Preview

Argumentative Essay: The Evolution Of Frogs

Good Essays
Open Document
Open Document
498 Words
Grammar
Grammar
Plagiarism
Plagiarism
Writing
Writing
Score
Score
Argumentative Essay: The Evolution Of Frogs
Frogs re-evolved "lost" bottom teeth after more than 200 million years, according to new research.
Tree-dwelling Gastrotheca guentheri are the only frogs with teeth on both their upper and lower jaw.
The reappearance of these lower teeth after such a long time fuels debate about whether complex traits are lost in evolution or if they can resurface.
Scientists suggest this new evidence identifies a "loophole" in previous theories.

The Gastrotheca genus of frogs carry eggs on their backs
Commonly known as "marsupial frogs", the Gastrotheca genus carry their eggs in pouches.
Unlike marsupial mammals such as kangaroos however, the frogs' pouches are on their backs.
The species Gastrotheca guentheri is even more unusual, being the only known frog to have teeth on its lower jaw.
Dr John Wiens led a team of scientists from Stony Brook University, New York to
…show more content…

The return of lower jaw (mandible) teeth in G. guentheri after more than 200 million years could make evolutionary biologists reconsider this law.
"The loss of mandibular teeth in the ancestor of modern frogs and their re-appearance in G. guentheri provides very strong evidence for the controversial idea that complex anatomical traits that are evolutionarily lost can re-evolve, even after being absent for hundreds of millions of years," Dr Wiens says.
Dr Wiens believes that this re-evolution can be considered a "'loophole' in Dollo's law".
He suggests that because the frogs have always had teeth on their upper jaw, the "mechanisms for developing teeth" have always been present.
"What G. guentheri did was to put teeth back on the lower jaw, rather than having to re-evolve all the mechanisms for making teeth 'from scratch'," says Dr


You May Also Find These Documents Helpful

  • Satisfactory Essays

    Postorbital ring 2. Dental comb 3. Tapetum Lucidum Tarsiers more like monkeys in their genetics Primate Fossil Ancestry: Events Preceding Primates Ca. 500 MYA: first vertebrates in fossil record Ca. 250 MYA: Pangea II forms- nearly all land is one big continent Ca.…

    • 1107 Words
    • 5 Pages
    Satisfactory Essays
  • Powerful Essays

    Stickleback Lab

    • 3141 Words
    • 13 Pages

    Pennisi, E. (2004). Changing a Fish 's Bony Armor in the Wink of a Gene. Science, 304(5678), 1736-1739.…

    • 3141 Words
    • 13 Pages
    Powerful Essays
  • Satisfactory Essays

    Lab Write Up

    • 766 Words
    • 4 Pages

    The tooth formula is a shorthand technique that biologist use to keep track of the teeth on a particular jaw. The formula consisted of two lines, top jaw and bottom jaw, which were used to count how many incisors, canines, premolars, and molar teeth a species had. Species A, Odocoileus virginiaus (white-tailed deer), had a tooth formula of 0033/3133. On the top jaw, the deer had zero incisor and canine teeth but have three of both the premolars and molars. On the bottom jaw, the deer had three incisors, one canine, three premolars, and three molars. Species B, Canis latrans (coyote), had a tooth formula of 3142/3143. On the top jaw, the coyote had three incisors, one canine, four premolars, and two molars. On the bottom jaw, the coyote has three incisors, one canine, four premolars, and three molars. Both the deer and coyote skull were long and skinny towards the nose and mouth. The coyote skull had a much rounder nose than the deer. Species C, Homo sapiens (human), had a tooth formula of 2122/2122. On both the top and bottom jaws, there were two incisors, one canine, two premolars, and two molars. In comparison to the deer and coyote skull, the human was an outcast. The human skull was a short distance from the back of the skull to the front. The human skull was very different in bone structure and longer in height than the deer and coyote skulls.…

