Chapter 2- Biodiversity and Classification

• Biology


  The study of living things
• All living things interact with other living and non-living things on our planet
• Biodiversity


  The great variety of life that exists in our biosphere
• Why classify organisms


  • Way of organising information
  • Allows biologist to analyse information about organisms
  • Allows biologists to communicate with one another
  • Invasive species can be identified more easily and accurately
• Taxonomic levels (taxa)


  • Domain
  • Kingdom
  • Phylum
  • Class
  • Order
  • Family
  • Genus
  • Species
• Binomial system for naming species


  • Genus name has first letter capitalised
  • Species name not capitalised
  • When hand written, the name is underlined e.g. Homo sapiens
  • When in print, the name is in italics e.g. Homo sapiens
• Characteristics used to classify organisms

  • Physical (morphological)
  • Methods of reproduction
  • Molecular sequences
• diversity of ecosystems 


  all components if ecosystems are tightly linked by the cycling of nutrients and raw materials within it

  materials include carbon dioxide, oxygen, water, nitrogen, phosphorus

  living organisms also linked by transfer if energy through system
• energy is transformed from 


  light to chemical energy in food molecules (sugars) through photosynthesis

  then transformed between organisms via tightly linked food webs
• biodiversity hotspot 


  relatively small area with numerous native species and a large amount of endangered and threatened species

  • must contain 1500 species of vascular plants found nowhere else on earth
  • must have lost 70% of primary native vegetation
• levels of biodiversity 


  species

  ecosystem,

  genetic diversity
• species 


  group of organisms that is capable of interbreeding under natural circumstances to produce fertile offspring
• ecosystem


  biotic and abiotic factors in an area and their interactions
• genetic diversity 


  all different forms of genes in a population adds to genetic diversity

  higher number of different forms of a genes in one species constitutes a higher genetic diversity for that species
• biological species concept 


  individuals within a species are reproductively isolated from individuals not belonging to that species
• biological species concept has important link to 


  process of evolution

  suggests that when population of individuals become unable to interbreed, evolution of a new species can occur
• limitations of biological species model 


  not possible to apply to fossils of extinct organisms, as it is impossible to know which individuals could interbreed

  cannot be applied to increase understanding of how our own species evolved
• hybrid organisms 


  non-viable infertile offspring

  resulted from mating two individuals from different species

  carries mismatched chromosomes of both species making it difficult to classify
• morphological species concept 


  characterises species by its form, used to examine and classify fossils
• phylogenetic species concept 


  identifies a species as being the smallest group of organisms who can trace their origins to a single common ancestor
• phylogenetic tree


  family tree of species that is based on their ancestry

  genetic techniques are used this concept on living organisms
• ecosystem concept 


  tool for understanding the complexity of life

  problem that is is difficult to determine dividing line between one ecosystem and another as all life is connected through the
• material do 


  cross boundaries

  separating on ecosystem from another
• different ecosystems provide 


  specialised habitat for different set of species adapted to their unique combination of biotic and abiotic factors

  largest scale of biological diversity important in maintaining species and genetic diversity
• genetic diversity 


  populations with higher genetic variety are more resilient, can better understand sudden changes to their environment

  populations that occupy different habitats and isolate from one another more likely to have different genetic composition
• smaller populations have 


  lower range of genetic population

  making them more prone to disease and less resilient to changed in environment
• biodiversity of Australia 


  Australian flora and fauna stand apart from the rest of the world

  different from those found anywhere else on Earth
• Australia diversity 


  1mil species of plants, animals, microorganisms

  representing 7% of world total, mega diverse country, possessing diverse ecosystems
• Australia has more species of 


  higher plants, more reptile species, endemic species that occur no where else in earth

  Australia biodiversity is large, unique and globally significant
• measures of biodiversity


  used to make comparisons across locations and at different times

  measuring along spatial and temporal scales reveal biodiversity patterns
• spacial scales 


  space being occupied

  understand the extent (size of an area) and distribution of all the individuals in a species
• distribution can be 


  observed in patterns

  common patterns include random (cacti in desert), clumped (gang of meerkats) and uniform (trees in forest)
• to determine distribution patterns 


  spatial studies happen, meaning locations of individuals are studied over time
• temporal scales 


  refer to time

  provide details about diversity in a certain area over a certain time period
• temporal scales measured 


  over time frames including geological period (prehistoric to modern day), to seasons, to generations
• use of temporal pattern to 


  monitor population

  if changes in population occur, scientists look for casual factors such as changes in weather patterns from climate change
• recording changes in populations over geological time can 


  estimate extinction rates

  studying patterns of biodiversity over time help scientists plan conservation strategies
• classification 


  features that can be used to describe an organism

  based on the idea that members of the same group share the same characteristics that is not present in other groups
• why classify organisms 


  way of organising information

  allows biologists to analyse information about organisms

  allows biologists to communicate with one another

  invasive species can be identified more easily and accurately
• way of organising information 


  allows us to see patterns and trends

  better understand relationships between organisms

  diversity of life is enormous, so classifying organises it