Saturday, February 28, 2015

Caterpillars and Butterflies: Two Different Species?

Butterfly Hunter
Der Schmetterlingsj├Ąger
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.

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'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).

I suppose we'll hear more about this if the theory holds up . . .



At 4:30 AM, Blogger Carter Kaplan said...

It sounds like science "fiction" to me.

Does the fossil record provide evidence of two species?

Christian de Duve's book Vital Dust offers a genealogy of the individual organelles within animal cells, and argues they were once independent organisms that entered in upon a symbiosis.

But otherwise considering the interwoven reproductive/life-cycle unity of the caterpillar and butterfly and our conventional definition of a "species", I would not be surprised to hear a convincing conclusion that says the large "S" Separate Species theory in this case plays semantic games.

At 6:58 AM, Blogger Horace Jeffery Hodges said...

The fossil record of butterflies is probably incomplete, but DNA analysis offers data for comparison.

For instance, we have some DNA evidence for the interbreeding of European Homo sapiens with Neanderthals in Europe, such that a small percent of European DNA today is from Neanderthals, whereas sub-Saharan Homo sapiens have none.

DNA analysis of butterflies and other species would likely offer more than the fossil record.

But what do I know?

Jeffery Hodges

* * *

At 2:17 AM, Anonymous Anonymous said...

The Bible speaks of Kinds, from which such species could diverge within the limits of the Kind


At 3:44 AM, Blogger Horace Jeffery Hodges said...

Uncle Cran, good to see you're back! I hope you're feeling better.

Would a creeping thing and a flying thing be of the same kind?

Jeffery Hodges

* * *

At 5:55 AM, Anonymous Anonymous said...

That is confusing stage of development with kinds. The biogenetic law of Haekel was disproved years ago. The creeping thing begun by two butterflies eventually develops into another butterfly. never another kind. So the answer is yes.


At 6:26 AM, Blogger Horace Jeffery Hodges said...

Uncle Cran, I wasn't referring to Haekel. I was referring to the theory described in the blogpost.

Consider your earlier comment:

"The Bible speaks of Kinds, from which such species could diverge within the limits of the Kind."

I thought you were suggesting that "kinds" could account for two different species mating successfully, as described in the theory referred to in the article.

Hence my question, namely, if creeping and flying things were of the same kind.

Jeffery Hodges

* * *


Post a Comment

<< Home