Emergence of trait variability through the lens of nitrogen assimilation in .

TitleEmergence of trait variability through the lens of nitrogen assimilation in .
Publication TypeJournal Article
Year of Publication2019
AuthorsBerube, PM, Rasmussen, A, Braakman, R, Stepanauskas, R, Chisholm, SW
Date Published2019 Feb 01

Intraspecific trait variability has important consequences for the function and stability of marine ecosystems. Here we examine variation in the ability to use nitrate across hundreds of genomes to better understand the modes of evolution influencing intraspecific allocation of ecologically important functions. Nitrate assimilation genes are absent in basal lineages but occur at an intermediate frequency that is randomly distributed within recently emerged clades. The distribution of nitrate assimilation genes within clades appears largely governed by vertical inheritance, gene loss, and homologous recombination. By mapping this process onto a model of macroevolution, we propose that niche-constructing adaptive radiations and subsequent niche partitioning set the stage for loss of nitrate assimilation genes from basal lineages as they specialized to lower light levels. Retention of these genes in recently emerged lineages has likely been facilitated by selection as they sequentially partitioned into niches where nitrate assimilation conferred a fitness benefit.

Alternate JournalElife
PubMed ID30706847
Grant ListOCE-1153588 / / National Science Foundation /
DBI-0424599 / / National Science Foundation /
OCE-1335810 / / National Science Foundation /
337262 / / Simons Foundation /
329108 / / Simons Foundation /
GBMF495 / / Gordon and Betty Moore Foundation /
GBMF4511 / / Gordon and Betty Moore Foundation /
509034SCFY17 / / Simons Foundation /