Wednesday, October 8, 2008

Darwin Theory of Evolution







Darwin's Theory of Evolution is the widely held notion that all life is related and has descended from a common ancestor: In a nutshell, as random genetic mutations occur within an organism's genetic code, the beneficial mutations are preserved because they aid survival -- a process known as "natural selection." These beneficial mutations are passed on to the next generation. Over time, beneficial mutations accumulate and the result is an entirely different organism (not just a variation of the original, but an entirely different creature).
One definition of a species is a group of organisms that can reproduce with one another and produce fertile offspring. When a species is separated into populations that are prevented from interbreeding, mutations, genetic drift, and natural selection cause the accumulation of differences over generations and the emergence of new species.




Natural Selection




While Darwin's Theory of Evolution is a relatively young archetype, the evolutionary worldview itself is as old as antiquity.." Natural selection acts to preserve and accumulate minor advantageous genetic mutations. Suppose a member of a species developed a functional advantage (it grew wings and learned to fly). Its offspring would inherit that advantage and pass it on to their offspring. The inferior (disadvantaged) members of the same species would gradually die out, leaving only the superior (advantaged) members of the species. Natural selection is the preservation of a functional advantage that enables a species to compete better in the wild.


Darwin's Theory of Evolution is a theory in crisis in light of the tremendous advances we've made in molecular biology, biochemistry and genetics over the past fifty years. We now know that there are in fact tens of thousands of irreducibly complex systems on the cellular level.




Soft Shell Turtle
Trionychidae is a taxinomic family which comprises a number of turtle genera commonly known as soft-shell turtles. It consists of some of the world's largest fresh water turtles, though many can adapt to living in highly brackrish areas. Members of this family occur in Africa, Asia, North America, and the East Indies.
They are called "soft shelled" because their carapace lacks horny scutes (scales), though the Spiny Softshell Turtle, Apalone Spinifera, does have some scale-like projections, hence its name. The carapace is leathery and pliable, particularly at the sides. The central part of the carapace has a layer of solid bone beneath it, as in other turtles, but this is absent at the outer edges. Some species also have dermal bones in the plastron, but these are not attached to the bones of the shell. The light and flexible shell of these turtles allows them to move more easily in open water, or in muddy lake bottoms. Females can grow up to several feet in carapace diameter, while males stay much smaller; this is their main form of sexual dimorphism.
These turtles have many characteristics pertaining to their aquatic lifestyle. Like all aquatic turtles, they need to be submerged to be able to swallow food. Most are strict carnivores, with diets consisting mainly of fishes, aquatic crustaceans, snails, amphibians, and sometimes birds and small mammals.
Snake neck turtle
The Common snake-neck turtle (Chelodina longicollis), also known as the Eastern long-neck turtle, Eastern snake-neck turtle, or Common long-neck turtle has as its most distinctive feature its extremely long neck. In some cases, this turtle's neck can be as long as its carapace. It is a type of side-necked turtle, meaning that it bends its head sideways into its shell rather than pulling it directly back.
The common snakeback turtle also has powerful webbed feet for swimming, digging, and tearing apart prey. Its carapace (shell) is flattened, broad, and brown with black-edged scutes. On the underside plates (plastron) there are distinctive black lines or seams.

These turtles are found in the inland slow-moving freshwater habitats such as swamps, dams, and lakes of eastern Australia.
They prefer a soft, sandy bottom and will bask on logs or rocks during the day. The common snake-neck turtle is carnivorous, eating a variety of animals. They feed on insects, worms, tadpoles, frogs, small fish, crustaceans, and molluscs.
Mud Turtle
Mud turtles are known for their dull shell colors and relation to the smelly musk turtles. African and American mud turtles are very different and are not closely related. Their only similarities are in their choice of habitat, both preferring shallow, slow moving bodies of water with muddy bottoms, and having a dome shaped carapace. They can grow up to about 5 inches. They live up to 50 years of age.
Mud turtles are primarily carnivorous and will consume almost anything they can catch including: fish, worms, insects, grubs, crustaceans, tadpoles, small berries and even carrion.
Mud turtles prefer damp, sandy or muddy dwellings as their name suggests. They will rarely go in the water unlike Aquatic turtles but they will occasionally go in fo a dip in a swamp or a pond.
Red foot turtle
Geochelone carbonaria sometimes also called red foot (or redfoot), redleg, or Savanna tortoises. Red footed tortoises live up to 50 years, possibly longer.
Red footed tortoises often reach a length of 10-14 inches, although they can be larger (16 inches or more). A slightly smaller "dwarf" variety is also being sold, commonly called the cherry-head that only attains a length of 10 - 12 inches as an adult. They can reach weights up to 30 pounds.

