When did animals begin to die?

I think that people may be inclined to believe differently based off of their belief of the Earth's age.

An old-earth believer may think that through guided evolution, God created the different species, thus signifying that some creatures must have died. I.e. the dinosaurs.

A young-earth believer would most likely believe that sin is the cause of death, and animals were immortal before the fall.

However, in Genesis 3:19 God states

 "By the sweat of your face you shall eat bread, till you return to the ground for out of it you are taken; for you are dust, and to the dust you shall return"

Physical, painful, 'death' is part of God's curse on man for their disobedience.

In Genesis 2:9 there are two trees described as being in the "midst" of the garden, the Tree of Life, and the Tree of the Knowledge of Good and Evil, which was forbidden for man to eat. (The Tree of Life was forbidden to animals before the fall, but not for man until after) We know man was tempted to eat the fruit of the Tree of Good and Evil, instead of the Tree of Life. The serpent would tempt man in what it doesn't already possess, rather than what it does. In this case, immortality.

Later, God specifically banishes Adam and Eve from the garden, because of the possibility of them also eating from the Tree of Life, and becoming immortal with the knowledge of good and evil.

Was man "immortal" before the fall?

I believe irrational animals such as sheep and cows were not mortal, but man was, as they had dominion over all animals and plants.

This would make sense in both and old-earth and new-earth viewpoint

When did animals become mortal?

From the Jehovah's Witness perspective, animals were created mortal.

The article "Death" from the Insight on the Scriptures brings out an interesting point:

Cause of Death in Humans. The first reference to death in the Scriptures occurs at Genesis 2:16, 17 in God’s command to the first man concerning the eating from the tree of the knowledge of good and bad, violation of which command would result in death. (See NW ftn.) However, death among animals as a natural process was evidently already in effect, since they are passed over completely in the Biblical presentation of the introduction of death into the human family. (Compare 2Pe 2:12.) The gravity of God’s warning about the death penalty for disobedience would therefore be understandable to his human son, Adam. Adam’s disobedience to his Creator brought death to him. (Ge 3:19; Jas 1:14, 15) Thereafter, Adam’s sin and its consequence, death, spread to all men.​—Ro 5:12; 6:23. (italics mine)

This brings to light two points.

1. According to 2 Peter 2:12, animals were created mortal.
2. If Adam had not seen death in animals, he would not have known how serious the outcome of disobedience would have been for him.

Romans 8:20 uses the word ktísis (G2937) which is most often translated as "creation". (See BibleHub's parallel translations)

If we are to take the Bible at face value, it would seem to tell us that animals became mortal when Creation was cursed (Genesis 3:17, Romans 8 19-22), following The Fall.

"Death came through sin" (Romans 5:12). The Bible clearly teaches that death is a consequence of sin. While some will argue that this refers only to human death, one must also ask what purpose is served by animals dying in a creation that was Very Good (Genesis 1:31). Certainly, it is quite difficult to argue that violence and suffering would be present in such a Creation, and we are further clearly told that animals were vegetarian before The Fall (Genesis 1:30), and that they will be again in the New Creation (Isaiah 11:6-9).

Some would further argue that human Sin would not cause animals to die, because animals didn't sin. Again, however, this is not what Romans 8 tells us, and Genesis 3:17, although referring to "the ground" and not mentioning animals specifically, states clearly that the effects of the curse extended to the larger Creation and not just to humans.

See also this, this and this.

Aside: I suspect the reason for wanting to believe that animals died before the fall is so that one may believe in the philosophy of Evolutionism. Again, millions of years of death and killing is not compatible with Genesis 1, nor is the haphazard process of Evolutionism compatible with a Creation that was Very Good. (See also this, this and this.) Accordingly, I, and many Christians across multiple denominations, believe that Evolutionism contradicts the clear teaching of the Bible, and belief in this philosophy requires picking and choosing what parts of the Bible to accept as true.

I would be interested to see an argument which rejects Evolutionism but still supposes that animals were subject to senescence and death prior to The Fall.

