Vedas refer to Ganesha as Gana Natha, the group leader. Vedic civilisation is based on mass cultivation and group living. A variety of rice known as ShaliPrasta was cultivated seasonally. The paddy saplings would be placed in a field to season. When seasoned it used to turn yellow in colour and this was known as Gaura Varna, referring to its colour. The group leader, Gana Natha, after prayers to all five elements, prithivi, vauyu, akasha, tejo, ap,would distribute the saplings to all groups based on their need and capability. Each group would replant their sapling. This is how concept of Gananatha or Ganesha came into existence.
Ganesha is also known as Shivas Son, an embodiment of auspiciousness. Ganesha has been described to have various roles in various yugas. He is creator in Sathya Yuga as called by Atharva rishi, Sustainer in Treta yuga, compiler of Mahabharatha in Dwapara yuga and remover of obstacles in present Kali yuga, as we know Him today.
As water is a significant resource for a civilisation based on cultivation the arrival of rain and rainy season is celebrated parallelly with measures taken for environmental and economic sustainability. Rain water brings with it fresh silt. This earth or clay was used to create murthy, offer prayers and oblations and be offered back to the water or river. This also serves as a means to cleanse the slit in water beds.
Symbolically Ganesha, has a big belly representing the fourteen universes, hiranya garbha, source of creation, good listener with a sharp vision and strength (tusk) to foresee and remove obstacles. The concept of holding one’s earlobes with both hand and squatting and standing-up a number of times was considered to plea to the Lord. Considered to be an admonishing way for errant children it is now marketed as “super brain yoga”, a method to rejuvenate brain wellness.
Shubam Astu
Source: http://hinducouncil.com.au/new/the-significance-of-ganesha/