Biology in Fiji

The Most Exciting Month Ever!!

Mechanisms of Speciation: The Red Mongoose

Hello everyone today I’ll be talking about speciation. I’ll be giving you guys a made up story to show you how speciation works.

Speciation is the process through which a new species is formed that can interbreed and produce viable offspring under natural conditions. New species form when barriers exist to prevent outbreeding; these are usually environmental (mountain ranges, climatic barriers, oceans) or biological (cannot produce an offspring).

The mongoose is an invasive species in Fiji. An invasive species is one that is non-native to the ecosystem it is found it and also one that can cause human, economic or environmental harm. The Small Indian Mongoose (Herpestes javanicus), native to areas going from Iran through India to Myanmar and the Malay Peninsula, was introduced into Fiji in the late 1800s mainly to control rats. The danger of the Small Indian Mongoose is that it posed a danger to native fauna and their evolved species; this mongoose is a trajectory of rabies and has also led to the extinction of many endemic birds, reptiles and amphibians. It is found on 11 Fijian islands including the two main islands: Viti Levu and Vanua Levu. In 2007, a new species of large, red coloured mongoose was found when trapping mongoose near Suva for testing the spread of leptospirosis in Fiji. DNA testing revealed that this recently discovered mongoose is of a new species: the Red Mongoose (Herpestes jalabicus).

Mongooses prey primarily on rats, and occasionally snakes. On one island in Fiji called Humunaka Veru there was a disease which caused all of the rats to perish. This removed a vital piece in the food web for this species; the mongoose was pressured since less food was available to them. The mongooses on this island grew more dependent on snakes as a food source and, in turn, they evolved to become better at catching snakes. Evolution caused the mongooses on this island to grow larger and stronger. Over generations, the coats of the mongooses got redder and redder which allowed them to better camouflage when stalking the snakes that enjoyed sunbathing on the beach. As well, the natural mating times of mongooses changed from nighttime to daytime. Previously, the mongoose had been a nocturnal animal; it hunted rats in the dark. Now, the red mongooses on Humunaka Veru were active primarily during the day since their prey (snakes) enjoyed coming out and sunbathing during the day. This evolution also affected the times of mongooses` mating. The mongooses on Humunaka Veru still mated during the early spring, just like the Small Indian Mongooses; however, they mated during the daytime rather than the nighttime.

The evolution of the new species of Red Mongoose (Herpestes jalabicus) is an example of speciation through reproductive isolation. This new species underwent ecological isolation since it lived on a separate island separated by the Pacific Ocean as well as temporal isolation since it mated at a different time. These two sub-types of reproductive isolation resulted in the evolution of a new species of mongoose: the Red Mongoose.

 

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Ecosystem Restoration in the Votua Village

Our Edutravel group went on a trip to Votua Village and we experienced the work they put in to restoring the coral reefs. The people in the village planted coral everyday to increase the biodiversity in the reefs and to affect the environment in a good way. Understanding and knowing biodiversity is crucial when it comes to coral because there are so many different types. Biodiversity is the variety of life in the world or in a particular habitat or ecosystem. Biodiversity is important because it boosts the ecosystems productivity where no matter what, each species has a role to play. For example; greater species diversity ensures natural sustainability for all life forms and healthy ecosystems can survive better and recover from a variety of disasters.

The ecosystem restoration project is a community-based resource management with the goal of conserving biodiversity, and replenish in store fish stocks specifically in the South Pacific. They are conserving biodiversity by planting coral which our class got to experience and even do it ourselves. The largest reef system in the South Pacific covers 32% of the South Pacific reef system, and the coral coast is the largest coral reef system in Fiji. It is amazing that something so small like coral can have such a large effect on tourism, fisheries, aquarium trade, and research/education.

The problem with coral reefs now is that the fishing grounds are damaged and cannot provide the same way they used to. Noticeable declines in coastal resources due to overfishing, coastal development and global climate change have prompted Fijian communities to take locally-managed actions to protect their coral reef resources.

I think it is great that the Votua Village cares so much for the coral reefs and it shows how much the Fijians truly care about the environment and about their islands. The Fijians are doing great things by teaching others and making them aware of what is happening to the coral reef system. If they continue to plant coral it will make such a difference in the long run because the more coral we have planted  in the ocean, the more positive changes we will see in the environment.

