Here's two examples of adaptation.

1. Arctic Terns require rich marine habitats in which to fish but the richest oceans are the polar seas. These birds migrate 20,000 miles every year, between the North and South Poles, in order to do their fishing. Their superb flying ability has adapted them to these long migrations, making the Arctic Tern the "champion" migrating bird in the world.
2. Water shrimp are eaten by ducks, so the shrimp normally hide quietly (still) in the vegetation. A parasite called the Spiny-headed Worm (Acanthocephalon) needs to transfer from the shrimp to the duck in order to complete its life cycle. Shrimp infected with Acanthocephalon swim around in circles and respond to duck sounds making them more likely to be eaten by ducks. That is, the Acanthocephalon (infection) causes the shrimp to behave so that it gets eaten! Many parasites can influence the behaviour of their hosts in order to make the transfer between species more likely. This is an important adaptation to their success.

In the past couple centuries three hypotheses have been put forward to explain adaptation:

1. Natural Theology
2. Inheritance of Acquired Characteristics
3. Decent with Modification (also known as Natural Selection)

Many people in different cultures have put forward the general idea that adaptation has come about by Natural Theology. William Paley is often credited as the father of its European version because he presented the idea (in 1802) so clearly. One day while wandering across a field Paley came across a watch. After admiring its artistic qualities, mechanical precession and complexity he concluded that someone had created the watch. It had not simply sprung out of the ground. Paley argued that a designer had made the watch. (And some unfortunate owner of the watch had lost it in this field.)

Paley extended his argument to Biology and the adaptations of life.
How could life's complexity, "mechanics" and beauty come about without a designer? Paley concluded that a designer was behind the creation of all life and was responsible for its adaptation.
Natural Theology is an argument from design - there cannot be design without a designer.

Is there a way to disprove Paley's hypothesis? Is Natural Theology falsifiable?

• Yes, there is a way to disprove Paley's hypothesis and thus show Natural Theology to be false.

• No, there is no way to disprove Paley's hypothesis so there is no way to prove Natural Theology to be false.