ISSN 1067-4136, Russian Journal of Ecology, 2017, Vol. 48, No. 1, pp. 1–9. © Pleiades Publishing, Ltd., 2017.
Original Russian Text © M.V. Kozlov, 2017, published in Ekologiya, 2017, No. 1, pp. 3–12.
Plant Studies on Fluctuating Asymmetry in Russia:
Mythology and Methodology
M. V. Kozlov
Section of Ecology, University of Turku, 20014 Turku, Finland
Received May 20, 2015
Abstract—A critical analysis of studies addressing f luctuating asymmetry (FA) of plant leaves, published
recently in Russia, demonstrated that most of these studies are based on insufficiently substantiated assump-
tions, employ outdated or inadequate methodology and do not contain sufficient information to support the
use of the reported results in further reviews and meta-analyses. Contrary to widespread opinion, the current
level of knowledge does not allow practical use of FA for bioindication. This use will only be possible after
controlled experiments verify the cause-and-effect relationships between the levels of FA and the impacts of
different stressors on plants. An adequate assessment of FA requires repeated, high precision measurements,
which should be conducted blindly. In this treatise, I discuss the prospective directions for FA research in
plants and provide recommendations on experimental design, data analysis and presentation of the results in
Keywords: bioindication, reproducibility, pollution, research methodology, environmental stress
Fluctuating asymmetry (FA) is defined as a small
and non-directional deviation from perfect symmetry in
morphological characters. This deviation is commonly
considered to arise from the decreased ability of an
organism to control its development when under genetic
or environmental stress (Palmer and Strobeck, 1986;
Zakharov, 1987; Møller and Swaddle, 1997). The his-
tory of FA studies was reviewed by Lajus et al. (2009).
The first FA studies, which reported increased FA
values in different organisms from disturbed habitats,
resulted in numerous recommendations for the use of
FA as an index of stress experienced by plants and ani-
mals (Zakharov, 1990; Clarke, 1992; Parsons, 1992;
Freeman et al., 1993; Zakharov and Clark, 1993;
Zakharov et al., 2000; Hume, 2001). In Russia, these
recommendations were approved at the governmental
level (Metodicheskie …, 2003), a quite unusual occur-
rence for ecological research methods. To the best of
my knowledge, no other countries have officially rec-
ommended methods for studying FA.
Studies addressing FA became widely popular
among Russian scientists, resulting in a rapid increase
in the number of publications on the topic. My estima-
tion is that, to date, Russian scientists have published
at least 500 papers on FA. The Russian scientific elec-
tronic library (elibrary.ru) lists 303 articles published
in Russian from 2001–2014 that contain the keywords
“fluctuating asymmetry”. The activity of Russian
researchers in this field, according to elibrary.ru, con-
tinues to grow rapidly: from 8 publications annually
from 2001–2009 to 45 publications annually from
2010–2014. Of these, approximately half are on plants.
However, this intensive accumulation of data has not
been accompanied by extensive analysis, as evidenced
by the absence of reviews (except for Lajus et al., 2009)
and theoretical generalisations.
In this review, I use publications that have explored
bilateral FA in plant leaves to analyse the methodology
employed by Russian scientists, to identify the com-
mon problems in data collection, analysis and presen-
tation of the results, and to suggest solutions for these
The characteristics of papers on plant FA were
obtained by analysing scientific publications in peri-
odicals from 2010–2014. A random sample of 50 pub-
lications in Russian was made from 122 references
found in elibrary.ru. This sample was compared with
the 34 papers published in English during the same
period by foreign authors and listed in the ISI Web of
Science database. In both databases, I searched for the
keywords “fluctuating asymmetry” (in Russian and
English, respectively) and then checked the identified
papers for their suitability for the planned analysis.
This approach allowed a comparison of the character-
istics of the Russian- and English-language publica-
tions and generalisation of the conclusions.
The article was translated by the author.