How do evolutionists explain the gastric brooding frog's reproductive system?

Question

On the one hand, we have one evolutionist who says that its reproductive biology could not have come about by a slow progressive change, but that it had to have been a single, huge, quantum step.

On the other hand, we have Charles Darwin who wrote:
"Natural selection acts only by taking advantage of slight successive variations; she can never take a . . . leap.”

Seems like evolutionists are contradicting each other.

So did the gastric brooding frog evolve and how?

http://www.jw.org/en/publications/magazines/g201407/gastric-brooding-frog/

Answer 1

The gastric brooding frog is indeed a remarkable example of an unusual reproductive strategy. We do not know how it evolved. Unfortunately, this frog has no closely related living species, which would usually shed some light on how its reproductive strategy could have evolved, because it is simply next to impossible for the evolution of a new reproductive system to have occurred in one giant leap forward. In other cases, we usually see similar strategies in similar species which may represent intermediate stages.



For example, the European fire salamander (Salamandra salamandra) retains the larvae within the female body but releases them into a stream to complete the metamorphosis. OTOH, the close relative Salamandra atra, which lives at higher altitudes, retains the larvae until they develop into miniatures of the adults, skipping the free swimming stage. S. salamandra therefore is an intermediate stage for what we observe in S. atra.



One possible intermediate stage for the gastric brooding frog is that its ancestor laid eggs on land, and the eggs then develop directly into froglets. There are many examples of such species within the family Leptodactylidae, which is a family of frogs closely related to the gastric brooding frog, which is classified in the Myobatrachidae. Frogs that reproduce this way often have females that will guard the eggs until they hatch into froglets. While the female is guarding the eggs, she is probably not going to be feeding regularly since that would mean having to leave the eggs behind. Since she was not going to be feeding while guarding the eggs, she does not need to keep producing gastric acids. In fact, if she can completely turn off gastric acid production during this fasting period, she is actually better off because she has less chance of getting an ulcer. Further, there are also some species in Australia that may aestivate for a year or even two years without eating, if the weather is too dry. These frogs obviously would not need to produce gastric acid for a longer period of time than the gastric brooding frog. So, it is possible that the ability to turn off gastric acid production may be more common among frogs than scientists realize. In fact, during the summer, many frogs go into aestivation for months without eating. Therefore they too may have a similar ability.



Hence we have a possible scenario for a frog to evolve the ability to turn off gastric acid production long before the evolution of gastric brooding. This plausible intermediate stage would then make it easier for some females to just go ahead and swallow the eggs without harming them. She can then go wherever she wants, instead of having to stay at one spot and be a proverbial sitting duck while guarding her eggs. Further, by having the eggs inside her, she could help keep them hydrated and not have to worry about laying eggs at a moist spot and hope that the weather does not suddenly turn too hot or dry. So, I have basically given you a plausible scenario of how gastric brooding could have evolved through multiple steps and showed you there is no need to assume that it had to evolve in a single step or giant leap forward. Hence, a fruitful area of further research will be to figure out whether a lot more frogs around the world have a similar ability to simply switch off gastric acid production.

Answer 2

Gastric Brooding Frog

Answer 3

A few points:

-Of course it evolved. Don't be an idiot.

-Darwin knew only a tiny, tiny fraction of what we know now about biology and evolution. He said a lot of stuff that we now know to be not quite correct. This is a GOOD thing, because it shows that we are learning. Unlike creationists, biologists do not depend on the writings of a magic book being completely infallible.

-The difference between "one large step" and "many small steps" is not as clear-cut as it may seem. "Large" and "small" are pretty vague terms. The only way to determine how many changes would be required would be to find the genetic determinant(s) of the gastric brooding behavior, which to my knowledge has not been done. Until we know that, whining about how many steps were involved is nothing but speculation.

-It's quite easy to postulate possible steps leading to this behavior. There are other animals out there that will guard their eggs and take them into their bodies when danger threatens. Unless you're claiming that that's also magic, selection could simply act upon that to extend the retention time, or simply to eliminate the "release" behavior.



In short, this is a non-issue, blown up by liars who are desperate to deny reality.

Answer 4

Genes don't propagate because God said "go forth and multiply." They propagate through the survival of selective pressures. In fact, some genes are propagated that are not necessarily that great, but are selected through some other environmental pressure. One example is sickle cell anemia. This trait is not necessarily good, but has been selected in regions where there is a prevalence of malaria. In sickle cell anemia, erythrocytes don't survive long enough to complete the life cycle of the parasite. So although people affected by this trait suffer from the ill effects of their misshapen red blood cells, it gives them a sort of protective benefit from malaria. God didn't perpetuate this gene. Nature and environmental pressure did. Intelligent design is pseudoscience. They attempt to use scientific terminology to sound legitimate, but the science is scant if not all together non-existent. I am not here to argue about the existence of some fairy tale magical being either. You can believe in anything you want. My little brother once asked me how this magician made his assistant disappear. I explained to him about sleight of hand, trap doors, distraction, and illusion in which his reply was "NO! It was magic." There was no convincing him otherwise. I don't care about convincing you to believe anything either. You can think whatever you want.

