Here's why:
* Nitrogenous waste elimination is a fundamental biological process that doesn't directly shape major structural differences between species. While the specific mechanisms might vary slightly, all mammals, including pigs and humans, eliminate nitrogenous wastes as urea.
* Structural differences between pigs and humans are primarily driven by evolutionary adaptations to their respective environments and lifestyles. These adaptations occur over long periods through genetic changes and natural selection, affecting a multitude of anatomical and physiological features.
* Examples of structural differences:
* Locomotion: Pigs are quadrupedal (walk on four legs), while humans are bipedal (walk on two legs).
* Digestive system: Pigs have a different digestive system adapted for omnivory, while humans have a digestive system adapted for more varied diets.
* Brain size and complexity: Humans have a significantly larger and more complex brain compared to pigs.
In summary, the structural differences between pigs and humans are not primarily due to differences in fetal nitrogenous waste elimination. These differences are a result of complex evolutionary processes driven by environmental factors, adaptation, and genetic variations.