In the wild, red footed tortoises are omnivores and eat a wider range of foods than many other tortoises. It is important to not overfeed animal protein, though; one very small serving of moistened low fat cat food or lean meat (e.g. 1 ounce for a full A large enclosure is needed - 4 feet by 6 feet or larger. Cypress grown red foot) every 1-2 weeks is enough. A variety of fresh leafy greens (dandelion greens, endive, mustard greens, escarole; not lettuce, spinach or kale), vegetables, and fruits should also be fed (they also tolerate fruit better than many other species). A calcium and vitamin D3 supplement should be used. This species is tropical and prefers a humid climate.
Texas box turtle
The American Box Turtle is one of the most highly recognized and loved turtles in North America. However, due to a loss of natural environment, an increase in roads, and indiscriminate gathering of these native turtles, they are becoming increasingly rare in the wild. Studies done over the last 50 years have shown a steady decline in the population of the American Box Turtle.
As with other box turtles, Gulf Coast box turtles can be very long-lived, possibly up to 100 years.
Males are slightly larger on average than females, the posterior lobe of their plastron is concave, and the claws on their hind legs are short, thick, and curved. Males also have thicker and longer tails. Females' rear claws are longer, straighter, and more slender, and the posterior lobe of their plastron is flat or slightly convex. Males have red irises and females have yellowish-brown irises.


In the northern regions, box turtles go into hibernation in October or November, but farther south they remain active later in the year. They may return to the same place to hibernate in successive years and sometimes more than one turtle hibernates in the same hibernacula. They usually emerge from hibernation in April.
When frightened, box turtles retract their head, tail, and limbs into their shell and clamp it shut. They wait in this position until the perceived threat is gone. While juveniles have several predators, very few species can prey effectively on adults due to this defense technique.
Russian Tortoise
When frightened, box turtles retract their head, tail, and limbs into their shell and clamp it shut. They wait in this position until the perceived threat is gone. While juveniles have several predators, very few species can prey effectively on adults due to this defense technique.
In the wild, the Russian Tortoise is considered vulnerable to extinction in the mid-long term. Human construction encroaching upon its habitat is the main cause of endangerment. Trade in wild animals is restricted, and captive-breds should be preferred as pets as they are hardier.
Russian tortoises are popular pets primarily because of their small size, but they are also an extremely hardy species.
They will also eat fruit, but should only be given it in small quantities, as excess sugars are not good for them. These tortoises use fiber for energy instead of protein.
Central American ornated wood turtle
The Central American Ornate Wood Turtle is also known as the Pracht-Erdschildkrote, Painted Wood Turtle, or Ornate Wood Turtle. They are native to Central America, as the name would suggest, and are a beautiful animal that is a gracious addition to any terrarium.
The Ornate Wood Turtle generally makes its home in damp woodlands and scrublands. They usually are found near water and during dry weather will wade and swim in water. The Ornate Wood Turtle is terrestrial rather than aquatic, meaning it spends most of its time on land. In the wild, the Ornate Wood Turtle is omnivorous, meaning it feeds on both plants and animals. They eat wildflowers, fruit, grasses, fish, worms, and insects. Ornate Wood Turtles are generally quite outgoing and curious. Ornate Wood Turtles are usually active creatures. When mating, males bob their head and nose the female's tail and shell. Later, the female and male both bob their heads. Ornate Wood Turtles can survive in temperatures as high as 44 degrees Celsius and can live in very dry conditions for an extended period.
A very attractive animal, the Ornate Wood Turtle is awash in red and black. The face is adorned with thin red lines, and the legs, tail, plastron (underside of the shell), and marginal scutes (sides of the shell) are heavily marked with red and black.
Ornate Wood Turtles can be found throughout Central America. They range between Sonora, Mexico, and Costa Rica. They are beneficial to human beings because they feed on many insects that often become pests. Unfortunately, people who want to sell them as pets are taking them out of their natural habitats. Central American Ornate Wood Turtles usually do not do well in captivity.

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