1. Marked with or having the form of a network; e.g. a reticulate leaf is one with a network of veins.

2. A form of evolution in which DNA from unrelated organisms is combined to form a new and distinct line of organisms. There are two principal mechanisms. In hybridization—which occurs naturally in many plants as well as some fish, amphibians, and invertebrates—usually individuals of two different species mate to form a genetically new species, or to re-form an ancestral lineage. The other is lateral gene transfer, which is common in bacteria and introduces new traits to existing strains or species. Reticulate evolution is typically represented in phylogenetic trees by a union, instead of a separation, of two branches—a depiction called a reticulation.