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

En los microbios, tiempos de generación cortos y a menudo grandes tamaños poblacionales pueden favorecer una evolución rápida. Evolucionan a través de procesos como la transferencia horizontal de genes, mutaciones, recombinaciones y deriva genética.La transferencia horizontal de genes mediante procesos como la conjugación permite que los genes se muevan entre diferentes cepas o especies.Este flujo génico introduce rasgos novedosos, como la resistencia a los antibióticos, que pueden propagarse rápidamente en poblaciones microbianas.La variación genética, a menudo causada por mutaciones aleatorias, puede permitir adaptaciones beneficiosas, como tolerar altas temperaturas o niveles extremos de pH.Los eventos de recombinación, como la integración de ADN externo en el genoma bacteriano, pueden producir nuevas combinaciones de alelos.Finalmente, deriva genética se refiere a los cambios aleatorios en las frecuencias alelares a lo largo de las generaciones, especialmente cuando las poblaciones son pequeñas o reducidas debido a un cuello de botella.Las variaciones genéticas introducidas por estos procesos pueden ser neutrales, perjudiciales o beneficiosas para el microbio. Con el tiempo, la selección natural hace que los rasgos beneficiosos sean más comunes, impulsando cambios evolutivos.

procesos evolutivos en microbios

La evolución microbiana ocurre rápidamente debido a tiempos de generación cortos y a una variedad de procesos genéticos, incluyendo la transferencia horizontal de genes, mutaciones, recombinaciones y deriva genética. Estos mecanismos, en conjunto, permiten a los microbios adaptarse rápidamente a los entornos cambiantes.La transferencia horizontal de genes (HGT) permite que los genes se muevan entre diferentes especies y ocurre a través de tres mecanismos principales: conjugación, transformación y transducción. La conjugación implica un contacto directo de célula a célula para el intercambio de ADN, mientras que la transformación permite la captación de ADN libre del entorno y la transducción implica la transferencia de ADN mediada por bacteriófagos. La HGT puede introducir rasgos novedosos —como resistencia a los rayos ultravioleta (UV) o a los antibióticos— que pueden propagarse rápidamente por poblaciones microbianas.Las mutaciones introducen variación genética al alterar las secuencias de ADN. Aunque muchas mutaciones son neutrales o dañinas, algunas confieren rasgos beneficiosos que mejoran la supervivencia bajo estrés ambiental, como la exposición a toxinas. Estas mutaciones ventajosas pueden proliferar rápidamente en las poblaciones mediante selección natural.La recombinación, incluyendo eventos como la integración del ADN de fagos en genomas bacterianos, remezcla el material genético y crea nuevas combinaciones de genes. Este proceso aumenta la diversidad genética y puede dar lugar a la aparición de nuevos fenotipos con mayor adaptabilidad.En poblaciones microbianas pequeñas, la deriva genética —fluctuaciones aleatorias en las frecuencias aleladas— puede influir significativamente en los resultados evolutivos. Este proceso estocástico puede llevar a la fijación o pérdida de rasgos, independientemente de su valor adaptativo.La selección natural actúa sobre la variación genética producida por estos mecanismos, favoreciendo rasgos que mejoran la supervivencia y la reproducción. Con el tiempo, esto impulsa la acumulación de adaptaciones beneficiosas y moldea la trayectoria evolutiva de las poblaciones microbianas.

Procesos evolutivos en microbios

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

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Education

Educación

JoVE Core

Microbiology

Microbiología

Unit

Unidad

Microbial Evolution

Evolución microbiana

KEY TERMS AND CONCEPTS

TÉRMINOS Y CONCEPTOS CLAVE

Evolutionary Processes in Microbes

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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evolutionary processes in microbes

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...

evolution of new traits in microbes

Microbial Adaptation in Changing Environments

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Reading Microbial Family Trees

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How DNA Defines Microbial Species

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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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