[Originally published in Nov. 2014 as Evolution of Insect Genetics]
Charles Darwin‘s fascination with insects began early in life. While studying at Cambridge University, his interest continued in earnest, sending James Francis Stephens, his professor of entomology (insects), specimens, and descriptions of the critters. At the time, discussing the evolution of insect genetics would have been as relevant as discussing moon landings.
Just months before setting sail on the HMS Beagle in 1831, Stevens published his recognition of
Darwin’s work on insects in his widely-popular Illustrations of British Entomology. Steven’s recognition fostered Darwin’s emerging credibility. In his autobiography, Darwin noted:
No pursuit at Cambridge was followed with nearly so much eagerness or gave me so much pleasure as collecting beetles.
During his 5-year voyage, Darwin’s “eagerness” for collecting insects continued. These were stored in crates and sent back to England for further study along with myriad other specimens. Various naturalists, including Darwin, later illustrated many specimens and sometimes accompanied them with a description.
Despite more than a century of study, however, not a single insect tree of life has withstood the test of time. Finally, scientists now have the tools to study the evolution of insect genetics to reveal insights into their evolutionary secrets.
The journal Science earlier this month published the most extensive insect genetics study ever undertaken. The study involved more than 100 scientists from 10 countries examining phylogenetics [phylo meaning family, race, tribe, or kind; genetics meaning “the genetic properties and phenomena of an organism] of 1,000 insect species — called the 1KITE project.
The project’s initial goal, launched in 2012, centered on tracing the “secrets of the evolutionary history of insects” entitled “Phylogenomics resolves the timing and pattern of insect evolution.”
The study was a logical necessity for the evolution industry. As lead author and professor Bernhard Misof of the Zoological Research Museum Alexander Koenig in Germany, explains in an interview with Will Dunham for Rutgers, “two-thirds of all known animal species are insects,” yet their evolutionary relationships remain a mystery.
This can be seen in the opening statement entitled “Toward an Insect evolution resolution:”
Insects are the most diverse group of animals, with the largest number of species. However, many of the evolutionary relationships between insect species have been controversial and difficult to resolve.
In the abstract, the investigators explain their reason for performing the study:
“Insects are the most speciose group of animals, but the phylogenetic relationships of many major lineages remain unresolved.”
The emerging genomic revolution finally provided the technologies for investigators to validate molecular evolutionary relationships scientifically. Sponsored by the German government, the project’s stated purpose was to develop a scientific consensus on insect evolution. Specifically:
Clarification of the phylogenetic tree and correct classification of the large insect groups are important prerequisites for being able to answer elementary questions related to evolutionary biology, ecology and biodiversity research.
The team planned to study “1478 single-copy nuclear genes obtained from genomes and transcriptomes representing key taxa from all extant insect orders and other arthropods” — a daunting undertaking.
In a study of this size, deciphering insect genetics proved to be a mind-blowing exercise. As Michael Wink of the University of Heidelberg explains:
The sequences of 50 species can theoretically produce 2.8 x 10 [to the power of ] 74 phylogenetic trees, a number which is much more than the number of atoms found in the universe.
To unravel insect genetics, supercomputers sorted and analyzed the genetic sequences. Unexpectedly, however, the findings were incompatible with initial expectations, even given the immense volume of data. As Kate Yandel, a science writer for The Scientist, noted:
“[Even using] an unprecedented quantity of genetic sequence information from insects… [uncovered] some unexpected conclusions.”
“The scale of the project is amazing, not only in terms of the number of collaborators and the kind of scientists that were brought together, but also the data. It was just enormous,” says Michelle Trautwein, assistant curator and Schlinger Chair of Dipterology at the California Academy of Sciences in San Francisco in an interview with PRI science writer Adam Wernick.
Jakub Prokop, an entomologist at Charles University in Prague, Czech Republic, noted that “the results of this work are immense and will be broadly adopted in general and systematic entomology books and textbooks.”
However, rather than discovering evidence to support basic evolution assumptions, the study unexpectedly undermined the theory, as Misof explains why: “Sequence misalignment, and deviations from the underlying assumptions of applied evolutionary models.”
The research team addressed “these obstacles by removing confounding factors in our analysis” — i.e., eliminating outliers from the study. In the end, only 144 species were included in the study rather than the planned original 1000 species. Amazingly, even by eliminating the outliers and reducing the number of species studied by nearly a factor of 10, they still failed to achieve the project’s initial goal.
The evidence points to stasis, not evolution. Karl Kjer of Rutgers University, one of the investigators, told Live Science:
If you had a time machine and you went back to the Jurassic, we entomologists would recognize all of the insects, and we could [classify] them into their proper order,… Many of them would look very similar to what we see today.
“Scientists have been working to uncover the insect tree of life for a century,” Wernick opined in an interview with Trautwein. “The new study didn’t so much ‘provide shockingly new results’ — although that certainly is the case in some parts of the tree — but it did provide a huge, comprehensive amount of data.”
The testing proved each insect species as genetically distinct and unique, contrary to initial speculations. No transitional links exist, as Darwin once predicted. This is why each species tested is illustrated on the top of each metaphorical phylogenetic tree branch, not one insect qualified as a transitional link in Misof’s study.
Insect genetic evidence reinforces Darwin’s long-standing transitional link dilemma. In The Origin of Species, Darwin argued that the absence of:
Numerous, successive, slight modifications [i.e., transitional links] is the most obvious and serious objection which can be argued against my theory.
Insects have no known transitional links — materializing Darwin’s feared “serious objection” nightmare — scientifically.
The absence of transitional links has long plagued the evolution industry. Legendary evolution advocate, Stephen J Gould (1977) of Harvard University, found this ubiquitous long-standing pesky problem even throughout the fossil record. In the article entitled “Evolution’s Erratic Pace” published in the journal Natural History, Gould noted:
The extreme rarity of transitional forms in the fossil record persists as the trade secret of paleontology. The evolutionary [phylogenetic] trees that adorn our textbooks have data only at the tips and nodes of their branches; the rest is inference, however reasonable, not the evidence of fossils.
Darwin’s dilemma intensifies as the reach of science continues to expand. Evolutionary scientist Geir Hestmark of the University of Oslo comments in the journal Nature (2000) remain relevant:
“Phylogenetic trees are common in today’s scientific journals, but there it is seldom realized how speculative they are because they look so real. This rhetorical power was significant in the popularization and triumph of evolutionary theory. Yet phylogenies are only sketches of historical hypotheses.”
Endangered Tree Metaphor
Misof’s insect genetics study further endangers Darwin’s once-famous tree metaphor — findings that align with evidence from the fossil record and molecular biology.
Eugene V Koonin (2011), of the Senior Investigator National Center for Biotechnology Information (NCBI) National Library of Medicine (NLM) National, in his book entitled the Logic of Chance, concedes to the now unavoidable conclusion:
The genomic revolution [has] effectively overturned the central metaphor of evolutionary biology, the Tree of Life.
“The tree of life [concept] has come upon hard times,” laments evolution advocate John Archibald (2014) in his book entitled One Plus One Equals One. “The overall picture emerging is one of mosaicism” — not through Darwin’s theory of producing transitional links through the “slight, successive” changes of evolution.
The genomic revolution continues to undermine long-held evolution speculations. However, the scientific evidence is compatible with the Genesis account written by Moses. Each species remains distinct and unique — as Mosfi’s insect genetics study demonstrates.