Unit 9 Reflection

        This unit was a whirlwind of different taxa, from the simple cell colonies of Porifera to the modern Mammalia. It covered many different kingdoms, phyla, and classes, organized in accordance with Linneas's binomial nomenclature system in different levels of organization.

Levels of organization

        The 3 domains are Bacteria, Archaea, and Eukarya. Bacteria are single-celled prokaryotes with flagella and cell walls made of peptidoglycan; they are somewhat comparable to the non-living viruses, which have capsids with DNA or RNA, and infect by taking control of cell machinery. The mysterious archaea domain are extremophiles and are difficult to compare with other taxa, a domain once thought to be part of Bacteria.
        In the domain Eukarya, some kingdoms include Plantae and Fungi, which have cell walls made of cellulose or chitin and have unique characteristics that help them survive in different environments. Our own kingdom, Animalia, is made up of phyla like Porifera, the sponges, and Cnidaria, the radially symmetrical polyps and medusas. Other phyla show the evolution of the digestive system, from the incomplete guts of Platyhelminthes, to the complete digestive tracts of Mollusca, to the coeloms of Annelida. The most common invertebrates are Arthropoda, which have segmented bodies with appendages, made up of a head, thorax (or cephalothorax), and abdomen). Of course, the phylum Chordata is one of the most advanced, featuring amniotic sacs and eggs, as well as a notochord and other embryonic features. The classes of Chordata go from the earliest fish (Agnatha, Chondrichthyes, Osteichthyes) to the first terrestrial vertebrates (Amphibia, Reptilia). From the dinosaurs evolved the phylum Aves, which had hollow bones, feathers, and fused collarbones to allow for flight. Of course, the phylum Mammalia eventually developed, composed of active endotherms including monotremes, marsupials, and eutherians (like us!).

A circular diagram of the tree of life

        In general, this unit was deeply satisfying to explore, as it covered one of my favorite topics in biology. The web of life is so infinitely complex, and its connections and history open our eyes to how everything, no matter how different, is so intricately linked. As deep as we have delved, I still have a plethora of questions brimming in my mind, from how anatomy and skeletal structures evolved, to the geological shifts that have facilitated the adaptation of these organisms. (learn more about Earth's history in my 20 Time here!) How did complex adaptations like the eye and the wing form? What were the intermediate structures, and what role did they play in the evolution of the taxa that possessed them? What were the key factors in coevolution and symbiosis, and in what cases was it thwarted by some other factors? Hopefully, my future academic endeavors will bring me answers to those questions, and beyond.

        In this unit, we completed the "What on Earth Evolved?" project, each exploring a specific species or group of organisms, in order to introduce various influential organisms in Earth's history. (we explored the history of the Earth in this project) I was given the task of researching stony corals, and I created (and presented) the above presentation. Take a look at the presentation above: corals are fascinating both internally and externally, and I gained quite a bounty of knowledge from this project. Additionally, I was able to practice designing a balanced presentation, and I improved my slide-making skills, juxtaposing images with researched information. I also learned how to embed the presentation into this blog, a skill I might find useful in the future. Ultimately, I was surprised at the ease with which I could convey my ideas to the class, which goes to show how important the practice I did was. In the future, however, I might try to enlarge the font to make the slides easier to read, and also research some additional background information in order to be able to better answer people's questions.
        All in all, this unit provided a very rewarding and eye-opening experience, and I look forward the next (and last) unit of Biology, which should provide a close-up perspective of the human body systems, in contrast with the "wide-lens" taxonomy we have been studying in this past unit.