During the creation of the material universe, Lord Krishna, the Supreme Personality of Godhead, simultaneously created 8,400,000 types of bodies, which will be given to the souls who incarnate there, according to their desire.

The different living species or life forms.

The varied bodies that distinct beings take are assigned according to the being's desires. There are:

900,000 aquatic species.

2,000,000 plant species.

1,100,000 species of reptiles and worms.

1,000,000 bird species.

3,000,000 mammal species.

400,000 human species.

This group includes the 8,400,000 varieties of bodies found on the various planets that make up a galaxy.

This is how the wanderings of the incarnate spiritual being, the human being, continue, through the effect of countless incarnations following the call of the various forms of material desires that he emits, and which reside in his mind.

There is certainly an evolution of species, but all the various forms of life exist simultaneously.

The fish, the human being, the tiger, and all other beings appeared at the same time during creation and were simultaneously injected by the Lord into the bodies they had in their previous existence. The incarnate being, according to their karma, can occupy one of these bodies, and all follow an evolutionary path.

Thus, after the fish, the next stage will be plant life. From there, the spiritual being can become an insect. From the insect stage, they will move on to that of a bird, then to that of a terrestrial mammal, and finally evolve into the human form.

If the individual soul distinct from God, which each of us truly is, proves worthy of its human condition, it can continue its evolution. Otherwise, it will have to enter the evolutionary cycle again. The human form therefore marks an important stage in the evolution of the incarnate being.

To put an end to this vicious cycle, let us, who are fortunate enough to occupy a human form, by the grace of God, prove ourselves worthy and turn to Krishna, the Supreme Personality of Godhead. Let us surrender to Him and serve Him with love and devotion, and the Supreme Lord will send His companions from His kingdom to come and fetch us and lead us to Him forever.

The Lord said, Only through devotional service, and thus alone, can one know Me as I am. And the being who, through such devotion, becomes fully aware of Me, can then enter My absolute kingdom and, likewise, truly see Me. Thus, and thus alone, can one penetrate the mystery of My Person.