Monday, 27 May 2019

The Conversation/Marcus Byrne: There’s still so much we don’t know about the star-gazing beetle with a tiny brain

The Conversation

    Edition:

Available editions
Africa

    Job Board

    Become an author
    Sign up as a reader
    Sign in

The Conversation
Academic rigour, journalistic flair

    Arts + Culture
    Business + Economy
    Education
    Environment + Energy
    Health + Medicine
    Politics + Society
    Science + Technology
    In French

There’s still so much we don’t know about the star-gazing beetle with a tiny brain
May 26, 2019 11.05am SAST
Author

    Marcus Byrne

    Professor of Zoology and Entomology, University of the Witwatersrand

Disclosure statement

Marcus Byrne receives funding from the South African National Research Foundation.
Partners

University of the Witwatersrand

University of the Witwatersrand provides support as a hosting partner of The Conversation AFRICA.

The Conversation is funded by the National Research Foundation, eight universities, including the Cape Peninsula University of Technology, Rhodes University, Stellenbosch University and the Universities of Cape Town, Johannesburg, Kwa-Zulu Natal, Pretoria, and South Africa. It is hosted by the Universities of the Witwatersrand and Western Cape, the African Population and Health Research Centre and the Nigerian Academy of Science. The Bill & Melinda Gates Foundation is a Strategic Partner. more
Republish this article

Republish our articles for free, online or in print, under Creative Commons licence.
A dung beetle wearing silicon boots to protect its feet from the hot soil, as part of an experiment. Courtesy of Adrian Bailey/baileyphotos.com

    Email
    Twitter6
    Facebook52
    LinkedIn
    Print

Edited extract from “The Dance of the Dung Beetles” published by Wits University Press.

Dung beetles have been ever-present in the history of the West – but oddly, less so elsewhere – in religion, art, literature, science and the environment. What we understand about them now mirrors our greater understanding of the important role they play in keeping our planet healthy.

The story of these beetles, which we tell in our new book “The Dance of the Dung Beetles”, comes with a few unexpected twists. It moves from the tombs of the pharaohs to the drawing rooms of directors of the Dutch East India Company to the remote forests of Madagascar. It is a big story carried on the back of a family of small creatures who seldom diverge from their dogged pursuit of dung in its infinite variety and abundant supply.

Like the housemaids of Victorian Britain, who tended fires and households in the small hours while the Empire swept across the globe, they remain largely unseen and ignored. Yet without those housemaids, the world would have a lot more dirt in it. In the same way, dung beetles are largely invisible. And yet without their vital activities, the world would have a lot more faeces in it.
More than “dung-grubbers”

Dung beetles have relatively minuscule brains, much of which is devoted to analysing smells. But they also process visual information that even humans with their vast brains struggle to comprehend. This was shown in a study we conducted with other scientists that revealed how dung beetles use the light of the Milky Way to orientate.

Read more: Scientists have worked out how dung beetles use the Milky Way to hold their course

The original story was picked up way beyond the scientific literature and spread rapidly around the world. We were struck by how the tale of a lowly beetle and the distant Milky Way engaged popular imagination when so much other information about dung beetles is equally impressive, if not even more fascinating.
Wearing a cap prevents this beetle seeing orientation cues in the sky. As a consequence it rolls its ball around in circles, like a human lost in a featureless desert. Courtesy Marcus Byrne

This realisation prompted us to respond on behalf of these little creatures, which can be found on every continent except Antarctica, to show that they deserve better press than to be seen as mere dung-grubbers – some of whom happen to orientate by the stars.

Together with earthworms and ants, dung beetles represent a trinity of earth transformers. They literally change the earth beneath us, and they do so at absolutely no cost to us. Dung beetles play a largely unexplored role in soil health, which is increasingly important in a hungry world full of people. There is still so much we do not know about the 6,000 species that clean our world.

We do not know, for example, exactly what they eat. Most eat dung, some eat carrion (dead animals). But getting by on low nutrient waste requires careful selective feeding performed by specialised mouth parts. Microorganisms in the dung and soil might also have a role, fixing nitrogen from the atmosphere to increase food quality and soil health.