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Lactase Evolution

Hi everyone today ill be talking to you about lactase evolution and the experiences I had in Fiji. It is probably very hard to believe for most that in today’s world, the majority of adults are lactose intolerant. In fact, about 65 percent of the humans today have a reduced ability to digest lactose after infancy. However, in certain populations, the exact opposite is true, such as in Canada and the United States. Most people consume milk on a daily basis without even thinking about it, they enjoy protein shakes, yogurt, ice cream and cheese.However, for some people milk constitutes a reaction int their stomach that causes stomach cramps, bloating, gas, throwing up, gurgling or rumbling sounds in the belly as well as diarrhea. This is because those people have a condition called lactose intolerance. Also known as lactase deficiency, lactose intolerance is a condition that stops certain humans from digesting lactose, a natural type of milk found in sugar and in dairy products. It is caused by the lack of a protein essential in the digestion of food molecules, called lactase, which is vital for the breakdown of milk sugar, lactose. Humans with this condition have difficulty digesting milk products, since they contain diary.

Unfortunately, even though lactose intolerance is not a severe condition, there is no cure for the condition However, the symptoms of lactose intolerance can be treated by limiting or avoiding milk products. Possible methods of reducing the uncomfortable symptoms include: using milk with reduced lactose, and substituting soy milk and soy cheese for milk and milk products. By doing these things, it is possible to eat yogurt without problems, especially yogurt with live cultures. Another helpful method of consuming dairy products consist of taking dietary supplements called lactase products that help digest lactose. Nevertheless, while it is possible to manage symptoms of lactose intolerance, the biggest concern for people with lactose intolerance is the lack of calcium intake. Milk contains many important nutrients, one being calcium but humans who are lactose intolerant cannot consume these nutrients as it is dangerous for them to intake dairy products.

One explication behind the inheritance of lactose intolerance is genetics.  In infants, lactose intolerance is caused by mutations in the LCT gene, whose responsibility is providing instructions for the production of lactase enzyme. Scientists believe that mutations that cause lactose intolerance interfere with the function of lactase, causing affected infants to have a severely impaired ability to digest lactose in their mother’s breast milk or in milk formulas. Furthermore, lactose intolerance can also be caused in adulthood. Adults inherit lactose intolerance by the slowly decreasing function of the LCT gene after the infant stage. Normal individuals are able to digest lactose because they inherit changes in a DNA sequence referred to as a regulatory element, which controls the LCT gene expression. The inherited changes in this element lead to normal lactase production in the small intestine which leads to sustained digestion of lactose. Nonetheless, the reason humans become lactose intolerant is because they do not inherit changes in the element which causes the inability to digest lactose as they approach adulthood.

Another reason behind the inheritance of lactose intolerance is evolutionary change. According to a study done by Reddy and Pershad, 50% of Indians in India appear to appear to be lactose intolerant. But on the contrary, Fijians have not had long contact with milk as an adult food. This is due to natural selection which originates from Darwin’s theory of evolution. Darwin’s theory of evolution states that all species change over time through a process called natural selection. Natural selection is the process whereby organisms better adapted to their environment tend to survive and produce more offspring. According to Charles Darwin, species gradually multiply and evolve into new species and surviving organisms have traits adaptive to a specific environment and pass these characteristics on to the next generation. The intolerance to lactose is created through a malfunction of the gene that inhibits the sugar lactose to be broken down through the enzymes. In the case of Indo-Fijians, since they were from India with a Hindu background, they had close connection with cows (these domestic animals had spiritual and religious significance in the country) and other dairy products that stem from cow milk. Since tremendous poverty existed in India, the population had to adapt to drink dairy products in order to avoid starvation. Therefore when the Indian population moved to Fiji, they carried that adaptation with them as well as their major source of food: cows. Since the Indo-Fijians were very used to drinking milk as part of their culture, the malfunction of the gene that prevents the sugar lactose to be broken down through lactase became less evident because their body adapted into being able to produce lactase more effectively. As for the native Fijians, they did not have any cows in their country (and still don’t) which meant they did not have the need to adapt to being tolerant to milk. This explains the Native Fijians’ lack of lactase and thus, their very high percentage of lactose intolerance.

