Copyright ©2006 NPR. For personal, noncommercial use only. See Terms of Use. For other uses, prior permission required.


This is DAY TO DAY I'm Mike Pesca.


And I'm Madeleine Brand. And now a story Spiderman would love. Scientists have discovered a tarantula that shoots webs from its toes.

NPR's David Malakoff reports.

DAVID MALAKOFF: The discovery that the toes of the Costa Rican Zebra Tarantula have comic book powers was a bit of a fluke.

Professor ADAM SUMMERS (University of California): The bizarre result came about in the most wonderful of serendipitous ways.

MALAKOFF: Adam Summers is a biologist at the University of California in Irvine. He's on the tarantula research team and he says a technician working with Stanislav Gorb of the Max Planck Institutes in Germany was making tarantulas walk across glass plates. He was studying how spiders get traction. And when the technician wanted to take a break he'd simply tilt the glass up at an angle.

Prof. SUMMERS: Tarantula spiders are quite worried about falling. And so if you tilt the glass up, they'll stop and they'll adhere with all eight legs as hard as they can; and this is actually an easier way to immobilize a tarantula than to pick it up and put it back in its cage and then go on your break.

MALAKOFF: One day, the technician came back from his break and noticed something unusual.

Prof. SUMMERS: The tarantula had slid backwards. All eight legs had slid and at the tip of each foot you could see an array of tiny pieces of silk - silk production from the completely the wrong end of the animal.

MALAKOFF: The strands of toe silk are tiny, almost invisible, which is why nobody noticed them before. But Summers said they clearly help the spider keep its footing. And the toe silk may provide hints about spider evolution. It could be he speculates...

Prof. SUMMERS: That what we're seeing in the tarantula feet is the most ancestral use of silk. That is silk evolved as a gluey adhesive and it became elaborated into the seven different kinds of silk that a spider might produce.

MALAKOFF: The tarantula study appears in the current issue of the journal Nature.

David Malakoff NPR News.

Copyright © 2006 NPR. All rights reserved. No quotes from the materials contained herein may be used in any media without attribution to NPR. This transcript is provided for personal, noncommercial use only, pursuant to our Terms of Use. Any other use requires NPR's prior permission. Visit our permissions page for further information.

NPR transcripts are created on a rush deadline by a contractor for NPR, and accuracy and availability may vary. This text may not be in its final form and may be updated or revised in the future. Please be aware that the authoritative record of NPR's programming is the audio.



Please keep your community civil. All comments must follow the Community rules and terms of use, and will be moderated prior to posting. NPR reserves the right to use the comments we receive, in whole or in part, and to use the commenter's name and location, in any medium. See also the Terms of Use, Privacy Policy and Community FAQ.