Wednesday, February 29, 2012

Primate!..


Lemurs            
Lemurs are small primates known as "prosimians," which, roughly translated, means "pre-primates" or "before monkeys." Native only to the island of Madagascar and the neighboring Comoro Islands, lemurs resemble the oldest ancestors of primates which existed tens of millions of years ago
Physical Traits
Lemurs all have relatively long and slender limbs, a longer muzzle than later primates do, and a slightly smaller brain. They all have a dental ‘comb’ comprised of the lower incisors, which they use for grooming. Lemurs use scent marking in addition to vocalizations as a means of communication and territorial marking… a behavioral trait rarely found in later evolving primates.
Diet
The diet of a lemur consists mostly of all vegetarian food, common parts of a lemur diet in the wild include fruits, leaves, and other edible plant materials. Insects may also be on the menu, especially for the smaller lemurs. Lemur’s diet depends up on their breed. The small species mainly eat fruits and insects, while the larger species are herbivorous eating only fruit and plant materials.

Spider Monkey
Spider monkeys (of several species) live in the tropical rain forests of Central and South America and occur as far north as Mexico.  The spider monkey is more primitive than old world monkeys. Their brains are less complex, their thumbs are not opposable and their nostrils are further apart. They have slender bodies and limbs with long narrow hands.
Physical Traits
They have long, lanky arms and prehensile (gripping) tails that enable them to move gracefully from branch to branch and tree to tree. These nimble monkeys spend most of their time aloft, and maintain a powerful grip on branches even though they have no thumbs.
Diet
Spider monkeys are primarily omnivorous find food in the treetops and feast on seeds, nuts, fruits (they eat the inside of fruits, and prefer them ripe), leaves, bird eggs, and spiders. They can be noisy animals and often communicate with many calls, screeches, barks, and other sounds.
Baboon
There are five different species of baboons. All of them live in Africa or Arabia. Baboons are some of the world's largest monkeys, and males of different species average from 33 to 82 pounds (15 to 37 kilograms). Baboons generally prefer savanna and other semi-arid habitats, though a few live in tropical forest. Baboons are very social in nature, applying facial expressions, hand gestures, and a wide range of different vocal sounds from low-sounding grunts to high-pitched screeches when communicating. Baboons are also very adaptable to change and are able to interact with humans very well
Physical traits
They are two most common baboons that can be found in East Africa; the olive baboon and the yellow baboon. The Olive baboon is larger and darker and is found in Uganda, west and central Kenya and northern Tanzania. The Yellow baboon is smaller, more slender and lighter in color, and inhabits the southern and coastal parts of Kenya and Tanzania. Both types are "dog faced," but the Yellow baboon's nose curls up more than the olive's. In fact, along with the muzzle, the animal's tail (38–58 cm) and four-legged gait can make baboons seem very canine. The tail almost looks as if it is broken, as it is held upright over the rump for the first quarter, after which it drops sharply.
Diet
Baboons are opportunistic eaters and, fond of crops, become destructive pests to many African farmers. They eat fruits, grasses, seeds, bark, and roots, but also have a taste for meat. They eat birds, rodents, and even the young of larger mammals, such as antelopes and sheep.
Gibbon
Gibbons are rare, small, slender, long-armed, tree-dwelling apes. These very acrobatic primates live in Southeast Asia. Gibbons are arboreal; they spend most of their lives in trees. Because they are so dextrous while moving in the trees, almost no predators can catch them. These arboreal primates are found in the forests of Southeast Asia and Sumatra, from lower Burma south through the Malay Peninsula and east throughout Thailand.
Physical traits
 They exhibit many of the general characteristics of primates: flat faces, stereoscopic vision, enlarged brain size, grasping hands and feet, and opposable digits; and many specific characteristics of apes: broad chest, full shoulder rotation, no tail, and arms longer than legs, but they are relatively small, slender, and agile. They have fluffy, dense hair. Gibbon has very long arms, which they use in a spectacular arm-swinging locomotion called brachiation. Their hands and fingers are also very long. The relatively short thumb is set well down on the palm, and their fingers form a hook, which is used during brachiation. Gibbons have very good bipedal locomotion, which they use on stable surfaces too large to grasp. When walking biped ally, arms are held up to keep from dragging and to assist with balance. Gibbons are sometimes observed putting their weight on their hands and swinging their legs through as if using crutches. Gibbons do not build nests like the great apes. They sleep sitting up with their arms wrapped around their knees and their head tucked into their lap.
Diet
Gibbons are omnivores (eating plants and meat). They forage for food in the forests during the day, eating fruit (which constitutes about 75% of their diet), leaves, flowers, seeds, tree bark, and tender plant shoots. They also eat insects, spiders, bird eggs, and small birds. Gibbons drink water, often by dipping a furry hand into the water or rubbing a hand on wet leaves, and then slurping up the water from their fur. Gibbons sometimes do this while dangling above the water from a thin tree branch.
Chimpanzees
Wild chimpanzees have demonstrated the most extensive tool manufacture and use of all the great apes, except for humans.
Physical Traits
Infant chimpanzees have light faces and a white tuft of hair on their behinds to signal their special status as a youngster adult male chimpanzees are moderately larger than adult females (contrast with the extreme size difference between adult male and female gorillas and orangutans.
Diet
Chimpanzees have the most varied diet of all great apes in the wild. Chimpanzee diets are composed mainly of ripe fruits but vary according to the time of the year and abundance of specific food items. They will spend many hours a day eating about 20 different species of plants and up to about 300 different species during a one year period.  They do not store food and will eat it at the place they find it.  They also enjoy eating young leaves particularly in the afternoon. In long dry seasons when fruit is scarce, tree seeds, flowers, soft pith, galls, resin and bark become an important part of their diet. They also eat many different types of insects; some chimpanzees regularly hunt and eat meat, such as the red colobus monkey.





