Editor's Note. Word has reached us of the death of Dr. George Ang Te, who
passed away late last year in New Hamburg, NY at the age of 67. Although I never met him, George Te’s
1970s-era research on the worldwide Physidae was a significant influence on my
professional career. In this final
installment of our three-part series, we examine Te’s 1978 dissertation, and
his continuing legacy. Subsequently published as: Dillon, R.T., Jr. (2019b) To identify a Physa, 1978. Pp 181-188 in Freshwater Gastropods of North America Volume 2, Essays on the Pulmonates. FWGNA Press, Charleston.
In the 1970s everybody was in love with computers. There was just the one computer on the
Virginia Tech campus, and it was a huge IBM 360/370, with walls of blinking
lights and massive tape drives. And if
you wanted to use it, you pretty much had to write the FORTRAN code yourself. There were a few “canned” statistical
packages available in those days, but even to use canned programs, you had to
write your own job control language. And
you had to punch your own cards, in a big room full of keypunch machines – one
line of code or data per card. And you
needed an “account” to use the machine.
(Tech undergraduates were allocated $25 per quarter.) And you left your deck of cards at the input
desk, and came back the next day, hoping to find a thick stack of tractor-feed
paper with meaningful results in your cubby.
I usually found two-page bombs, with unintelligible error codes, and
hefty charges to my account for the service.
I loved computers in the 1970s.
In the 1970s the world of systematic biology was completely
consumed by warfare between the forces of phenetics and the forces of cladistics. Phenetic analysis was seamlessly able to
bring the power of electronic computing to bear on problems of
classification. Pheneticists told us to count,
measure or score 100 characters on 100 “operational taxonomic units,” punch our
cards, and let the room full of blinking machinery objectively classify our
OTUs by their overall similarity.
But whatever else the world of systematic biology was
focused upon in the 1970s, organisms were not it. The process of classification was important,
and the OTUs being classified, not so much.
And it was into this world that George Te stepped when he entered the
PhD program at the University of Michigan in the fall of 1971.
So in addition to J. B. Burch, serving on George Te’s PhD
committee were two much-decorated officers in the cladist army, Warren (“Herb”)
Wagner and George Estabrook. Wagner was
an exellent botanist, carried to stardom by an algorithm to estimate
phylogenetic relationships that became known as “Wagner parsimony.” Estabrook was a computer scientist, entirely
unsullied by any taint of organismal biology, with a head full of very original
ideas for estimating cladistic classifications based on character
compatibility. And I think it was
primarily Estabrook’s influence that ultimately turned George Te’s dissertation
focus, and indeed George Te himself, away from biology.
But he made a promising start at it. Last month [1] we reviewed Te’s (1975) survey
of the Physidae of Michigan, which I characterized as “the zenith of classical
malacology in North America.” So broadening
his scope toward a dissertation, Te expanded his regional survey to include
12,163 museum lots of worldwide physids from seven major museums, among which
he initially recognized 85 “basic taxa.”
For these 85 basic taxa he scored 71 characters: 37 of shell and 34 of
anatomy, each character taking some number of discrete “states” [2].
Estabrook gave George Te two sets of computer programs, one
phenetic and the other cladistic. The
former was called “Simgra,” a quirky method of clustering OTUs by a matrix of
similarity coefficients. The latter was
a two-part affair, Estabrook’s test for character compatibilities followed by a
J. S. Farris routine to extract “cliques.”
The meat of Te’s dissertation was what can only be
characterized as methodological gear-grinding, the details of which simply do
not matter today. But what ultimately popped
out of the roomful of blinking machinery was a reduced set of 48 “species
units,” in five groups with two outliers.
See George Te’s Figure 42, scanned above.
Throughout this retrospective I have tried to refrain, as
much as humanly possible, from judging George Te by 21st century
standards. But I ordered a copy of his
dissertation from University Microfilms in 1982, and my contemporary
impressions of the work were profoundly mixed.
Te’s dissertation did include at least one significant
advance – the description of a fifth type of penial morphology, which he called
“type-bc, indicating its intermediate nature.”
This was the basis of his physid “Group V – the cubensis group.” He misclassified most of the species in the
group, including cubensis. But his
characterization of this intermediate-but-nonetheless-distinct morphology
provided a critical clue to Amy Wethington and me as we began our work on the
specific relationships among southeastern physids 20 years later [3].
On the other hand, however, it was as clear to me 30 years ago
as it is today that the distinctions between most of George Te’s 48 “species
units” were largely illusory and entirely undocumented. Te recognized 27 species units in his “Group
IV – acuta” group, for example. For OTU-66
acuta itself, he wrote “appears to be part of the heterostropha continuum…but
is geographically disjunct … and is therefore treated here as separate [4].” For OTU-50 concolor, he wrote “forms part of
the heterostropha continuum, and is the predominant taxon with the type-c
penial complex in the northwest.” He
observed that OTU-60 virgata “is the principal southwestern North American
component of the heterostropha continuum,” and that OTU-52 osculans “is the
predominant taxon of the heterostropha continuum in Mexico,” and that OTU-68
pomilia “is part of the heterostropha continuum and is a southeastern
geographic variant of OTU-70 heterostropha.”
