ORNITORRINCO: ¿Por qué pone HUEVOS si es un mamífero?

The video explores the platypus as an evolutionary anomaly that initially baffled scientists when the first specimen was sent from Australia to England in 1799, with many believing it was a hoax combining duck and beaver parts. The speaker explains that mammals evolved over hundreds of millions of years into three main groups: placental mammals (like humans) with complex placentas and advanced development, marsupials with shorter gestations and pouch development, and monotremes - the oldest lineage from 200 million years ago. Monotremes, including platypuses and echidnas, are the only egg-laying mammals because they preserved ancestral DNA instructions that other mammals lost over time, such as genes for producing egg yolk and flexible egg shells. The platypus has numerous other extraordinary features: it hunts underwater completely blind by closing all sensory organs and using its beak as a radar system that detects electrical fields from muscle contractions and pressure changes in water. Despite appearing bird-like, its beak is actually a soft, flexible snout covered in sensitive skin. Platypuses are born with teeth but lose them as adults, have no stomach (esophagus connects directly to intestine), and males possess venomous spurs used for territorial fights during mating season. They have a single opening called a cloaca for all bodily functions, 10 sex chromosomes instead of the typical 2, and fluorescent fur that glows green-cyan under ultraviolet light for unknown purposes.