After all these research I found that that gibbon, like the gorilla, chimpanzee and orangutan, are ape, not monkeys.  The chief characteristics distinguishing apes from monkeys are the absence of a tail, their more or less upright posture and the high development of their brain. Primates share characteristics—such as five-fingered hands with opposing thumbs, forward-facing eyes, and color vision—but they do vary greatly, especially from prosimian to monkey to ape. The environment plays an important fact in their behavior as well as their diet. Great Apes are thinking, self-aware, intelligent beings.

Friday, February 24, 2012


The gray wolf or common wolf (Canis lupus) is the largest extant member of the dog family of mammals, the Canidae. The species was the world's most widely distributed mammal but has become extinct in much of Western Europe, in Mexico and much of the USA. Wolves occur primarily but not exclusively in wilderness and remote areas. Gray wolves are social predators that live in nuclear families consisting of a mated pair, their offspring and, occasionally, adopted immature wolves. They primarily feed on ungulates, which they hunt by wearing them down in short chases. Gray wolves are typically apex predators throughout their range, with only humans and tigers posing significant threats to them. Genetic studies reaffirm that the gray wolf is the ancestor of the domestic dog.
The domestic dog (a union of Canis lupus familiaris and Canis lupus dingo is a subspecies of the gray wolf (Canis lupus), a member of the Canidae family of the mammilian order "Carnivora". The present lineage of dogs was domesticated from gray wolves about 15,000 years ago. Remains of domesticated dogs have been found in Siberia and Belgium from about 33,000 years ago. Dogs perform many roles for people, such as hunting, herding, pulling loads, protection, assisting police and military, companionship, and, more recently, aiding handicapped individuals. Most breeds of dogs are at most a few hundred years old, having been artificially selected for particular morphologies and behaviors by people for specific functional roles. Through this selective breeding, the dog has developed into hundreds of varied breeds, and shows more behavioral and morphological variation than any other land mammal.
Gray Wolf                                                                   Dogs
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C. lupus