    • 766 Words
    • 4 Pages
    Satisfactory Essays
  • Better Essays

    I will consider the dwarfing hypothesis in the context of analyzing whether the morphological features of the callitrichids are primitive or derived. Although the callitrichids have many common features (including twinning, small body size, reduction of the molar tooth row, simplification of the upper molars, and claws) in this paper I will focus on the morphological features: body size, claws and the dental features of the Callitrichidae (twinning is an important common character of the callitrichids, but will not be considered here). One important hindrance to finding support for the dwarfing hypothesis has been gaps in the fossil record. However, using the available fossil data and modern studies of callitrichids I will show why each feature is primitive or derived, and how it applies to the dwarfing hypothesis.…

    • 1798 Words
    • 8 Pages
    Better Essays
  • Good Essays

    Instead of the typical turtle beak we know today, Pappochelys had a lizard-like skull filled with many peg-like teeth. He used these teeth to eat insects, and rather cannibalistically, other small lizards.…

    • 569 Words
    • 3 Pages
    Good Essays
  • Best Essays

    Cane Toad

    • 3042 Words
    • 13 Pages

    ^ Tyler, M. J. (1994). Australian Frogs A Natural History. Reed Books. p. 112. ISBN 0-7301-0468-0.…

    • 3042 Words
    • 13 Pages
    Best Essays
  • Good Essays

    In the past few years, citizens of Minnesota have discovered deformed frogs scattered throughout the state. There are many speculations as to how the frogs got such deformities. Some scientists believe that its something in the waters of the Minnesota wetlands, other factors could be parasites or ultraviolet radiation. Minnesota is not the only location in the world that has reported deformed animal sightings, but almost three-quarters of the deformed frogs were reported in Minnesota. This is not necessarily because Minnesota contains the most deformed frogs, because scientists are unsure if that is true. Residents of Minnesota are most aware to the problem, so they are basically looking out for the frogs. Deformed frogs are most commonly missing limbs, have extra limbs, or have some bent limbs. Also, there are internal deformities that one would not be able to tell just from looking at the frog. These include digestive and urinary problems, and a slow ability to eat, avoid predators, and move. Because of this most frogs do not survive the winter, and if they do, deformed frogs do not advance on to a second year of living. Deformities do not occur in all frogs, the most common frogs with these malfunctions include the wood frog, American toad, and the northern leopard frog. Since deformed frogs have been found in ponds and both the urban and rural parts of Minnesota, scientists have concluded that well water can produce such malfunctions. Several tests have been preformed on the water that Minnesota residents are drinking and nothing has been found. The Minnesota Pollution Control Agency and the National Institute of Environmental Health Sciences have been performing tests to help solve the problem of deformed frogs in Minnesota.…

    • 674 Words
    • 3 Pages
    Good Essays
  • Good Essays

    Your Inner Fish

    • 1366 Words
    • 6 Pages

    Your Inner Fish: A Review of Chapter 4 In Your Inner Fish, a book about the study of evolution in mammals, chapter four is dedicated to the study of teeth. Neil Shubin is explicit in his insistence that teeth are extremely important when studying evolution of the human body. He uses three main points to explain this to the reader. First, through the function of teeth. Then by revealing the anatomy of teeth. And finally by discussing tooth-to-tooth occlusion. Teeth are used to manipulate larger objects so that they may fit into a smaller mouth. Shubin writes ”Mouths are only so big, and teeth enable creatures to eat things that are bigger than their mouths” (Shubin 60). Without teeth creatures would have a smaller variety of options when it came to food choices. Bigger fish could only eat smaller fish and so on. As explained by Shubin “… teeth can be the great equalizer: smaller fish can munch on bigger fish if they have good teeth” (Shubin 60). So we derive from this that teeth can play an important role in the food chain and thus in evolution. However, teeth play a more important part than this. By studying the anatomy of teeth many secrets can be revealed about ancient reptiles and mammals. For instance, Shubin relates that “The bumps, pits and ridges on teeth often reflect the diet” (Shubin 60). By knowing the diet of an ancient creature, it is reasonable to see how a paleontologist and evolutionist can follow the emergence of the omnivore over the carnivore and herbivore. And the hardness of teeth make it the “best-preserved animal we find in the fossil record for many time periods” (Shubin 61). This clue to these ancient animal’s diets can “give us a good window on how different ways of feeding came about” (Shubin 61). So, the shape of the teeth and the general mineral make-up both contribute to the usefulness of teeth to the scientist.…

