Incipient Ridges

[Lonnette Kendoll]

During a recent e-mail exchange with Mary Beeton she mentioned that a collegue had noted that when incipient ridges were observed in fingerprints of an individual they were very rarely observed in the palm impressions. A quick check of approximately 100 palm cards in our files yielded two cards in which incipient ridges were observed in the thenar area. I posed this question to Charlie Parker, who also checked about 100 palm print cards in his files and located four in which incipient ridges were observed; but again only in the thenar area. So my question to anybody that may know, is why incipient ridges are rarely found in palms and then why we would only see them in the thenar area?

[Pat A. Wertheim]

Pure speculation here, Lonette, based on my limited understanding of ridge formation. Incipient ridges are newly forming ridges between mature ridges at the point when ridge formation ceases. If they had been allowed to mature, the incipients would have become mature ridges. But there is a hormonal trigger that shuts down further development and when that trigger interrupts new ridges before they have matured, incipients result.

Since the fingers are the fastest growing parts of the baby's hand at that period of development, it seems logical that more new ridges would be forming there to accommodate the more rapid growth of the fingers and resultant stretching of the skin. Now, on the index, middle, ring, and little fingers, there are the distal, medial, and proximal phalanges. In the thumb, maybe the thenar area is equivalent to the proximal phalanges of the other fingers, so maybe it is still growing more rapidly than the hypothenar and the interdigital when that hormonal trigger stops development of new ridges, thus preserving them as incipients.

Kasey? Alice? Any ideas here? What would Babler say?

[Gerald Clough]

Simple speculation, now, but it seems to make sense when we consider both the in utero behavior of the finger pads and the nature of the thenar region. Since the finger pad topography is dynamic during ridge formation, they display all sorts of formations that are, we might say, frozen when the process is complete. The thenar is fleshy, while the remainder of the palm is relatively flat, with much less subcutaneous tissue. I seems to me the thenar areas go through growth changes that are not quite like those of the finger pads but produce some of the same effects.

It's known that incipient ridges form in areas that are under greater pressure stresses, and that more incipient ridges appear with age, the incidence increasing from 34 percent to 52 percent beyond the age of twenty, believed due to increased finger size and wear. So, I suppose wear might also be a factor in the thenar area, since it is more prominent and prone to wear.

This leads me to wonder is the incidence of incipient ridges is greater on finger pads with the patterns formed by greater enlargement of the finger pad.

[g.]

I don't know why they are less common in the palms. Pat's hypothesis is a good starting point.

However, I do have a nice image of incipients in the hypothenar. If you would like to see it, email me. (or someone tell me how to post an image to this board...I can't figure out how to using the IMG function)....

g.

[Steve Everist]

[g.]

Thanks Steve...looks great...to give props, I think Kasey gave this image to me years ago when I was first starting out. I had this very question about incipients in palms.

One thing that we can consider as examiners is the presence of incipients in palm prints has more weight (due to the rarity) than say in a thumbprint, where they can be, especially around the core, quite common.

I hope someone reading this will undertake a nice larger scale study, maybe teaming with those with APIS to search palms to get a sense of rarity. Perhaps we can determine how much extra weight to provide these features.

Hint hint: you newbies looking for an easily conducted, low-cost study to cut your teeth on and get published...yeah I am talking to you: young, bright, edu-mah-cated, motivated scientists (ahem: FBI? Army Crime Lab? Las Vegas Metro?) =) Yeah, I just called you out...what of it? =)

g.

[H. B. James]

I hope someone reading this will undertake a nice larger scale study, maybe teaming with those with APIS to search palms to get a sense of rarity. Perhaps we can determine how much extra weight to provide these features.

I'd say the first rights of refusal go to Lonnette and Charles. What about it, you two? A couple of Texans ought to be able to knock this one out, and you've both already started counting palm cards. Let's see you put your incipients on display here.

[g.]

HB:

Yeah good point, sounds a'ight to me....

Or better yet...a friction ridge research 'smack down': Texans v. Non-Texans...

Of course, we know the Texans will do it Bigger and Better than anybody else...

g.

[Charles Parker]

Very good, Ha Ha, I am laughing HB and G. No can do any studies because I have not learned to count over 100 yet.

Better be careful or I will send some more snow your way.

But speaking of studies I would like to see one on the percentage of palmprints with Vestiges. Also the average lenghth of a vestige. The opposite of open fields it seems the smaller ones are a lot less common. I have one on a case I am working that is a vestige of about 2 ridges. The cutest little thing you ever did see. I cannot find that sucka though. Talk about target area.

