Weather, Climate, place they are living
These chemical substances released to the synaptic cleft are known as neurotransmitters
example
dopamine
The slow twitch muscle fibres have a higher count of mitochondria which means it can process quicker, it receives a energy, it receives a good blood supply since it has a high amount of capillaries, which means it has a good supply of oxygen, which helps to maintain the use of the aerobic energy system for longer, making type 1 fibres more effect for endurance, while the type 2 fast twitch have less mitochondria and rely more on glycolysis.
All of these represent something called "competition and predation", in which the species competes for strength, or when one species coordinates attacks against a prey species, or when one species hunts another.