And on and on he went. Surprisingly,
he wrote “OTU-71 integra is a predominant Group IV taxon in the Midwest, and is
not part of the heterostropha continuum.”
It was extremely frustrating to me in 1982 that, although George
Te explicitly stated that his observations quoted above were based on 33
nominal acuta specimens, 13 concolor, 24 virgata, 19 osculans, 29 pomilia, 28
integra, and so forth, he did not tell us where any of his samples came from,
and so we who followed him could not verify his observations for ourselves. With the benefit of 30 years’ hindsight, we
now understand that acuta, heterostropha, virgata [7] and integra are
conspecific. We do not know about
osculans or concolor [8]. But we do know
that pomilia is a distinct species [9], correctly classified in Group V, not
Group IV, and the inescapable conclusion must be that none of the 29 individual
snails Te examined came from a bona fide pomilia population.
But returning to contemporary times, my bottom line
impression of George Te’s 1978 dissertation was one of disappointment. It could not be used to identify a
Physa. Which is all I ever really wanted
it to do.
And can 48 meaningless OTUs be classified in some meaningful
way? Te proposed a system of two
subfamilies, four genera, three subgenera, and two “sections,” which yielded
the seven baskets he needed for his 48 “species units.”
But by the date of his defense, in December of 1978, it
seems clear to me that George Te’s interests had strayed afield from systematic
biology, and toward computer science. Of
the 324 pages comprising his dissertation, over 35% were devoted to analytical
arcana. His section on phenetic
relationships, for example, was 54 pages of “Simgra” results, showing dozens of
“linkage diagrams” at various “similarity levels.” The roomful of blinking, spinning machinery
was beginning to carry George Te away.
His dissertation [10] was never published. All that ultimately emerged was a six page paper
in Archiv fur Molluskenkunde, entitled “New classification system for the
family Physidae” [11]. By the 1979 date
of that publication, George Te was giving his address as University of Michigan
Department of Computer Science.
But to his tiny, obscure 1979 paper must (in all fairness)
be added the entire treatment of the Physidae in J. B. Burch’s immensely
influential “North American Freshwater Snails,” which first appeared as an EPA
publication in 1982. George Te’s dissertation
results became the de facto standard for the classification of the Physidae in
the United States, right up in the pantheon beside Baker’s Lymnaeidae, Basch’s
Ancylidae, and Goodrich’s Pleuroceridae.
And that quirky physid classification, for all its faults and failings, was
the only system adopted by Burch that was, in any sense, objective.
I never met George Te.
But he was, by all accounts, a very nice man. And he was extremely helpful to me at an
early stage of my career. In a span of
just eight years, from 1971 – 1978, he was able to bring order out of taxonomic
chaos in one of the most important elements of the North American freshwater
benthic fauna. He advanced our
science. Rest in peace.
Notes
[2] If this essay were really about George Te’s
classification, we’d stop right here. Only
14 of his 71 characters were legitimately discrete, and his character scoring
system was a nightmare, and his entire analysis a house of cards. But in 2014 it just doesn’t matter.
[3] Wethington, A.R., J. Wise, and R. T. Dillon (2009)
Genetic and morphological characterization of the Physidae of South Carolina
(Pulmonata: Basommatophora), with description of a new species. The Nautilus 123: 282-292. [PDF]
- True Confessions - I described a new species [7Apr10]
“Although OTU-66 acuta is widely introduced to many parts of the world, its occurrence in North America has rarely been reported. Considering the amount of transaction between Europe and North America, the absence of OTU-66 acuta in North America is puzzling. The logical conclusion is that where OUT-66 acuta has been introduced in North America, it probably interbred and merged with indigenous North American “Physa” (i.e., those taxa in the heterostropha continuum).”
It was not until 2002 that we finally
confirmed heterostropha to be conspecific with acuta [5]. Te was a good, conscientious worker, and his
observations have substantial scientific value, in direct contrast to some of
his contemporaries, who just made stuff up [6].
[5] Dillon, R. T., A. R. Wethington, J. M. Rhett and T. P.
Smith. (2002) Populations of the European freshwater
pulmonate Physa acuta are not reproductively isolated from American Physa
heterostropha or Physa integra.
Invertebrate Biology 121: 226-234.
[PDF]
[6] See footnote #10 in this essay:
- Red Flags, Water Resources, and Physa natricina [12Mar08]
[8] The nomen “concolor” is my lead candidate for the “Snake
River acuta-like Physa” or “SRALP,” about which I posted a big series last year:
- The mystery of the SRALP – A bidding [5Feb13]
- The mystery of the SRALP – A twofold quest! [1Mar13]
- The mystery of the SRALP – Dixie cup showdown [2Apr13]
- The mystery of the SRALP - “No Physa acuta were found” [2May13]
[10] Te, G. A.
(1978) A systematic study of the
Physidae. Ph.D. Dissertation, University
of Michigan, Ann Arbor. 324 pp.
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