Relevance: GS III (Science & Tech – Bio-inspiration; Ecology) | Source: The Hindu / Integrative Zoology

1. The Human Context: A Female “Superpower”

In the forests of Madagascar, a biological marvel exists. The Darwin’s Bark Spider weaves webs that span entire rivers—up to 25 meters wide.

• The Feat: Its silk is the toughest biological material known to science—three times tougher than steel.
• The Discovery: A new study reveals a fascinating gender gap: only adult females possess this “superpower.” Males and younger spiders produce much weaker silk.

2. The Science: Why So Tough?

• The Secret Ingredient: The female’s silk is packed with Proline, an amino acid that acts like a microscopic spring, giving the web extreme elasticity.
• The Trade-off: Making Proline is expensive (high energy cost).
• Ecological Logic:
  • Females: They are giants (compared to males) and need to build massive bridges across rivers to catch large prey like dragonflies. They choose “Quality over Quantity,” making less silk but ensuring it’s unbreakable.
  • Males: Their main job is reproduction. They don’t need to build mega-structures, so they don’t waste energy on “super-silk.”

3. Why It Matters (Biomimicry)

• This isn’t just spider trivia. Understanding how the female spider “switches on” this high-performance gene could help scientists engineer synthetic super-materials—like lighter bulletproof vests or stronger surgical sutures.

UPSC Value Box

Q. With reference to the “Darwin’s Bark Spider” (Caerostris darwini), recently seen in the news, consider the following statements:

1. It is an endemic species found exclusively in the rainforests of Madagascar.
2. The silk produced by this species is known to be tougher than steel and Kevlar.
3. Recent studies indicate that the high toughness of the silk is unique to the adult males of the species.

Which of the statements given above is/are correct?

(a) 1 only

(b) 1 and 2 only

(c) 2 and 3 only

(d) 1, 2 and 3

Correct Answer: (b)