Final answer:
Sauropods developed long necks as an evolutionary advantage to access food resources that were unreachable to others, similarly to Giant Tortoises observed by Darwin. They had long tails to maintain balance while walking upright on two legs, demonstrating the natural selection behind these features.
Step-by-step explanation:
When examining the evolution of certain dinosaur species, particularly sauropods, we can see that they developed long necks, which offered them a significant evolutionary advantage. This could be compared to observations made by Darwin regarding the Giant Tortoises of the Galápagos Archipelago, where tortoises with longer necks were more likely to survive during times of drought because they could reach more leaves and food. Similarly, dinosaurs like Apatosaurus, part of the Saurischia clade, which are known for their long necks, likely followed a similar pattern of natural selection for features that allowed them to access food resources that others could not. Bipedal dinosaurs also evolved to have long tails, which were important for balance when they walked upright on two legs. These anatomical features developed over time, leading to the ultimate survival and prevalence of these traits.