BIO 326 Lecture Notes - Lecture 1: Ventral Nerve Cord, Panarthropoda, Odonata
14 Dec 2017
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Document Summary
Defined by morphological characteristics: 3 body segments (head, thorax, abdomen, 2 pairs of wings (usually) present, 3 pairs of jointed legs, one pair of antennae. The insects are a class (insecta) within the phylum arthropoda, defined by these characteristics. Invertebrate animal: exoskeleton, segmented body, jointed appendages. Over one million described insect species: coleoptera: 350,000, diptera: 150,000, lepidoptera: 150,000, hymenoptera: 115,000, odonata: 6,000. Nobody knows how many undescribed species exist, though taxonomists try to guess. Evolutionary history of insects dates back to carboniferous, coinciding with appearance and diversification of vascular plants. Insects provide a good model for studying basic questions related to biodiversity and how biological communities form. Dominate terrestrial and freshwater habitats; rarely occur in marine systems. One of only 2 phyla to evolve powered flight. Explains taxonomic diversity: good models for basic science. Insects have been used to investigate problems in: neuroscience, exercise physiology, social network dynamics, aging studies at cell/tissue levels, genetics and heritability, full-genome sequencing.
