170
7. EPILOGUE
translocation of nutrients in marine sessile organisms, for example stony
corals. In for example the accretive growth models presented in Sect. 4.6
one of the basic assumptions is that translocation can be neglected and that
local growth velocities can be directly related to locally absorbed food particles or local light intensities. It not yet clear how important is the role and
the magnitude of translocation of nutrients in sponges and stony corals. In
Sect. 2.2.3 it was demonstrated that fluid transport in the gastrovascular system of colonial hydrozoans controls morphological plasticity. One approach
for investigating the importance of this phenomenon is to develop simulations in which a certain translocation parameter is included and to study the
impact on morphogenesis. To be able to verify the assumed translocation
factors, actual measurements are required.
GENETIC REGULATION OF GROWTH AND FORM. In the Sect. 2.2.4 on genetic regulation in sponges and stony corals it is demonstrated that there is,
albeit fragmentary, knowledge available on the biological regulation of the
growth process. In order to capture the genetic regulation of growth and
form in simulation models, much more detailed information is required on
the developmental biology of marine sessile organisms. Especially when it
is possible to translate the biological regulation into a diffusive patterning
mechanism, as for example was done in the preliminary experiments with
the isomone model in Sect. 4.6.6, it seems to be feasible to include the effect
of biological regulation in models. Of course one of the weak points in this
example is that the physical carrier of the growth regulation, the isom one, is
still to be discovered.
IMPACT OF HYDRODYNAMIC FORCES ON GROWTH AND FORM. From
Sect. 2.1.1 it becomes clear that the flexibility in many of the marine sessile
organisms and the physical stress due to hydrodynamic forces have a major
impact on the growth process. Inclusion of hydrodynamic forces and mechanical effects, for example deformation and physical damage, in growth
models may provide new insights into the role of these biomechanical effects
in the growth process. In Sect. 4.3.1 on computational methods for modeling
and simulating the influence of hydrodynamics, it was mentioned that one
of the advantages of the lattice Boltzmann method is that during the computation of the flow velocities, the values of the local hydrodynamic forces are
already more or less available "for free". This indicates that a model of the
impact of hydrodynamic forces on the growth process, using the lattice Boltzmann method, and a comparison to in vivo in vitro measurements, could be
an interesting option.
EFFECTS OF LIVING TISSUE IN GROWTH MODELS OF STONY CORALS. In
Sect. 2.2.3 it was mentioned that corals cannot grow tissue without skeleton
and they cannot grow skeleton without tissue. Also in Sect. 6.2 on the coral
records the role of living tissue was mentioned. Until now in all growth
models the effects of living tissue were neglected. Particularly in models of
Porites, which have an important application in investigating bioarchives, it
is clear that living tissue should also be included in the models.
BASIC TYPES OF GROWTH PROCESSES. When looking in detail at the level
of cells (meristems in seaweeds) or skeleton elements in sponges and corals,
7. EPILOGUE
translocation of nutrients in marine sessile organisms, for example stony
corals. In for example the accretive growth models presented in Sect. 4.6
one of the basic assumptions is that translocation can be neglected and that
local growth velocities can be directly related to locally absorbed food particles or local light intensities. It not yet clear how important is the role and
the magnitude of translocation of nutrients in sponges and stony corals. In
Sect. 2.2.3 it was demonstrated that fluid transport in the gastrovascular system of colonial hydrozoans controls morphological plasticity. One approach
for investigating the importance of this phenomenon is to develop simulations in which a certain translocation parameter is included and to study the
impact on morphogenesis. To be able to verify the assumed translocation
factors, actual measurements are required.
GENETIC REGULATION OF GROWTH AND FORM. In the Sect. 2.2.4 on genetic regulation in sponges and stony corals it is demonstrated that there is,
albeit fragmentary, knowledge available on the biological regulation of the
growth process. In order to capture the genetic regulation of growth and
form in simulation models, much more detailed information is required on
the developmental biology of marine sessile organisms. Especially when it
is possible to translate the biological regulation into a diffusive patterning
mechanism, as for example was done in the preliminary experiments with
the isomone model in Sect. 4.6.6, it seems to be feasible to include the effect
of biological regulation in models. Of course one of the weak points in this
example is that the physical carrier of the growth regulation, the isom one, is
still to be discovered.
IMPACT OF HYDRODYNAMIC FORCES ON GROWTH AND FORM. From
Sect. 2.1.1 it becomes clear that the flexibility in many of the marine sessile
organisms and the physical stress due to hydrodynamic forces have a major
impact on the growth process. Inclusion of hydrodynamic forces and mechanical effects, for example deformation and physical damage, in growth
models may provide new insights into the role of these biomechanical effects
in the growth process. In Sect. 4.3.1 on computational methods for modeling
and simulating the influence of hydrodynamics, it was mentioned that one
of the advantages of the lattice Boltzmann method is that during the computation of the flow velocities, the values of the local hydrodynamic forces are
already more or less available "for free". This indicates that a model of the
impact of hydrodynamic forces on the growth process, using the lattice Boltzmann method, and a comparison to in vivo in vitro measurements, could be
an interesting option.
EFFECTS OF LIVING TISSUE IN GROWTH MODELS OF STONY CORALS. In
Sect. 2.2.3 it was mentioned that corals cannot grow tissue without skeleton
and they cannot grow skeleton without tissue. Also in Sect. 6.2 on the coral
records the role of living tissue was mentioned. Until now in all growth
models the effects of living tissue were neglected. Particularly in models of
Porites, which have an important application in investigating bioarchives, it
is clear that living tissue should also be included in the models.
BASIC TYPES OF GROWTH PROCESSES. When looking in detail at the level
of cells (meristems in seaweeds) or skeleton elements in sponges and corals,