I would think a natural predator - like man or beast - otter....seal -
stopped
eating the larger ones and they just kept growing.

Martin

Allen Aigen wrote:
> The New York Times Science section(March 24)has a short note: Hidden in Plain Sight, a Bigger Shell on a Snail Facing a New Predator.  Jonathon A.D. Fisher, Queens University, Ontario, Peter S. Petraitis, University of Pennsylvania et al, in the Proceedings of the National Academy of Sciences, reported that Nucella lapillus (Atlantic Dogwinkle, an intertidal muricid) on Mount Desert Island, Maine, increased in length by about 23% since collections made in 1915-1923.  This is reported to be an apparent result of adaptation to the introduced crab Carcinus maenus which preys on the smaller specimens.  Therer is no indication in the article if there was a change in the genetics of the snail or if the variability was part of the genotype, waiting for a need to be expressed.
>
> Allen Aigen
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--
Martin H. Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
TSRA, Endowed; NRA LOH & Patron Member, Golden Eagle, Patriot's Medal.
NRA Second Amendment Task Force Charter Founder
IHMSA and NRA Metallic Silhouette maker & member.
http://lufkinced.com/

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