Key Features of Mammals:
* Warm-blooded: Mammals regulate their own body temperature, maintaining a consistent internal temperature regardless of the external environment.
* Hair or fur: Mammals have a coat of hair or fur, which helps with insulation and sometimes camouflage.
* Mammary glands: Female mammals have mammary glands, which produce milk to nourish their offspring.
* Live birth: Most mammals give birth to live young, with the exception of monotremes (platypuses and echidnas) who lay eggs.
* Three middle ear bones: Mammals possess three tiny bones in the middle ear (malleus, incus, and stapes) that transmit sound vibrations.
* Four-chambered heart: Mammals have a highly efficient circulatory system with a four-chambered heart, which separates oxygenated and deoxygenated blood.
* Diaphragm: Mammals have a diaphragm, a muscular sheet that separates the chest cavity from the abdomen and helps with breathing.
* Larger brain: Mammals generally have a larger brain relative to their body size compared to other vertebrates.
* Highly developed nervous system: Mammals have a sophisticated nervous system that allows for complex behaviors and communication.
* Diverse adaptations: Mammals exhibit a wide range of adaptations depending on their environment and lifestyle, including flying, swimming, digging, and climbing.
Examples of Mammals:
* Humans
* Dogs
* Cats
* Whales
* Dolphins
* Bats
* Elephants
* Monkeys
* Kangaroos
* Bears
Evolution of Mammals:
Mammals evolved from a group of reptiles called synapsids over 200 million years ago. They diversified and radiated into a wide range of species, becoming dominant terrestrial vertebrates after the extinction of the dinosaurs.