All creatures were created mortal, if not - there would be no need for the tree of life. The tree of life was something only given to mankind, not animals.

Animals do not possess Torah, nor Knowledge of good and evil. The ox doesn't know it gored the neighbor, thusly we are responsible for paying back the damage done.

Exo 21:28-36 ULT If an ox gores a man or a woman to death, the ox must surely be stoned, and its flesh must not be eaten; but the ox’s owner must be acquitted of guilt. But if the ox had a habit of goring in the past, and its owner was warned but did not keep it in, and the ox has killed a man or a woman, that ox must be stoned, and its owner also must be put to death. If a payment is required for his life, he must pay whatever he is required to pay. If the ox has gored a man’s son or daughter, the ox’s owner must do what this decree requires him to do. If the ox gores a male servant or a female servant, the ox’s owner must pay thirty shekels of silver, and the ox must be stoned. If a man opens a pit, or if a man digs a pit and does not cover it, and an ox or a donkey falls into it, the owner of the pit must repay the loss. He must give money to the dead animal’s owner, and the dead animal will become his. If one man’s ox hurts another man’s ox so that it dies, then they must sell the live ox and divide its price, and they must also divide the dead ox. But if it was known that the ox had a habit of goring in time past, and its owner has not kept it in, he must surely pay ox for ox, and the dead animal will become his own.

The ox doesn't have the capacity to follow Torah, nor does the ox need salvation from sin (transgression of Torah).

The ox (or any animal) doesn't have a covenant with God to receive the promised land, which was revealed in the Gospels and Revelation as His kingdom to come on Earth, where the righteous will be resurrected to life and the unrighteous to eternal damnation.

And what does Messiah say? Rev 22:11-15 TS2009 “He who does wrong, let him do more wrong; he who is filthy, let him be more filthy; he who is righteous, let him be more righteous; he who is set-apart, let him be more set-apart. “And see, I am coming speedily, and My reward is with Me, to give to each according to his work. “I am the ’Aleph’ and the ‘Taw’, the Beginning and the End, the First and the Last. “Blessed are those doing His commands, so that the authority shall be theirs unto the tree of life, and to enter through the gates into the city. “But outside are the dogs and those who enchant with drugs, and those who who*e, and the murderers, and the idolaters, and all who love and do falsehood.

The people who chose to uphold Torah (summation of verse 14) are those who will be able to enter the garden again, and take of the tree of life.

Animals cannot "do" the commands, as Torah itself points out. They are morally neutral, and while they will exist in the renewed creation, they still will not be immortal - like the angels.

When did senescence enter the animal kingdom?

To speak openly we may not know the exact moment when they became dying? But we have a few key points that the Scriptures can help in giving some perspectives on the question.

Immediately after Adam and Eve sinned, we are told that they made clothing for themselves.

Then the eyes of both were opened, and they knew that they were naked. And they sewed fig leaves together and made themselves loincloths. Genesis 3:7 ESV

However, after God comes into the garden, He also makes clothing for them.

And the Lord God made for Adam and for his wife garments of skins and clothed them. - Genesis 3:21 ESV

This seems to indicate that animals seemed to die immediately after the fall of Adam. But we do not know definitively in this was actually the case.

When one asks the question whether animals ”become dying at the time of the fall of Adam and Eve or had it happened earlier at the fall of Satan, which may be what Romans 8:20 is hinting at?”

For the creation was subjected to frustration, not by its own choice, but by the will of the one who subjected it, in hope. (Rom 8:20)

The material universe was created by God and when man was created, he was given dominion over God’s creation; but when Adam and Eve sinned, sin and death entered the world.

12 Wherefore, as by one man sin entered into the world, and death by sin; and so death passed upon all men, for that all have sinned:

13 (For until the law sin was in the world: but sin is not imputed when there is no law.

14 Nevertheless death reigned from Adam to Moses, even over them that had not sinned after the similitude of Adam's transgression, who is the figure of him that was to come.

