Reviewed by Gehan de Silva Wijeyeratne
Fjeldså, J., Christidis, L. & Ericson,
P.G.P. Eds. (2020). The Largest Avian Radiation: The Evolution of Perching
Birds, or the Order Passeriformes. Lynx Edicions, Barcelona. Pages 445.
This book is an excellent example of how to make deep science less intimidating. I had wondered how Lynx Edicions that had carved a niche for being at the interface between hard science and popular natural history would tackle a subject that would appear to most people to be dense and impenetrable. Superb design and excellent writing and editing have resulted in a book which not only keen birders but others interested in topics such as speciation and biogeography would find interesting.
The first thing that strikes you
about the book is the design. Chapters and section headings are announced in
capital letters in bright colours. There is generous use of delightful bird
illustrations (by the multi-talented Jon Fjeldså, the lead editor) which
although accurate have a lightness that leans towards arty than illustrative.
All of this creates the right ‘mood music’ for anyone who may have been otherwise
intimidated by the prospect of delving into the details of molecular
phylogenetics.
Over the years, many books, in
particular those in the excellent Helm Family Monograph series have included
introductory sections or chapters explaining molecular phylogenetics. Many
books on birders’ bookshelves also contain the branching diagrams or
phylogenetic trees arising from genetic studies. Furthermore, attendees of
popular talks at the more serious end of ornithology are also used to
discussions on molecular phylogenetics. Technical knowledge in the world of
birding has come a long way in the last few decades and I suspect most birders
will be comfortable with the vast majority of the text in this book. However, I
would caution this is not a book for everyone with an interest in birds. You
need to be someone who is already following with interest, the science behind
splits and lumps at species level to follow the discussions in this book although
the book is focussed at the higher taxonomic levels of families.
The book is in three sections.
Most people may find that this book can be approached by reading ‘Section 1
Background’ followed by ‘Section 3. Thematic chapters’. At the core of the book is ‘Section 2.
Classification and families of passerine birds’ (pages 45- 318). Section 2
begins with an ‘An Updated Classification of Passerine Birds’ which discusses
past attempts to classify the passerines and concludes with a new family tree
that shows various higher taxonomic levels including suborders, infraorders,
parvorders, superfamilies, subfamilies and families. The design is excellent
and uses indentation, boldfacing and colours to help with easy and comfortable
visual navigation. Chapters 6 to 14 discuss each family of passerines. The
families are grouped in the chapters under higher taxonomic groupings. For
example, chapter 8 is titled the ‘Cohort Corvoides: the crow like passerines’.
Whether you have a special interest in a family, or doing some background
reading in anticipation of seeing new families on a forthcoming birding trip or
one of the growing band of birders who are trying to see every bird family,
these chapters will be of absorbing interest, provided you are not fazed by a
sciencey text. If the presence of bracketed citations and the phylogenetic
diagrams are ignored, almost all of the text is readable to a keen birder of
the sort who would be subscribing to a journal like ‘British Birds’. Occasionally
a family account may have extensive discussion on revisions based on molecular
phylogenetics; examples include the sunbirds and tanagers. Admittedly, these can be heavy reading.
Although this is a book on
passerine birds, the first four chapters will be useful reading to anyone with
an interest in any animal groups, especially vertebrates. There is useful
background information here on systematics and taxonomy and forces behind
evolutionary change. We also learn of the important role of New Guinea as a
staging post for the passerines to spread across the world from an origin in
the Southern Hemisphere. ‘Section 3. Thematic chapters’ (pages 319 to 369) and
the first of two appendices (on a short earth history) also have useful
background information. Chapter 15 on ‘The worldwide variation in biodiversity:
some central questions and concepts’ and chapter 16 on ‘How new species evolve’
with their chapter headings, give a clear sign on the many interesting topics
that are covered in these chapters. Having lived on islands, discussions on
speciation models are of particular interest to me. But even a large continent
like Africa has over geological time functioned as a patchwork of ecologically
isolated areas or islands which has given rise to a number of endemic animals
which are confined to limited areas. Island geography or more generally
geographical isolation is not the only factor in speciation and chapter 16 also
discusses factors such as song in the speciation process. One thing I would
have liked to have seen included is a Geological Time Scale. I printed one off
the internet to make it easier for me to follow some of the time scales
discussed in various chapters.
The references in the end
sections are extensive (pages 397 to 432) and reinforce the point that this
book is a synthesis of the work of over a thousand papers published on
passerine molecular phylogenetics. But as the editors note, this is only a
stock take of work done so far and further advances will arise from whole
genome sequencing. The lack of a good fossil record and other issues in
constructing a molecular phylogeny means that the exact placement of some avian
families is still uncertain. An example being the Kinglets or Crests (family
Regulidae). This is a family I
am familiar with as its members include the Goldcrest, a bird I encounter in
parks with conifers in London. As with many family accounts, there is an
evocative introduction to the family followed by the nitty gritty of molecular
phylogenetics. In this case the surprising conclusion is that the placement of
the family is still unresolved. All birders have their favourite bird families
and will find it easy to be absorbed by the family accounts of their favourite
families.
On the whole it is a remarkable
book for its contribution of deep science and insights made accessible to
serious birders through good writing and design. I suspect no other group of
biological organisms has a cutting edge science book of this genre devoted to
it that is aimed at a popular market. The book also casts a light on birders as
being a sociological phenomenon. Birders are an economically very valuable
group of hobbyists who number in the several hundred thousand and are a subset
of a few million birdwatchers world-wide. They generate millions of dollars in
revenue for industry sectors from tourism to publishing. But interestingly, probably
no other special interest group of this number of adherents follows the outcomes
of cutting edge science with such keen interest.
