biodiversity and evolution

• biodiversity - refers to every little thing, including plants, bacteria, animals and humans
• evolution - the process by which species adopt over time in response to their environment
• fossil records - traces of organism that lived in the past and were preserved by natural process or catastrophic event
• geologic time scale - era is the largest region of geologic time scale, namely precambrian, paleozoic, mesozoic, and cenozoic
• homologous - May perform different functions in the species living in the different environment, or it may have the same origin but different functions.
• analogous - Structures of unrelated species having similar functions but different origins
• embryonic development - an embryo is an early stage of development in organisms. includes stages such as blastula, gastrula, and organogenesis. The embryo of fishes, salamanders, lizards, birds, cats, and humans are similar during the first stage of their embryonic development; and have several homologous structures that are not present when the organisms are adults.
• lamarckian theories

  • theory of need
  • theories of use and disuse
  • theories of acquired characteristics
• theory of need - state that organisms change in response to their environment
• theory of use and disuse - organs not in use will disappear while organs in use will develop
• Acquired characteristics - were believed to be inherited by offsprings and propagated by the next generation
• darwinian theory


  theory of natural selection - the idea that evolution is driven by natural selection and that the survival of the fittest is the driving force