No evidence for magnetic field effects on the behaviour of Drosophila

Abstract

No evidence for magnetic field effects on the behaviour of Drosophila Bassetto M, Reichl T, Kobylkov D, Kattnig DR, Winklhofer M, Hore PJ, Mouritsen H. No evidence for magnetic field effects on the behaviour of Drosophila. Nature. 2023 Aug 9. doi: 10.1038/s41586-023-06397-7. Abstract Migratory songbirds have the remarkable ability to extract directional information from the Earth's magnetic field1,2. The exact mechanism of this light-dependent magnetic compass sense, however, is not fully understood. The most promising hypothesis focuses on the quantum spin dynamics of transient radical pairs formed in cryptochrome proteins in the retina3-5. Frustratingly, much of the supporting evidence for this theory is circumstantial, largely because of the extreme challenges posed by genetic modification of wild birds. Drosophila has therefore been recruited as a model organism, and several influential reports of cryptochrome- mediated magnetic field effects on fly behaviour have been widely interpreted as support for a radical pair- based mechanism in birds6-23. Here we report the results of an extensive study testing magnetic field effects on 97,658 flies moving in a two-arm maze and on 10,960 flies performing the spontaneous escape behaviour known as negative geotaxis. Under meticulously controlled conditions and with vast sample sizes, we have been unable to find evidence for magnetically sensitive behaviour in Drosophila. Moreover, after reassessment of the statistical approaches and sample sizes used in the studies that we tried to replicate, we suggest that many-if not all-of the original results were false positives. Our findings therefore cast considerable doubt on the existence of magnetic sensing in Drosophila and thus strongly suggest that night-migratory songbirds remain the organism of choice for elucidating the mechanism of light-dependent magnetoreception. pubmed.ncbi.nlm.nih.gov

AI evidence extraction

Main findings

In an extensive, meticulously controlled study, the authors report being unable to find evidence for magnetic-field-sensitive behaviour in Drosophila in either a two-arm maze assay or negative geotaxis. They also reassessed prior studies they attempted to replicate and suggest many or all original positive findings were false positives.

Outcomes measured

• behaviour in a two-arm maze
• negative geotaxis (spontaneous escape behaviour)
• evidence of magnetically sensitive behaviour / magnetic field effects on behaviour

{
    "study_type": "other",
    "exposure": {
        "band": null,
        "source": "magnetic field",
        "frequency_mhz": null,
        "sar_wkg": null,
        "duration": null
    },
    "population": "Drosophila (flies)",
    "sample_size": 108618,
    "outcomes": [
        "behaviour in a two-arm maze",
        "negative geotaxis (spontaneous escape behaviour)",
        "evidence of magnetically sensitive behaviour / magnetic field effects on behaviour"
    ],
    "main_findings": "In an extensive, meticulously controlled study, the authors report being unable to find evidence for magnetic-field-sensitive behaviour in Drosophila in either a two-arm maze assay or negative geotaxis. They also reassessed prior studies they attempted to replicate and suggest many or all original positive findings were false positives.",
    "effect_direction": "no_effect",
    "limitations": [],
    "evidence_strength": "moderate",
    "confidence": 0.7800000000000000266453525910037569701671600341796875,
    "peer_reviewed_likely": "yes",
    "keywords": [
        "magnetic field",
        "magnetoreception",
        "cryptochrome",
        "radical pair mechanism",
        "Drosophila",
        "behaviour",
        "two-arm maze",
        "negative geotaxis",
        "replication",
        "false positives"
    ],
    "suggested_hubs": []
}

Comments

Log in to comment.

No comments yet.