Vestigial Structures

Vestigial Structures are structures that have lost their original function or seem to have no function at all. (Examples: coccyx, wisdom teeth, appendix, etc.) At one point in time these structures probably had some sort of function, but through the evolution process we may have had no further use for them. Vestigial structures aren't just found in humans they're also found in animals, such as a whale has remnants of a hind leg bones, and pythons have pelvic spurs (Which are thought to be the remnants of legs.) Monkeys have extrinsic ear muscles that allow them to move their ears in all directions. Humans have the same extrinsic ear muscles but for us they have no function. At one time for our ancestors perhaps the ear muscles helped them to locate food or know if an enemy was nearby. With all these vestigial structures, do you ever wonder what their purpose is?

http://evolution.about.com/od/evidence/tp/Vestigial-Structures-In-Humans.htm

Exploring Biology in the Laboratory - page 220 - Murray Paton Pendarvis; John L. Crawley.

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Evolution

Life has a history. Every Species has changed over time, different species also share common ancestors. Species with common ancestors come from the same family tree or a phylogeny, this is where certain characteristics were passed on to certain descendants while other characteristics were passed to descendants on a different branch on the family tree. All phylogenetic trees are a hypothesis about the relationship among organisms. There are three domains these organisms fall under: Archaea, Bacteria, and Eukaryota. Homologies and analogies help to determine if animals have a common ancestor or not. For example, four limbs of tetrapods are a homologous characteristic Birds, mice, bats, and crocodiles all have four limbs, whereas sharks and other fish don't The ancestors of tetrapods evolved four limbs making this an inherited feature in their descendant. This presence means this group would be considered a homology.

http://evolution.berkeley.edu/evolibrary/article/evo_01
Biology Concepts and Connections - Pages 256 - 262 - Jane B. Reece; Jean L. Dickey; Martha R. Taylor; Kelly Hogan; Eric J. Simon; Neil A. Campbell.

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DNA and RNA

DNA or deoxyribonucleic acid stores the genetic information for every living organism on the planet. It can also copy it and pass it from generation to generation. DNA and RNA are both nucleic acids that consist of long chains called nucleotides. These nucleotides are joined by a covalent bond formed between the sugar of one nucleotide and the phosphate of the next. The four nucleotides found in DNA are Thymine (T) and Cytosine (C) which are single ringed structures known as Pyrimidines, and Adenine (A) and Guanine (G) which are double ringed structures known as Purines. RNA (also known as ribonucleic acid) is different from DNA because the sugar in it is ribose instead of deoxyribose. Another difference is that instead of using Thymine like DNA does, RNA uses a nitrogenous base called Uracil (U.)

Biology Concepts and Connections - Chapter 10: Molecular Biology of the Gene - pages 184 - 185 - Jane B. Reece; Jean L. Dickey; Martha R. Taylor; Kelly Hogan; Eric J. Simon; Neil A. Campbell.

http://www.astrochem.org/sci_img/dna.jpg

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Panda Triplets

A panda at a zoo in southern China gave birth to triplets. These are the first known surviving triplets, since the mortality rate is so high with twin and triplet panda cubs the zoo announced the miracle birth 2 weeks after the babies were born. In the wild it is rare for cubs to survive because of the mothers ability to only care for one cub at a time. Even so, a set of twins is more likely to survive than a set of triplets would be. Baby pandas are born blind, they are also small and undeveloped which causes them to need constant attention. Because of this is would be difficult for the mother to provide constant attention to triplets. They will wait one-hundred days to name the panda cubs, which follows a Chinese tradition. This will also help to keep people from getting too attached to them in case something were to happen.

 

Triplets! Giant Panda Gives Birth to 'Rare' Trio in China - Laura Geggel - August 14th, 2014 - LiveScience

 

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Fish Do Feel Pain

Many people think fish can't feel pain, or that they're too simple minded to feel pain. That's basically like saying fish aren't alive, or fish aren't a source of meat. Scientist have researched and studied fish for years and they come to the conclusion that the pain system in fish is almost identical to the pain system of mammals. There has never been any form evidence that any animal could survive without the ability to feel pain. Fish always appear cautious. Fish have nociceptors and opioid receptors within their nervous systems. In fish, the nociceptors are connected to the brain in a way that is almost identical to that of a mammal and a human. This means that fish feel the exact amount of pain that we would feel. With all the evidence that scientist have come up with to support that fish are able to feel as much pain as we can, why don't people believe that fish can feel pain?

Forget the Pseudoscience --- All Fish Feel Pain - by Ila France Porcher - October 17th, 2014 - LiveScience

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Puppy-Sized Arachnid

When we think of spiders we think of the small little jumping spiders we see hopping around or of a black widow with only the red hourglass for color. But what about puppy sized spiders? The Goliath Bird Eater of Northern South America is the biggest spider in the world with a leg span that reaches up to a foot and a body the size of a large fist. It has several defense mechanisms including a pair of 2 inch long fangs. Although it's venom isn't poisonous to humans being bitten by the spider would feel like driving a nail through your hand. Despite its name, the Goliath Bird Eater doesn't actually eat birds. Since it hunts during the nighttime, it would rarely encounter a bird. Its diet consists of mostly earthworms and other insects that it finds in the foliage on the forest floor. These spiders aren't very common. Piotr Naskrecki, an entomologist and photographer at Harvard University's Museum of Comparative Zoology, says that in the last 10 to 15 years, he's only come across this spider three times.

Goliath Encounter: Puppy-Sized Spider Surprises Scientist in Rainforest - by Tanya Lewis - October 17th, 2014 - LiveScience.

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