Caterpillars and Butterflies: Two Different Species?
Carl Spitzweg (1840)
Not being an expert (even though my 4H project was entomology), I don't know what to make of this theory to be explained below, namely, that caterpillars and butterflies are different species. I first learned about this theory in an article by Ted Olsen titled "Are Butterflies a New Creation After All?" (Behemoth, Issue 16, February 19, 2015), but links to more scientific information are given below:
In 2009, the prestigious journal Proceedings of the National Academy of Sciences (PNAS) published an article by British zoologist Donald Williamson. He argued that butterflies and caterpillars essentially evolved separately, as two different organisms - and that somewhere along the line the two species accidentally but successfully mated.I've only glanced at the scientific arguments, but whether they prove valid or not, the possibility is intriguing that caterpillars and butterflies were distinct species that somehow accidentally though successfully mated (or united through parasitism or through some sort of virus infusion of DNA).
The theory makes a lot of sense, University of Vermont biologist Bernd Heinrich wrote in his 2012 book on animal death, Life Everlasting. During metamorphosis, caterpillar DNA is essentially "turned off," and butterfly DNA, which had been suppressed, is "turned on." Heinrich writes:
A new theory claims that because the metamorphosis . . . is so radical, with no continuity from one to the next, that the adult forms of these insects are actually new organisms. . . . In effect, the animal is a chimera, an amalgam of two, where first one lives and dies and then the other emerges. . . . Regardless of how it came about, there are indeed two very different sets of genetic instructions at work in the metamorphosis . . . and these are as different as different species, or even much more so. They thus represent a reincarnation, not just from one individual into another, but the equivalent of reincarnation from one species into another.As Heinrich notes, it's an aberrant view among biologists. Williamson was ridiculed for proposing it, and PNAS quickly published a rebuttal (but not a retraction).
I suppose we'll hear more about this if the theory holds up . . .