acknowledged that most of the defining characters of bacteria were negative and so
were of no phylogenetic value. The new technique of electron microscopy had,
however, clearly shown clear differences between bacterial cells and those of protists
and yeasts. This solved the long-standing dispute about the true relationship of bluegreen bacteria (later cyanobacteria) to nonphotosynthetic bacteria and algae. These
authors argued that the terms prokaryote and eukaryote, adopted from Édouard
Chatton, should be used to distinguish these two types of cellular life. Although
they did not seem to ascribe any evolutionary significance to this grouping, they did
mention that the two groups likely had separate evolutionary histories, implying an
evolutionary coherence within each lineage, a notion later proven false.
Stanier later confessed that he was not proud of his 1941 paper (Stanier 1980). He
had persuaded van Niel to put his name on it, which was unlike van Niel to
do. Stanier considered that work to be “the last gasp (at least in bacteriology) of
speculative ‘phylogenetic’ system-building before molecular biology took over and
brought some solid facts to the assessment of evolutionary relationships.” Stanier
was a bit harsh on himself in this remembrance. In 1941 he was a 25-year-old
student, only a few years into the study of microbiology, so the speculations of an
excited, naive student can be forgiven.
Others continued the challenge of puzzling out the early evolution of life, using
sometimes creative reasoning. Geneticist Norman Horowitz, who had shown that
biochemical processes occurred in pathways of enzymes each encoded by single
genes, proposed in 1945 that pathways had evolved in the reverse direction of their
current activity (Horowitz 1945). He did not, though, link this evolutionary process
to any organisms and so did not contribute to the search for bacterial evolutionary
relationships. In the same year, forensic chemist Erik M. P. Widmark said he did not
believe that chemicals could have come together to form living matter, what he
considered the disproven notion of spontaneous generation (Widmark 1945).
Instead, reviving the spirit of Lamarck fully (though not acknowledging it), he
said that life arose through a manifestation of a “vital principle.” He went on to
state that, “Evolution, if such exists, has for its sole object the creation of the ideal
vital substance.” Microbiologist Darryl C. Reanny wrote an unusual treatise on
bacterial evolution that posited that bacteria arose from a eukaryote-like ancestor
that lost genes through genetic streamlining (Reanney 1974).
2.7 The “Dark Ages” of Bacterial Evolution Studies
Carl Woese named the state of mid-twentieth-century microbiological science as the
“Dark Ages” of bacterial evolution studies (Woese 1994). Although this is an
exaggerated characterization, it is true that this was a time that serious study of
bacterial evolution diminished to short musings in the Discussion sections of
research articles about how the biochemical phenomenon of the article might have
arisen during evolution. There were some who still wrote longer treatises on the
evolution of specific microbial traits or process. Engelbert Broda was prolific in this,
36
K. M. Noll
were of no phylogenetic value. The new technique of electron microscopy had,
however, clearly shown clear differences between bacterial cells and those of protists
and yeasts. This solved the long-standing dispute about the true relationship of bluegreen bacteria (later cyanobacteria) to nonphotosynthetic bacteria and algae. These
authors argued that the terms prokaryote and eukaryote, adopted from Édouard
Chatton, should be used to distinguish these two types of cellular life. Although
they did not seem to ascribe any evolutionary significance to this grouping, they did
mention that the two groups likely had separate evolutionary histories, implying an
evolutionary coherence within each lineage, a notion later proven false.
Stanier later confessed that he was not proud of his 1941 paper (Stanier 1980). He
had persuaded van Niel to put his name on it, which was unlike van Niel to
do. Stanier considered that work to be “the last gasp (at least in bacteriology) of
speculative ‘phylogenetic’ system-building before molecular biology took over and
brought some solid facts to the assessment of evolutionary relationships.” Stanier
was a bit harsh on himself in this remembrance. In 1941 he was a 25-year-old
student, only a few years into the study of microbiology, so the speculations of an
excited, naive student can be forgiven.
Others continued the challenge of puzzling out the early evolution of life, using
sometimes creative reasoning. Geneticist Norman Horowitz, who had shown that
biochemical processes occurred in pathways of enzymes each encoded by single
genes, proposed in 1945 that pathways had evolved in the reverse direction of their
current activity (Horowitz 1945). He did not, though, link this evolutionary process
to any organisms and so did not contribute to the search for bacterial evolutionary
relationships. In the same year, forensic chemist Erik M. P. Widmark said he did not
believe that chemicals could have come together to form living matter, what he
considered the disproven notion of spontaneous generation (Widmark 1945).
Instead, reviving the spirit of Lamarck fully (though not acknowledging it), he
said that life arose through a manifestation of a “vital principle.” He went on to
state that, “Evolution, if such exists, has for its sole object the creation of the ideal
vital substance.” Microbiologist Darryl C. Reanny wrote an unusual treatise on
bacterial evolution that posited that bacteria arose from a eukaryote-like ancestor
that lost genes through genetic streamlining (Reanney 1974).
2.7 The “Dark Ages” of Bacterial Evolution Studies
Carl Woese named the state of mid-twentieth-century microbiological science as the
“Dark Ages” of bacterial evolution studies (Woese 1994). Although this is an
exaggerated characterization, it is true that this was a time that serious study of
bacterial evolution diminished to short musings in the Discussion sections of
research articles about how the biochemical phenomenon of the article might have
arisen during evolution. There were some who still wrote longer treatises on the
evolution of specific microbial traits or process. Engelbert Broda was prolific in this,
36
K. M. Noll