Part Five -The Patterns and Processes of Evolution 463

25. Reconstructing and Using Phylogenies 542

25.1 What Is Phylogeny? 543 All of life is connected through evolutionary history 544 Comparisons among species require an evolutionary perspective 544 25.2 How Are Phylogenetic Trees Constructed? 545 Parsimony provides the simplest explanation for phylogenetic data 546 Phylogenies are reconstructed from many sources of data 547 Mathematical models expand the power of phylogenetic reconstruction 548 The accuracy of phylogenetic methods can be tested 549 Ancestral states can be reconstructed 550 Molecular clocks add a dimension of time 551 25.3 How Do Biologists Use Phylogenetic Trees? 551 Phylogenies help us reconstruct the past 551 Phylogenies allow us to compare and contrast living organisms 552 Biologists use phylogenies to predict the future 553 25.4 How Does Phylogeny Relate to Classification? 554 Phylogeny is the basis for modern biological classification 555 Several codes of biological nomenclature govern the use of scientific names 555