Answer 5

The theory of evolution has evolved since Charles Darwin proposed his version of it. That isn't contradiction. That's science moving forward.



Sometimes, a very small mutation in one gene can make a substantial change in the phenotype of the animal, so evolution can move in jumps. That's basic evolutionary theory.



But that's reality. You probably don't want to face reality.

Answer 6

I don't see the issue with the reproductive system.

Answer 7

Anything that any Jehovah's Witness has to say about biology is probably wrong, anything they have to say about evolution, is guaranteed to be a flat lie. You have no idea what evolution is and what it isn't.

Answer 8

The source of your quotes is a Jehovah's Witness Magazine. Not exactly an unbiased source of information on evolution, is it? There is no indication how or where they got the quotes from the biologist doing the study. A Google Search cannot find the quote outside of the Magazine or those that cite the magazine. Conclusion.... it is unlikely the biologist published that information in his works. This magazine shows no references on the frog page as to where they got the information from. No citations. Typical of poor scholarship or an attempt to stop people from following up on the article. That doesn't work on this science board.



OK.... Let's play the game but on MY TERMS. A creationist poses a rhetorical question on Y!, usually with no knowledge of evolutionary principles. S/he may provide unreferenced quotes, misquotes, made up quotes, misstatements, YouTube videos, Creationist websites, or outright lies. S/he are usually proud of their willful ignorance and wear it like protective armor.



Then, they pick the answer that agrees with their anti-science, anti-evolution, anti-knowledge, pro-creationist world view and claim "success". I guess they seek comfort in their views and ignorance, but they certainly don't seek new information.



So.... thanks for the opportunity to present REAL REFERENCES to readers that might never have seen Creationism EXPOSED as a non-science, and evolution shown as very much a falsifiable set of predictions and mechanisms to explain the diversity of life on this planet. In 150 years of research in the fields of biology, biogeography, geology, molecular biology, anthropology, paleontology, population genetics, and others, the theory of evolution has been modified (see below for the definition of a theory), but NEVER FALSIFIED.



If I were to suggest only one thing for you to read, it would be the 2005 court case where Creationists pushing Intelligent Design wanted it taught in the science curriculum of public schools as science. The conservative judge, after hearing evidence IN A COURT OF LAW, including TESTIMONY from the leading Creationists, ruled that Creationism was a religious approach and not scientific. Creationism/Intelligent Design did not use the methods of science and had NO EVIDENCE to support it. End of discussion.



http://www.talkorigins.org/faqs/dover/kitzmiller_v_dover_decision.html



Also you should see the position of the National Academy of Sciences. If you haven't heard of them: http://www.nasonline.org/about-nas/mission/ "The National Academy of Sciences (NAS) is a private, non-profit society of distinguished scholars. Established by an Act of Congress, signed by President Abraham Lincoln in 1863, the NAS is charged with providing independent, objective advice to the nation on matters related to science and technology. Scientists are elected by their peers to membership in the NAS for outstanding contributions to research. The NAS is committed to furthering science in America, and its members are active contributors to the international scientific community. Nearly 500 members of the NAS have won Nobel Prizes, and the Proceedings of the National Academy of Sciences, founded in 1914, is today one of the premier international journals publishing the results of original research." Note: Are you a member of NAS by any chance?



This is part of a statement by them about evolutionary theory.... http://www.nas.edu/evolution/TheoryOrFact.html "The formal scientific definition of theory is quite different from the everyday meaning of the word. It refers to a comprehensive explanation of some aspect of nature that is supported by a vast body of evidence.



Many scientific theories are so well-established that no new evidence is likely to alter them substantially. For example, no new evidence will demonstrate that the Earth does not orbit around the sun (heliocentric theory), or that living things are not made of cells (cell theory), that matter is not composed of atoms, or that the surface of the Earth is not divided into solid plates that have moved over geological timescales (the theory of plate tectonics). Like these other foundational scientific theories, the theory of evolution is supported by so many observations and confirming experiments that scientists are confident that the basic components of the theory will not be overturned by new evidence. However, like all scientific theories, the theory of evolution is subject to continuing refinement as new areas of science emerge or as new technologies enable observations and experiments that were not possible previously"



To the OP. Keep up your rhetorical questions and your obvious ignorance of evolutionary science, and I'll counter with a real court decision disallowing Creationism as a science, and a real statement from the scientific community supporting evolutionary theory as very much an accepted field of science. OP, let's see who accomplishes their goal on this board in the long run.