[Taxacom] Review of Reinvention of Australasian Biogeography

John Grehan calabar.john at gmail.com
Mon Jun 12 18:59:02 CDT 2017


Book Review Biogeography Comes of Age Down Under: Review of Reinvention of
Australasian Biogeography – Reform, Revolt, and Rebellion, 2017 by Malte
Ebach. CSIRO Publishing, Clayton South, Victoria. 180.pages.

from Botanical Society of Otago newsletter 81: 17-18 (pdf copy at
http://www.johngrehan.net/files/6314/9731/0105/Reinvention_Australasian_biogeography.pdf
)

One sign that Australasian biogeography has come of age is that it has now
become the subject of a history. With Malte Ebach's intriguing new book,
the science of biogeography in Australia and New Zealand may be said to
have reached this threshold. Its geography may suggest that Australasia is
a remote backwater, but Ebach‟s book shows that its biogeography is well
established, diverse, dynamic, controversial, and above all an integral
part of the major theories and practices of global evolutionary biology.

Malte Ebach is a biogeographer at the University of New South Wales and has
a long history of investigating the theory and methods of biogeography and
systematics (see http://mcebach.net/). In Reinvention of Australasian
Biogeography, Ebach avoids a linear narrative and focuses on the way the
work of many biogeographers, including many in the present, have only
repeated earlier mistakes or problems. Biogeography is one of those
subjects in which nearly all natural historians have a strong opinion, and
it is probably impossible to ever write a truly dispassionate account.
Ebach‟s book begins by presenting the thesis that establishing a natural
biogeographic classification is essential for a scientific biogeography.
Reinvention of Australasian Biogeography then illustrates the diversity of
efforts to create natural biogeographic regions in Australasia and the
inherent difficulties in identifying criteria for recognising biogeographic
areas that are truly natural. Ebach shows how the construction of these
various areas, regions, and biomes has been strongly influenced by theories
about where and how ancestors originated. The development of biogeographic
classification has been a major concern for many prominent Australasian
biogeographers, including the influential works of Sir Charles Fleming in
New Zealand, although panbiogeographers have focused on biogeographic nodes
rather than on defining areas.

The biogeographic classifications of Australasia that were made in the 19th
and early 20th century provide a historical context for the chapters of
Ebach‟s book that examine three principal themes in Australasian
biogeography. The first theme is the increasing acceptance of cladistic
principles by Australian researchers in the 1970s and 1980s that led to the
equal treatment of fossil and living taxa in the construction of
phylogenetic trees and the analysis of biogeographic patterns. The second
theme concerns the development of panbiogeography in New Zealand beginning
in the late 1970‟s. Ebach recognises this approach, with its focus on
distribution patterns, as a major effort to avoid the history of
biogeographic reinvention. He notes that despite its wide development and
application, particularly among research students, the approach was
successfully stifled by established scientists.

The third of Ebach‟s themes is the continued prominence of dispersalism in
New Zealand biogeography. This theory is maintained in a new form,
"neodispersalism‟, which relies on fossil-calibrated molecular clocks to
provide actual dates of origin, and assumes that the location of endemics
is explained by their physical movement. While the involvement of molecular
technology in neodispersalism gives the appearance of progress, Reinvention
of June 2017 BSO Newsletter 81 18 Australasian Biogeography illustrates how
its application to Australasia actually represents a reinvention of a
twentieth century notion: the idea that all endemic plants and animals in
New Zealand must have arrived from somewhere else. Ebach draws attention to
the latest, molecular-enhanced version of this theory, the idea that New
Zealand was entirely submerged in the Oligocene and so all its biota must
have dispersed to the islands. Nevertheless, it is now clear that there is
no supporting biogeographic and or geological evidence.

Ebach concludes that rather than advancing biogeography, adopting such
molecular approaches has meant that neodispersalism simply reinvents the
theory and practice of early twentieth century palaeontology. Ebach
concludes his book by returning to a theme presented at the beginning,
namely that the future of biogeography lies in moving away from creating
narratives to developing an analytical framework. His preferred framework
is to identify the relationships between areas as represented by the
phylogenetic relationships of their taxa. Conflicting patterns of
relationships for multiple taxa indicate the existence of artificial areas
(such as Australia or New Zealand), while matching (congruent) patterns
support the existence of actual areas. While this method is described in
its broad outlines, its detailed application to the biogeography of
Australasia remains for the future.

Naturally a book that focuses on the perspectives of biogeographers as well
as actual practice is going to arouse strong responses - whether positive
or negative. While I do quite strongly disagree with some of the views
expressed in this book, I found the attempt to outline the theoretical
themes connecting individual biogeographers to be refreshing. Perhaps the
principle weakness, though, was the attempt to assess the contributions of
panbiogeography (particularly with respect to the extensive analyses of
Australasian, New Zealand, and pantropical patterns) in relation to those
of area cladistics, the method that Ebach favours. Whatever one‟s
perspective may be on this and other issues, this book will provide
excellent material for further debate, perhaps assisted by a good kiwi
beer.


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