Q.Viviparity is considered to be more evolved because:

Viviparity is a reproductive strategy where the embryo develops internally within the mother's body. This mode of reproduction offers significant evolutionary advantages primarily because the developing young are protected from predators and adverse environmental conditions throughout their gestation.

Additionally, viviparous organisms often provide parental care even after birth, further enhancing the survival rates of their offspring. This continuous protection and nourishment, both before and after birth, drastically increase the chances of the young ones surviving to reproductive age compared to s …

Life on Earth exhibits diverse strategies for reproduction, broadly categorized into oviparity and viviparity. Oviparous animals, such as birds and most reptiles, lay eggs, and the embryo develops outside the mother's body within these eggs. In contrast, viviparous animals give birth to live young that have developed internally within the mother's body. This internal development, coupled with subsequent care, is a key reason why viviparity is regarded as a more evolved reproductive strategy.

Viviparity offers several distinct advantages that contribute to a higher survival rate of offspring:

• Internal Protection: The developing embryo is housed within the mother's body, providing a highly stable and protected environment. This shields the embryo from external threats such as predators, harsh environmental fluctuations (like extreme temperatures or desiccation), and mechanical damage. Unlike eggs laid externally, which are vulnerable to the elements and predation, the internal environment offers continuous security.

• Maternal Nourishment: In viviparous organisms, particularly placental mammals, the mother directly provides nourishment to the developing embryo. Specialized structures, such as the placenta, facilitate the continuous exchange of nutrients, oxygen, and waste products between the mother and the fetus. This constant and regulated supply of resources ensures optimal growth and development, which is a significant advantage over the finite resources available within an egg.

• Post-Natal Care: A crucial aspect of viviparity, especially evident in mammals, is the extensive parental care provided to the young ones after they are born. This care can include feeding (e.g., lactation), protection from predators, teaching essential survival skills, and maintaining warmth. This prolonged period of parental investment significantly enhances the chances of the young surviving to reproductive age.

These combined factors—internal protection, direct maternal nourishment, and subsequent parental care—drastically reduce the mortality rate of offspring compared to those developing externally in eggs.

Compare the two reproductive strategies on a single axis — how much control the parent has over the embryo's environment. An egg laid outside the body is at the mercy of predators, temperature swings, and drying out, with the parent able to help only from outside; a viviparous embryo develops inside a living, temperature-regulated, continuously nourishing body, with the parent …