Serendip is an independent site partnering with faculty at multiple colleges and universities around the world. Happy exploring!

Theosis: Humanity's Homology

Aimee's picture


Theosis: Humanity’s Homology

Aimee Heerd

            Compare the forelimb of a lizard with the arm of a human or the fin of a whale, and you will first notice their myriad differences. Rough scales cover the lizard’s leg; an opposable thumb gives flexibility to the human hand, and the whale’s fin stretches flat and wide with no discernable digits. But if you peeled away the flesh from the limbs of these creatures, you would see a remarkably similar morphology –or structure– in their very bones. The whale, human, and lizard each possess a humerus, radius, and ulna – the long bones of the arm – that anchor the carpals, metacarpals, and phalanges firmly in place. How could the delicate bones in our hands and arms, so pivotal to our skillful tool making, also be present in the clumsy fin of a whale?

            The bones of our hands, a universal trait in all tetrapods, exist because of our mutual evolution. In the present day, humans bear little resemblance to reptiles or aquatic mammals, but our similar bone structure was, “inherited [millions of years ago] from a common ancestor that also had that character,” in an example of evolution known as homology (Understanding Evolution).  Although the lines linking tetrapods diverged after the extinction of our four-legged common ancestor, we still recognize a connection between lizards, whales, and us, because of our homology.

            If we trace the course of evolution over millions of years, greater numbers of homologies arise. We are terrestrial organisms, we have spinal cords, we are multicellular, we are alive. Through our shared characteristics, the magnitude of life becomes evident; not only are humans similar to other mammals: we are interconnected with every organism that lives now, or has ever lived. Humanity is one miniscule part of an extensive family tree, and if we acknowledge the vastness of life, we unify ourselves with it.

            With the plentitude of homologies linking us to animals, what traits distinguish us from them? We, too, evolved over millions of years, and aside from bipedal motion and an odd lack of hair, our anatomy is comparable, in terms of parts and functions, to most organisms in the animal kingdom. Indistinguishable from animals physically, we have a unique role mentally: We speak, feel complex emotions, invent tools that require construction, and believe, almost universally, in God.

            Entertain, for a moment, the idea that our mental prowess arises from a soul, a distinct but unified part of our being, given exclusively to humans by a divine creator. This belief, held by many people, typifies humans separately from animals. As Genesis explains, “So God created man in His own image,” further separating us from other organisms. Physically, we may share our anatomy with animals, but God has assured, through the installment of a soul and a conscience, that we share with Him an element of the divine.

            The human physique unifies us with animals, but humans seek to unify the soul with their God. The Eastern Orthodox Church developed the concept of theosis, derived from Psalm 82 – “You are gods, and all of you are children of the Most High” – attempts to reunite the human essence with God’ greatness. Theosis is, at its simplest level, “ the understanding that humans can have real union with God …the means of becoming ‘like God’ is through perfection in holiness” (Theosis). Theosis is evolution of the soul, a lifelong process of remembrance. Remember you have a soul, practitioners believe, remember the conscience it gives you, and remember to live as God wants you to. By living like God, humans can understand and partake in His spirit.

            Although theosis is a doctrine unique to the eastern Christian tradition, other religions share the belief that “perfection in holiness” advances a person’s spiritual goals. Buddhists meditate so that it “leads ultimately to enlightenment and spiritual freedom,” unifying the meditator with the “Buddhist truths of ‘no-self’ and impermanence” (Buddhist Meditation). The Buddhist quest for enlightenment might be described as a form of spiritual evolution, one that may develop over several rebirths in order for the “self” of a person to meet “impermanence.” Evolution of the soul – a journey to unify with the divine - inspires the Muslim Hajj to their Holy Land, Jewish prayers at the Wailing Wall, and even the flagellants of the Medieval Ages, who sought repentance for sins by whipping themselves, thus experiencing the agony of Christ on the cross.  

            Humans are unique for the souls they possess. Religion is humanity’s homology, our interconnectedness with a primitive desire to seek out the divine within us. We might share our physiology with a multitude of organisms, but our souls have told us through the ages that humans are more than animals. Our role on Earth is exceptional – a mixture of  physical relationships with animals; mental, soulful relationships with people; and spiritual relationships with God. Compare the religions of a Buddhist, a Jew, and an Eastern Orthodox Christian, and initially you will find only differences. But study the faiths closer, and you will see a mutual human desire to contemplate the divine.




Works Cited


"Buddhist Meditation - ReligionFacts." Religion, World Religions, Comparative Religion            

  - Just the Facts on the World's Religions. Web. 22 Sept. 2010.            



"Genesis 1:27 So God Created Man in His Own Image, in the Image of God He Created            

  Him; Male and Female He Created Them." Online Parallel Bible: Weaving God's            

  Word into the Web. Web. 22 Sept. 2010. <>.


"Homologies and Analogies." Understanding Evolution. Web. 21 Sept. 2010.            



 "Theosis: Partaking of the Divine Nature." Antiochian Orthodox Christian Archdiocese.          

     Web. 21 Sept. 2010. <>.