations are small or reduced in numbers due to a bottleneck.The genetic variations introduced by these processes can be neutral, deleterious, or beneficial for the microbe. Over time, natural selection makes the beneficial traits more common, driving evolutionary changes.

evolutionary processes in microbes

Microbial evolution occurs rapidly due to short generation times and a variety of genetic processes, including horizontal gene transfer, mutation, recombination, and genetic drift. These mechanisms collectively enable microbes to adapt swiftly to changing environments.Horizontal gene transfer (HGT) allows genes to move between different species and occurs through three main mechanisms: conjugation, transformation, and transduction. Conjugation involves direct cell-to-cell contact for DNA exchange, while transformation enables uptake of free DNA from the environment, and transduction involves DNA transfer mediated by bacteriophages. HGT can introduce novel traits&#8212;such as ultraviolet (UV) resistance or antibiotic resistance&#8212;which may rapidly spread through microbial populations.Mutations introduce genetic variation by altering DNA sequences. Although many mutations are neutral or harmful, some confer beneficial traits that enhance survival under environmental stress, such as exposure to toxins. These advantageous mutations can rapidly proliferate in populations through natural selection.Recombination, including events like phage DNA integration into bacterial genomes, shuffles genetic material and creates new gene combinations. This process increases genetic diversity and can lead to the emergence of new phenotypes with enhanced adaptability.In small microbial populations, genetic drift&#8212;random fluctuations in allele frequencies&#8212;can significantly impact evolutionary outcomes. This stochastic process can lead to the fixation or loss of traits, irrespective of their adaptive value.Natural selection acts on the genetic variation produced by these mechanisms, favoring traits that improve survival and reproduction. Over time, this drives the accumulation of beneficial adaptations and shapes the evolutionary trajectory of microbial populations.

Evolutionary Processes in Microbes

Microbial evolution occurs rapidly due to short generation times and a variety of genetic processes, including horizontal gene transfer, mutation, ...

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JoVE Core

Microbiology

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Microbial Evolution

KEY TERMS AND CONCEPTS

how microbes gain new traits

Microbes gain new traits through fast genetic change. Their short generation times help evolution happen quickly. Mutation, horizontal gene transfer, recombination, and genetic drift all contribute to this process. Together, these mechanisms help microbial populations adjust to changing environments.

Horizontal gene transfer, or HGT, moves genes between different species. It happens in three main ways: conjugation, transformation, and transduction. Conjugation requires direct cell-to-cell contact for DNA exchange. Transformation is the uptake of free DNA from the environment, and transduction is DNA transfer by bacteriophages.

HGT can spread useful traits through a population. These traits can include ultraviolet, or UV, resistance and antibiotic resistance. Mutation also adds genetic variation by changing DNA sequences. Many mutations are neutral or harmful, but some improve survival under stress, such as exposure to toxins. Natural selection can then increase those helpful mutations in the population.

Recombination reshuffles genetic material and creates new gene combinations. One example is the integration of phage DNA into a bacterial genome. This increases genetic diversity and can produce new phenotypes, or observable traits, with better adaptability. In small microbial populations, genetic drift can also shape evolution. Genetic drift is a random change in allele frequency, and it can lead to the fixation or loss of traits even when they do not affect fitness.

Natural selection acts on the variation created by these processes. It favors traits that improve survival and reproduction. Over time, beneficial adaptations build up in microbial populations. This pattern helps shape the evolutionary path of microbes.

How Microbes Gain New Traits

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Microbes gain new traits through fast genetic change. Their short generation times help evolution happen quickly. Mutation, horizontal gene transfer, recombination, and genetic drift all contribute to this process. Together, these mechanisms help microbial populations adjust to changing environments. Horizontal gene transfer, or HGT, moves genes between different species. It happens in three main ways: conjugation, transformation, and transduction. Conjugation requires direct cell-to-cell...

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key terms and concepts

Explore how microbes gain new traits through mutation, horizontal gene transfer, recombination, genetic drift, and natural selection in changing environments.

How Microbes Gain New Traits | JoVE K12

JoVE Core Microbiology provides an engaging introduction to the microbial world and its influence on health, industry, and the environment. This comprehensive collection covers key concepts such as microbial structure, metabolism, genetics, and ecology. It introduces essential laboratory techniques and microscopy methods through visually engaging animations. Corresponding scientist-in-action videos bridge classroom concepts with real-world research and applications.

microbiology

How Microbes Gain New Traits

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