Evolutionary theory predicts that senescence – a decline in reproduction and survival with increasing age - can evolve as a trade-off between the investment in reproduction on one side and in somatic maintenance and repair on the other side. The ecology of a species is crucial here, since it provides the external causes of death that determine the statistical limit to a species’ lifespan. Filamentous fungi are generally believed to be non-senescent, and there are indeed spectacular examples of very old fungal individuals in nature. Yet, for some fungi the growth conditions are ephemeral and therefore senescence is expected to have evolved, like in the coprophilic Podospora anserina, the only well-studied filamentous fungus with intrinsic senescence. Here we hypothesize that rapid senescence is more common in fungi than generally believed and that the phylogenetic distribution of senescence correlates with its ecology. We examined a set of Sordariomycetes for their lifespan and constructed phylogenies based on several nuclear sequences. Part of the strains were from the CBS culture collection, originally isolated from various substrates, some of which ephemeral. In addition we isolated new strains from short-lived substrates. Senescence was observed throughout the phylogeny. Correlation tests support the hypothesis that in the Sordariomycetes senescence is a trait that has arisen as an evolved adaptation to ephemeral substrates, and that it has evolved repeatedly and independently along the phylogeny.,Alignment ITS sequencesFasta (txt) file with all the aligned ITS sequences of all strains from our culture collection and isolated from dung, used in the analysis to detect correlated evolution between substrate and (rapid) senescence.Alignment non-redundant ITS sequencesFasta (txt) file with the aligned non-redundant ITS sequences, used in the analysis to detect correlated evolution between substrate and (rapid) senescence.Character matrix-non-redundant scenarioBinomic character matrix of the strains used in the non-redundant scenario; Character states: Ephemeral substrate: 1=ephemeral substrate, 0= non-ephemeral substrate; Senescence:1=(rapid) senescence, 0= not senescent within 8 weeks of growth (pdf-file).Character matric-non-redundant scenario.pdfCharacter matrix-best scenarioBinomic character matrix of the strains used in the 'best case' scenario; Character states: Ephemeral substrate: 1=ephemeral substrate, 0= non-ephemeral substrate; Senescence:1=(rapid) senescence, 0= not senescent within 8 weeks of growth (pdf-file).Character matrix-final scenarioBinomic character matrix of the strains used in the final scenario; Character states: Ephemeral substrate: 1=ephemeral substrate, 0= non-ephemeral substrate; Senescence:1=(rapid) senescence, 0= not senescent within 8 weeks of growth (pdf-file).Character matrix-worst case scenarioBinomic character matrix of the strains used in the 'worst case' scenario; Character states: Ephemeral substrate: 1=ephemeral substrate, 0= non-ephemeral substrate; Senescence:1=(rapid) senescence, 0= not senescent within 8 weeks of growth (pdf-file).Tree-all Most Parsimonious ITS trees allAll most Parsimonious trees based on the ITS sequences of all strains. In newick format (Mega5; 1000 bootstraps).Tree-all Most Parsimonious trees non-redundantAll most Parsimonious trees based on the ITS sequences of non-redundant strains. In newick format (Mega5; 1000 bootstraps).Tree-Maximum Likelihood ITS non-redundantMaximum Likelihood tree based on the ITS sequences of the non-redundant strains. In newick format (Mega5; 1000 bootstraps).Tree-Maximum Likelihood ITS tree allMaximum Likelihood tree based on the ITS sequences of all strains. In newick format (Mega5; 1000 bootstraps).Tree-Minimum Evolution ITS Tree allMinimum Evolution tree based on the ITS sequences of all strains. In newick format (Mega5; 1000 bootstraps).Tree-Minimum Evolution non-redundantMinimum Evolution tree based on the ITS sequences of the non-redundant strains. In newick format (Mega5; 1000 bootstraps).