Genes only get copied to future generations if the bodies they help to build succeed in surviving and reproducing. These sort of genes thrive in the gene pool and genes that build unsuccessful bodies don't. This blindingly obvious fact is at the very core of understanding evolution by natural selection.
Being born, finding food and shelter, escaping predators, fighting opponents, attracting a mate and raising the next generation - the challenges faced by living things are daunting. At every stage there is competition from other bodies built by other genes struggling for survival in the same environment.
Evolution has devised astonishing strategies to win at any cost and the battle begins even before birth. Here are a couple of examples of the sort of thing Herbert Spencer had in mind when he coined the phrase "survival of the fittest".
Great Egrets often have enough food for only two chicks, although a mother egret typically bears three. By sometimes allowing their older children to kill the youngest, the parents guarantee that they raise two well-fed, strong chicks who have an excellent chance to mature and reproduce. The two oldest egret chicks are destined for success even before birth. Douglas Mock and colleague Hubert Schwabl recently discovered that the first egg to form inside the mother egret always gets the highest dose of the hormones, or chemical messengers, that trigger aggressive behaviour. The second egg in line gets the same dose. But egg number three gets only about half the amount. With less tendency to be aggressive, the youngest chick is less able to defend itself against its more aggressive siblings.
Female sand tiger shark produces 400 to 500 embryos at a time. While still in the womb, these embryo sharks grow razor-sharp teeth, the embryonic sharks start to eat other embryos. Within a few months, three to four dominant sharks engage in a life-or-death struggle until only one survives. By the time it is born, the sole-surviving shark pup has become an experienced predator. Amazing film taken inside the womb recently appeared on UK television clearly demonstrating this behaviour.
These are just two of countless examples of the carnage that is the experience of all living things. Unlike the cartoon characters of Disney, animals don't live happy ever after. They die in pain and in distress from predation, parasites, starvation, exposure or disease.
Every anatomical feature of an animal, from its skeleton, camouflage, jaw and teeth, digestive system, eyesight, claws, hearing, even the molecular structure of the myosin in its muscle fibre equips it to kill or escape predation.
All of this makes perfect sense in the light of evolution by natural selection.
If on the other hand "god's invisible qualities are clearly seen from the world's creation" what does it tell us about god?
"Who trusted God was love indeed
And love Creation’s final law–
Tho’ Nature, red in tooth and claw
With ravine, shriek’d against his creed" - In Memoriam by Alfred Lord Tennyson
Evolution is a Fact 1 - 30 Index...
#31 Ten Questions For Creationists ...
The basic facts about reality covered so far pose an impossible challenge to creationism.
#32 Sexual Selection
How female mating preferences led to some of the most remarkable features of living things.
#33 A Tale About Tails
Human embryology reveals our primate history.
#34 Hiccups and Tadpoles
How hiccups are a relic of our amphibian ancestors.