Living Systems from the Biological Perspective

INTRODUCTION TO LIVING SYSTEMS

Systems

  • Systems are interconnected set of elements that are coherently organized to perform a specific function/purpose
  • Are Coherently Organized
    • Its elements are unified and working together and are able to perform their function and purpose
  • Ex: Organ systems
    • Elements → several organs that work together to perform each of their functions
    • Digestive system - organs that function for digestion of food and absorption of nutrients
    • Circulatory system - transports nutrients + exchange of gasses
    • These systems are embedded in another system and are also embedded in a larger system
    • These organ systems all comprise an organism

Categories of Systems

  • Man-made systems
    • Highly influenced, governed, and controlled by humans
    • Most of the elements of this kind of system are created by humans
    • Ex: Computer Systems
    • Different elements - keyboard, screen, mouse, etc → all work together and they ultimately perform their function
    • Other examples: Telecommunication Systems, Political Systems
    • Without humans, these systems will not be working.
  • Natural Systems
    • Naturally exist in nature
    • Ex: Solar Systems, Molecular Systems, Cellular Systems
    • Cellular System → organelles function and perform together for the survival of the cells
  • Living Systems
    • Majority of its components are living
  • Non-living
    • Majority or all of its components are non-living

LIVING SYSTEMS

  • Living systems should have elements or components
    • These elements and components should all be interacting with each other, having relationships with each other
  • Living systems should also have a function or purpose
    • Usually, the main function of living systems is to survive

Properties of Living Systems

  1. LivingSystemsareorganizedintohierarchieswithspecializationoffunctionsandcomplexityemergingfromloverleveltohigherlevelsoforganization,alsoknownasemergentproperties.Living Systems are organized into hierarchies with specialization of functions and complexity emerging from lover level to higher levels of organization, also known as emergent properties.
  • Ecological Hierarchy: (Atoms → Molecules → Organelles →) Cell → Tissue → Organ → Organ System → Organism → Population → Community → Ecosystem → Landscape → Biome → Ecosphere
  • Each level in the ecological hierarchy exists in physical space and time
  • They are also expected to have unique emergent and collective properties with increasing complexity
    • This is brought about by internal dynamic interactions and exchanges with their environments
  • There are also seven basic functions operating at all levels
    • Energetics → studies energy and matter conversion because living systems need specific types and amounts of matter-energy for stability
    • Behavior and Development
    • Evolution
    • Diversity
    • Integration and Regulation → brings separate components or subsystems together into a unified or stable unity
  1. LivingSystemsareOpenSystemswithPurposesandGoals.Living Systems are Open Systems with Purposes and Goals.
  • Living Systems continue indefinitely within the natural cycles to attain sustainability
  • Photosynthesis makes Living System an Open System
    • During photosynthesis, plants convert energy from sunlight (input) to chemical energy which is used by plants to do work
    • This energy is then transferred to higher trophic levels and eventually lost from the ecosystem as heat (output).
  • However matter makes the living system relatively closed
    • Cycling of matter from plant to animals (through consumption) and the breakdown of these matter back to its elemental form (through decomposition)
    • Matter is only being cycled and recycled
  • Living Systems form a Feedback Mechanism.
    • Purpose → keeping the cycle in control
    • Negative Feedback
    • Decreasing the quality and quantity of resources, which eventually decreases population and alleviates pressure on the environment
    • Positive Feedback
    • Happens when humans depart from this natural cycle.
    • Failure of the human society to continue indefinitely within these natural cycles due to greed or self-interest will eventually lead to the collapse of the human system

Living Systems are Open Systems

  • Living systems are open systems  → Their boundaries are permeable and can be penetrated
  • Living systems are open systems with respect to energy (Photosynthesis)
    • During photosynthesis, plants convert energy from sunlight (input) to chemical energy which is used by plants to do work
    • This energy is then transferred to higher trophic levels and eventually lost from the ecosystem as heat (output).
  • However, matter is already a closed system
    • Matter present in the earth is only being cycled and recycled by different biogeochemical cycles
    • Thus, the matter present now has already been present years ago → we are simply reusing it