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Antibiotic Resistance

 

Hi everybody today ill be talking about antibiotic resistance. During our stay in Fiji, we learned about unicellular organisms and multicellular organisms such as bacteria, which can be both. Bacteria are living organisms existing as single cells. They are found everywhere around us and luckily most don’t cause any harm, and can sometimes even be beneficial. However, some bacteria are harmful and can cause illness by invading the human body, multiplying, and interfering with the regular functions of the human body.

Until the 1940s, when antibiotic drugs were discovered, people with infections like tuberculosis, pneumonia and site sexually transmitted infections often died because the existent treatments were not very effective. But then due to the discovery of antibiotic drugs in the early 1940’s, the ability to fight diseases improved dramatically. Antibiotics are very useful natural substances secreted by bacteria and fungi to kill other harmful bacteria that are competing for limited nutrients. They kill harmful bacteria by stopping their growth and reproduction. Examples of antibiotics include penicillin, first antibiotic drug to be discovered, and tetracycline. They are the most widely used medications to treat, and prevent bacterial infections. One of the examples of antibiotics that have been a very purposeful discovery in medicine is antimicrobial chemotherapy. This form of chemotherapy has been a leading cause for the dramatic rise of average life expectancy in the 20th century and has saved many lives.

However, in recent years doctors and scientists have been shocked to discover that some bacteria have become resistant to certain antibiotics through various mutations and alterations in their DNA. The resistance of harmful bacteria to antibiotics is called antibiotic resistance. It is very shocking to hear that recently about 70 percent of the bacteria that cause infections in hospitals are resistant to at least one of the drugs most commonly used for treatment of various dangerous diseases and illnesses. Wound infections, and illnesses such as gonorrhea, tuberculosis, pneumonia and childhood ear infections are just a few of the diseases that have become very difficult to treat with antibiotic drugs. In a study conducted in 2012, 25% of bacterial pneumonia cases were shown to be resistant to penicillin, and an additional 25% of cases were resistant to more than one antibiotic. Also, some organisms are resistant to all approved antibiotics and can only be treated with experimental drugs.  One of the major reasons behind this medical problem is the resilience of bacteria and other microorganisms to resist antibiotics and other antimicrobial drugs. Lately, hospitals have become a breeding ground for antibiotic resistant bacteria. The second explanation to this problem is the significantly increasing use, and misuse, of existing antibiotics in human and veterinary medicine, as well as in agriculture.

The bacteria’s capability of fighting against antibiotics is a example of evolution. Antibiotic resistance evolves naturally by evolutionary change through which random mutations in the bacteria’s genes occur and multiply rapidly. When an antibiotic is given, it kills the sensitive bacteria, but any resistant ones can survive and multiply. The more antibiotics used, the greater the “selective pressure” will be, favouring resistant bacteria. This is an example of Charles Darwin’s idea of “natural selection” which supports his Theory of Evolution.

Additionally, an overuse or inappropriate use of antibiotic drugs in preventing or treating infections in people, animals and plants was found to accelerate the spread of antibiotic resistant bacteria. When antibiotics are used inappropriately, the weak bacteria are killed, while the stronger, more resistant ones survive and multiply. An example of improper use of antibiotics deals with not finishing the entire prescription. When the prescription is not terminated, the small quantity that remains in the bacteria grows resistant to that antibiotic and is easily capable of spreading and infecting other humans who have not taken any antibiotics. Then once resistance has been established, it is an irreversible and destructive cycle of resistant bacteria evolving rapidly. In fact, overnight, one bacterium can multiply to become a billion.

Antibiotic resistance is to some extent inevitable because we cannot stop using antibiotics, but physicians and patients can both stop or slow down the antibiotic resistant bacteria from developing and spreading. Physicians should stop prescribing antibiotics for inappropriate uses such as mild coughs, colds and sore throats because antibiotics cannot cure viral infections, which include simple coughs. Instead, antibiotics should only be prescribed if the patient shows signs of a bacterial infection. Also, doctors should always advise their patients, if they are prescribed antibiotics, to complete the full course; because stopping before the end of a course may facilitate the development of resistant bacteria. This is absolutely essential for more severe illnesses such as tuberculosis. Also, it is important to reduce the use of antibiotics in farm animals because usually resistant bacteria develop in animals and are transferred to humans through food. Lastly and evidently, hygiene and sanitation should certainly not be disregarded, especially in hospitals where resistant bacteria proliferate.

