The average porcupine has 30,000 needle-sharp quills, each with 800 barbs at the tip. Usually, these miniature spears lie flat along the back, sides, and tail of the animal. But if it’s attacked, they suddenly leap up for defense. The quills aren’t thrown, despite popular ideas on that score. An attacker, such as a dog or fox, can easily get a very painful snout full. Each quill only requires half the strength of a hypodermic needle for insertion and that isn’t much. Yet a newborn porcupine passes through its mother’s birth canal without causing her any injuries.

How?

The answer, of course, is that the quills are soft. They stiffen a few hours after delivery. Otherwise, there would never have been another generation of porcupines.

In a similar fashion, horse foals and giraffe calves are born with temporary, gelatinous coverings on their razor-sharp hooves. The scaly anteaters of Africa and Southeast Asia have razor-sharp scales covering their entire body. Nonetheless, they are born with soft scales that rapidly harden when exposed to air. Is this a lucky accident (for the mom)?

How does it happen that hardening of quills, hooves, and scales is delayed until after birth? If that trait wasn’t present from the beginning, there would have been either no hard quills or hooves, or no live births.

Nature doesn’t get to experiment if the trait is essential from the beginning. Is this designed with foresight? It definitely seems so. This could not have happened by natural selection or trial and error.

Source:

Geoffrey Simmons, “Porcupine Quills and Other Examples of ‘Nature’s’ Foresight,” Evolution News (8-23-18)