Molecular Phylogeny Lab Report

Phylogeny of Ungulates

Intro to Bio

Purpose:

The purpose of this lab is to examine the morphological and molecular characteristics in the horse, pig, cow, deer, sheep, goat, pronghorn, and human. Based on the observable similarities between ungulates, it is probable that the goat and sheep are the most closely related. We collected the morphological data about dentition, digestive systems, headgear structures, and foot morphology; also the molecular data from the LDH isozyme patterns and cytochrome b sequence information from Geneious. From these exercises, we summarized that cow, sheep, and goat are the most closely related; horse and pig are less closely related.

Results:

Based on dentition, most artiodactyls had hypsodont (high-crowned tooth) and, thus, able to withstand the wear from eating a silica-rich herbivorous diet (Table 1). They include cow, goat, sheep, deer and pronghorn. They have evolved selenodont cheek teeth with crescent-shaped cusps. However, they lacked incisors and canines in their upper jaws, thus, their mouths are used for eating, not for display or aggression. By contrast, omnivorous artiodactyls like the pig have brachydont (low-crowned tooth) cheek teeth with rounded bunodont cusps for rolling and crushing a variety of foods. Perissodactyls have strong jaws that include an upper and lower set of incisors for biting abrasive grasses and a back set of molars for chewing. An example of perissodactyl would be the horse.

Table 1: Summary of ungulate morphological data obtained from dentition analysis.

| Upper Incisors / Canines (Y/N) | Diastema (Y/N) | Type of Cusp | Crown Height | Order (perisso- or artiodactyl) |

Horse | Y | Y | Lophodont | Hypsodont | Perissodactyl |

Pig | Y | Y | Bunodont | Brachydont | Artiodactyl |

Peccary | Y | Y | Bunodont | Brachydont | Artiodactyl |

Cow | N | Y | Selenodont | Hypsodont | Artiodactyl |

Deer | N | Y | Selenodont | Hypsodont | Artiodactyl |

Sheep | N | Y | Selenodont |...