There are many reasons for different rates of resistance that can include antibiotic use, underlying diseases, immunization rates, social factors and quality of hospital care. Unfortunately for Fiji, because it is still a developing country it has a higher resistance to antibiotics. One of the reasons behind this is because developing countries have considerably lower control of the use of antibiotics. The inappropriate use of the antibiotic drugs thus, allows the rapid overtaking of resistant bacteria. The remote villages and islands of Fiji definitely have higher antibiotic resistance rates compared to a developed country like Canada because not only there medical care is not nearly as advanced but they are not offered adequate antibiotic treatment and the immunization rates are lower-all of course because of poverty issues.

Clearly, antibiotics have saved many lives in the second half of the 20th century due to their powerful ability to kill harmful bacteria meanwhile helping cure severe illnesses such as tuberculosis. But while rapid medical discoveries were continually being unfolded, lately, the harmful bacteria originally being killed off by the drugs have started showing strong resistance to the antibiotics thus decreasing their useful effects. Additionally, to make matters worse for developing countries such as Fiji, the lack of careful and appropriate use of antibiotics has increased the spread and effect of antibiotic resistance over the course of the last few years.

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Mealybugs

Hi everyone today il be talking about the mealybug. Mealybugs are serious pests of a range of plants. Mealybugs can be found on the leaves of a large variety of plants from flowers in homes, greenhouses, fruit trees and shrubs. They also can be found on fruits, branches and cause substantial damage to crops or host plants. They feed by sucking out sap and often they are associated with ants, which feed on the excretions of mealybugs. Mealybugs are mobile and easily spread by crawling, dropping from overhead plants and floating on air currents. They can also be spread by moving infested plants.

Mealybugs can be easily mistaken for whiteflies and scale insects. The mealybug has a soft body which is covered with white cotton-like filaments. It has multiple body shapes: oval, flat, or globular. Mealybugs are 1-4mm long and there is a species that has tails (the long tailed mealybug is common in Fiji). A mealybug has 3 life stages: egg, larvae and adult.

Mealybugs attack citrus, mangoes, pawpaw, pumpkin, kavika, soursop guava, egg plant, chillies, young coconuts, and ornamental plants like palm, rose, fern, orchid, croton’s, vasili, sinu, heliconias, jale, and ginger.

There are many predators that can be used to control mealybugs. Some common mealybug predators are green lacewings and ladybird beetles. Mealybugs can be suppressed using isopropyl alcohol, horticultural oil, insecticidal soaps and mineral oil.

 

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Prokaryotes in Fiji

Hi everyone ill be talking about prokaryotes today. A prokaryote is a organism whose cells do not have a membrane-bound nucleus. Prokaryotes live in almost all environments on Earth. They receive energy from organic and inorganic matter and they can decompose dead matter create energy. A type of prokaryotic cell is Cyanobacteria. Cyanobacteria has helped build reefs on earth for three million years.   Cyanobacteria can be found in most terrestrial and aquatic habitats, through plants and animals.  The way that this type of prokaryote gets its energy is through photosynthesis. A eukaryote cell is different from a prokaryote because a eukaryote cell has a membrane-bound nucleus.

 

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Plant study: Lantana Camara

Hi everyone I’m here to teach you about the Lantana camara.

Lantana camara Spreading Sunset

www.gardensandplants.com

The Lantana camara is a plant found in tropical and warm regions around the world. Including the islands of Fiji. The Lantana camara reproduces like most other plants using pollination and seeds. This plant is identified by its square stem that has prickles on it and also its corse and opposite leaves. Another characteristic to identify it is it’s flat topped and head-like inflorescence of multicoloured flowers. This plant has some incredible healing properties which include the ability to help the healing of insect bites and small cuts it is also used as a disinfectant.

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www.treknature.com

The Lantana camara transports water and nutrients through it’s roots and up is’s stem through tubes called xylem and phloem. It uses these to transport water and other nutrients up the stem using a capillary action that gets its suction using evaporation of water in the leaves to create suction which pulls the water up the stem and delivers it to the rest of the plant. The Lantana camara requires very little water and nutrients to grow.
Some of the restricting factors for the Lantana camara are the temperature and rainfall in the area. The Lantana camara is accustomed to warm temperatures and little rainfall so it is easy to restrict the growth by introducing lower temperatures and increased rainfall.

