Fitting and comparing models of phyletic evolution: random walks and beyond

摘要: Abstract For almost 30 years, paleontologists have analyzed evolutionary sequences in terms of simple null models, most commonly random walks. Despite this long history, there has been little discussion how model parameters may be estimated from real paleontological data. In paper, I outline a likelihood-based framework for fitting and comparing models phyletic evolution. Because its usefulness historical importance, focus on general form the walk model. The long-term dynamics depend just two parameters: mean (μstep) variance (σ2step) distribution transitions (or “steps”). value μstep determines directionality sequence, σ2step governs volatility. Simulations show that these can inferred reliably data regardless completely evolving lineage is sampled. addition to suitable modification likelihood function permits consideration...