feature

=Julian Pena And Kevin Hughes.=

Dogs: Wolf to Man’s Best Friend?

By: Jonnee Sulzberger

You may have not known this, but your dog is actually a bunch of different dogs mixed together. This is all possible because of artificial selection. Artificial selection is the same concept as selective breeding. Selective breeding is mixing breeds intentionally to get desired traits. This is commonly used in various house pets. Different breeds of dogs are due to selective breeding.

It all started with the grey wolf about 15,000 years ago. They were domesticated, which changed them into different types of dogs because they adapted to certain environments all over the world. Then as time went on, people discovered selective breeding, and gradually more breeds of dogs were developed. The breeds of dogs we know today were mostly developed over the past 150 years. They were mixed intentionally with other dogs that would produce the desired traits.

It’s pretty amazing how all these different dogs that are so different, all came from the same descendant. The evolution of breeding dogs is more important than most people realize. Dogs were bred to protect us, hunt for us, and be our best friends. So without dogs by our side, mankind would be much different than it is today.

[|www.pbs.org/wbgh/evolution/library/01/5/l_015_02.html]

[|www.pbs.org/wbgh/nova/dogs]

[|www.animals.howstuffworks.com/pets/dogs2.htm]

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 * The Fantastic Fransesco Redi (final draft) **
 * By Andrea Grubaugh **

If you have taken a science class, you know all about controlled experiments and how organisms are created. It’s hard to imagine modern scientists not knowing this knowledge. And if it wasn’t for Italian scientist Fransesco Redi, we might not have this basic knowledge.

Francesco Redi was born in the 17th century, on February 18th 1626. Redi attended the University of Pisa as an adult, and eventually became court physician to the Grand Duke of Tuscany. In addition to this, Redi was the first to challenge the idea of Spontaneous Generation, which is the idea that life appears out of thin air. In 1668, Redi performed his famous experiment, which is also the first recorded example of a controlled experiment (an experiment that has a control group to compare results with). Redi’s experiment used six flasks and six pieces of raw meat. In his experiment, he left two of the flasks uncovered, put gauze over two of the flasks, and covered the final two flasks completely. His experiment was to see if maggots appeared from meat alone or if there was another variable in creating maggots. When the experiment was over, only the pieces of meat that were in the completely uncovered flasks had maggots in them. This proved that maggots didn’t just appear in meat, but when flies laid their eggs on the meat and the eggs hatched into maggots. To let people know about his findings, he published his greatest piece of work, “Experiments on the Origin of Insects”. Unfortunately, this book wasn’t as groundbreaking as he would’ve hoped. While a lot of people didn’t accept the experiment’s results, and even Redi himself still believed in some forms of spontaneous generation (like gall flies and intestinal parasites), this was still the first experiment to challenge and prove the spontaneous generation theory wrong. If it wasn’t for Redi, we might still believe maggots from meat. And that’s why I decided to make a feature about the great Italian scientist and physician known as Francesco Redi. = = = = = = = = = = = = =﻿ = = = Dogs: Wolf to Man’s Best Friend?

By: Jonnee Sulzberger = =

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= = You may have not known this, but your dog is actually a bunch of different dogs mixed together. This is all possible because of artificial selection. Different breeds of dogs are due to selective breeding. It all started w ith the grey wolf about 15,000 years ago. They were domesticated, which changed them into different types of dogs because they adapted to certain environments all over the world. The breeds of dogs we know today were mostly developed over the past 150 years. They were mixed intentionally with other dogs that would produce the desired traits. The evolution of breeding dogs is more important than most people realize. Dogs were bred to protect us, hunt for us, and be our best friends. So without dogs by our side, mankind would be much different than it is today.  =Horsing Around = By: Laura Wood P.3(Final Draft)

Horses have been around for a very long time, but they weren’t always the skyscrapers of muscle known today. Like all things the modern horse is a result of evolution and has overcome obstacles overtime. Today when a horse runs by there are rippling muscles, a whipping mane, and the thud of hooves. Millions of years ago they would not be recognizable and would be barely the size of a small dog, not even making a sound.

The horse first started out in North America as a species named //Eohippus//. They had four toes in the front and three in the back with pads much like a dog and a n arched back. //Orohippus// a subspecies of //Eohippus// was the onlyone to continue evolving into new species through time. The process that took //Eohippus// and turned it into //Equus// the modern horse took time though, as environments and predators shifted. The “modern day horse known today is the result of over 55 million years of evolution”(“The Equestrian and Horse”). Over time the horse took in its surroundings and molded itself to it, becoming a player in Darwin’s “survival of the fittest” game. The horse survived changes through a theory many believed, called natural selection.

Natural selection is the process where organisms better adapted to their environment tend to survive and produce more offspring. This theory was first thought of by Charles Darwin and is now believed to be the main process that brings about evolution. The horse adapted to its environment, kept surviving and in turn managed to reproduce. The horse still remains today because evolution took charge and kept going. Horse step by step gained more mass with elongated bodies, necks, legs, and faces. Their feet slowly grew closer and closer together forming hooves making it easier to run great distances on the packed ground along with better shock absorption. Their bodies and legs became longer and stronger for better strides and speeds to out run predators. Horses longer necks and adapted flat teeth made it easier to reach and grind their organic food source. Even their wide set eyes and tall ears now a day help in their survival, giving them better sensory direction. Each of these slow adaptations that represent the modern horse have been refined over many years for survival. As the horse took in its environment sculpted itself to better compliment its surroundings and helped itself be better equipped in the changing world. It wasn’t a straightforward change either, there were many trials and errors, “** t **hese traits do n ot necessarily evolve together, or at a steady rate. The various morphological characters each evolved in fits and starts”( Hunt). Evolution is a slow and constantly tiring fight or progression, many species have lost to it but others like the horse have learned to conquer it.

Each process of evolution has a reason, though, something that caused it. Many reasons point to changing environments, food supplies, and predators. Almost every one of the horse adaptations can be connected to those factors, getting bigger and stronger with wide set eyes and ears help the horse defend and be aware of lurking predators. The longer neck and teeth help to get food and eat that particular food source of grains, plants, and fruit. The hooves and long legs help to move better over the current environment along with the thin coat meant to keep their body from over heating. All of these adaptations were motivated from survival, the need to go on and to live.

The horse was taken through natural selection and Darwin’s game of “survival of the fittest" as said before, but survival is no game. Species like the horse had strength and determination that they used to shape themselves into something that was part of the environment, not something struggling against the environment. With each new obstacle thrown into the horse’s w ay it embraced it and kept moving forward. In the fight for survival, evolution was and is serious, there is no time for horseplay, no horsing around allowed.

Works Cited

Hunt, Kathleen. “Horse Evolution.” //Talk Origins Archive: Exploring the Creation/ Evolution Controversy.// 2003. Web. 20

May 2011.

“ Evolution of the Horse.” //Equestrianandhorse.com.// The Equestrian and Horse. 2011. Web. 19 May 2011.

Final Draft, Ismenia Castelan, Pd.7

1st Draft, Ismenia Castelan, Pd.7 [|The Stretch of the Giraffe.doc]

Jake Drahos Period 4

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