Archaeological Study Shows Human Activity May Have Boosted Shellfish Size

在一项违反直觉的发现中，北卡罗来纳州立大学的新研究表明，在过去3000年中，在太平洋地区广泛消费的一种贝类实际上已经增加了，尽管并且可能是由于该地区的人类活动增加了。

“What we’ve found indicates that human activity does not necessarily mean that there is going to be a negative impact on a species – even a species that people relied on as a major food source,” says Dr. Scott Fitzpatrick, associate professor of sociology and anthropology at NC State and co-author of the study. “The trends we see in the archaeological record in regard to animal remains are not always what one would expect.”

At issue is the humped conch,年代trombus gibberulus, a small mollusk that has been a food source in the Pacific islands for thousands of years. The researchers dated and measured more than 1,400 humped conch shells found at an archaeological site on the island of Palau in the western Pacific. They expected the size of the conchs to decrease over time, based on the conventional wisdom that an expanding human population would result in the conchs being harvested before they could achieve their maximum size.

取而代之的是，研究人员惊讶地发现，海螺的平均规模实际上随着人口不断增长的形式增加。具体而言，在过去的3000年中，平均海螺的长度增加了约1.5毫米（mm）。这听起来可能并不多，但是当您认为海螺仅约30毫米长时，这很重要 - 这意味着现在的海螺几乎比以前大了5％。

Fitzpatrick believes the size increase is likely related to an increase in nutrients in the conch’s waters, stemming from increased agriculture and other human activities.

“In the big picture,” Fitzpatrick says, “this study tells us to focus on the physical evidence and beware of conventional wisdom. It also tells us that using a large number of samples is important. Previous studies had shown a decline in conch size at Pacific archaeological sites – but they used smaller sample sizes. Maybe that is a factor in their findings.”

The study was co-authored by Fitzpatrick, Christina Giovas of the University of Washington, and two NC State undergraduates, Meagan Clark and Mira Abed. A paper describing the study, “Evidence for size increase in an exploited mollusk: humped conch (年代trombus gibberulus) at Chelechol ra Orrak, Palau from ca. 3000-0 BP,” will be published in a forthcoming issue of theJournal of Archaeological Science. The samples used in the study were collected as part of a National Science Foundation-funded research initiative.

NC State’s Department of Sociology and Anthropology is a joint department under the university’s College of Humanities and Social Sciences and College of Agriculture and Life Sciences.

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Note to editors:The study abstract follows.

“Evidence for size increase in an exploited mollusk: humped conch (Strombus gibberulus) at Chelechol ra Orrak, Palau from ca. 3000-0 BP”

Authors:克里斯蒂娜Giovas,华盛顿大学;年代cott M. Fitzpatrick, Meagan Clark, Mira Abed, North Carolina State University

Published: Forthcoming,Journal of Archaeological Science

Abstract:Past research has suggested that the humped conch (年代trombus gibberulus), a species common in many prehistoric archaeological sites in the Pacific, declines in size and/or abundance over time. Explanations for this phenomenon largely revolve around the possibility that they were overharvested by human populations. In this study, we measured the length and width of over 1400 individual specimens of年代. gibberulus贝壳从西密歇根州帕劳的Chelechol ra Orrak地点回收，可追溯到约。3000 bp到现在。统计分析表明，与以前的报告相比，该分类单元的大小增加，这可能是人为因素和环境因素组合的结果。我们讨论影响软体动物大小的变量，并建议，鉴于其相互作用的复杂性和考古学组合的数据限制，因此可能并非总是可能改变软体动物大小变化的原因的明确确定。