Are mammals that lay eggs rather than giving live birth?

The platypus is one of only five species of monotremes in the world. These are mammals that lay eggs instead of giving birth to live young. The other four are species of echidna (a mammal that looks a bit like a porcupine).

Why do animals lay eggs instead of giving birth?

Why do some animals lay eggs, and others give live birth? The reason that some animals lay eggs is because that is more beneficial to them than than it is to give birth to a live offspring. Birds, for example, all lay eggs because they can’t fly with the weight of their babies inside of them.

Is laying eggs the same as giving birth?

There is strong evidence that egg-laying is ancestral to live birth, meaning it came first. Many physiological changes were necessary for live birth to have evolved from egg-laying. With this transition, some structures were lost, including the hard outer eggshell.

Do any male species lay eggs?

Seahorses, and their close relatives – pipefish and seadragons – belong to the scientific family Syngnathidae. While male seahorses are the only ones that hold developing eggs in a true pouch, male pipefish and seadragons carry developing eggs attached to an area on the underside of their bodies.

Why mammals do not lay eggs?

“If early mammals laid tiny eggs, the young must have been much less developed when they hatched,” Panciroli says. But if the young developed inside, they could become more mature before being ushered into the outside world and would be less vulnerable after being born.

What is the advantage of laying eggs?

Both methods have benefits. Laying eggs allows greater mobility for the female, which will not be encumbered by developing embryos inside her body during a prolonged period of time. Since the mother’s body isn’t weighed down, she is able to escape danger and also hunt for food.

Did humans used to lay eggs?

Scientists have unraveled the origins of human pregnancy by tracing how our early mammal ancestors first evolved to give birth to live young. They found rogue fragments of DNA that jumped around the genome millions of years ago caused switched off the processes needed to lay eggs.