Lesson 1: Adaptations

Factors Affecting an Ecosystem:

1. Abiotic Factor - it’s the non-living factors that affects an organism in the ecosystem.

In a terrestrial ecosystem, these include factors such as temperature, humidity, nutrient availability, water availability, sunlight, soil, wind, atmosphere, etc. 

In a marine ecosystem, these include factors such as salinity, light availability, and ocean currents. 

2. Biotic Factor - it’s the living factors that includes other organisms in the ecosystem which affects the organism.

Example includes producers, consumers, and decomposers.

Ecological Niche

Ecological Niche is the interrelationship of a species with all the biotic and abiotic factors affecting it.

It is an inclusive term that involves not only the physical space occupied by an organism but also its functional role in the community. It describes an organism’s response to the distribution of food and competitors.

Fundamental vs Realised Niche

Both fundamental and realized niches refer to the environmental position that species occupy in an ecosystem. 

• Fundamental niches represent all the environmental conditions where a species is able to live.
  

• Realized niche is where the species actually lives.
  

A realized niche is therefore defined as the space in the environment where a species is most highly adapted to play its role and reproduce.

Responses

All living things need to respond to their environment to allow them to survive. 

Reasons to respond:

1. To find a more favourable environment, or leave an unfavourable environment (food, water, mates, nutrients, oxygen). 

2. To reduce competition for resources

3. To protect themselves

4. To find a mate to reproduce with

Tolerance refers to the range of conditions that an organism can withstand.

An organism’s behaviour and adaptations are designed to keep it within its tolerance level. They function best in optimal condition.

Animal’s Responses

Animals need to be able to detect changes in their environment to determine how to respond. They do this by using their senses (sight, hearing, touch, smell, and taste).

This causes a change in behaviour accordingly.

How it works:

• They use their senses (receptors) to gather information, which is then sent to the CNS.

• The CNS then sends an electrical signal to the effectors (muscles and glands) to response to the stimulus such as moving, attack/retreat, posturing/expressions, sounds, being aggressive or submissive.
  

Receptors are the sense organs. They are responsible for collecting information on environmental conditions.

Effectors are the muscles and glands that cause the response to the stimuli.

Behaviour

Behaviour is anything an animal does in response to an environmental stimulus to aid in the animal’s survival, which can be innate or learned.

Types of Behaviour

1. Innate - refers to the behaviour that is inherited (not learned)

   - animals inherits the genetic basis for a trait (survival of the fittest)

   - it’s the automatic responses and instinct

2. Learned - refers to the behaviour that is a result of practice, experiment, or observation.

The Importance of Adaptations

An organism’s environment is always changing and so organism’s need to respond to these changing situations in order to survive and reproduce.

This response of an organism to its environment is termed as behaviour (also known as responses in plants).

An adaptive behaviour is any behaviour that contributes to the survival and reproduction of an organism. In nature, the well-adapted organisms are able to survive and reproduce.

Adaptations can be:

• Structural - adaptations that involve the structure of the body (what the organism has, eg. claws for hunting)

• Behavioural - adaptations that involves an organism’s behaviour in response to a stimuli (what the organism does)

• Physiological - adaptations that involves the aspects of chemical processes of the body (how the organism functions)