Fossils, embryos and other clues provide evidence that fish evolved before birds. The evolutionary record indicates that limbs and wings developed over millions of years after fish evolved.Know More
Approximately 400 million years ago, evidence indicates that lobe fish first came in to existence. Lobe fish are fish whose fins are bonier and contain more muscle than that of other fish, a precursor to limbs. Limbs evolved over tens of millions of years into creatures that were fully able to walk on land.
Feathers first appear in the known fossilized record about 150 million years ago and are currently thought to have evolved from the scales of reptiles.Learn more about Zoology
Birds that can swim include penguins, cormorants, anhingas, and other darters and alcids, such as puffins, dovekies and razorbills. These birds enter water in search of prey, but penguins can spend most of their lives in the water.Full Answer >
The exact form organisms will evolve into in the future is very nearly impossible to predict. Evolution is usually described as being opportunistic, rather than deterministic, and so species' gene pools tend to adapt to the surrounding environment. Insofar as the environment of the future is difficult to predict, the forces driving natural selection also cannot be predicted.Full Answer >
The anatomical and physiological features birds and mammals have in common are possessing a spinal cord and vertebral column, four-chambered hearts and warm-bloodedness. Birds and mammals also both generally invest a great deal of time and energy into raising their young, and are energetic and active consumers. Both birds and mammals have flying, fully terrestrial and amphibious members, although mammals have a wider range of lifestyles.Full Answer >
Female birds turn the end of the oviduct inside-out to lay an egg and allow the egg to emerge. A bird currently laying an egg can be identified by a rhythmic moving and opening and closing of the bill, though time varies by species from a few seconds to a few minutes. After copulation with a male bird, a female bird can store sperm in tubules.Full Answer >