    • 1366 Words
    • 6 Pages
    Good Essays
  • Good Essays

    Horned Toad

    • 179 Words
    • 1 Page

    The common name “Horned Toad” for Texas Horned Lizards comes from two of its most prominent physical characteristics. Phrynosoma cornutum has two large horns on the center of its head accompanied by lots of smaller horns around it (Bockstanz 2016). It is commonly called a “toad” due to its short flattened body and short legs (Seymour 2016). Spines are found all over the body of the Texas Horned lizard and down its tail (Seymour 2016). Sexual dimorphism between males and females can be seen in two ways, body size with females being larger and the presence of femoral pores on males (Figure2). It has been shown that southern populations of P. cornutum are on average larger that northern populations (Henke & Montemayor 1997). In southern populations…

    • 179 Words
    • 1 Page
    Good Essays
  • Good Essays

    Equine Research Papers

    • 970 Words
    • 4 Pages

    Teeth on grazing horses had roots that were open and allowed many blood vessels to enter, which supply the teeth with lots of nutrients, this allowed the teeth to keep growing during the whole existence of the horse3. This development allowed for a great diversity in the horse family, which included species of Miohippus. After the Miohippus there were the Merychippus, that were found in North America about 17 million years ago, their long legs made it possible for them to travel long distances2. Relating skeletal development incorporates a stretching of the facial bones and a developing of the lower jaw. Equinae lost their footpads and late Equinae individuals show the single toe attributes of present day…

    • 970 Words
    • 4 Pages
    Good Essays
  • Good Essays

    Today many people have tooth decay, which accurse if you have eaten to much sugary things, the skeletons found didn’t have tooth decay,…

    • 452 Words
    • 2 Pages
    Good Essays
  • Good Essays

    Dental Implants Essay

    • 696 Words
    • 3 Pages

    Since time immemorial, humans have used dental implants in one form or other to replace missing teeth. The first evidence of dental implants is attributed to the Mayan population roughly around 600 AD where they succeeded in utilizing pieces of shells as implants as a replacement for mandibular teeth. Radiographs taken in the 1970’s of Mayan mandibles show compact bone formation around the implants. Moreover, around 800 AD, a stone implant was first prepared and placed in the mandible in the early Honduran culture.13…

    • 696 Words
    • 3 Pages
    Good Essays
  • Satisfactory Essays

    Poison Dart Frog

    • 273 Words
    • 2 Pages

    | The third species to be discussed is the Darwin Frog and the ability to take care of its tadpoles is interesting to note.…

    • 273 Words
    • 2 Pages
    Satisfactory Essays
  • Good Essays

    Bullfrog Essay

    • 924 Words
    • 4 Pages

    I was amazed to find out just how ancient frogs are. For 190 million years, the ancestors of modern frogs have roamed the earth, looking much the same as they do today. This means that at one time when there was a huge dinosaur eating a plant, there could have been some type of frog down by its feet. About 3,800 species of frogs and toads have developed since the dinosaur days. The secret to their success is their amazing adaptability. Frogs have evolved to live in a large variety of climates. They can be found just about anywhere there is fresh water- on all continents except Antarctica. Though they thrive in warm, moist tropical climates, frogs also live in deserts and high on 15,000-foot mountain slopes.…

    • 924 Words
    • 4 Pages
    Good Essays
  • Good Essays

    Rainforest Animals

    • 1321 Words
    • 6 Pages

    Many people love animals. I can’t necessarily teach you about all of the animals in the world, so I’ll just teach you about the animals from my favorite place, the Rainforest!…

    • 1321 Words
    • 6 Pages
    Good Essays

Related Topics