That analogy can be justified by the condition of the soul after the fall of Adam, not that the soul is linked to an animal (Monkey) After the fall, feelings (sentiency) had a great effect over rational intelligence so that man had a propensity to follow his feelings rather than his reason, this was one of the effects of original sin. When man follows these feelings contrary to his reason his acts are reduced to that of an animal. He is a rational animal known as a human being
I hope this is what you have been looking for: dialnet.unirioja.es/servlet/articulo?codigo=5244649 Click on Texto completo and download the full article. The title of the article is: “The Rational Credibility of a Literal Adam and Eve.” It was reviewed prior to publication by at least two, probably three, professional scholars.
This is an article in a peer-reviewed Spanish Thomist philosophical journal that addresses the major scientific objections raised against theological monogenism. It should resolve your doubts and difficulties. The editor of this journal is Dr. Enrique Martinez, who is a member of the Pontifical Academy of St. Thomas Aquinas. They are very careful about publication criteria.
I have another peer-reviewed article, exploring the same topic in even greater depth, scheduled for publication in an American theological journal, Nova et Vetera. It may appear early in 2017.
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