Highlights•Viral gene amplification allows rapid adaptation, especially for large DNA
viruses.•Amplifications often incur fitness costs for viral replication.•Adaptive mutations can …

In the present article we examine clonality in virus evolution. Most viruses retain an active
recombination machinery as a potential means to initiate new levels of genetic exploration …

Two lines of the bacteriophage T7 were grown to fix mutations indiscriminately, using a
combination of population bottlenecks and mutagenesis. Complete genome sequences …

The remarkable capacity of some viruses to adapt to new hosts and environments is highly
dependent on their ability to generate de novo diversity in a short period of time. Rates of …

Overlapping genes represent an intriguing puzzle, as they encode two proteins whose
ability to evolve is constrained by each other. Overlapping genes can undergo “symmetric …

The masking of deleterious mutations by complementation and the reassortment of virus
segments (virus sex) are expected to increase population genetic diversity among …

Multipartite viruses are formed by a variable number of genomic fragments packed in
independent viral capsids. This fact poses stringent conditions on their transmission mode …

Conflicting selection pressures occurring over the life cycle of an organism constitute serious
challenges to the robustness of replication. Viruses present a credible model system for …

Overlapping genes are commonplace in viruses and play an important role in their function
and evolution. However, aside from studies on specific groups of viruses, relatively little is …

The mechanisms by which DNA viruses adapt and evolve over time include minor
accumulated changes associated with genetic drift–such as single nucleotide changes and …