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Conservation Biology & Systematics
I. Systematics provides the basic system of nomenclature
II. Classifications allow biological prediction
III. Phylogenies allow biological prediction
IV. Relevance of existing taxonomy in conservation
A. Determining number of distinct biological entities or kinds
B. Determining taxonomic level of distinct evolutionary units
C. Bad taxonomy kills:
V. Species definitions
VI. Using phylogeny in conservation
VII. The agony of choice: prioritizing conservation actions
A. Choosing among areas
B. Choosing among taxa
VIII. Identifying lineage or phylogenetic effects
I.
Systematics provides the basic system of nomenclature:
* names and classifications are vehicles for information
storage and retrieval
* names are anchors to which we attach, search, and then
retrieve information
* provide framework into which samples are sorted and
stored
"Getting things by the right name is the beginning of knowledge"
paraphrased ancient Chinese saying
II. Classifications allow biological prediction
* biological classifications are fundamentally grounded
in hypotheses about common ancestry and presumed
evolutionary relationships
* natural classifications allow biological prediction that
can inform our research, hypothesis making, etc.
* every level in a hierarchical classification allows
prediction
Every level in a hierarchical classification allows prediction
Kingdom
Phylum
Class
Order
Family
Subfamily
Genus
Species
Animalia
Arthropoda
Insecta
Lepidoptera
Nymphalidae
Argynninae
Speyeria
idalia
III. Phylogenies allow biological prediction
* if (natural) classifications are good, phylogenies are even better
* phylogenies could be used to identify sister species/taxa
* learn much about rare species based on knowledge/experimentation with
its sister taxa
Example: Captive breeding protocols: in cases where little is known about
the biology of a rare or endangered animal, captive breeding protocols
might be established using the sister species.
* use life tables for related taxa to infer critical stages in a life cycle (that
might be amenable to management)
IV. Relevance of existing taxonomy in conservation
A. Determining number of distinct biological entities or kinds
* for better or worse, numbers of recognized species is common currency for
making conservation decisions (making policy, land use decisions, etc.)
B. Determining taxonomic level of a distinct biological entities
* The more distinct an entity, the higher taxonomic level that it is accorded
* Much of the Federal Endangered Species Act is about subspecific taxa
- 24/44 (55%) of the insects are imperiled subspecies
- unnamed vertebrate segregates can be protected under the ESA if they
can be shown to be genetically or otherwise distinct
- invertebrates and plants must be named entities
C. Bad taxonomy kills…
San Bruno Mountain, San Mateo, California
Taxonomic Level
“Good” Taxon
Laspeyresia edwardsii (lana)
species
no (Wagner)
Speyeria callippe callippe
subspecies
yes (Arnold)
Euphydryas editha bayensis
subspecies
yes (Ehrlich & Murphy)
no (Arnold)
Taxon
Tuatara (Sphenodon guntheri)
* disjunct populations (on different islands)
“lumped” in conservation legislation
* subsequent molecular data (Daugherty et
al. 1990) indicated three distinct lineages
- but molecular data came too late
- near extinction of one species and
probable loss of subspecies
V. Species definitions
* much of the above dependent on what definition
one adopts as a biologist or conservation biologist
* if you use BSC you’ll come to different
conclusions than if you were to adopt a
phylogenetic or cohesion species concept
* if phylogenetic species concept applied to birds,
arguably one of our best-studied groups, we would
see a significant increase in the number of bird
species…but would that be a bad thing?
Connecticut Trap Rock Butterflies
VI. Using phylogeny in conservation
* molecular systematics critical tool for recognizing Evolutionary
Significant Units (ESUs)
- thoroughly sample existing populations
- analyze for phylogenetic (or evolutionary) structure
* as noted above, existing taxonomy is often inadequate
- tuatara, a case in point
VII. The agony of choice
* in a perfect world we have enough money and time to preserve all
taxa or elements
* in reality we must make decisions and prioritize our efforts…the agony
of choice
* any number of political, social, economic, and scientific criteria bear on
our choices:
* even ignoring these there are multiple criteria for “choosing”
- vulnerability/susceptibility to extinction (for an area and/or a taxon)
- species richness (for an area)
- levels of endemism (for an area)
- ecological role or importance (for a taxon)
- evolutionary or ecological distinctiveness
- etc.
