I believe that an orderly universe, one indifferent to human preoccupations, in which everything has an expla nation even if we still have a long way… - Richard Dawkins

Each generation is a filter, a sieve; good genes tend to fall through the sieve into the next generation; bad genes tend to end up in bodies that die young or without reproducing.

Individuals are not stable things, they are fleeting. Chromosomes too are shuffled into oblivion, like hands of cards soon after they are dealt. But the cards themselves survive the shuffling. The cards are the genes. The genes are not destroyed by crossing-over, they merely change partners and march on. Of course they march on. That is their business. They are the replicators and we are their survival machines. When we have served our purpose we are cast aside. But genes are denizens of geological time: genes are forever.

Ignorance, to a scientist, is an itch that begs to be pleasurably scratched. Ignorance, if you are a theologian, is something to be washed away by shamelessly making something up.