Butterfly effect

life might be emerged on earth because of some speck of organic dust carried on by a random meteorite which decided to hit up on earth on the right spot which have all other stuff for sustained evolution ,with out that single meteorite nothing would have ever happened or will ever one know about nothing happened

 Mark Twain's Description of Evolution

Adam is fading out. It is on account of Darwin and that crowd. I can see that he is not going to last much longer. There's a plenty of signs. He is getting belittled to a germ—a little bit of a speck that you can't see without a microscope powerful enough to raise a gnat to the size of a church. They take that speck and breed from it: first a flea; then a fly, then a bug, then cross these and get a fish, then a raft of fishes, all kinds, then cross the whole lot and get a reptile, then work u...

 Infer From the Present to the Past

As historians, we refuse to allow ourselves these vain speculations which turn on possibilities that, in order to be reduced to actuality, suppose an overturning of the Universe, in which our globe, like a speck of abandoned matter, escapes our vision and is no longer an object worthy of our regard. In order to fix our vision, it is necessary to take it such as it is, to observe well all parts of it, and by indications infer from the present to the past.