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Body Painting and Insect Attraction: A Look at Culture as Adaptation

Mercado, Anica (2018) BION01 20161
Degree Projects in Biology
Abstract
Horse flies and other biting Diptera are not only annoying pests, but can inflict numerous diseases on the people and animals they bite. Studies in recent years have shown horse flies are less attracted to striped surfaces, providing evidential support that zebra stripes have evolved as biting fly protection. The Omo River Valley tribes in the historical zebra range of southwest Ethiopia regularly paint themselves in stripes, and may have been doing so for thousands of years. Whether this cultural act gains the same biological benefit of biting fly protection is the focus of this thesis.
To fully explore this theory, a review on the hypotheses of zebra stripes, history of body painting and modification, with a focus on Africa, and the... (More)
Horse flies and other biting Diptera are not only annoying pests, but can inflict numerous diseases on the people and animals they bite. Studies in recent years have shown horse flies are less attracted to striped surfaces, providing evidential support that zebra stripes have evolved as biting fly protection. The Omo River Valley tribes in the historical zebra range of southwest Ethiopia regularly paint themselves in stripes, and may have been doing so for thousands of years. Whether this cultural act gains the same biological benefit of biting fly protection is the focus of this thesis.
To fully explore this theory, a review on the hypotheses of zebra stripes, history of body painting and modification, with a focus on Africa, and the theory of culture as a biological process are examined. Two experiments were conducted, testing horse fly attraction on various models of body modifications found in the Omo River Valley. An analysis and interpretation of the experimental results and their implication on the hypothesis is performed, as well as a literature overview. While results from the experiments were inconclusive, future studies in this area would further our understanding of biting fly behavior, provide possible solutions to reduce bite frequency, and aid in preserving and documenting disappearing cultural traditions of the region. (Less)
Popular Abstract
Evolution’s Helping Hand? Body Paint and Insect Attraction

Have you ever wondered why zebras have stripes? You’re not alone, as Darwin himself argued over why evolution would allow such a strange and striking thing to occur. Though many theories still abound, recent research shows that biting flies, such as horse flies, avoid stripes and subsequently the zebras that sport them. A body of stripes is not unique to zebras though; people around the world have been covering their bodies with stripes through paint, tattoos, and scarification for thousands of years.

Is it possible striped body art provides the same protection against these painful and potentially disease-carrying bites? It isn’t outside the realm of possibility, or even... (More)
Evolution’s Helping Hand? Body Paint and Insect Attraction

Have you ever wondered why zebras have stripes? You’re not alone, as Darwin himself argued over why evolution would allow such a strange and striking thing to occur. Though many theories still abound, recent research shows that biting flies, such as horse flies, avoid stripes and subsequently the zebras that sport them. A body of stripes is not unique to zebras though; people around the world have been covering their bodies with stripes through paint, tattoos, and scarification for thousands of years.

Is it possible striped body art provides the same protection against these painful and potentially disease-carrying bites? It isn’t outside the realm of possibility, or even that far-fetched. While other animals have evolved physical changes over time to live in specific habitats, it is argued we used our big brains to change our culture and behavior to adapt instead. This allowed for much quicker changes than the slower process of evolution could manage. As a result, humans live and thrive in more environments than any other species on the planet, from the Kalahari Desert to the Arctic Circle.

Covering the body in stripes could be one of these adaptive behaviors, people painting like zebras to keep biting flies at bay. To test the theory, inflatable mannequins and wooden boards were painted in different patterns based off of body painting in eastern Africa, both historically and today. These were then covered in glue and put in the field for a month to catch horse flies.

Unfortunately, the weather was mostly cloudy, windy, and rainy, the exact opposite of what horse flies prefer. They made up only seven of the nearly 7,000 insects that were caught. However, robber and snipe flies, hoverflies, wasps, and other flies came out in force. They mostly preferred to land on the plain white and striped patterns over the pure black or red.

While it is still possible the stripes protect against biting flies, like they do with zebras, it might be at a cost, since it seems to attract more pest flies. Red, a common painting pattern seen throughout much of Africa, was shown in other studies to prevent mosquito bites almost as effectively as commercial insect repellent. Perhaps red manages to be unattractive to both biting flies and pest flies, which could be why it is more commonly practiced. Further studies are needed, but knowing more about what these flies avoid could be an important additional tool to helping prevent dangerous insect bites and their diseases.

Master’s Degree Project in Biology, 45 credits, 2018
Department of Biology, Lund University

Advisor: Susanne Åkesson
Evolutionary Ecology (Less)
Please use this url to cite or link to this publication:
author
Mercado, Anica
supervisor
organization
course
BION01 20161
year
type
H2 - Master's Degree (Two Years)
subject
language
English
id
8935602
date added to LUP
2018-02-12 13:56:55
date last changed
2018-02-12 13:56:55
@misc{8935602,
  abstract     = {Horse flies and other biting Diptera are not only annoying pests, but can inflict numerous diseases on the people and animals they bite. Studies in recent years have shown horse flies are less attracted to striped surfaces, providing evidential support that zebra stripes have evolved as biting fly protection. The Omo River Valley tribes in the historical zebra range of southwest Ethiopia regularly paint themselves in stripes, and may have been doing so for thousands of years. Whether this cultural act gains the same biological benefit of biting fly protection is the focus of this thesis.
To fully explore this theory, a review on the hypotheses of zebra stripes, history of body painting and modification, with a focus on Africa, and the theory of culture as a biological process are examined. Two experiments were conducted, testing horse fly attraction on various models of body modifications found in the Omo River Valley. An analysis and interpretation of the experimental results and their implication on the hypothesis is performed, as well as a literature overview. While results from the experiments were inconclusive, future studies in this area would further our understanding of biting fly behavior, provide possible solutions to reduce bite frequency, and aid in preserving and documenting disappearing cultural traditions of the region.},
  author       = {Mercado, Anica},
  language     = {eng},
  note         = {Student Paper},
  title        = {Body Painting and Insect Attraction: A Look at Culture as Adaptation},
  year         = {2018},
}