• Biological Organisation

    Biological Organisation

    • Biological organisation is the hierarchy of complex biological structures and systems that define life using a reductionistic approach. The traditional hierarchy, as detailed below, extends from atoms to biospheres. The higher levels of this scheme are often referred to as a ecological organisation concept, or as the field, hierarchical ecology.

      Each level in the hierarchy represents an increase in organisational , with each "object" being primarily composed of the previous level's basic unit. The basic principle behind the organisation is the concept of emergence—the properties and functions found at a hierarchical level are not present and irrelevant at the lower levels.

      organisation furthermore is the high degree of order of an organism (in comparison to general objects). This order typically correspond to an interpendence between heterogeneous parts. To an extent, individual organisms of the same species have the same arrangement of the same structures. For example, the typical human has a torso with two legs at the bottom and two arms on the sides and a head on top. It is extremely rare (and usually impossible, due to physiological and biomechanical factors) to find a human that has all of these structures but in a different arrangement.

      The biological organisation of life is a fundamental premise for numerous areas of scientific research, particularly in the medical sciences. Without this necessary degree of organisation, it would be much more difficult—and likely impossible—to apply the study of the effects of various physical and chemical phenomena to diseases and physiology (body function). For example, fields such as cognitive and behavioral neuroscience could not exist if the brain was not composed of specific types of cells, and the basic concepts of pharmacology could not exist if it was not known that a change at the cellular level can affect an entire organism. These applications extend into the ecological levels as well. For example, DDT's direct inseciticidal effect occurs at the subcellular level, but affects higher levels up to and including multiple ecosystems. Theoretically, a change in one atom could change the entire biosphere.

      For particles smaller than atoms see subatomic particles
      A-cellular level
      Pre-cellular level
      Molecule Groups of atoms
      Biomolecular complex Groups of (bio)molecules
      Sub-cellular level Organelle Functional groups of biomolecules, biochemical reactions and interactions
      Cellular level Cell Basic unit of all life and the grouping of organelles
      Super-cellular level
      (Multicellular level)
      Tissue Functional groups of cells
      Organ Functional groups of tissues
      Organ system Functional groups of organs
      Ecological levels Organism The basic living system, a functional grouping of the lower-level components, including at least one cell
      Population Groups of organisms of the same species
      (or biocoenosis)
      Interspecific groups of interacting populations
      Ecosystem Groups of organisms from all biological domains in conjunction with the physical (abiotic) environment
      Biome Continental scale (climatically and geographically contiguous areas with similar climatic conditions) grouping of ecosystems.
      Biosphere or
      All life on Earth or all life plus the physical (abiotic) environment
      For levels larger than the planet, see Earth's location in the Universe

      Parable of the Watchmakers

      There once were two watchmakers, named Hora and Tempus, who made very fine watches. The phones in their workshops rang frequently; new customers were constantly calling them. However, Hora prospered while Tempus became poorer and poorer. In the end, Tempus lost his shop. What was the reason behind this?

      The watches consisted of about 1000 parts each. The watches that Tempus made were designed such that, when he had to put down a partly assembled watch (for instance, to answer the phone), it immediately fell into pieces and had to be reassembled from the basic elements.

      Hora had designed his watches so that he could put together subassemblies of about ten components each. Ten of these subassemblies could be put together to make a larger sub-assembly. Finally, ten of the larger subassemblies constituted the whole watch. Each subassembly could be put down without falling apart.

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    • Biological Organisation