Flight in birds developed over time as a result of multiple evolutionary steps. The development of feathers, hollow bones, large flight muscles, and efficient gas exchange were all vital for flight. Describe the order in which these adaptations likely evolved and explain your reasoning.

Eels have slender bodies that facilitate moving through narrow cracks in rocks when searching for prey. In 2-3 sentences: Provide a scenario describing how and why slender bodies of eels may have evolved, according to the principles of natural selection.

The ancestors of extant tetrapods first evolved the ability to live out of water over 350 million years ago. Which of the following had to have been true for natural selection to have favored the original evolution of limbs? A) Closely related lineages that remained in the ocean must have gone extinct. There must have been differences in survival and or/reproduction based on size, musculature, bones or other (B functional aspects of early limbs. Large predators must have been a major source of mortality for populations that spent more time in the water and less on land. The ability of some ancestral fish-tetrapod transitional forms to move from one body of water to another during D droughts must have led to decreased mortality. E There must have been less competition for food on land.

Dinosaur and ancestral bird fossil data from the Triassic, Jurassic, and Cretaceous time periods were used to estimate body mass. Scientists are examining the connection between body mass, niche saturation, and extinction of species in the Triassic, Jurassic, and Cretaceous time periods. The terrestrial dinosaurs’ neck length and diet are compared to the evolution of the winged dinosaur through the three time periods.   Which of the following statements best states the null hypotheses regarding winged dinosaurs? The greater number of herbivore dinosaurs throughout all the periods inhibited the evolution of winged dinosaurs due to a lack of available resources and habitat. A greater number of winged dinosaurs of the early Cretaceous period become extinct as fewer winged dinosaurs with greater body mass evolve to take over their niche. The extinction of long-necked herbivores in the late Jurassic period provided a greater amount of habitat and food resources for early Cretaceous…