Frog legs and fish eggs: When scientists compare DNA, there are usually thousands upon thousands—or even millions—of nucleotide bases involved. A computer then scans the sequences and aligns them in a way that provides the best match. In some cases, the computer will add “blank” spaces to improve alignment. Such spaces represent nucleotides that were added or deleted as opposed to changed in one or more lineages. In this level, you’ll get the hang of analyzing DNA by looking at a tiny 4-base snippet. A dash (–) represents either a blank space added to improve alignment or a position that is not important for the analysis you’ve been asked to do. To make things easier, the information from the species compare tab is shown below. However, don’t forget to read the species tabs—they might help you. Question 3 Position 1 2 3 4 Midas cichlid (outgroup) - C C - W. Indian Coelacanth - C T - Western Clawed frog - C T - On your phylogenetic tree, which two species are grouped together? (1 point) Responses Cichlid and frog Cichlid and frog Cichlid and coelacanth Cichlid and coelacanth Frog and coelacanth
