Spider Silk Outshines Steel in Strength

The Darwin's bark spider, native to Madagascar, produces silk that surpasses steel in strength and toughness, making it the most resilient biological material discovered. This extraordinary silk is not universally produced by all spiders; research indicates that only large, adult female spiders spin these exceptionally strong threads. Their silk boasts a tensile strength approximately three times that of iron.

The production of this high-performance silk is metabolically costly, with specific proteins like proline contributing to its elasticity and strength. Scientists found that only large adult females weave this tougher silk, often in sparser web designs that maximize each thread's capacity to absorb force. Juvenile and male spiders, conversely, produce weaker, more dense webs.

This adaptation appears driven by the spiders' ecological role and body size. The superior silk is crucial for supporting the enormous webs spun by female Darwin's bark spiders, which can span up to 25 meters. This allows them to capture swarms of flying insects, a feat few other spiders can achieve. The strategy optimizes energy investment for greater survival advantage.