A. Criteria for choosing among areas:
1) identify and preserve biodiversity “hotspots”
- pick areas with high alpha diversity, e.g., Rio Madeira
drainage on the eastern slope of the Andes or Tambopata
Peru which has > 1250 species of butterflies—300 more
than all of North America
2) pick areas with high endemism, e.g., Transvaal in South
Africa is wildly diverse but even more importantly has
incredible levels of endemism
3) complementarity
- maximize representation by picking areas that complement
one another
High Endemism: South Africa
Eastern transvaal
Pitch pine scrub oak community below Mansfield Hollow Dam
Reserve Complementarity: Vane-Wright, Humphries, Williams et al.
Area
Total No.
Species
Previously
Unrepresented
Occurrences
Myles Standish State Forest
60
-
Otis Air Force Base
50
3
Martha's Vineyard State Forest
38
5
Montague, MA
35
3
Westfield, MA
12
1
Method:
a. determine taxic diversity
b. first priority is area with highest species diversity
c. second area would have next highest complimentary diversity
--not the area with second highest diversity
d. not yet represented species are recalculated at each step
B. Choosing among taxa
* not all taxa are equal
* some are more biologically distinct than others
- systematics, and in particular phylogeny, can
play a central role in making conservation
decisions
* early methods used branching pattern (cladogram)
- simply counted nodes, e.g. Vane-Wright et al
* isolated taxa got higher priority
* taxa closer to tips accorded less weight
* newer methods employing branch lengths
* also efforts to consider biological novelty
Preserving evolutionary frontiers
* Erwin (1991) warns that emphasis on basal and isolated branches may be wrong
- What if unique basal lineage are merely “living fossils?”
- Might such taxa be ecologically doomed…
evolutionary dead ends in today’s world?
- They are interesting and worthy of protection, but perhaps they are on their
way out
* Should we not also be preserving taxa and associated areas that show recent
speciation?
- they may be the future, the evolutionary frontline, the source of burgeoning
species biodiversity
* evolutionary equivalent to identifying an evolutionary “hotspot”
Interesting issue: Should we be preserving the pattern or should we be protecting the
process?
Faith 1992, 1994, and 1996 key proponent of using branch lengths and
“feature diversity” to prioritize conservation decisions
* Patristic distance (branch lengths) generally correlate with ecological,
behavioral, and morphological diversity:
“The features are not directly countable; instead, general feature diversity
patterns are predictable from phylogenetic information. Because branch
lengths in cladistics predict the relative number of times that one feature
changes into another, the phylogenetic diversity of subset of taxa is given
by the total of the lengths of those branches on the cladogram that are
spanned by the subset. A subset of taxa with high phylogenetic diversity
therefore is expected to have correspondingly high feature diversity
(Faith 1992).”
VIII. Lineage or Phylogenetic Effects
* Are certain clades more susceptible to extinction?
* If they are, maybe it pays for conservation biologists to pay attention
to phylogeny
* Among North American Butterflies: blue and fritillary butterflies are
much higher rates of imperilment: 20% of all blues are in trouble
* 70% of all NA mussels are imperiled (or extinct)
* dusky wing (Erynnis) butterflies and stalk borer (Papaipema) moths in
CT
* suggests a historical or phylogenetic component to extinction risk.
- liken to a cancer risk factor: they don’t tell you why
only to watch out
* Once clades are identified we can look for susceptibility factors
- “What factors are shared by all members of a clade in trouble?”
SELECTIVE PATTERNS OF
IMPERILMENT AMONG THE
BUTTERFLY SPECIES OF EASTERN
NORTH AMERICA
Objectives
• Identify species characteristics and ecological associations (i.e.,
niche parameters) that distinguish imperiled species from those
that are not
• Statistically separate the effects of these factors in order to
determine their relative importance
• Predict the conservation status of individual species
• Hypothesize causal mechanisms for the observed relationships
between niche parameters and imperilment
Species Characteristics and
Ecological Associations
• Size of geographic range
• Host plant specificity (number of host
plant genera)
• Habitat associations
• Habitat specificity
• Mean number of annual broods
• Average wingspan
• Number of congeners
• Taxonomic family
A few summary points:
Taxonomy provides basis for many conservation actions/decisions
Existing nomenclatures, with all their shortcomings, still carry considerable amounts of
information
But be aware: existing classifications are often inadequate (tuatara)
Use population data/structure to identify important ESU’s
Systematics and the “Agony of Choice.” Use cladograms/phylogenies to
evaluate patristic distance (evolutionary distinctiveness)
identify evolutionary frontiers
Phylogenies can help identify clades with high extinction risk