15 But not as the offence, so also is the free gift. For if through the offence of one many be dead, much more the grace of God, and the gift by grace, which is by one man, Jesus Christ, hath abounded unto many.

16 And not as it was by one that sinned, so is the gift: for the judgment was by one to condemnation, but the free gift is of many offences unto justification.

17 For if by one man's offence death reigned by one; much more they which receive abundance of grace and of the gift of righteousness shall reign in life by one, Jesus Christ.)

18 Therefore as by the offence of one judgment came upon all men to condemnation; even so by the righteousness of one the free gift came upon all men unto justification of life.

19 For as by one man's disobedience many were made sinners, so by the obedience of one shall many be made righteous. - Romans 5:12-21

St. Paul alludes to this in Romans:

For we know that the whole creation groans together and travails in pain together until now. - Romans 8:22

Ultimately we may never truly know or understand when animals become dying?

Many Catholics, Orthodox and other fellow Christians may believe in evolution. In this scenario, it would be obvious the animals died before sin entered the world. What percentage of Christian hold to this theory I am not aware of.

The Catholic Church holds no official position on the theory of creation or evolution, leaving the specifics of either theistic evolution or literal creationism to the individual within certain parameters established by the Church. According to the Catechism of the Catholic Church, any believer may accept either literal or special creation within the period of an actual six-day, twenty-four-hour period, or they may accept the belief that the earth evolved over time under the guidance of God. Catholicism holds that God initiated and continued the process of his evolutionary creation and that all humans, whether specially created or evolved, have and have always had specially created souls for each individual.

To say the least, the fact is that the Church has been very comfortable with evolution as a scientific theory since at least the pontificate of Pius XII and his encyclical Humani Generis (1950). Popes John Paul II and Benedict XVI in particular have made strong statements in favour of evolution and its compatibility with Christian teaching about God and creation.

36. For these reasons the Teaching Authority of the Church does not forbid that, in conformity with the present state of human sciences and sacred theology, research and discussions, on the part of men experienced in both fields, take place with regard to the doctrine of evolution, in as far as it inquires into the origin of the human body as coming from pre-existent and living matter - for the Catholic faith obliges us to hold that souls are immediately created by God. However, this must be done in such a way that the reasons for both opinions, that is, those favorable and those unfavorable to evolution, be weighed and judged with the necessary seriousness, moderation and measure, and provided that all are prepared to submit to the judgment of the Church, to whom Christ has given the mission of interpreting authentically the Sacred Scriptures and of defending the dogmas of faith. Some however, rashly transgress this liberty of discussion, when they act as if the origin of the human body from pre-existing and living matter were already completely certain and proved by the facts which have been discovered up to now and by reasoning on those facts, and as if there were nothing in the sources of divine revelation which demands the greatest moderation and caution in this question.

37. When, however, there is question of another conjectural opinion, namely polygenism, the children of the Church by no means enjoy such liberty. For the faithful cannot embrace that opinion which maintains that either after Adam there existed on this earth true men who did not take their origin through natural generation from him as from the first parent of all, or that Adam represents a certain number of first parents. Now it is in no way apparent how such an opinion can be reconciled with that which the sources of revealed truth and the documents of the Teaching Authority of the Church propose with regard to original sin, which proceeds from a sin actually committed by an individual Adam and which, through generation, is passed on to all and is in everyone as his own.

This evolution theory is to some degree accepted by major Christian churches, including the Catholic Church, Evangelical Lutheran Church in America, Episcopal Church (United States), and some other mainline Protestant denominations; virtually all Jewish denominations; and other religious groups that lack a literalist stance concerning some holy scriptures. Various biblical literalists have accepted or noted openness to this stance, including theologian B.B. Warfield and evangelist Billy Graham.

See: Acceptance of evolution by religious groups.

For further information, one may peruse the following articles at one’s leisure:

• Did Animals Die before the Fall?
• Death before Sin?
• Animal Death Before the Fall: What Does the Bible Say?