My Science School

The first thing you will notice when comparing an alpaca and a llama is their size difference. Llamas are significantly bigger than alpacas. 

In regards to their height, llamas are taller, reaching 42 to 46 inches (106 to 117 cm) on average. Alpacas measure between 34 to 36 inches (86 to 92 cm) on average.

However, the weight difference between these two animals is even more significant. On average, llamas weigh between 280 and 450 pounds (127 to 204 kg). That is quite a lot compared to the 106 to 185-pound (48 to 84 kg) average weight range for alpacas.

Llamas have a longer face with a larger muzzle. Alpacas, on the other hand, have round, smooshed faces. They also have fluffy fur on their face, especially on their foreheads. Llamas tend to have short and thin fur around their face. 

Alpacas have softer facial features than llamas. Because of this, many people believe alpacas are the cuter of the two.

Llama ears are tall and long. They stand up in a shape that looks like a banana. Alpacas have shorter, pointy ears. Their fuzziness continues onto their ears, whereas llamas tend to have smoother and straighter fur around their ears. 

Credit : Peru For Less

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Llamas are hardy, smart animals that are easy to train. Native to Central and South America, they are used as pack animals as they can carry a generous load of weight. However, when they are overloaded, they simply lie down and refuse to move. Did you know llamas spit and kick when provoked or threatened?

Llamas, guanacos, vicuñas (Vicugna vicugna), and alpacas (V. pacos) are known collectively as lamoids. Unlike camels, llamas and other lamoids do not have the characteristic camel humps; they are slender-bodied animals and have long legs and long necks, short tails, small heads, and large pointed ears. Gregarious animals, they graze on grass and other plants. When annoyed, they spit. Lamoids are able to interbreed with one another and produce fertile offspring.

The llama is the largest of the four lamoid species. It averages 120 cm (47 inches) at the shoulder, with most males weighing between 136 and 181.4 kg (300 and 400 pounds) and most females weighing between 104.3 and 158.7 kg (230 and 350 pounds). A 113-kg (250-pound) llama can carry a load of 45–60 kg and average 25 to 30 km (15 to 20 miles) travel a day. The llama’s high thirst tolerance, endurance, and ability to subsist on a wide variety of forage makes it an important transport animal on the bleak Andean plateaus and mountains.

Credit : Britannica

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Tympanic membrane, also called eardrum, thin layer of tissue in the human ear that receives sound vibrations from the outer air and transmits them to the auditory ossicles, which are tiny bones in the tympanic (middle-ear) cavity. 

The eardrum has three layers: the outer layer, inner layer, and middle layer. The middle layer is made of fibers that give the eardrum elasticity and stiffness. Cartilage holds the eardrum in place.

The eardrum covers the end of the external ear canal and looks like a flattened cone with its tip pointed inward toward the middle ear. It is transparent and is about the size of a dime.

The eardrum divides the outer ear from the middle ear. The eardrum sits between the end of the external ear canal and the auditory ossicles, which are three tiny bones in the middle ear, called the malleus, incus, and stapes.

Sometimes an infection may cause the eardrum to rupture. Symptoms of a ruptured eardrum include hearing loss, ear pain, itching, and fluid draining from the ear. Usually, eardrums that rupture heal on their own.

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Our ear has three sections – outer, middle and inner ear. Stapes in the middle ear is the smallest bone in the human body. A stirrup-shaped bone, it transmits sound vibrations from the incus, another tiny bone in the middle ear, to the oval window, a membrane covering the entrance to the cochlea in the inner ear.

The two branches of the stapes, known as the inferior and superior crus, convey sound vibrations to the bone’s flat base.

From there, the vibrations enter the inner ear, where they are processed into neural data to be transmitted to the brain via the cochlear and the auditory nerve.

If the stapes becomes damaged, such as from severe head trauma, a person may lose some or all of their ability to hear. Because the ossicles are a chain of bones, this also holds true for the incus and malleus.

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Although webs are the most well-known use for spider silk, not all spiders make webs to catch their prey. In fact, less than half of the 37 spider families in Britain do.

However, even spiders that don't make webs have uses for silk, including creating moulting platforms, sperm webs for males, and retreats.

Jan adds, 'Jumping spiders, for example, make little silken cells in which to hide in during the day - a bit like a sleeping bag.'