The Lantana camara is also known for the toxicity of it’s foliage, which is known to cause loss of live stock due to the commonness of this plant in regions where herds are known to graze. This plant spreads using berries that are eaten and distributed around the surrounding area by the animal that ate it.

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Humans vs. Dolphins

Hi everyone,

Today I will talk to you about the comparison of humans and dolphins.

Dolphins and humans have many similarities.  They live in groups which serve as their family even if it is more than just parents and their children.  They seem to have emotions and attitudes like humans and have been seen to be mean or nice to other dolphins around them. They can communicate with others like humans do but dolphins don’t use speech but clicks, whistle-like sounds and other vocalizations. Both humans and dolphins carry their babies for a long time; humans for 9 months and dolphins for 12 months. One of the most interesting things is that humans and dolphins have the very similar brains. Dolphins have very good eyesight both in and out of the water. They also have very good hearing; dolphins can hear frequencies at least 10 times above the upper limit of human hearing. For dolphins, it is believed that both the ears and the teeth are used for echolocation to pinpoint the exact location of an object. Dolphins have a very good sense of touch but don’t have, if they have one at all, a good sense of smell.  Dolphins also don’t have hair and whatever hairlike structures they do have perform sensory functions. They also have similar bone structure in some ways.

The human arm and the dolphin pectoral fin have similar bones in them. As seen by the photo they have the exact same bones in them but in different shapes and sizes. These bones being so similar makes a great statement on the evolution of life. There are significant differences in both structure and function between the fin bones of dolphins and the limb bones of terrestrial mammals. Dolphins do not actually swim with their pectoral fins…but mostly use them to steer. Also dolphins do not have a movable elbow joint and hold their pectoral fins rather rigidly out from the body. Their only mobile joint is at the shoulder…which is unsuitable for walking or grasping. Dolphins also use their pectoral fins for balancing when they are stationary.  An interesting thing to note is that dolphins touch each other with their pectoral fins when in groups.  This can be thought of as similar to humans shaking hands in social groups. All of the dolphin fins consist mainly of strong connective tissue with only the pectoral fins containing bones.  They all have a network of blood vessels which play a big role in thermoregulation.  Dolphins lose excess heat by pumping blood through these vessels and the cold water surrounding the fins cools the blood.

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evolutionbioc334.blogspot.com

When looking at the entire skeleton of the dolphin, the skull has a more elongated shape and the jaw extends farther out than the nasal passage (nose in humans, blowhole in dolphins).  There are also fewer fused neck vertebrae in dolphins than in humans or other land mammals so that dolphins can have more neck flexibility.  In looking at the back end of the dolphin, we see that dolphins do not have any legs but we see that there are bones that look like the pelvis and the femur of humans. The actual structure of the dolphin skeleton is different than terrestrial mammals in that it is much more spongy and thus lighter and has almost no weight in water so the dolphin’s skeleton doesn’t really have to support the full body weight in its natural environment.  The human skeleton is created in a way that allows humans to support their full body weight.

The respiratory system of dolphins and humans are similar but not completely alike. Dolphins breathe consciously, not unconsciously as humans do. Everything the dolphin does is be interrupted by its need to breathe. Humans breaths are automatic,the dolphin decides itself when it wants to breathe and it could be a life or death decision. Dolphins take 0.3 seconds to exhale and inhale but can hold their breath for at least 15 minutes.  Dolphins breathe in air through a blowhole on the top of their head when they break the surface of the water.  Dolphins have lungs just like humans but their lungs are smaller yet more efficient in exchanging oxygen than humans are; they can exchange around 90% of the air in their lungs and humans exchange around 10% in theirs. Dolphins have lungs that are slightly different shaped than humans; they are long and flat.  The lungs of dolphins are found lengthwise in the back of the dolphin and human lungs are positioned horizontally and protected inside the ribcage.

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www.emc.maricopa.edu                                                  hpsanatomy.wikispaces.com


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Monocot vs. Dicot

Hello everyone today Ill be talking about dicot plants vs monocot plants. This plant is a clear example of a dicot plant because it has flower parts in multiples of five. Also the major leaf veins are reticulated this is a clear indicator of a dicot plant. The reason this is not a monocot plant is because it does not have flower parts in multiples of three, and after looking at the leafs on the plant you can clearly see that the major veins on the plant are not parallel. All these points show that the plant I have shown is a dicot plant and not an monocot plant.

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