Domesticated
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Gray wolves are slender, powerfully built animals with large, deeply descending ribcages and sloping backs. Their abdomens are pulled in, and their necks heavily muscled. Their limbs are long and robust, with comparatively small paws.
-          The front paws have five toes each, while the back paws have four. They are also capable of running at speeds of 56–64 kilometers per hour (35–40 mph).
-           In cold climates, wolves can reduce the flow of blood near their skin to conserve body heat. The warmth of the footpads is regulated independently of the rest of the body, and is maintained at just above tissue-freezing point where the pads come in contact with ice and snow.
-          The teeth are heavy and large, being better suited to bone crushing than those of other extant canids, the canine teeth are robust and relatively short (26 mm).
-           The animal can develop a crushing pressure of perhaps 1,500 lbf/in2 compared to 750 lbf/in2 for a German shepherd. This force is sufficient to break open most bones, as well as cut through half inch lassos with one snap.
-          The wolf relies on its sense of hearing as well as smell more so than sight. Their vision is comparable to that of humans. The wolfs eyes lacks a foveal pit. A depression at the back of the eyeball. This is what is used to focus at greater distances. It is believed that they can not distinguish much beyond 100 to 150 feet.
Like most predatory mammals, the dog has powerful muscles, a cardiovascular system that supports both sprinting and endurance, and teeth for catching, holding, and tearing.
-          A Siberian husky is a medium-sized dog. It has a compact and furred body. A male is about 21 to 23.5 inches and 45 to 60 pounds (20.5 to 27kg). A female is about 20 to 22 inches and 35 to 50 pounds (15.5 to 23cm). It has lots of colors and patterns. Common colors are black and white, grey and white, copper-red and white, and all white.
-          The Siberian husky’s coat consists of two different layers, an undercoat and a topcoat. It helps the dog resist the rough weather. It can stand up to the temperature as low as -58 to -76 (-50 to -60). It does not have the undercoat during the shedding twice a year
-          Dogs have disconnected shoulder bones (lacking the collar bone of the human skeleton) that allow a greater stride length for running and leaping.
-          They walk on four toes, front and back, and have vestigial dewclaws on their front legs and sometimes on their rear legs
-          Dogs are predators and scavengers, possessing sharp teeth and strong jaws for attacking, holding, and tearing their food.
-          Like most mammals, dogs are dichromats and have color vision equivalent to red-green color blindness in humans.
-          Dogs detect sounds as low as the 16 to 20 Hz frequency range (compared to 20 to 70 Hz for humans) and above 45 kHz (compared to 13 to 20 kHz for humans), and in addition have a degree of ear mobility that helps them to rapidly pinpoint the exact location of a sound.

The domestic dog was originally classified as Canis familiaris and Canis familiarus domesticus by Carolus Linnaeus in 1758, and was reclassified in 1993 as Canis lupus familiaris, a subspecies of the gray wolf Canis lupus, by the Smithsonian Institution and the American Society of Mammalogists. Overwhelming evidence from behavior, vocalizations, morphology, and molecular biology led to the contemporary scientific understanding that a single species, the gray wolf, is the common ancestor for all breeds of domestic dogs. Although mDNA suggest a split between dogs and wolves around 100,000 years ago no specimens predate 33,000 years ago that are clearly morphologically domesticated dog.
The wolf looks like its distant cousin the dog with the exception of longer legs and larger paws. One major difference anatomically speaking is a pre-caudal gland on the upper surface of the tail, a feature totally absent in all domestic dogs.

