Introduction
In this research paper I will be discussing the Yellow-Bellied Three-Toed Skink and how instead of this reptile laying eggs like most reptiles would do, it is giving birth to live young instead. The Yellow-Bellied Three-Toed skink (Saiphos equalis) is a small reptile in size that closely resembles that of a snake, but with four legs. This specific species of skink can be found in New South Wales, Australia. It has been discovered that in the cold regions of New South Wales this organism is producing live young. However in the warmer regions of New South Wales this same exact species is laying eggs. (Handwerk, 2010). As stated in the National Geographic News, “Evolutionary records shows that nearly a hundred reptile lineages have
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Meaning that the babies are able to stay in a warm place for an extended period of time due to the geographic region that this skink is located in. So basically what the mother is doing is protecting her young. That idea is the root of what evolution is and makes perfect sense as to why scientist are saying that this organism is currently going through an evolutionary change. With that being said it is also believed that during this process the eggshell gets reduced to a much thinner one (Packard et al., 1977). This thin egg shell is then gone by the time the babies are ready to be born, thus the appearance of live birth. The normal skink egg shell is a thicker one that made up of proteins and …show more content…
The skinks that retain the eggs (produce live birth) were taken from the Southeastern part of New South Wales, and the skinks that laid eggs were taken from the Northern part of New South Wales (Smith and Shine, 1997; Linville et al., 2010). The skinks were then placed in a care facility at the University of Sydney in groups of up to 6 females in a glass aquarium set to room temperature at 20 °C. Each aquarium was provided with food, water, and a 25-W incandescent light bulb. (Stewart, 2010). The skinks were then euthanized and an oviduct was removed from each female so the embryo could be tested. Each embryo was then stained with one of the four protocols, 1. Hematoxylin and eosin, for general structure, 2. Alcian blue, for carboxyl and sulphate-ester groups of acid, 3. Periodic acid Schiff, for neutral hexose sugars, and 4. Dihydroxy-6, 6'disulfide-dinapthyl, sulphydryl and disulfide groups (Kiernan, 1981). The
In reproduction, the female produces clusters of eggs that she carries in one or two egg sacs that are attached to her abdomen. Once hatched, The T. Californium’ life cycle has quite a few stages. The first being six naupliar (young) stages lasting 4 – 10 days. Next come the 6-copepodite stages (7-14 days for the first 5 stages) ending in the last stage where T.californicus is a sexually mature adult. Adults then live from 40 – 90 days after the stages are complete (Rickets and Calvin 1985).
On the first stage of development the litter could be of 2 to 7 minks. They are born blind and deaf with little to no fur. They grow reddish hair when they are 2 weeks old. When they are finally 5 weeks old their eyes will star to open in the mean time the mothers have to feed them and protect them from predators.
The differences are due to the differences in environment, habits, size etc. One example is the fact that minks and humans both have lugs of similar shape but different lobes. Each of these similarities and/or differences benefit both the human and the mink, in their own unique way, with each structure having its own function. Overall, the mink is a very complex animal and so is an individual.
The Eastern chipmunk is a small rodent of the Sciuridae family. This chipmunk is closely related to the red and grey fox, the flying squirrel, and the woodchuck. Its Taxonomic name is Tamias Striatus. The word Tamias, Means collector or keeper and Striatus refers to its bold stripes and coloring.
Today, eutherians have effectively outcompeted its fellow mammals marsupials and monotremes for ecological niches. They are found in virtually every part of the world native to Europe, Africa, Asia and America, including oceans. Monotremes and marsupials are mostly found in Australia and New Guinea only (Archibald, 2001). The ability to outcompete fellow mammals is characterised by their method of gestation where they foster their young within the mother’s body by the placenta, allowing nutrients, oxygen and excretory exchanges between young and mother with the help of umbilical cord (Smith, 2015).This enables greater maturity and development of the young when born, increasing their chances of survival. Furthermore, eutherians lack epipubic bones (which are present in monotremes and marsupials), which allows prolonged expansion of the abdomen during pregnancy (Tarver, 2016). On the
The specifics of the skinks mating behavior and habitats during breeding season is unknown. They have a low fecundity, with one to five skinks born in a litter, with one litter born per year. The skinks are born in December (December, January, and February being the Australian summer months) and because they are ovoviviparous they give birth to live young rather than eggs that would hatch outside the body.
