title: Long-term evolution is surprisingly predictable in lattice proteins.
abstract: It has long been debated whether natural selection acts primarily upon individual organisms, or whether it also commonly acts upon higher-level entities such as lineages. Two arguments against the effectiveness of long-term selection on lineages have been (i) that long-term evolutionary outcomes will not be sufficiently predictable to support a meaningful long-term fitness and (ii) that short-term selection on organisms will almost always overpower long-term selection. Here, we use a computational model of protein folding and binding called 'lattice proteins'. We quantify the long-term evolutionary success of lineages with two metrics called the k-fitness and k-survivability. We show that long-term outcomes are surprisingly predictable in this model: only a small fraction of the possible outcomes are ever realized in multiple replicates. Furthermore, the long-term fitness of a lineage depends only partly on its short-term fitness; other factors are also important, including the 'evolvability' of a lineage-its capacity to produce adaptive variation. In a system with a distinct short-term and long-term fitness, evolution need not be 'short-sighted': lineages may be selected for their long-term properties, sometimes in opposition to short-term selection. Similar evolutionary basins of attraction have been observed in vivo, suggesting that natural biological lineages will also have a predictive long-term fitness.
authors: Department of Biology, Stanford University, Gilbert Hall, Stanford, CA 94305-5020, USA. mepalmer@charles.stanford.edu
authors: Michael E
authors: ME
authors: Palmer
authors: Arnav
authors: A
authors: Moudgil
authors: Marcus W
authors: MW
authors: Feldman
mesh_terms: D019143:Evolution, Molecular; D014644:Genetic Variation; D008957:Models, Genetic; D017510:Protein Folding; D011506:Proteins / Q000737:chemistry / Q000235:genetics*; D012641:Selection, Genetic / Q000502:physiology*
chemical_list: D011506:Proteins