DNA evidence suggests that the first wild canine that was domesticated was the grey wolf; however, other types of wolves and also jackals, coyotes, wild dogs, dingoes, and even some varieties of fox got into the mix as well, as a result any dog may have a combination of genes from all these various members of the canine family. Researches know this fact because domestic dogs can interbreed with most of this species ( with some exceptions) so the offspring from such mating are live, healthy and fertile which is taking as evidence that they are all the same species or according to evolutionary theory have a relatively common ancestor. No wonder why so many different breeds have so many different physical appearances, behavioral styles and personalities.
The definition of Phenotype is "the genetically and environmentally determined physical appearance of an organism." In other words, (the parents and) the conditions create the appearance.
Malamutes & Siberians Husky’s LOOK like wolves, and in certain instances, ACT like wolves, because:
All dogs and wolves descended from a common ancestor (or primitive version of the wolf, the debate rages); and, the phenotype of the Northern Breeds is the best solution to the problem of the Arctic weather and conditions. The Northern breeds did not evolve MUCH past that phenotype, as other breeds have because most variations to the phenotype would be killed off.  A boxer would not survive because he wasn't built for the situation.
The phenotype for Northern Breeds describes what works in the Arctic:
-          Thick, waterproof, double coat;
-          Bushy tail he can curl around his nose to warm his breath while sleeping; Long nose to warm the air before it reaches his lungs;
-          A seasonal oil deposit under his eyebrows which moves when he shakes his head and helps to shake off accumulated snow;
-          Thickly furred, prick ears to prevent frostbite;
-          Long legs to get through accumulated snow;
-          Pain tolerance;
-          Ability to think for himself in order to survive in a hostile environment;
-          Pack mentality that helps hunting & pulling (i.e. community survival);
-          Friendliness to strangers (lack of guarding instinct) in a nomadic community where people come and go frequently;
-          Howls, to communicate across large distances with the rest of the pack/family; and almond shaped, obliquely shaped eyes to keep them from freezing in the cold wind.
So any Northern Breed that did NOT have these specific characteristics would have a harder time surviving in the Arctic, whether it was a wolf or a dog. Manipulation of the phenotype is nothing new for the domesticated dog breeds. We have manipulated every breed of dog for desired results.
-          Golden Retrievers were bred to retrieve, and you can't stop them from chasing a tennis ball;
-          Australian Shepherds have had the "kill" instinct modified to make them good herders;
-          Basset Hounds have been bred for short legs to go to ground easier;
-          Bloodhounds have been bred to produce the floppy jowls and ears that aid tracking;
-          Afghans are leggy sprinters with keen eyesight to chase prey visually;
-          Malamutes were bred big and strong to pull great weights; and
-          Siberians are small and energetic to move cargo quickly.
In summary, environmental pressure has kept the Northern breeds close to the original phenotype. In the process we have tailored these dogs to their specific job, i.e. pulling in harness and living in human society; but the Malamute and the Siberian DID evolve past the original phenotype because of the changing environment. Northern breeds are puppy versions of the wolf.  Compared to adult wolves, they have shorter & blockier muzzles, shorter legs, stockier bodies, larger heads, and they are smaller (with a few individual exceptions). Their behavior is also puppyish, i.e., submissive to humans, and generally friendly to other dogs (again exceptions).  These are important differences.  Dogs have been domesticated for thousands of years; at best, wolves are socialized or tamed, but they are NOT domesticated


Tuesday, February 14, 2012

rRNA and DNA


C T A A T A C A C C T A A C A C C T C A C T C T T A C C T T C T C T A T C C G C T

Saturday, February 11, 2012

Darwin & Lamarck and the evolution


1 .- Jean-Baptiste lamark was a French naturalist who attempted to explain the evolucionary process, suggesting a dynamic relationship between species and environment. His model of evolution proposed that individuals were able to pass to their offspring characteristics acquired during their own lifetimes. Lamarck's proposal that species did not go extinct, but instead evolved into another form; In fact, Lamarck went further, stating that evolution produced more complex organisms from simple ancestors, and that this process of change took time.
 Lamarck thought that changes were acquired during the life of a parent organism and then transmitted to their offspring while Darwin deducted that changes were already present in the parent organisms, and that the best adapted to that situation survived to breed, which meant that those genetic changes become common in the following generations.
2.- Lamarckian evolutionism was what became known as the inheritance of acquired characters. This described the means by which the structure of an organism altered over generations. His theory help us to understand in certain way how everything develops in order to achieve in a better way new tasks.
3.-  Darwin Vs Lamarck
All organisms have the potential of reproducing exponentially
* Resources are limited.  Our planet has a limit of much it can hold and produce.  Here is where Lamarck and his example about the giraffes fits, looking for food giraffes expand their necks to reach.
*Organisms with better access to resources will be more successful in their reproductive efforts. 
* If the environment changes, the traits that are helpful or adaptive to that environment will be
Different,.
* In order for natural selection to occur, reproduction MUST occur!  Survival is not enough.  If you
don’t pass on your traits, evolution will not occur
* In order for traits to evolve and change, they MUST be heritable; we all know now that trait acquired by lifetime thatb are not in our genetic information cannot be pass from one generation to another./
4.- Probably yes, but the other theories help Charles Darwin  to develop a better way to study the  interactions between animals, and his view about them and also their relation with the world.

5.- Darwin took over twenty years to research, prepare, write, and eventually publish his great work. Its well known the great opposition and hostility that its publication inspired from the religious authorities and from a great part of the intellectual community of the mid-nineteenth century England.
The Origin of the Species which indicates that Darwin suppressed publication of his work because he was reluctant to face the “religious indignation that .. greeted its eventual publication. He did not suppress or delay publication because of religious or political factors; he simply did not feel that his work was ready to do what he hoped to do: make as strong a case as possible for natural evolution of species in the face of centuries of belief in God’s creation of animal and plant species in static, unchanging forms.