For years I never identified a latent palm print with a vestige and then in the space of 6 weeks I had two of them on different cases.

Vestiges are my friend.

You will need to find someone like HB or g to do the study. Or like you said those FBI folks----I hear they have their case load knocked down pretty low these days.

PS Thanks g and Steve for the incipient in the Hypothenar. Does someone out there have one in the interdigital? Don't all scurry away looking now.

[g.]

I think I can help you there Charles.

Two German profs (Tietze and Witthuhn) wrote a book called "Papillarleisten-struktur der menschlichen Handinnenflache", 2001. It's an amazing book with all the stats you'd ever want on hands: creases, ridge flow, etc. Tons of great pictures, tables, and stats.

As you might have guessed, the problem is: it's in German. All the German examiners and Swiss Germans, for that matter, use the book and it's a part of their standard training. Ron Smith even gets a nod on Page 2.

So they have the data, it's just hard to decipher. I speak (very poorly and slowly) German, but I can read it a lot better. So I looked up your question. They don't call them "vestiges", they refer to vestiges on the whole as "patterns in the thenar". They break vestiges down into: standing and hanging loops, columns, whorls, etc.

They say:

"Papillarleistenmusterbildungen im Daumenballen sind sehr selten: bei 6.66% im rechten und 15.61% in linken Daumenballen..."

I am pretty sure this translates to "Ridgepatternformations in the thenar are somewhat rare: about 6.66% in the left hand and 15.61% in the right hand thenars". And it looks like from their tables, this is coming from approximately 35,000 people (70,000 palm prints)...pretty cool, huh?

Anyone else proficient in German (Cedric, Nicole, Christophe?) feel free to correct me, if I am translating wrong. I am going off of p. 43.

So tentatively Charles, I hope that answers your question.

g.

[Steve Everist]

Using Alta Vista's Babelfish translator (http://babelfish.altavista.com/ ), it comes out to:

Papillarleistenmusterbildungen in the thumb bundle are very rare: with 6.66% in the right and 15,61% in left thumb bundles

[clpexco]

more incipient ridges appear with age, the incidence increasing from 34 percent to 52 percent beyond the age of twenty, believed due to increased finger size and wear. ...

There are a couple more theories for the increase in the appearance of incipients with age I can think of also:

1) The breakdown of microfibrils causing more elasticity and flattening of the friction ridges in old skin. Since the ridge profile flattens, incipients contact the surface more often (or more prominently)

2) The increase of secondary ridge depth. Misumi studied fetal, 'new', and 'old' skin and found increasing complexity of the sub-structure that we knows feed the furrows with skin cells. I don't like this theory as much because it involves dealing with a root system that changes over time, cutting to the heart of traditional, life-time 'permanence'. However, it is a theory based on scientific research that showed objective scientific evidence of changing root structure, so it definitely deserves mention. What still baffles me is that we could see such consistency of level 3 detail over decades.

On that topic, I like the FBI example used in some of the Daubert hearings of the permanence of level 3. If anyone else has examples of level 3 features that persist over 30 or 40 years, I would be VERY interested in posting them as a Weekly Detail. If anyone is interested in coordinating this project or writing it up, please e-mail me: kaseywertheim@aol.com

[Charles Parker]

g. It sounds like a good book. Maybe one of our German Counterparts might be able to post where to purchase the book?

Interesting 6.66% in the right and 15.61% in the left. Now if I can get my hands on a 1,000 sets of palm prints I might take a run through and see if the percentages are close (+ or - 3%) to what is stated for Texas Bad Apples.

[Steve Everist]

g. It sounds like a good book. Maybe one of our German Counterparts might be able to post where to purchase the book?

Interesting 6.66% in the right and 15.61% in the left. Now if I can get my hands on a 1,000 sets of palm prints I might take a run through and see if the percentages are close (+ or - 3%) to what is stated for Texas Bad Apples.

I found a copy for you Charles. You've got email!

[H. B. James]

I have not learned to count over 100 yet.

Now if I can get my hands on a 1,000 sets of palm prints I might take a run through and see if the percentages are close (+ or - 3%) to what is stated for Texas Bad Apples.

Okay, Charles, if you can only count to 100, how will you know if you have 1,000 sets of palm prints (how many palm prints are there in 1,000 sets?) and how will you be able to evaluate 6.66% versus 15.61%?

Sounds like Texas talk to me.