BIOL 127 Lecture Notes - Lecture 1: Biogeochemical Cycle, Carbon Cycle, Integumentary System
Document Summary
Lecture #1 introduction: ecology: the study of the relationship of organisms with the place where they live. Studies the relationships between communities and their environments. Why study insect ecology: more than half the world"s species are insects, approx. half of them feed on plants, approx. half of them are predaceous, parasitic or necrophagous/saprophagous (feed on dead/decaying matter, taxonimically diverse, variety of food resources. Insects are potential regulators of ecosystems: primary productivity, biogeochemical cycling, carbon flux, community dynamics. What factors contributed to the radiation of the insects: primitively terrestrial, exoskeletal integumentary system, tracheal system: efficient use of atmospheric oxygen, flight. Apterygote ( primitively" flightless) groups are depauperate (lacking in numbers; imperfectly developed: metamorphosis, small size. Insects possess the following ecologically significant characteristics: small size, ectothermic, plasticity, highly mobile (flight, microenvironments are numerous, high reproductive rate and short life span, rapid population growth, metamorphosis - different life stages occupy different niches.
