How have all those exquisite adaptations of one part of the organisation to another part, and to the conditions of life, and of one organic being to another being, been perfected?

Species that struggle to adapt to survive will become extinct.

In the long history of humankind (and animal kind, too) those who learned to collaborate and improvise most effectively have prevailed.

What's dangerous is not to evolve, not to invent, not to improve the customer experience.

Man, like every other animal, has no doubt advanced to his present high condition through a struggle for existence consequent on his multiplication; and if he is to advance still higher, it is to be feared that he must remain subject to a severe struggle.

Who can explain why one species ranges widely and is very numerous, and why another allied species has a narrow range and is rare? Yet these relations are of the highest importance, for they determine the present welfare, and, as I believe, the future success and modification of every inhabitant of this world.