Hobbies And Interests
Eggs
The beginning of life for humans and many beasts and insects has always been the simple egg, or ovum. Sometimes this egg is a microscopic cell that germinates into a living creature within its mother's body. Other times, the egg becomes something different: a hard or soft-covered container housing new life outside of the womb. Birds and frogs both lay eggs in the latter fashion. A bird's may be hard-shelled and a frog's soft, but all the same they share the beginning of life in common.
Embryos
Within each egg sleep embryos. An embryo is simply an organism that has yet to develop into the noticeable form of a fetus (which looks like its parents) and is still developing. During the time the embryo is developing within the egg, the new life will go through many different cell divisions until it is prepared to hatch. In some cases, it may even look similar to the developing embryos in related, but different, animals. Once the creature has come to that point in development, it can exist outside of the confines of its protective structure. Yet, this does not mean that the newborn will be ready to live on its own, or will look exactly like an adult.
Appearance of Adult Characteristics
Once the bird and frog have hatched from their respective eggs, each will look totally different from the other. A bird is a fuzzy chick that peeps, is featherless and is dependent on its parents for food, warmth and protection. A frog is a tadpole and looks more fish than frog as it swims through its home waters avoiding predators and eating when it can. Though their developments may be different at this stage, with one growing arms, legs and a body that will carry it out of the water and back inside, the fact remains that both do require more time to develop the characteristics of their parents. Hatchlings will molt and grow feathers, learn to fly and learn to hunt what their parents have given them to eat. Tadpoles will finally be able to leave the water as frogs, though they will spend their lives near moisture, and will develop long tongues to help them catch their prey.
Evolution and Similarities
Some might ask why there would be similarities, even the few listed, between a warm-blooded bird and a cold-blooded amphibian. The answer rests in how they evolved. Birds are the descendants of certain forms of dinosaur. Reptiles and amphibians also share ancestors from millions and millions of years ago, far older than that of birds. In fact, amphibians came first, and gave rise to the reptiles. Science is still discovering many important things about how animals today are related through time, and so other similarities between separate species may yet come to light.