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sition information to be detected when the spatial resolution of the data is sufficient
to capture individuals.
7.5 Cautionary Notes
The integration of leaf spectra and phylogenies can provide breakthroughs in how
we detect biodiversity, explain how spectral variation between species and lineages comes to be, and make inferences about the evolution of leaves. We should,
nevertheless, be aware of the limitations inherent in making inferences about the
deep past, be mindful of the sampling requirements and statistical assumptions of
our analyses, and be careful to interpret our findings in a biologically meaningful way.
7.5.1 Is the Sampling Adequate for Making Evolutionary
Inferences?
Inferences about the evolutionary process or that rely heavily on it—such as the
degree of phylogenetic signal or the pace of evolution—are dependent on how
well a lineage has been sampled. Evolutionary biologists usually target a particular lineage and strive to include in their analysis as many close relatives as possible regardless of their location. Ecologists, on the other hand, tend to focus on a
specific geographic area of interest and end up sampling whatever species are
there. This likely results in very severe undersampling of the total phylogenetic
diversity represented by the particular species pool. For example, the 20 seed
plants at a study site belong to a clade that has about 300,000 species, harbors
incredible morphological and physiological diversity, and goes back 350 million
years. Evolutionary analyses of undersampled will very likely yield poor estimates of the evolutionary parameters: The species in that area can tolerate a subset of all the climate conditions other seed plants can handle, for example.
In addition, ecological processes themselves can lead to bias in estimates of evolutionary parameters. For example, extremely arid conditions may act as an environmental filter that curbs colonization by species with low leaf water content, reducing
the amount of variability in leaf succulence. As a consequence, estimates of the rate
of evolution of leaf succulence based on species found in that hyper-arid community
may be artificially low.
These caveats should be kept in mind when analyzing spectra in an evolutionary
context. Finding that certain spectral regions have high phylogenetic signal in a
large forest plot does not necessarily mean that those regions are truly phylogenetically conserved.
J. E. Meireles et al.
sition information to be detected when the spatial resolution of the data is sufficient
to capture individuals.
7.5 Cautionary Notes
The integration of leaf spectra and phylogenies can provide breakthroughs in how
we detect biodiversity, explain how spectral variation between species and lineages comes to be, and make inferences about the evolution of leaves. We should,
nevertheless, be aware of the limitations inherent in making inferences about the
deep past, be mindful of the sampling requirements and statistical assumptions of
our analyses, and be careful to interpret our findings in a biologically meaningful way.
7.5.1 Is the Sampling Adequate for Making Evolutionary
Inferences?
Inferences about the evolutionary process or that rely heavily on it—such as the
degree of phylogenetic signal or the pace of evolution—are dependent on how
well a lineage has been sampled. Evolutionary biologists usually target a particular lineage and strive to include in their analysis as many close relatives as possible regardless of their location. Ecologists, on the other hand, tend to focus on a
specific geographic area of interest and end up sampling whatever species are
there. This likely results in very severe undersampling of the total phylogenetic
diversity represented by the particular species pool. For example, the 20 seed
plants at a study site belong to a clade that has about 300,000 species, harbors
incredible morphological and physiological diversity, and goes back 350 million
years. Evolutionary analyses of undersampled will very likely yield poor estimates of the evolutionary parameters: The species in that area can tolerate a subset of all the climate conditions other seed plants can handle, for example.
In addition, ecological processes themselves can lead to bias in estimates of evolutionary parameters. For example, extremely arid conditions may act as an environmental filter that curbs colonization by species with low leaf water content, reducing
the amount of variability in leaf succulence. As a consequence, estimates of the rate
of evolution of leaf succulence based on species found in that hyper-arid community
may be artificially low.
These caveats should be kept in mind when analyzing spectra in an evolutionary
context. Finding that certain spectral regions have high phylogenetic signal in a
large forest plot does not necessarily mean that those regions are truly phylogenetically conserved.
J. E. Meireles et al.