The early Devonian period is largely considered to be a world of a diverse array of lobe-finned fish, including lungfish, coelacanths, and bony fish. Over the course of time, vertebrates made evolutionary strides with provided them with the ability to travel on land. Coelacanths developed a single boned shoulder girdle, lungfish developed paired fins, and sauripterus developed the major structures on the arm (humerus, radius, and ulna). As these developments progressed and environmental pressures were amounting in aquatic environments, vertebrates began to venture onto land. Sometimes it was for short excursions, sometimes a bit longer.
Paleontologists look for features from one way of life to another. They create a tree of life that separates species according to their common structure. Fossils show how tetrapod legs evolved from fins and genes studies show how mutation and natural selection resulted into long limb bones from the fins (Hoff). In this case, they have uncovered how a species that lives on water transitioned to a terrestrial way of life. Perhaps descendants found land a source of abundant food and a haven from competition.
At some point of their life they had a dorsal hollow nerve cord, a notochord, pharyngeal pouches, and a tail that extends beyond the anus. The development of the jaw was useful with the teeth and muscles, by... ... middle of paper ... ...parates species according to their common structure. Fossils show how tetrapod legs evolved from fins and genes studies show how mutation and natural selection resulted into long limb bones from the fins (Hoff). In this case, they have uncovered how a species that lives on water transitioned to a terrestrial way of life. It took millions of years for evolution to generate certain animal adaptations.
Amphibians are cold-blooded vertebrates animals that live under water and on land. Ichthyostega is considered the first amphibian and land vertebrate. Eusthenopteron is one group of fish that evolved during the Devonian and made a significant... ... middle of paper ... ...Devonian period influence these fish to use their exaptations to explore a new habitat. This is the Ecological Opportunity hypothesis, which suggest that these fish undergo an adaptive radiation onto the terrestrial environment. This occurs when an environmental change influence the organisms to develop more suitable features and use it under different conditions.
Abstract: The early tetrapods were the first vertebrates to actually walk the solid earth. They began their conquest of land in the Paleozoic era around 360 million years ago. The question many paleontologists have been asking for a long period of time is whether the anatomy for locomotion on land was developed in water for swimming purposes, or if it was adapted after the creatures became terrestrial. Recent findings of fossils indicate that the transformations of the aquatic creatures happened underwater in order to help them survive in the changing world. When looking for answers, they had to examine forearm, hip, wrist, finger, and other bones, as well as the lungs or gills of the early tetrapod fossils.
The earliest known reptiles originated 340-335 million years ago during the carboniferous period, having evolved from advanced reptile-like amphibians that became increasingly adapted to life on dry land. Although there are some reptiles who live on land, water or land and water, reptiles come in all different shapes, sizes, color’s. There are many diverse reptile groups that are extinct due to massive extinction events. Reptiles are a tetrapod vertebrates meaning they have four limbs, or like snakes being descended from for limb ancestors. Most reptiles are oviparous meaning they are egg layers, although there are some reptiles that are viviparous meaning they carry a fetus in there stomach.
Elaborated vocal ability is seen in aquatic mammals. A large brain is seen in aquatic mammals such as seals and toothed whales. Brain asymmetry leads to an aquatic ancestor in human evolution history. Result: Homo Aquaticus? I think so.
Biological Evolution Biological evolution is the change in the inherited and genetic characteristics of a species. Much of what makes us human is our physical appearance and biological adaptations. Human ancestry originates in primates and over time, we have physically evolved a great deal in order to become the modern humans that we are today. Humans have larger brain sizes, longer legs, and are habitually bipedal all of which biologically separate humans from other animals and create the human identity. One of the most important and pivotal physical and biological adaptations that separate humans from other mammals is habitual bipedalism.
“…Modern cetaceans are highly specialized, with numerous adaptations that allow them t... ... middle of paper ... ...ls. J. G. M. Thewissen and his colleagues changed the way in which scientists thought about the early lifestyles of whales. The evolution of the ancient artiodactyls was discovered to be joined with the well-known group of cetaceans. The tertiary period was a time of terrestrial life forms. Every mammal walked the earth.
The first type of fish to appear during the Ordovician era were called Ostracoderms. They had their head and flanks covered with a bony armor while they had a cartilaginous back. The shield was used to keep off predators. The extinction of the Ostracoderms during the Devonian period saw the emergence of Placoderms. These types of fish were also armored, but their functional jaws distinguished them from their predecessors.