Gene duplication

Definition

Gene duplication is a molecular process in which a segment of DNA is copied, resulting in two identical or nearly identical copies of a gene within the genome. This phenomenon is crucial for evolutionary processes as it provides raw material for the development of new functions and increased genetic diversity. Gene duplication can lead to functional divergence, where one copy retains the original function while the other may evolve new functions or regulatory mechanisms.

5 Must Know Facts For Your Next Test

1. Gene duplication is thought to be a major driver of evolutionary innovation, as duplicated genes can acquire mutations that allow for new functions.
2. There are various mechanisms for gene duplication, including unequal crossing over during meiosis and replication slippage during DNA replication.
3. Not all gene duplications lead to beneficial outcomes; some can be harmful or lead to gene loss if the duplicate genes accumulate deleterious mutations.
4. Gene duplications are often preserved when they confer an adaptive advantage, such as providing redundancy for essential functions or enabling novel traits.
5. Comparative genomics shows that many gene families in different species arose from ancestral gene duplication events, illustrating the role of these events in genome evolution.

Review Questions

• How does gene duplication contribute to genetic diversity within populations?
  • Gene duplication contributes to genetic diversity by creating multiple copies of genes that can evolve independently over time. This allows for one copy to maintain its original function while the other can acquire mutations that lead to new functions or regulatory roles. As these duplicated genes diverge, they can contribute to the adaptability and evolutionary potential of populations, allowing them to respond to changing environments.
• Discuss the different mechanisms through which gene duplication can occur and their potential evolutionary implications.
  • Gene duplication can occur through several mechanisms such as unequal crossing over during meiosis and replication slippage during DNA replication. Each mechanism may result in different types of duplications, such as tandem duplications or segmental duplications. The evolutionary implications are significant; for example, duplications that happen in critical developmental genes can lead to major phenotypic changes, while those in non-essential genes may provide opportunities for innovation without immediate consequences.
• Evaluate the role of gene duplication in major transitions of evolution, such as the development of complex multicellularity.
  • Gene duplication has played a crucial role in major transitions of evolution by providing the necessary genetic material for developing new functions and complexity. In the case of complex multicellularity, duplications of genes involved in signaling pathways, cell differentiation, and development allowed organisms to evolve sophisticated systems for coordination and communication among cells. This increased complexity is essential for the emergence of specialized tissues and organs, showcasing how gene duplication acts as a catalyst for major evolutionary advancements.

Related terms

Polyploidy: A condition in which an organism has more than two complete sets of chromosomes, often resulting from gene duplication events, and is common in plants.

Homologous genes: Genes that are similar in sequence and function due to shared ancestry, which can arise from gene duplication events.

Neofunctionalization: The process by which one of the duplicated gene copies acquires a new function that was not present in the original gene, contributing to evolutionary innovation.