Well actually most meat people eat comes from animals raised for the sole purpose of consumption (cows, chickens, pigs, etc...). If people stopped eating meat, then there would be no reason for farmers to raise this livestock, and therefore would not exist at all. In this way, people eating less meat would mean less animals.

Where you are correct is with animals like deer, or other wild animals. Because most of the local predators for these animals have reduced populations, or in some cases are completely wiped out, there numbers probably would increase. When you factor in the amount of domesticated animals, however, there would more than likely be an overall decrease.

In your argument you make a couple of assumptions that I disagree with.

First, we do not know time is infinite. We know that our own universe began around 14 billion years ago, and that (assuming the universe continues to expand) eventually all energy and matter in the universe will eventually become uniform heat (second law of thermodynamics). What this means is that, although time will stretch for a very long time, it is not infinite. This is important because it means that not every extremely improbable event has to happen.

Now let me examine your second claim: that we have lived our lives infinite times, and will live our lives again, infinite times. I'm going to use you as an example.

What are you? You could say a human, a living organism, or any number of vague terms, however at the most basic level, you are a collection of atoms. What is most important though, is that your collection is not arbitrary. There was no dice rolled, or anything of that sort. A very long series of events, starting billions of years ago, and ending with this very moment has led to the ever changing grouping of atoms that is you. That grouping is different now then when you first began reading this argument, and will be different again when you finish. Each moment of your life has changed you. And before your life, it was your parents lives that shaped you, up until your conception. And before them it was there parents and so on until you trace yourself all the way back to our primitive single celled ancestors who had just come out of the primordial soup.

I am not even including in this the multitude of outside factors that played a part in shaping who you are today. There were solar flares, asteroids, windy days, snow, and floods that all played a part in the arrangement of the cells which make up you.

I am going to assume that you are familiar with chaos theory, and therefore know that any change during the past 14 billion years, up until now, no matter how infintesimally small, would have meant that you, as you are right now, would not have existed.

What this also means is the chances of the same type of atoms of the same number coming into the exact same formation is indescribably improbable. In an infinite universe, like the one you described, it may still be possible for this to happen, however, in the actual universe, there is a limited window for you or anyone else to be created.

Therefore I can safely say that this is your only life...enjoy it.

In order for there to be an afterlife, some part of you would have to survive death.

When you die, your physical self ceases to function. This means your brain, your nervous system, your eyes, your ears, your nose etc... cease to function.

We know that memory is stored within the brain. If the brain ceases to function, you no longer have memory.

We can trace instincts, and emotions to different centers of the brain. If the brain ceases to function, then once again we lose the ability to have these instincts or emotions.

Cognitive thought also takes place in the brain, and like the others I mentioned would be impossible without the brain.

In fact, there are conditions in which the brain is damaged and we can witness what happens when parts of the brain cease to function. Alzheimer's for example causes people to lose their memory.

So the question is, if some part of you did survive after death, would it even be you?

There would be no thought, no emotions, and no memory. You wouldn't be able to see (no eyes) or even process sight (no living nerve cells).

Essentially, what you experience after death is the same as what you experience before birth. Nothing.

Therefore, unless you can point to some specific part of a person that exists outside of the body, and could continue on after death then the only logical conclusion is that there is almost certainly no afterlife.