Tuesday, July 24, 2007

A creationism vs. evolution discussion,. Part 4

Here’s a shorter one…

The question
Male humans have one less pair of ribs than female humans.
Correct answer- False
Although the Bible states that Eve was created from Adam's rib, males have exactly as many ribs as females.

Marcsana’s response:
8. Ribs can grow back. Basic biology.

My response
The question specifically asks if males have fewer ribs than females. They don’t. No dispute.

But as for Marcsana’s claim- ribs regrowing after removal may be basic biology…if you are a salamander. Mammals, including humans, do not regrow removed ribs.
Mechanics of bone regeneration
Bone has the capability to regenerate, forming new osseous tissue at locations that are damaged or missing. Although this capability extends to regeneration of whole limbs in some animals, in humans regeneration is on a more limited scale and occurs during defect healing, e.g., after the removal of bone screws; fracture healing; distraction osteogenesis (during limb lengthening), and integration of orthopaedic implants with the host bone.

Edited to add:
I did some more research on this subject. Answers in Genesis claims that entire ribs, when removed, will regrow. However (as is, unfortunately, typical for the site) they had no checkable references or sources. So I did some research on my own.
Ribs do have some capacity for regeneration, consistent with the quote above. Free Bone Grafts states that the maximum donor size for rib grafts is 14 cm. (about 5.5 inches)- not the length of a whole rib. When entire ribs are removed, grafts or scaffolds are used to stimulate bone regrowth, such as a gel matrix
bone graft, or, esperimentally, beta-tricalcium phosphate cylinders. Without the scaffolding, rib regrowth may not occur at all. Nor is the bone that regenerates identical to the original- as an article in Plastic and Reconstructive Surgery stated, "Regeneration after a proper costectomy [rib removal] is possible, but the regenerate is thin, flat, and lacking cancellous bone." So, in summary, as expected, some rib regrowth is possible, but easy regrowth of entire ribs is not.


Anonymous said...

This will be a shorter post.

Regarding rib regeneration, please see this link:

As you learned, ribs grow back when the periosteum is intact. That is the end of the matter. There isn't much written on this subject yet as the article above indicates. I think it's of note to see that after a year, ribs were very well regenerated without the mentioned gel. Were they less than perfect? Yes. And this is what you would expect after 6,000 years of degeneration in our DNA.

Furthermore, no knowledgeable Christian will say that Adam had one less rib, so men have one less rib. This isn't part of our argument and for obvious reasons. Let's say a man gets his finger cut off. Does this mean that his future children will have one less finger? Of course not. Again, if a person loses an eye, will their children be born without an eye? Not hardly. Neither of these scenarios would modify DNA. I'm aware that some Christians have tried to use this before, but it is not an argument they should use. It is just plain wrong and it does not have a place among creation scientists (or any scientists for that matter).

Cris Waller said...

Thanks for your brevity in this comment.

The reason I included this question is my original quiz was that, despite your claim that "no knowledgeable Christian will say that Adam had one less rib, so men have one less rib," this myth still does exist- witness the fact that, on the quiz in question, with 10,356 plays, 37% of the people taking this quiz said that it was true that males have more ribs than females! So ignorance is out there on this question, and I am glad we both agree that it is nonsense and needs to be refuted.

I will not argue the "degeneration in our DNA" argument right now, it will come up in the segment on information.