Sex in the postgenomic era

The possible existence of ancient asexual lineages has long puzzled evolutionary biologists because a lack of recombination should, in theory, cause such lineages to be short lived. Recent research on what was considered to be a classic example of a such a lineage, an all-female polyploid hybrid complex of Ambystoma salamanders, not only refutes previous allegations of sexual abstinence in this complex, but also provides insights into unprecedented flexibility in interactions between genomes residing within individuals. These studies have important implications for understanding mechanisms for maintaining a functional balance between hybridizing genomes. They also demonstrate how combining genomic tools with older techniques can change current views on the rules governing genetic exchange.