Most of us know that frogs extend their tongues which stick to their prey, and then draw it back into their mouths. High-speed videos show that frogs unroll their tongues like party horns and wrap their targets in an adhesive hug. What science has not understood is how frogs swallow. What happens when they close their mouths? Rachel Keeffe is a National Science Foundation Graduate Research Fellow who has released a study showing how frogs process whatever their tongues bring into their mouths.
Keeffe and her colleagues attached metallic beads at various points in the mouths of cane toads, among the largest frog species. They wanted to study what happens to food once it is in the frog’s mouth. There is a very complex system of cartilage and muscles traveling so far down the frog’s throat that it butts up against the heart. Once there, chemicals secreted in a stomach-like chamber digest it, bringing the nutrients into the frog’s vascular system.
When we examine how frogs swallow, we see that even the simplest life forms have highly complex systems. Frogs control insects and other forms of life that threaten humans. In turn, a variety of birds and fish eat frogs. The world around us speaks volumes of God’s wisdom and design, allowing life to exist on Earth. Romans 1:20 tells us that we can know there is a God through the things He has made. We see that again in the design of how frogs swallow.
Researchers constantly find things in the natural world that show special arrangements, allowing life to exist. For example, tiny frogs called dotted humming frogs (Chiasmocleis ventrimaculata) share a home with large tarantulas in a mutualistic relationship.
Large tarantulas eat frogs, but these tiny frogs have toxins in their skin that make them unpalatable to the tarantulas. Scientists studying this arrangement have seen young spiders pick up a dotted humming frog, taste it, and then quickly put it back down. However, these frogs have a symbiotic relationship with large tarantulas known as Columbian lesserblacks (Xenesthis immanis). The tarantulas share their burrows with the frogs. As a result, the spider protects the frog and its eggs from predators, while the frog protects the spider’s eggs from ants and other insects by eating them.
Life that endures requiresthinking and planning, and everywhere we look, we see wisdom at work, allowing our planet to teem with living things. Proverbs 8 finds Wisdom challenging us to understand: “Does not wisdom cry out and understanding put forth her voice? … Unto you O men I call… Oh, you simple ones, understand wisdom, and you foolish ones have an understanding heart…” We can learn from the animals as we find ways to protect our food supply rather than saturating our world with toxic chemicals.
Ectotherms are animals that are often described as “cold-blooded.” This group includes amphibians (such as frogs) and reptiles (such as snakes). These animals absorb heat from their surrounding environment instead of generating it internally from the food they eat. For that reason, they don’t need as much food to survive as a “warm-blooded” (endotherm) mammal or bird needs. That is one of the advantages of cold blood.
The food required for one mammal could feed 20 reptiles of the same size. So when food is in short supply, reptiles can survive when mammals may not be able to. Another advantage for ectotherms is that when the weather is cold, and food is scarce, they become inactive and don’t need to eat. This design allows for the efficient use of natural resources.
Also, ectotherms generally lay eggs and allow their young to hatch and survive on their own. The young can get their own food and even defend themselves. When temperatures are lower, frogs produce a larger number of females, and when it’s warmer, there are more males. This design considers the fact that cold weather makes the survival of the young less likely, so the larger number of females to lay eggs keeps the population steady. When survival is more likely because of warmer weather, not as many females are needed.
Without this system and the advantages of cold blood, the populations would vary widely. Cold-blooded animals are well designed to conserve resources and maintain the balance in nature. Design suggests a Designer.
We tend to think of frogs and toads as fairly common creatures, varying only in color and size. Dr. William Duellman has done extensive studies of the amphibian order Anura which includes more than 3800 separate species of frogs. His studies show enormous frog reproduction variations.
Some frogs lay eggs in clutches near, but not in, the water. They glue the eggs to vegetation or rocks where the tadpoles drop into the water when the eggs hatch. Other frogs lay eggs in a protective foam that protects the eggs and provides food and water that can last for up to ten days. One-fifth of all frog species hatch into froglets instead of tadpoles. Each four-legged froglet has an attached yolk to supply nutrition until it can catch its own food. The males of one frog species glue themselves to the back of the larger females. The female digs a burrow in the ground to lay the eggs. She then wets the eggs with water from her bladder, and the male fertilizes the eggs.
The males of the African hairy frog develop rigid hairlike extensions of their skin during breeding, so when the male sits on the eggs, he protects them from predation. In the poison dart frog of Costa Rica, both sexes guard the eggs. When they hatch, the female brings unfertilized eggs to the tadpoles to eat until they can find food on their own. The females of the Jamaican tree frog lays water-filled capsules along with the eggs to provide adequate water for the tadpoles. In some species, the tadpoles crawl onto the back of either parent. Some frogs have pouches on their backs that hold eggs that have gill-like structures that enable the embryos to breathe.
Other unconventional frog reproduction variations include Darwin’s frog in Chile. The male scoops up the newly hatched tadpoles into his mouth and broods them there for several weeks until they mature. Even more bizarre is an Australian frog in which the female swallows the eggs after fertilization and incubates them in her stomach. This process, called gastric-brooding, usually takes six weeks in which the female does not eat. The tadpoles secrete a substance called prostaglandin E-2, which neutralizes the hydrochloric acid and pepsin normally used for digestion.
All of these reproductive strategies are designed to cope with different environments. Frogs can exist in a desert or a tropical rain forest or even a polar area. Survival is only possible because their reproductive systems are designed to fit the environment in which they live. The intricacy of frog reproduction variations is an excellent example of the intelligence and design God has built into the simplest of living things.
In Genesis 8 we read about a plague against Pharaoh that involved frogs. The frogs came upon the land of Egypt in such numbers that they got into everything, including beds and food preparation areas. Verse 5 indicates that this abundance of fogs came from the rivers, ponds and streams. Is a plague of frogs possible?
Skeptics have suggested that such an event is not possible. They have even suggested that this is just an attempt at humor by the biblical writers. Preachers have generally just shrugged their shoulders and said, “Well, God can do anything.”
Palm Beach Gardens, Florida, recently experienced a mini-plague. In March of 2019, people awoke to an infestation of thousands of baby bufo toads covering the city. There were so many that one resident described it as a plague of frogs “covering every square inch. You couldn’t walk through grass without stepping on one.”
A singe female frog can produce a vast number of eggs. It isn’t hard to visualize how this plague could happen. Like all of the plagues directed at the Pharaoh, the message is more important than trying to figure out how the plague was accomplished. But, of course, “God can do anything that is according to His will and nature.”