As the Siddhas were men who knew and transformed themselves from the gross to the subtle, similarly they bring us from the gross to the subtle. Our journey here is not merely living an existence but to bring this realization into a reality. Science says that the physical body is "composed of living cells and extracellular materials and organized into tissues, organs, and systems. Chemically, the human body consists mainly of water and of organic compounds—i.e., lipids, proteins, carbohydrates, and nucleic acids." (Source: https://www.britannica.com/)
Pon. Govindasamy in his "Vallalaarum Brahma Gnana Sangamum", Bharath Book Bureau, Chennai, draws a chain of evolution here. The souls that were once atoms took on the form of Bhuta Ganangal. Later changing into minerals, took on the plant form. Entering the forms of animals, they were reborn as humans. Finally, they end the journey here as Jeevan Muktas attaining the perfected body.
அணுக்களாகயிருந்த ஆன்மாக்கள், பூதவர்க்கங்களாக உருவெடுத்துப் பின் தாது வர்க்கங்களாக மாறி, பின் தாவர வர்கத்தையடைந்து, பின் விலங்கு வர்க்கத்தில் புகுந்து, பின் மானிட வர்க்கத்தில் ஜனனம் எடுத்து, இறுதியில் ஜீவன் முக்தர் வர்க்கத்தில் பரிபூரண தசையையடைகின்றன.
Agathiyar mentioned the Bhuta Ganangal too. He told us that when we fully understand ourselves and gain self-realization; when we understand the Ganangal or Bhuta Gnanangal; and come to finally realize that nothing is permanent, at that moment we shall enter and remain in the void of space (Vezhi Kadappathu), a state of Sunyam or void or silence that is the true state of Being or Summa Erupathu.
உன்னை நீ முழுதும் அறிந்து உன்னைச் சுற்றி இருக்கும் கணங்கள் அறிந்து எதுவும் நிலை அற்றது என்று நீ அறியும் அத்தருணம் வெளிக்குள் நீயே வெளி கடப்பாய். அத்தருணமே சும்மா இருப்பது.
Could these Bhuta Ganangal be the very first living organisms that progressed to take the form of mineral, plants, animals, and later humans?
"By far the longest portion of the history of life on Earth, therefore, has involved the biochemical evolution of these single-celled micro-organisms, bacteria and archaea." (https://www.physicsoftheuniverse.com/)
Agathiyar in revealing the journey back to the source says when the Udal or body that took a form as the result of a merger of five tattvas and again returns back to these tattvas, the Uyir or breath merges in the Atma or Soul and reaches the state of Jothi or Light.
உடல் என்பது பஞ்ச பூதங்களில் உரு பெற்று மீண்டும் பஞ்ச பூதங்களிடம் சென்று விட்டால் உயிராகியது ஆன்மா வோடு கலந்து ஜோதிநிலையில் எம்மை வந்து அடையும். உடல் கூறு தத்துவமும் இதையே உமக்கு உணர்த்தும்.
Rather than let nature break it down into the elements upon death, the Siddha transformed the very body that came as a result of karma back into its elements and merged the breath with the soul to reach the state of light. The cells are purified to attain a pure body or Suddha Deham that is further refined into the that of the Pranava Deham or Omkara. If generally Siddhis are associated with the acts or performing what generally is consided magic, in its true essence gaining Siddhis means the perfection of a state. Perfecting that which came as a result of karma is gaining Karma Siddhi. After having perfected his body, he perfects his breath through Pranayama making it more refined and subtle too. As man perfects each state he walks into or comes by, he progresses into a more subtle state. Man who has gone through the purification process now is divine in nature gaining the Pranava Deham. Just as the heat of the sun or fire evaporates the water bodies, infusion of Light within from Godhead or Cosmic Consciousness breaks down the cells dislodging them and thence producing intense vibration. He takes the subtle form and carries on his divine journey and work here. This Pranava Deham merges in the or Oli Deham or Light eventually. The Siddhas can take on or assemble these various bodies for their divine purpose or if the need arises. If these transformations are retold by the saints who have been there and back, for now it is a theory that is unconceivable for us till we to step into this transformation and experience it.
Alan Kay in saying "The best way to predict the future is to invent it", echoes Tavayogi's reminder to us that we do not need to read the Nadi to predict our future once we have come to the Siddhas. Taking the hands of the Siddhas we invent it. Together we chart a new destiny.