How is it private opinion when the Orthodox simply repeat the clear and explicit teachings of the holy fathers who rejected Evolution subsequent to the madness of Darwin, such as St. Nectarius the Wonderworker, St. John of Kronstadt, St. Andronik of Perm, St. Nikolai Velimirovich (and his spiritual son Fr. Justin Popovich), etc.?
St. Nectarios of Aegina "Study on the Soul of Man and of the Animal" (Peri tes Scheseos kak Diaphoras tes Psyches tou Anthropou), Athens, 1885, pp. 216-217:
"The followers of pithecogeny [the derivation of man from the apes] are ignorant of man and of his lofty destiny, because they have denied him his soul and Divine revelation. They have rejected the Spirit, and the Spirit has abandoned them. They withdrew from God, and God withdrew from them; for, thinking they were wise, they became fools… If they had acted with knowledge, they would not have lowered themselves so much, nor would they have taken pride in tracing the origin of the human race to the most shameless of animals. Rightly did the Prophet say of them: `Man being in honour, did not understand; he is compared to the dumb beasts, and is become like unto them."
St. John of Kronstadt - My Life in Christ:
The Holy Scriptures speak more truly and more clearly of the world than the world itself or the arrangement of the earthly strata; the scriptures of nature within it, being dead and voiceless, cannot express anything definite. "Where wast thou when I laid the foundations of the earth?" Were you with God when He created the universe? "Who hath directed the Spirit of the Lord, or being His counseller, hath taught Him?" And yet you geologists boast that you have understood the mind of the Lord, in the arrangement of strata, and maintained it in spite of Holy Writ! You believe more in the dead letters of the earthly strata, in the soulless earth, than in the Divinely-inspired words of the great prophet Moses, who saw God.
Bishop Nikolai Velimirovic:
EUROPE (speaking to CHRIST): You are old fashioned.
In place of your gospel we discovered biology and
zoology. And now we know that we are not descended
from you and your heavenly father, but from orangutans
and gorillas, that is to say, from apes...
CHRIST: You are more obstinate than the ancient Jews
were. I raised you up from the darkness of barbarism
to the Heavenly Light, but you have gone back to the
the darkness like a water buffalo goes into the mud...
EUROPE: Get away from us. We do not recognize you.
We follow European civilization and culture...Science
is the star that guides us...You are only an old myth
our grandmothers and grandfathers believed in.
Furthermore, ancient fathers like St. Ambrose of Milan plainly and explicitly refuted Darwin's madness centuries ago. For example, in his ninth homily on the Hexaemeron:
"The Word of God permeates every creature in the constitution of the world. Hence, as God had ordained, all kinds of living creatures were quickly produced from the earth. In compliance with a fixed law they all succeed each other from age to age according to their aspect and kind. The lion generates a lion; the tiger, a tiger; the ox, an ox; the swan, a swan; and the eagle, an eagle. What was once enjoined became in nature a habit for all time. Hence the earth has not ceased to offer the homage of her service. The original species of living creatures is reproduced for future ages by successive generations of its kind."
Evolution is incompatible with Holy Scripture and with the teachings of all the Holy Fathers regarding the creation of the world and of man.
It's actually an ancient heresy of the pre-Christian Greek philosopher Anaximander, combined with the Epicurean notion that the world was created by chance collisions. St. Chrysostom plainly states on multiple occasions that the world was not created by chance or accident. So does St. Hilary and others.
Eusebius of Caesarea Preparation For the Gospel, Ch. VIII:
"Further, he says that man at first was generated from animals of other kinds, because while the other animals quickly find food of themselves, man alone needs to be nursed for a long time; and for this reason, being such as he is, he could not in the beginning have been kept alive. These then are the opinions of Anaximander."
As you can see, it's not as if Darwin came up with some newfangled concept that had never occurred to anyone before. No Christians were ever tempted by such nonsense in antiquity, except perhaps Origen, but this pagan philosophy masquerading as (pseudo) science has only arisen in more recent times, so that's why there are no historical councils, although it most certainly should be formally condemned in our day since simple folk are easily deceived by such fabulous myths.