Yesterday I asked an intentionally provocative question motivated by this remarkable image of a fruit fly that seems to have two insects tattooed onto its wings.
Our SearchResearch questions were:
1. Do you believe that these are images of insects on the wings of this fly? (Yes or no.)
2. WHY do you believe whatever-it-is-you-believe about this? Can you give evidence for your belief about this?
Here's the story from my perspective...
You know what it's like... you're reading along, and then something grabs your attention. In this case, the fly with images of other insects on its wings. My first reaction was that this is pretty amazing. But then my "critical response" kicked in. And this is probably the big lesson here:
Whenever something strikes you as especially remarkable, you probably ought to check out the story.
This is really the basis of all research. As Isaac Asimov purportedly said, "The most exciting phrase to hear in science, the one that heralds new discoveries, is not “Eureka” but “That's funny...”
And that's the case here. If something stands out from the background, it's because you've seen something that violates your expectations. It's "funny." Perhaps it's a stroke of color in an oil painting that you didn't expect, perhaps it's the strange appearance of an insect on the wing.
So when I saw this, my Spidey-sense started tingling, and I (being a curious sort of fellow), did a little digging.
Like most of you, I read the article on the Why Evolution is True blog carefully. I noted the scientific name of the fly (Goniurellia tridens), the photographer (Peter Roosenschoon), where (Dubai Desert Conservation Reserve), etc. I followed the links back to the NYTimes Dot Earth column and read that.
Interestingly, since I first read the NYTimes article, an update has been made. At the very top, the article has a few new lines that link to another blog, Biodiversity in Focus, by an entomology graduate student, Morgan Jackson. Jackson's article, Ants, Spiders, or Wishful Thinking? is excellent, and gives a learned background story that's well worth reading.
1. Are images of insects on the wings of this fly?
Answer: They certainly look insect-like, but as Jackson points out, its probably just an accident of wing coloration patterns that look like insects to humans. It's really a Rorschach inkblot test that is projecting images of bugs onto the wings. So, I'd say no. (But keep reading.)
2. WHY do you believe whatever-it-is-you-believe about this?
Answer: I'm certainly struck by the depth and careful analysis of Jackson's commentary on this. But, being skeptical myself, I went and looked up some original source material. I did a search on the family name: Tephritidae and found a few entomology books. Here's one I found that was pretty interesting...
Fruit fly genera south of the United States (Diptera: Tephritidae) Author: Richard Herbert Foote, United States Science and Education Administration, (1980)
Yes, it's from the New World, but the genus is the same, and so I poked around a bit in this book (using the "search in this book" function) and found the wings from closely related fruit flies.
|Side-by-side Tephritidae fly wings of different species, including tridens. Pg. 72.|
And, just for grins, I extracted the wing image from the picture above and put it side-by-side with the wing of the fly in the top picture. I converted it to gray scale, and erased a bunch of the peripheral clutter.
As you see, these look pretty similar. I'm not sure how variable these wing patterns are, but this definitely seems like it's within the normal range of variation.
It IS remarkable, but perhaps more in the same way that a cloth can be said to have an image of Christ on it. (I'm not making this up: this happens often enough that there's a word for it, a veronica.)
In any case, in a dispute among experts--here, the entomologist is going to win. His argument is well-reasoned, and he gives a good bit of background information about mimicry in other animals, and when there's functional mimicry, as opposed to accidental imitation that we humans perceive as being a mimic.
But there's more... The fact that the NYTimes posts updates to their science columns with information that amplifies and somewhat contradicts their original posting AND that they didn't modify the original article to make it seem like they knew what they were doing all along... That suggests to me that the NYTimes science writers are being truthful, honest, and open in their disclosures about what they knew, and when they learned it.
Part of understanding what it means to find a credible resource relies on knowing something about that source.
In my mind, the NYTimes Science section just went up another couple of notches in credibility. (And they were already pretty far up there.)
Search lessons: First, when something odd, peculiar or funny strikes you (and of course, especially when it's material to something you're trying to understand), it's worth doing just one-more-query to see if the odd/surprising thing holds up to a little scrutiny. For SearchResearchers I advocate making this part of your daily inquiry practice--check out one "fact" a day. You'll be surprised at what holds up, and what doesn't.
Second, as you research various topics, be sure to take note of how reliable, consistent and credible your sources are. Sites that use inflammatory language usually have a position they're advocating--you don't need to ignore them, but you DO need to understand what their slant is going to be. And when you find high quality credible sites, remember them. You'll come back to them in the future.