SCIENTISTS define brain as an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals, not only that the brain is located in the head. Usually close to the sensory organs for senses such as vision, physiologically, the function of the brain is to exert centralised control over the other organs of the body.
Moreover the brain acts on the rest of the body both by generating patterns of muscle activity and by driving the secretion of chemicals called hormones, this centralized control allows rapid and coordinated responses to changes in the environment also some basic types of responsiveness such as reflexes can be mediated by the spinal cord or peripheral ganglia. But sophisticated purposeful control of behavior based on complex sensory input requires the information integrating capabilities of a centralized brain.
Scientists say through researches on fossils they have discovered that the first creature that carried a brain evolved about 250 million years ago, that happened after the development of hindbrain on mammals. Researchers go further by saying the cerebrum first developed about 200 million years ago and from that time it evolved to be responsible for higher cognitive functions for example, language, thinking, and related forms of information processing.
At the same time the world’s history shows that mammals evolved on the Earth about 320 million years ago but they were less known to other creatures until 250 million years ago. When a mass extinction event killed 70 percent of vertebrates, and from an egg laying mammal, evolution of this group passed different stages but from those days to date their offspring start life without teeth to cut or grind food stuffs.
Scientists say different fossils records show that mammals evolved into their full stage about 170 million years ago when they acquired a placenta which helps them to carry, protect and feed the embryo inside their bodies.
Scientists say among different species of mammal through different stages the brain is one of the first organ to be developed after fertilization. In biology the fusion of gametes to initiate the development of a new individual organism or offspring. Through this cycle of fertilization and development that a new individuals brought around being a product of what is called sexual reproduction.
Scientists believe that the smartness of the brain is contributed by the time an offspring spends in its mother’s womb. Gestation is the period of development during the carrying of an embryo or fetus inside viviparous animals. It is typical for mammals, but also occurs for some non-mammals. Mammals during pregnancy can have one or more gestations at the same time for example in a multiple birth, and among mammals. Pregnancy begins when a zygote or fertilised ovum implants in the female's uterus and ends once the fetus leaves the uterus.
Although different biological factors contribute on the level of intelligence of an individual but after spending between 12 to 18 months inside their mother’s womb. A baby dolphin or calf is born while carrying one of the smart brain among the animals kingdom. Dolphins are marine mammals closely related to whales and porpoises. There are almost forty species of dolphin in 17 genera found worldwide mostly in the shallower seas of the continental shelves. They are carnivores eating mostly fish and squid.
Unlike most mammals, dolphins do not have hair. Except for a few hairs around the tip of their rostrum or beak which they lose shortly before or after birth. Most species of dolphins have acute eyesight, both in and out of the water. They can hear frequencies ten times or more above the upper limit of adult human hearing.
Though they have a small ear opening on each side of their head. It is believed hearing underwater is also possible, if not exclusively, done with the lower jaw, which conducts sound to the middle ear via a fat filled cavity in the lower jaw bone. Hearing is also used for echolocation, which all dolphins have on other side dolphin teeth are believed to function as antennae to receive incoming sound and to pinpoint the exact location of an object.
Scientists say beyond locating an object, echolocation also provides the animal with an idea on the object's shape and size. Though how exactly this works is not yet understood, some species may dwell and thrive in darkness and use the mechanism effectively blind. This may be because not much light penetrates the waters.
Dolphins are often regarded as one of Earth's most intelligent animals. Though it is hard to say just how intelligent, comparing species' relative intelligence is complicated by differences in sensory apparatus, response modes, and nature of cognition.
These are social animals living in pods of up to a dozen individuals. Scientists say pods can merge temporarily, forming a big group with more than 1,000 dolphins. It is believed that individuals communicate using a variety of clicks, whistle like sounds and other vocalizations. Membership in pods is not restricted because interchange is common. However, dolphins can establish strong social bonds and they will stay with injured or ill individuals. Even helping them to breathe by bringing them to the surface if needed.
These are friends to humans, they have been seen protecting swimmers from shark’s attacks by swimming in circles around the swimmers or charging the sharks to make them go away. Dolphins also display culture or something long believed to be unique to humans and possibly found among primate species such as bonobo and chimpanzee.
Dolphins are playful animals and occasionally leap above the water surface, and sometimes perform acrobatic figures. The game is an important part of dolphin culture, they appear to enjoy riding waves and frequently surf coastal swells and the bow waves of boats, at times “leaping” between the dual bow waves of a moving boat and occasionally they may play with swimmers.
Among mammals in the savannah fertilization may occur at any time of the year but some clever species have a well defined calendar for this important stage for life but others like wildebeests are able to prolong their gestation until situation allow the expected offspring to be delivered in a conducive environment.
In the same environment, standing between 2.7 and 3.7 meters, while weighing more than 7,500 kilograms the body of an African bush elephant may grow more than 3 meters long which makes the mammal to be the largest terrestrial animal in the world.
The African Bush Elephant gives birth to an offspring weighing about 100 kilograms after the longest gestation period among mammals of 22 months. A calf or baby elephant starts its life by drinking nutritious milk from its mother for five months. It is estimated that in a single day a baby elephant is capable to drink 15 liter of milk rich in fat and protein.
At the same time in zoology fertilization or impregnation is the process of uniting gametes to initiate the development of a new individual organism. Among mammals and other animals this process which is called sexual production and involves combining together an ovum and a sperm to create a zygote which develop into an embryo.
Scientist say among the long list of mammals which dwell in the vast tropical savannah of Africa. The structure of elephants brain has a unique complexity which is compared with that of human brain. Elephant are powered by a five kilogram brain which is said to be bigger than any other animal is dwelling in the wild with one of the most sophisticated organ among members of the might animal’s kingdom.
All elephants display great usefulness with the trunk but it takes baby elephants a number of years to become truly expert in their use capable of lifting up to 250 kilograms at a time. A trunk is a long, prehensile tube with two nostrils running down the centre and a mass of flesh, muscle, fat, nerves blood and connective tissue, weighing about 140 kilograms it is a nose, an arm, a hand, a voice, a straw, a hose, weapon, a fifth leg and much more for an elephant.