Oh, don't get me started about other planets.:) I can remember living on other planets. It is a big universe where almost anything is possible.
I see you are discussing heartbeats with someone else (I have him on ignore, by the way). A beating heart is not real evidence that a spirit is present. I have left my body and gone other places. My heart kept beating while I was out of my body.
Humans have a complicated system of doing things. There is a type of "life" that exists solely to "run bodies." We humans do not know how to make our hearts beat. We don't know how to regulate blood pressure, digest food, etc. These functions are part of what scientists call the "autonomic nervous system." It's more than a nervous system however. There is a non-physical entity involved. Some call it the "body elemental." Scientologists call it the "genetic entity." It's truly amazing what information it has -- it has experiences from past evolution even.
Cognition is another strange phenomenon. Some children can recall past lives at first. They tend to forget them as they grow up. Two things are involved, I think. Our culture tells them such memories are not real, and second we tend to lose access to certain records over time. Records of past lives are not kept on the earth. Think of how boring life would be if we knew we'd done this all before. Part of enjoying life is experiencing things in a new way -- so some people want to forget. Then too, there are people born with a purpose to correct a spiritual problem. If they mess up, that is another reason to want to forget things. Finally, there is karma -- and if someone is creating more karmic debts in this life, there is no point at all in allowing him to know about past karmic debts.
I think "human life" begins when a spirit "covers" a fetus. He is aware of it, takes possession of it and begins to program its brain cells. That has next to nothing to do with the autonomic nervous system which operates separately. There is not person here who can honestly say his heart would stop beating if he stopped commanding it to beat.
There is also the phenomenon of the "vegetative state" -- where no intelligence can be discerned -- but the body keeps living. What I have called the "body elemental" earlier is still there, running the body. The Bible refers to this type of "vegetative" intelligence too. It compares men to grass and trees. Grass is very undeveloped. Psalms speaks of men being like grass. We all start off with "grass" being our vegetative intelligence. Jesus used "herb" when speaking of the mustard plant.
Isaiah 40:6 The voice said, Cry. And he said, What shall I cry? All flesh is grass, and all the goodliness thereof is as the flower of the field:
7 The grass withereth, the flower fadeth: because the spirit of the Lord bloweth upon it: surely the people is grass.
8 The grass withereth, the flower fadeth: but the word of our God shall stand for ever.
When we know what Psalms also says about grass, why are we confused about what Revelation says about grass?
Revelation 8:7 The first angel sounded, and there followed hail and fire mingled with blood, and they were cast upon the earth: and the third part of trees was burnt up, and all green grass was burnt up.
Revelation 9:4 And it was commanded them that they should not hurt the grass of the earth, neither any green thing, neither any tree; but only those men which have not the seal of God in their foreheads.
Such "grass" can grow and become a tree, according to Jesus' teaching about the mustard seed. Moses also said directly that man is a tree, although it's almost universally terribly translated. Young's Literal Translation got it almost right: Man is a tree.
YLT Deuteronomy 20:19 When thou layest siege unto a city many days, to fight against it, to capture it, thou dost not destroy its trees to force an axe against them, for of them thou dost eat, and them thou dost not cut down -- for man's [is] the tree of the field -- to go in at thy presence in the siege.
A parallel is being made there: Don't cut down the fruit tree that bears fruit -- it's like a man.
A beating heart is a wonderful thing, and it's even more wonderful if a spirit takes possession of that body, and both body and soul are changed and brought into the kingdom -- not staying as grass.