"On Tuesday, I met with the student to go over animal kingdom evolution, variety, and comparison. We covered all major animal groups of invertebrates and vertebrates. We spent time clarifying how a cladogram shows the relations among organisms. We spoke in more detail about cladograms for chordates and primates. I pointed out that the most simple organism in the family is always located on the left side of a cladogram. Each group of animals to the right in the cladogram gains a new major feature, separating the animals from their common ancestors and forming a new subdivision. For example, in Chordata, minnows accrued jaws and some cranial cartilage, as compared to their ancestors. Sharks got cartilage skeleton all over their body and got fins, as compared to minnows. Bony fish got solid bones instead of cartilage. In addition to this, amphibians developed limbs, lungs, a 3-chambered heart (instead of 2 chambers in fish), learned how to live on land instead of water, etc. We discussed early embryonic development in animals, signified by the formation of blastopore and three embryonic germ layers (ectoderm, mesoderm and endoderm). We spent some time learning the differences between protostomes ("first mouth," the majority of invertebrates) and deuterostomes ("second mouth," Echinodermata and Chordata). We compared different body systems in the earthworm, rat, and frog. We briefly covered evolutionary changes in circulatory (the heart evolving at some point in large complex animals, then increasing its number of chambers from one in invertebrates to four in mammals), respiratory, and excretory systems. In greater detail, we spoke about primates and Hominids. We discussed bipedal locomotion, skeletal changes, cranial transformation, the advantage of the opposable thumb, nails, and binocular vision. The student's analytical skills and organization were superior. We started from rather general discussions followed by answering more focused questions for test preparation. The student did not waste any time; he switched easily to writing answers rather than simply listening, and he asked important questions during discussions. I feel that he gained some understanding of animal evolution and classification. It looked like he navigated through his textbook a little bit easier by the end of our session. I suggested that he use tables to help compare the different animal types or a specific system's evolution. Overall, he did an amazing job learning new concepts."