lichenization

As a result, lichenization has been viewed as a highly successful nutritional strategy.

Lichenization is an ancient nutritional strategy for fungi.

However, Lutzoni et al. (2000) indicate that lichenization probably evolved earlier and was followed by multiple independent losses.

The Dictyonema fungus is a basidiomycete, so it discovered lichenization independently from the ascomycete lichens.

Recent (2009) studies suggest that the ancestral ecological state of the Ascomycota was saprobism, and that independent lichenization events have occurred multiple times.

In 1995, Gargas and colleagues proposed that there were at least five independent origins of lichenization; three in the basidiomycetes and at least two in the Ascomycetes.

The evolutionary adaptation from an aquatic to a terrestrial lifestyle necessitated a diversification of ecological strategies for obtaining nutrients, including parasitism, saprobism, and the development of mutualistic relationships such as mycorrhiza and lichenization.

Interestingly, molecular data indicates that lichenization has evolved independently at least twice, and perhaps three times, within these four genera, which suggests that for some reason the fungi in Hygrophoraceae are predisposed to evolve into lichens.

While the new study suggests at least five separate origins for lichens over the eons of evolution, researchers say it is by no means the final count and biologists' understanding of the history of lichenization is very likely to continue to evolve as more data come in.