Government views Monarch Butterfly Releases as a threat to We stern Milkweeds

[Patrick Foley]

Dear Lepsters,

As Paul Cherubini must well remember, I have contested Bruce Walsh's claims that small
amounts of displaced Monarch release do not confuse phylogeographic studies. Consult the
archive for more.

The sampling argument is just bad. Outliers are often used to understand the rare gene
flow events that do characterize metapopulations. See the work of Sewall Wright or
volumes edited by Ilkka Hanski and Michael Gilpin. Rare alleles are specifically used in
the methods of Montgomery Slatkin (UCBerkeley) to detect gene flow. Why not ask Monty
what he thinks about the subject?

DNA techniques are wonderful and improving, and as we gather more data using them, we
will increasingly detect the influence of releases, without being able to distinguish
these effects from natural migration.

Clearly Bruce and Paul want to have it both ways: 1) Our techniques are so bad that we
won't even sample the release effects and 2) The old flawed techniques are giving way to
new and improved techniques.

Perhaps scientists should give up studying the Monarch. I am willing to concede that
scientific research should not always trump the needs of wedding planners. But it is just
self-delusion to believe that artificial migration will not confuse studies of natural
migration.

And yes I do distinguish anthropogenic butterfly "migration" as unnatural. So are
landfills.

Patrick Foley
patfoley at csus.edu

Paul Cherubini wrote:

> Ken Kaufman wrote:
>
> > Paul,  Thank you for passing along this very well reasoned opinion
> > from Dr. Karen Oberhauser.  Her points are certainly persuasive,
> > and provide more strong reasons to avoid shipping Monarchs any
> > distance for release.  I'm glad to see you providing something
> > useful to the discussion this time.
>
> Ken, I personally have a difficult time understanding the scientific basis of
> Dr. Karen Oberhauser's concerns. I ask myself, are they reasonable, legitimate
> scientific concerns based on a negligible risk standard or are they questionable
> concerns based on a zero risk standard?  Perhaps you can help me understand
> the scientific basis of some of Dr. Karen Oberhauser's concerns.
>
> Karen says "there is evidence that monarchs become genetically differentiated
> [based on the old, 1978  method of using  protein (electrophoretic) markers]
> by the end of the summer," and "If shipping monarchs from Minnesota to
> Maine has even the slightest chance of disupting genetic structure, or of
> making it difficult to study that structure, I don't think we should do it."
>
> Ken, what I'd like you to do (or anyone else on the list) is is explain
> how a modest amount of human assisted shipping of Minnesota
> monarchs to Maine (or vice versa) has even a slight chance of disrupting
> the genetic structure of the recipient population or how these introductions could
> make it difficult for a researcher to study that structure in late summer?
>
> Dr. Bruce Walsh at the  University of Arizona, Tucson, offered
> the following analysis of these questions last year:
>
> Bruce wrote:
>
> "The short answer to the issue of releases confusing studies of local population
> structure is that this is indeed correct with the older methods of using protein
> markers (electrophoretic markers) to look at population structure. However,
> the point is somewhat moot for several reasons.
>
> First, releases are likely to be such a very small proportion of the population
> as to not likely be sampled in any random sample of the population used to
> examine local structure.
>
> Second, suppose that indeed a very genetically different strain is released
> and somehow incorporated into a random sample from the population that
> is used for looking at population structure. Typically, researchers use
> genetic markers to reconstruct what amounts to a phylogenetic tree of
> relationships among individuals (marker genotypes) in the sample. Any
> distinct individual from the new population will show up as major outliners on
> the tree, with no connecting individuals. If such a tree is not attempted to be
> reconstruct, these individuals can give larger Fst (a statistical for population
> structure) than is indicated by the true population. However, studies failing to
> attempt to reconstruct the local phylogeny are very poorly done and are unlikely
> to be published under today's standards.
>
> Third, DNA markers are now the norm. Unlike protein markers, one
> can use dead museum material in many cases for DNA. Hence,
> material predating any release is likely available if the research simply
> looks in local collections. Further, using tightly-linked genetic
> markers (SNPs, for single nucleotide polymorphisms), it is again
> straightforward to find those individuals that are very distinct, and
> again we expect gaps between the local individuals and the released
> individuals.
>
> In summary, unless the released material makes up a significant fraction
> of the local breeding population (at least over 1 percent and likely over 5 percent),
> it is unlikely to be obtained in a random population sample. Even if such
> distinct genotypes are included, standard methods using DNA markers
> to look at population substructure can detect such extreme, outliers, and
> hence these do not compromise the studies."
>
>
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