The female does most of the incubating of the eggs and caring for the babies. The male will catch the food and bring it to them. When the babies are older, the male and female will bring them food.
Reproduction in spotted eagle rays are very unique; the eggs develop inside of the uterus, and hatch within the mother prior to emerging. Once the embryos are released from the egg, they are nourished by a yolk sac, rather than a placenta. (2) Multiple males chase the females during mating season, suggesting polygyny. An interesting trait of the spotted eagle rays is that they have been known to breech, to assist in giving birth, as pictured below (2).
The reptiles show a very wide variety of animals that show either crypsis or aposematism. The Bothriechis schlegelii (Eyelash pit viper) is an example of a snake that is highly toxic. The snake’s venom (poison) is being injected into its prey to immobilize it quickly. The B.schlegelii has a wide variety of colors including yellow, green, brown and even pink. Its coloration has no specific relation to advertising its toxicity form other predators or hiding, however, it is used for hunting (Sinnett 2011). The Anolis carolinensis is a species of a non-toxic reptile, yet it shows change in coloration. The change in coloration can be stimulated by various factors such as excitement, temperature, lighting and shade on the background behind the animal. The ability to change colors is due to 3 layers of pigmented cells (chromatophores) providing 3 colors, blue, yellow and brown. The A.carolinensis can change its color by mixing the 3 types of chromatophores on the epidermis layer. By changing the outer more layer of its skin the A.carolinensis changes the visible light its skin absorbs or reflects. Even though it has only a few variations in color (green- brown) it uses these variations to camouflage itself in it’s own habitat (Losos 2012). These animals are only two species of a wide class of reptiles. Many members of this class show wide varieties of camouflages as means of protection. Others use colora...
Smith, D. G., & Schenk, M. P. (n.d.). A Dissection Guide & Atlas to the Mink. Google Books. Retrieved May 27, 2014, from http://books.google.com/books?id=kifAAgAAQBAJ&pg=PA83&lpg=PA83&dq=male+mink+reproductive+system&source=bl&ots=6Q8L-rNG76&sig=L2TpamuuykxepCG7uaLJdmyTeuM&hl=en&sa=X&ei=aa-DU8XFA8OhqAa2yIKYAw&ved=0CF0Q6AEwCA#v=onepage&q=male%20mink%20reproductive%20system&f
The defenition of a monotreme is an unusual mammal that lays eggs instead of giving birth to live babies. A few examples are the echidna and the platypus. Their skulls have certain features that resemble reptiles. They have three bodily systems, they have the digestive system, urinary system, and reproductive system. These systems all end up in the same chamber for monotremes called the cloaca. Cloaca means “one hole’’ so it fits perfectly with the monotremes situation. After monotremes give birth they suckle their young after hey hatch out of their eggs. They also have bones like the marsupials called eupubic bones that are connected to the pelvis. The baby monotremes have teeth but they do not go through their gums and real functional teeth are not shown in the adult monotremes.
The Eastern Indigo Snakes’ population has been slowly declining. They have been endangered since 1971. By the time an Eastern Indigo Snake is three to five years old, they are matu...
One potential confounding variable is that the scissor beak, seen in chick number seven, could have resulted from genetic abnormalities. Although the scissor beak is commonly associated with genetic issues, the missing eye is not commonly found in addition to the scissor beak. Throughout the experiment the incubator was opened and closed several times. This could have resulted in an inconsistent temperature and humidity level producing difficulties
...ecial cells, the queen puts the eggs from which a new queen will emerge. After the larvae develop from the eggs, the cells are covered with wax.
Both Lamarck and Darwin have contributed theories to evolution but Darwin’s theories of natural selection and survival of the fittest correlate better with the evolution of the Tasmanian devils and their reproductive trends. As the Tasmanian devils struggles with DFTD, it has adopted evolutionary measures such as earlier reproduction causing the possible birth of more litter and the devils with immunity can reproduce to make the fittest survive. Therefore, Charles Darwin’s theory is more suited towards the evolution of Tasmanian Devils and the change in their reproductive trends.