Animal Architecture, Mike Hansell, 2005: Animal
Bukupedia , 25.05.2005 - 335 Seiten
My aim in this book is to investigate and celebrate the biology of animal architecture.
I believe that by writing this comprehensive overview, it can be seen
that this is a coherent biological topic which gives us important insights. I last
did this 20 years ago (Hansell 1984), so it is interesting for me not only to see
how much the subject has developed during that time, but also how my views
have changed too.
Animal builders are patchily distributed through the animal kingdom, but
research effort is also unevenly distributed within that. Spiders in particular
have received a lot of research attention, from the level of their building material
to the functional design of webs and their foraging ecology. Bird nests still
remain rather under-researched, but there is a flurry of exciting research on
bowerbird displays. The book reveals a need for more information in a number
of areas, for example, on the composition and properties of self-secreted
building materials other than silk, and the mechanical properties of nearly all
structures other than spider webs. On the other hand we now have a much
better understanding of how simple organisms can build large complex structures,
and there have been developments in the ecological and evolutionary
concepts of niche construction and ecological inheritance to which studies of
animal builders have contributed.
This book recognises three broad categories of structure: homes, traps and
displays. Chapter 1 looks at the functional role of these: homes to protect
builders from the hostile forces of the physical and biological world, foraging
and feeding assisted by burrowing or by the use of nets or webs, and structures
for intraspecific communication, in particular the displays of bowerbirds.
Chapter 2 tests predictions relating to building materials: that self-secreted
materials will tend to be more standardised and more complex than collected
materials and that, because of this, they will tend to be more characteristic of
dynamic structures like traps than of static ones, exemplified by houses. In
fact, collected materials prove to be quite highly standardised, while the synthesis
of self-secreted materials does show some flexibility.
The process of building is examined in Chapters 3 and 4. Building anatomy
is shown to be generally unspecialised for delicate manipulative skills but
modified for power in many burrowing species. Building behaviour is found
to be simple and repetitive. These findings support predictions I have previously
made (Hansell 1984, 2000). The creation of very large and complex
structures is shown to be possible largely through a dialogue between the
builder and the developing structure in which building actions in response to
local stimuli change the stimulus situation; complex architecture is an emergent
property of self-organising processes. These principles apply equally well
to building by large workforces of social insects as to single individuals.
Animal tools are considered in the light of these findings, because they are
generally regarded as important in the context of human evolution, in spite of
being small and often of simple construction. Some tool makers are found to
show evidence of advanced learning and cognition, but assessment of these
attributes in builders generally suffers from lack of evidence.
Mechanics, growth, and design are the subjects of Chapter 5. Animal homes
show how building rules can be conserved while the structures grow with the
size of the individual or colony occupying them. Spiders' webs provide models
for the study of engineering in tension, while display structures, in particular
those of bowerbirds, provide possible models for the investigation of the
evolution of an aesthetic sense. In Chapter 6, the cost of home building and
its trade-offs with other life history traits is examined using examples of birds'
nests and caddis cases; on trap building costs and their consequences, spider
webs again supply the majority of the evidence.
Buildings change the world both for builders and organisms that associate
with them. These are the themes of Chapters 7 and 8. Predictions (Hansell
1987a, 1993) that builders, as ecosystem engineers, will tend to stabilise habitats,
resist extinction, and promote biodiversity are examined. The last of these
is clearly supported, although this is found to be largely through facultative
associations by organisms with constructed habitat niches. The limitations of
animal built structures as evidence of phylogeny is discussed, and the concept
of a key adaptation examined with the conclusion that arthropod silk has the
strongest claim to this title. Evidence that building has contributed to social
evolution (Hansell 1987a) is found to be inconsistent. Finally, builders are seen
to alter the course of their own evolution through ecological inheritance, the
passing on to their descendents of habitats that they have altered.
Was andere dazu sagen - Rezension schreiben
nature origins and processing
behaviour and anatomy
4 Work organisation and building complexity
5 Mechanics growth and design
6 Building costs optimal solutions and tradeoffs
7 Animal architects as ecosystem engineers