Parallel Saltational Evolution of Ultrafast Movements in Snapping Shrimp Claws

Parallel Saltational Evolution of Ultrafast Movements in Snapping Shrimp Claws How do stunning functional innovations evolve from unspecialized progenitors? This puzzle is particularly acute for ultrafast movements of appendages in arthropods as diverse as shrimps [1], stomatopods [2], insects [3–6], and spiders [7]. For example, the spectacular snapping claws of alpheid shrimps close so fast (∼0.5 ms) that jetted water creates a cavitation bubble and an immensely powerful snap upon bubble collapse [1]. Such extreme movements depend on (1) an energy-storage mechanism (e.g., some kind of spring) and (2) a latching mechanism to release stored energy quickly [8]. Clearly, rapid claw closure must have evolved before the ability to snap, but its evolutionary origins are unknown. Unearthing the functional mechanics of transitional stages is therefore essential to understand how such radical novel abilities arise [9–11]. We reconstructed the evolutionary history of shrimp claw form and function by sampling 114 species from 19 families, including two unrelated families within which snapping evolved independently (Alpheidae and Palaemonidae) [12, 13]. Our comparative analyses, using micro-computed tomography (microCT) and confocal imaging, high-speed video, and kinematic experiments with select 3D-printed scale models, revealed a previously unrecognized “slip joint” in non-snapping shrimp claws. This slip joint facilitated the parallel evolution of a novel energy-storage and cocking mechanism—a torque-reversal joint—an apparent precondition for snapping. Remarkably, these key functional transitions between ancestral (simple pinching) and derived (snapping) claws were achieved by minute differences in joint structure. Therefore, subtle changes in form appear to have facilitated wholly novel functional change in a saltational manner. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Current Biology Elsevier

Parallel Saltational Evolution of Ultrafast Movements in Snapping Shrimp Claws

Loading next page...
 
/lp/elsevier/parallel-saltational-evolution-of-ultrafast-movements-in-snapping-ktSEBkvB5J
Publisher
Elsevier
Copyright
Copyright © 2017 The Authors
ISSN
0960-9822
D.O.I.
10.1016/j.cub.2017.11.044
Publisher site
See Article on Publisher Site

Abstract

How do stunning functional innovations evolve from unspecialized progenitors? This puzzle is particularly acute for ultrafast movements of appendages in arthropods as diverse as shrimps [1], stomatopods [2], insects [3–6], and spiders [7]. For example, the spectacular snapping claws of alpheid shrimps close so fast (∼0.5 ms) that jetted water creates a cavitation bubble and an immensely powerful snap upon bubble collapse [1]. Such extreme movements depend on (1) an energy-storage mechanism (e.g., some kind of spring) and (2) a latching mechanism to release stored energy quickly [8]. Clearly, rapid claw closure must have evolved before the ability to snap, but its evolutionary origins are unknown. Unearthing the functional mechanics of transitional stages is therefore essential to understand how such radical novel abilities arise [9–11]. We reconstructed the evolutionary history of shrimp claw form and function by sampling 114 species from 19 families, including two unrelated families within which snapping evolved independently (Alpheidae and Palaemonidae) [12, 13]. Our comparative analyses, using micro-computed tomography (microCT) and confocal imaging, high-speed video, and kinematic experiments with select 3D-printed scale models, revealed a previously unrecognized “slip joint” in non-snapping shrimp claws. This slip joint facilitated the parallel evolution of a novel energy-storage and cocking mechanism—a torque-reversal joint—an apparent precondition for snapping. Remarkably, these key functional transitions between ancestral (simple pinching) and derived (snapping) claws were achieved by minute differences in joint structure. Therefore, subtle changes in form appear to have facilitated wholly novel functional change in a saltational manner.

Journal

Current BiologyElsevier

Published: Jan 8, 2018

References

You’re reading a free preview. Subscribe to read the entire article.


DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Search

Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly

Organize

Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.

Access

Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

DeepDyve

Freelancer

DeepDyve

Pro

Price

FREE

$49/month
$360/year

Save searches from
Google Scholar,
PubMed

Create lists to
organize your research

Export lists, citations

Read DeepDyve articles

Abstract access only

Unlimited access to over
18 million full-text articles

Print

20 pages / month

PDF Discount

20% off