God's Webspinners Give Chemists Free Lessons

by Jonathan Sarfati

Introduction

Spider silk is an extraordinary material that surpasses man-made fibers like Kevlar® in strength and elasticity. Danish spider expert Fritz Vollrath describes spider silk as stronger and more elastic than even Kevlar®, which is considered the strongest man-made fiber. The main support for a spider's web, known as dragline silk, is a hundred times stronger than steel. In fact, a cable made from this silk, just a little thicker than a garden hose, could support the weight of two full Boeing 737 aircraft. Spider silk can also stretch to 40% of its length, while the flagelliform silk in web spirals can stretch to over 200%.

The Superiority of Spider Silk

Spider silk outperforms man-made fibers like Kevlar® in multiple ways. While Kevlar® production requires harsh conditions involving boiling sulfuric acid and the generation of dangerous chemicals that are costly to dispose of, spiders can produce silk at ordinary temperatures using a much milder acid bath produced by special ducts. Furthermore, spiders have the ability to adjust the speed at which they produce silk, unlike most industrial chemical processes that would result in inferior quality if the speed varied significantly. Additionally, spider silk is environmentally friendly, as spiders consume their own webs when they no longer require them.

Unraveling the Complexity of Spider Silk

The remarkable strength and elasticity of spider silk can be attributed to its intricate structure. Unlike man-made fibers, which are typically simple strands of material, a silk fiber consists of a core surrounded by concentric layers of nanofibrils (tiny threads). Some layers contain parallel-aligned nanofibrils, while others contain coiled nanofibrils resembling a spiral staircase. These coiled nanofibrils allow the silk to stretch without breaking.

The nanofibrils themselves are highly complex, comprising tiny protein crystals embedded in a shapeless matrix of tangled protein chains. These nanocrystals possess electrical charges that prevent the chains from slipping, thereby providing strength. The amorphous material surrounding the nanocrystals is rubbery, allowing the fiber to stretch.

Attempts at Replicating Spider Silk

Scientists have attempted to reproduce spider silk by forcing a solution of silk proteins, known as spidroin, through tiny holes. However, the resulting fibers are less than half as strong as those produced by spiders. It appears that spiders achieve the required complexity by ensuring the spidroin goes through a liquid crystal phase, similar to the phase used in Kevlar® manufacture. This liquid state aligns the protein molecules, forming nanocrystals and coiled nanofibrils. Researchers believe this occurs in the spider's long s-duct, where water is squeezed and pumped out. This process brings hydrophobic parts of the proteins to the surface, facilitating the formation of nanocrystals and enabling fiber formation.

The Purpose of Spiderwebs

While spiders predominantly use their webs for capturing insects and other prey, some baby spiders catch pollen for nourishment. This observation provides a potential clue regarding the pre-Fall function of spiderwebs.

Why This Matters

The incredible properties of spider silk highlight the superior design found in nature. The complexity and strength of spider silk far surpass anything humans have been able to create artificially. This serves as a testament to the ingenuity and wisdom of God as the ultimate designer.

Think About It

Consider how the intricate structure and properties of spider silk point to purposeful design rather than random chance. Does this reinforce your belief in a Creator?

Note: The above article is based on an archived piece published in Creation magazine in 2002. For more recent information on this topic, we recommend consulting up-to-date scientific research.

In summary, spider silk is an incredible material that surpasses man-made fibers in terms of strength and elasticity. Its superior properties, along with the environmentally friendly and efficient production process of spiders, suggest intelligent design. Spider silk serves as a testament to the Creator's wisdom and ingenuity, challenging us to consider the purpose behind its remarkable features.