Comments on: A Flurry of Frog Legs

By: John James

John James — Thu, 21 Feb 2013 11:55:26 +0000

If biodiversity dampens disease transmission, why are the most biodiverse areas (the tropics) losing so many amphibian populations to disease?

By: Susmita Dey

Susmita Dey — Mon, 18 Feb 2013 09:22:37 +0000

Interesting article.

By: Gabmarineandforestlife.

Gabmarineandforestlife. — Sun, 17 Feb 2013 02:54:22 +0000

I also saw one.. A tree frog who has 6 legs

By: Jim Thomerson

Jim Thomerson — Fri, 15 Feb 2013 21:47:07 +0000

Multilegged frogs were discussed in a population genetics course I took in 1964. At the time there was suspected to be a genetic basis for the phenomenon. My point is that the phenomenon was known 30 years before the 1990s.

By: David Skelly

David Skelly — Fri, 15 Feb 2013 03:29:55 +0000

Hi Carl:

Thanks for covering this issue. One clarification. Someone could read this piece and walk away thinking that Ribeiroia is the major cause of amphibian limb deformities. That is looking to be less and less likely as we learn more about the natural history of deformities. In fact the vast majority of deformities found in nature involve missing limbs or parts of limbs whereas extra limb deformities tend to dominate when amphibians are infected with Ribeiroia (well over 90% of field deformities are missing parts and well over 90% of media images of deformed amphibians show extra limbs). And we also know that Ribeiroia is absent from large areas where deformities have been very common. Ribeiroia gets a lot of attention because we know it can cause deformities and because some very nice work has been done on the mechanism by which development is disrupted. But that doesn’t mean it is a particularly common mechanism – it probably isn’t. Unfortunately, it is much less clear what other mechanisms might be responsible although injury by predators has been getting more attention in the last few years.

By: Ashley

Ashley — Thu, 14 Feb 2013 16:35:28 +0000

I don’t like the way some scientists/writers these days talk about these mutations in such a negative way. Reason being, haven’t “mutations” always been the key to the phenomenon of evolution? Who is to say that these frogs won’t benefit from this mutation in the long run? Sure, they may not quite know how to utilize these extra limbs for the time being, but sometime in the future, I would assume that having extra limbs, especially for frogs, would benefit them highly! Especially if the parasite stops “working” at that point.
Also, the researchers seem concerned with the parasite’s affect on the frogs’ well-beings, but how many of those “studied” 24,215 amphibians would have lived a perfectly healthy, meaningful existence? I understand the need for testing, but that’s 24k+ amphibians that were not killed by parasites, but by researchers that are concerned about their well-being. It just seems kind of like a contradiction of intentions….
Love the information though!

[CZ: These are not mutations--in other words the genes of the frogs have not changed. These are more like birth defects caused by chemicals. And the experiment I described shows that these deformities are terrible for the frogs, because it pretty much means you get killed by a predator or otherwise die an early death.]

By: BPM

BPM — Thu, 14 Feb 2013 14:48:43 +0000

The transportation is how the parasite deals with the snail population crashes. I bet the parasite populations circulate between nearby bodies of water.

By: BPM

BPM — Thu, 14 Feb 2013 14:40:48 +0000

Its not just that they can only reproduce in a bird gut. The bird carries the parasite far and wide, spreading it to new areas. Its why plants wrap their seeds in a fruit. They get transportation in return.

By: AlexL

AlexL — Thu, 14 Feb 2013 04:21:08 +0000

I was a teenager when these “mutant” frogs were circulating the news, but I didn’t have quite the biology interest at the time, so I never followed up on. Now I know the story, which is a lot more fascinating now, especially since it involves parasites.

By: Eva G

Eva G — Wed, 13 Feb 2013 18:50:52 +0000

Wait, you left me wondering. Why does it want to get into a bird? What does it get from the bird or do to the bird? [CZ: I've updated the text to clarify. They reach their final adult stage in birds and produce eggs inside them, which are shed in the birds' droppings.]