We know how dung beetles use celestial cues to orientate, but it’s not clear how a brain so small can process or remember such information. We know they are attracted to the smell of dung, but we do not really understand how that works, or if that sense switches off when they turn their attention to the visual task of rolling a dung ball. Does their neural limitation preclude parallel processing of disparate information?
Evolution of science

In our history of the development of contemporary science, we have seen the evolution of belief in magic, to one of stocktaking and empirical observation, to interpretation and deepening levels of sophisticated tunnelling into the smallest known particles. We have gone from myth, symbols, vague observation and interpretation of a world run by the gods, to a world with one God, and then a world in which the boundaries of religion no longer act as the limit to our knowledge.

The quest for money rather than scientific or natural interests drove much early exploration. Gold, and then trade, became the vehicles for global expansion and settlement. The knowledge we now have of how the world works comes with the recognition that so much of what there is, is threatened by the very pursuits that opened up our world.

It is an irony that cannot be lost on us as we look at the growing list of flora and fauna on the brink of destruction and extinction. The relevance to what we still do not know about creatures as small and seemingly insignificant as dung beetles is that we are beginning to understand what German naturalist and artist Maria Sibylla Merian showed in her paintings: that the world is deeply and fundamentally interconnected.

Biological evolution represents the history of a dynamic process – but evolution has its own timetable. So, even though many creatures can adapt relatively rapidly to the environmental changes we have induced, there are hundreds of thousands of species that cannot. Dung beetles are however, excellent models of rapid evolution and speciation.

The development of the magnificent horn of many dung beetles can be switched on or off in the same gene carried by males and female dung beetles, allowing natural selection – that is, chances of survival – to be balanced against sexual selection (chances of reproducing) in different habitats. The export of dung beetles to different continents, for control of dung-breeding flies, has created a massive natural experiment which will eventually reveal which way evolution will drive those species.

If we need a reminder of how much we do not know, then the study of one little sub-family of unseemly beetles is instructive. Their endless complexity and variety has absorbed the energies of so many researchers across the globe since the Egyptian Horapollo recorded the first observation of them rolling their ball “from East to West, looking himself towards the East” 3,000 years ago.

Dr Helen Lunn co-authored “The Dance of the Dung Beetles”, which is published by Wits University Press.

    Milky Way
    Evolution
    Biodiversity
    Species
    Beetles
    Dung beetles

    Tweet
    Share
    Get newsletter

You might also like
As the dust of the election settles, Australia’s wildlife still needs a pathway for recovery
I’m an evolutionary biologist – here’s why this ancient fungal fossil discovery is so revealing
An outlaw yeast thrives with genetic chaos – and could provide clues for understanding cancer growth
Biodiversity loss has finally got political – and this means new thinking on the left and the right
Sign in to comment
1 Comment
Oldest Newest

    Marguerite Garling

    inscrit via Google

    Sitting round a campfire deep in the Sahara desert many years ago, we were told the stories of Hamfoussa the dungbeetle, who survives through persistence, cunning and intelligence. Ever since then, I’ve had a soft spot for this little critter. I’m glad to hear s/he has book devoted to these attributes.
    4 hours ago
    Report

Most popular on The Conversation

    Kipchoge’s marathon success remains a mystery: some clues from my research
    Africa has lost Binyavanga Wainaina. But his spirit will continue to inspire
    South Africa has a new presidential advisory unit. Will it improve policy?
    Data fails to capture complexity of South Africa’s unemployment crisis
    Radical ideas are needed to break the DRC’s Ebola outbreak. Here are some

    Ramaphosa’s cabinet: who and what’s needed to end South Africa’s malaise
    There’s still so much we don’t know about the star-gazing beetle with a tiny brain
    How do Nigerian gay and bisexual men cope? This is what they told us
    Why the Indian Ocean is spawning strong and deadly tropical cyclones
    First ladies in Africa: a close look at how three have wielded influence

Expert Database

    Find experts with knowledge in:*

Want to write?

Write an article and join a growing community of more than 84,500 academics and researchers from 2,854 institutions.

Register now
The Conversation
Community

    Community standards
    Republishing guidelines
    Research and Expert Database
    Analytics
    Job Board
    Our feeds

Company

    Who we are
    Our charter
    Our team
    Partners and funders
    Resource for media
    Contact us

Stay informed and subscribe to our free daily newsletter and get the latest analysis and commentary directly in your inbox.
Email address
Follow us on social media

Privacy policy Terms and conditions Corrections

Copyright © 2010–2019, The Conversation Africa, Inc.

No comments: