Vertebrate

Vertebrates are any of the species of animals that possess a vertebral column (backbone). They are the most widely known group of animals on earth, and unmatched in their variety of species. They range from the tiny sardine, to the great blue whale, the mighty elephant, to the common mouse. Within any given kind of vertebrate there is an amazing amount of diversity that exemplifies the adaptive capability they were provided with by God. Vertebrate habitats range from the deepest part of the ocean to the highest peak of the mountains; and from the lush tropics to the frozen Arctic.

Vertebrates are assigned to the taxonomic subphylum Vertebrata, which includes about 45,000 different species that live all over the world. The most widespread vertebrates are humans, which are known by the scientific name Homo sapiens. Humans can live almost anywhere on the earth due to their extraordinary design features and intelligence. Although all vertebrates, to some degree, can learn how to react and possibly change the environment in which they live, humans stand apart from the animals. There are three main types of intelligence and all vertebrates possess one or more of the three. They are: Inborn behavior, Conditioned behavior, and Intelligent behavior.



Anatomy
The anatomy of vertebrates is very diverse because of the large variety of species and classes in the Subphylum Vertebrata. However despite their differences, all vertebrates share several similar characteristics.


 * Spinal Cord: The spinal cord, or the backbone, is made up of vertebrata, which gives the name of the Subphylum. The spinal cord provides support for the organism; it also protects the nerve cord that runs inside of the spinal cord. The spinal cord is also what allows your body to communicate to the brain. The nerves cells in your body sends impulses to your brain through the spinal cord.


 * Skull: The skull is made up of many individual bones that have many different types of functions. The majority of the bones provide support and it also protects the brain.  The skull also allows the head to remain upright and to not collapse down.


 * Internal Skeleton The skeleton is divided into two types: The Axial and the Appendicular skeleton.  The Axial skeleton is made up of the vertebral column, ribs, and the skull.  This part of the skeleton helps relay messages, and it protects the vital organs such as the heart and the brain.  The Appendicular skeleton normally has two girdles: the pelvic, at the hips, and the pectoral at the shoulders.  The Appendicular skeleton is also made up of the legs and arms of the vertebrates.


 * Closed Circulatory system All vertebrates have a closed Circulatory system that is made of three main types of blood vessels: Arteries, capillaries, and Veins.  Arteries are the blood vessels that carry blood with oxygen away from the heart and to the muscles.  Veins carry blood without oxygen to the heart from the muscles.  Capillaries exchange the blood from the arteries for the blood from the veins.


 * Outer Covering: All vertebrates have some form of skin that encase all of the vertebrates internal structures.  This covering can be specialized based on where the creature lives.  Those that live in the desert will have very thick skins, while those that live near the water will have a thinner skin that is more suited for water.

Reproduction
All vertebrates can reproduce sexually and almost all species need a male and a female, however, some species are hermaphroditic, meaning they have both male and female sex organs. All vertebrates have to be sexually mature before they can actually reproduce. The time when they become sexually mature varies between species ranging from a few weeks to several years. When the time is right to reproduce there are two ways for it to happen. These ways are internal fertilization and external fertilization. In external fertilization the female lays the eggs then the male releases sperm onto them. This type of fertilization always happens in the water of an ocean or river, because there is no shell protecting the egg. Internal Fertilization occurs when the male places the sperm into the female and fertilizes the eggs inside the female's body. This type of fertilization has three types: Oviparous, Viviparous, and Ovoviviparous.


 * Oviparous Oviparous reproduction occurs when the offspring are encased inside of an egg. Birds, reptiles, and fish all use this method to give birth.


 * Viviparous Viviparous are nurtured to birth while in direct contact with the mother. The developing embryo will be attached to the uterus and that will supply them with their food, water, and air.  Most animals uses this method of birth.


 * Ovoviviparous This method has the male place the sperm inside of the female where the female will then lay an egg inside of her body.  When the egg is ready to hatch the mother will give live birth and the animal will be able to move and breathe.

Ecology
With vertebrates living all over the world their ecology is very difficult to determine. Some species of vertebrates are very small and have very little impact on the environment. However other vertebrates such as humans cause massive changes to the environment.

Marine Vertebrates
The marine vertebrates are all the vertebrates that live in the ocean. This group is made up of primarily five different classes: the Actinopterygii (Ray-finned fishes), the Sarcopterygii (Lungfishes and Coelacanths), the Chondrichthyes (Sharks and Rays), the Myxini (Hagfishes), and the Cephalaspidomorphi (Lampreys). All of these animals live at least part of their lives in the ocean.

Food Source: The food source for all of the vertebrates differs because of the diversity, however there are several main types of food.


 * Plankton: Plankton is a microscopic organism that many different species of vertebrates depend on for food.  Some examples of what eat plankton are small fish, as well as crabs and even some types of whale all eat plankton.
 * Fish: Many small fish, and even some larger ones can be eaten by bigger fish.  Even the Great White Shark will be eaten either when it is dead, or if it encounters a swarm of other sharks that are hungry enough.  Almost all vertebrates in the sea will eventually be eaten and provide food for another organism.

Habitat The habitat of marine vertebrates ranges from the close shallows to the depths of the ocean at more than 36,200 feet. However most of the vertebrates live at depths of about a 1,000 ft. The Ocean can be divided into several divers regions and each one provides in different ways to the animals that live there.


 * Estuaries: In Estuaries, which are areas where salt-water from the ocean mixes with fresh-water from the land and form an area of brackish water that is best suited for raising the young of many species.  Certain types of crabs, birds, and fish all allow their young to be raised in Estuaries.
 * Kelp forests: Kelp forests are made up of algae that grow to enormous sizes and bind together to form floating patches of kelp in the ocean.  These patches of kelp provide places for small fishes to hide, as well as for other animals to find food that will frequent the kelp forests.
 * Coral reefs: Coral reefs are made up of millions of coral skeletons that bonded together and formed a giant reef that is home to thousands of individual animals.  The reef is also a home to many diverse species and provides a large selection to the carnivores that will frequent the reefs for a meal.
 * Ocean depths: The ocean depths begin at about 20,000 ft. under the sea and the animals that live their are very different then any other species.  These differences are so diverse that if a fish from another region went down their it would soon die from the enormous pressure.  Some types of fish that live there are the angler fish, viper fish and many other types of fish.

Land Vertebrates
The land vertebrates are all vertebrates that live on land and get oxygen from the air. Their habitats range from the frozen arctic, to the lush rain forests, to the barren desert. Although the land vertebrates live in such diverse areas, they have the same basic needs.

Food Source All vertebrates gain their nutrients through one of three methods. These methods are carnivorous, herbivorous, and omnivorous. The difference between these methods is diverse enough to separate classes by what they eat.
 * Carnivorous: Animals that  obtain the essential nutrients are considered carnivores.  Some examples of carnivores are: alligators, wolves, vultures, and eagles are all carnivores.
 * Herbivores: Animals that obtain their essential nutrients from plants, and berries are herbivores.  Examples of herbivores are: deer, cows, sheep, and horses.
 * Omnivores: Omnivores can obtain their nutrients from both plants and animals.  Some types of omnivores are bears,pigs, rats, and humans are all omnivores.

Habitat The land area of earth is divided into section called biomes which can be divided into four main areas. They are the tundra, deserts, grasslands, and the forests.
 * Tundra: The tundra is a flat treeless region in the northern regions and on high mountains.  It is characterized by low biodiversity rates, short season for growth and reproduction, and an extremely cold climate.
 * Deserts: Deserts are areas where little water is available which contain many specialized species of life.  Not all deserts are the same, as they range from the blistering heat of the Sahara to the freezing cold of the Gobi. However, most deserts can only support life to specialized species that were designed by God to live in these environments.
 * Grasslands: As the name implies, grasslands are covered in grass, and don't have shrubs or trees.  Grasslands are characterized by hot and dry conditions which are unable to support larger vegetation, although the occasional tree will grow in the area.
 * Forests: Forests are characterized by being dominated with lots of trees and other shrubs.   Forest characterizations include: supporting large groups of life, trees are the dominate vegetation, and it is affected by the seasons.

Origin of Vertebrates
The origin of Vertebrates depends on your world view. The same fossil, or evidence given to a scientist from each world view will provide to very different results as to when it was fossilized. To a creationist the origin of vertebrates is very simple, however to an evolutionist it is very hard to explain. According to the Biblical creation point of view God created the Vertebrates on day five and day six of creation. On day five of creation God created the birds, and the fish. Then on day six he created the animals that live on the land. Therefore vertebrates were created on both day five and day six of creation.

Evolution
According to evolution, the world was created over 4.6 billion years ago, then about 500 million years ago the first vertebrates evolved. According to evolutionists the first vertebrate was a less complicated organism and gradually evolved into more complex organisms. These fish evolved into the Cartilaginous fish.


 * Class Agnatha: The members of Class Agnatha is cited as being the beginning of the vertebrates because they do not have any paired fins, and no jaws. Evolutionist say that Class Agnatha evolved during the Ordovician period and had all died out by the Devonian period; except for a few surviving species, such as hagfish, and lampreys.


 * Class Placodermi: Members of the Class Placodermi evolved during the Silurian period.  These fish which include sharks, and skates, and they lack lungs, swim bladders, and have skeletons made of cartilage, not bone.  These fishes then evolved into the bony fish.


 * Class Osteichthyes: These fish have a skeleton made of bone, as well as possessing lungs and swim bladders, and have paired fins.  This class evolved during the late Silurian period and eventually evolved into amphibians.


 * Class Amphibia: The amphibians evolved during the Carboniferous period and were the first vertebrates to venture out onto the land.  Amphibians evolved during the early Carboniferous period, and possess moist skin, legs, and reproduce with external fertilization.  The amphibians remained closely tied to their aquatic habitats and most species spend their early lives in the water.


 * Class Reptilia: Reptiles evolved during the Carboniferous period and replaced the amphibians as the dominant class on the land.  Reptile possess scales, strong legs, and hard shelled eggs.  The reptiles legs which were positioned under the reptile enabled greater mobility then the amphibians legs which were to the side of the creature.


 * Class Aves: During the early Jurassic period the birds evolved from reptiles.  The birds evolved wings, feathers, hollow bones, and large lungs.  These modifications allowed them to learn to fly, until  they evolved into mammals.


 * Class Mammalia: The mammals mark the end of the evolutionary chain.  They possess a four chambered heart, mammary glands, and are warm blooded.  They also give live birth, except for certain species.  The last major characteristic is fur.  All mammals possess at least some fur on their body.



Challenges
The first Archaeopteryx fossil was discovered in 1855, then over the next 100 years about 8 more of the fossils were discovered in mainly Germany, and one in England. Since their discovery the fossil has remained controversy as to what it originally looked like and if it could fly. Today evolutionist claim that the Archaeopteryx is a missing link between birds and reptiles. Some characteristics of the Archaeopteryx that appear to be reptilian include: teeth, wing claws, and unfused vertebrae; and some features that appear to be avian include: perching feet, feathers, and adequate flight muscle attachment. While most evolutionist claim that this is a missing link most creationist simply regard it as a unique organism. Also there is no reason that God could not have put teeth and claws on some birds as well as some bird like feature on some reptiles.