Do the animals have these bodies because of their past Karma? Or will they eventually progress into human and then higher forms and eventually seek liberation?
Do the animals have these bodies because of their past Karma?
If a human being commits sins in the present life and dies without atoning for those sins, then he goes to hells first and receive punishments there. And, after that he/she gets born in animal/plant Yonis. Depending on the severity of sins committed, the person gets a animal body or a plant's.
The following verses from Vishnu Smriti XLIV are self-explanatory:
1. Now after having suffered the torments inflicted in the hells, the evil-doers pass into animal bodies. 2. Criminals in the highest degree enter the bodies of all plants successively. 3. Mortal sinners enter the bodies of worms or insects. 4. Minor offenders enter the bodies of birds. 5. Criminals in the fourth degree enter the bodies of aquatic animals. 6. Those who have committed a crime effecting loss of caste, enter the bodies of amphibious animals. 7. Those who have committed a crime degrading to a mixed caste, enter the bodies of deer. 8. Those who have committed a crime rendering them unworthy to receive alms, enter the bodies of cattle.
The text also gives long lists of animal/insect bodies that are obtained after committing particular sins. Few such verses are:
- One who has stolen clarified butter, becomes an ichneumon.
- One who has stolen meat, becomes a vulture.
- One who has stolen fat, becomes a cormorant.
- One who has stolen oil, becomes a cockroach.
- One who has stolen salt, becomes a cricket.
One who has stolen sour milk, becomes a crane. ......................
He who has taken by force any property belonging to another, or eaten food not first presented to the gods (at the Vaisvadeva offering), inevitably enters the body of some beast
- Women, who have committed similar thefts, receive the same ignominious punishment: they become females to those male animals.
Now, with suffering in these animal/plant bodies the soul gets it's sins burnt off and as a result obtains finally a human birth.
Following verses from Vishnu Smriti XLV explain that:
- Now after having undergone the torments inflicted in the hells, and having passed through the animal bodies, the sinners are born as human beings with (the following) marks (indicating their crime):
- A criminal in the highest degree shall have leprosy;
- A killer of a Brâhmana, pulmonary consumption;
- A drinker of spirits, black teeth;
- A stealer of gold (belonging to a Brâhmana), deformed nails;
- A violator of his spiritual teacher's bed, a disease of the skin;
- A calumniator, a stinking nose.
With the human body being obtained the soul can now strive for liberation. Because it has arrived at the stage from where liberation can be achieved. Now, whether it will achieve the same or go downwards again depends.