Why are some animals like birds and reptiles born from eggs while most mammals are not?

2.48K views

Why are some animals like birds and reptiles born from eggs while most mammals are not?

In: Biology

Anonymous 0 Comments

Evolution, laying eggs was probably the best route for reptiles and birds. A few come to mind like birds can lay the eggs in tall trees away from predators and if they had to carry a fetus it would weigh them down. Mammals are warm blooded so keep the fetus at a good temperature for development, and it protects the fetus from predators/the environment