Most spiders use silk to wrap their eggs. Ballooning is another spectacular use for silk, allowing the mass dispersal of spiderlings and small adults.

Spiders that don’t build webs catch their prey by other means,  such as ambushing it from a hole in the ground (like trapdoors spiders), or stalking it and leaping on it (like jumping spiders). Those that don’t construct webs still use silk, but for other purposes. These include building retreats, safety drag-lines (constantly connected as the spider moves around) and for dispersal in a process called ballooning. One of the most common uses of silk in the spider world is in the construction of egg sacs that are used to protect their eggs.  

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Did you know spiderwebs were used as bandages to treat injuries in ancient times? Spiderwebs are made of spider silk. They were believed to have antiseptic and anti-fungal properties. They helped prevent infection and were said to promote clotting of blood. Now research in spider silk is going on all over the world to explore its relevance to areas of medicine and industry.

If you are in midst of a forest, and get cut by a machete and there’s profuse bleeding, what do you do? You find a cobweb. Funny as it may sound, putting a bunch of cobweb on your wound will make the blood coagulate much faster. Thanks to those thousands of strands of nanowires which act as nucleation lines.

Besides that, since the cobwebs are proteins basically, they are good places for fungi and bacteria to grow. So, the spider knows that and has evolved to keep these bacterial and fungi growths away from its web. Cobwebs are in fact antiseptic and antifungal too. As long as the web is clean, it will not cause any kind of infection if you put it on an open wound.

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The specks that are visible on the outside of a strawberry are actually the plant’s ovaries called achenes. Each of them is a separate fruit with a single seed inside. It is these seed-like fruits that are mistaken for seeds. Strawberries do not rely on the seeds inside the achenes to reproduce. Each plant can send out thin runners that take root and give rise to multiple new plants.

When a strawberry flower is pollinated, the fruit doesn’t swell. The fertilized ovaries in the flower form separate, small, dry fruits. Those “seeds” on the outside of a strawberry are actually the fruits, each of which contains a single seed.

The ripe, red, fleshy part that we think of as the strawberry “fruit” is actually swollen receptacle tissue – the part of the plant that connected the flower to the stem. When a strawberry flower is pollinated, it triggers the receptacle tissue to grow and change.

But that still doesn’t answer the question, it just changes it a little. Why are the small, dry fruits located on the outside of the red, sweet thing that we all like to eat?

The short answer is that we don’t really know which evolutionary forces caused the strawberry to develop the way that it did.

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Do you know what's common among SARS-CoV-2, HIV AIDS, Ebola, SARS, MERS, Nipah, H1N1 flu (swine flu) and H5N1 flu (bird flu)? Yes, all of these are zoonoses, that is, they are animal-bome diseases.

A zoonosis is any disease or infection that is naturally transmissible from vertebrate animals to humans. Zoonoses have different modes of transmission. In direct zoonosis, the disease is transmitted from animals to humans through air, bites or saliva. In indirect zoonoses, the transmission occurs via an intermediate species (referred to as a vector), which carries the disease pathogen. These pathogens can be viruses, bacteria, fungi or parasites.

Though the world has seen the emergence of diseases throughout history, in the last 50 years, a host of new infectious diseases has spread rapidly after making the evolutionary jump from animals to humans. According to the World Health Organisation (WHO), 70% of emerging human pathogens come from animals. In the last century, at least 10 infectious diseases jumped from animals to humans, it says.

What has led to this?

Globalisation, deforestation, encroachment of wild environments, human-animal conflicts and wildlife trade have led to the spike in zoonosis outbreak, says a report by the WHO, released in September 2019. It has also warned that the risk of a global pandemic is growing and that zoonotic diseases will continue to emerge and re-emerge.

The deadly ones

As the world grapples with the new coronavirus, which is thought to have spread from bats, let's take a look at some of the major zoonotic diseases and their outbreaks...

Bubonic plague

Bubonic plague was the cause of the Black Death that swept through Asia, Europe and Africa in the 14th Century and killed an estimated 50 million people. It took centuries for some societies to recover. Plague is a bacterial disease caused by Yersinia pestis. It is carried by rodents and cats. The infection in humans is caused by the bite of an infected flea.

HIV-AIDS

HIV, the virus that causes AIDS, originated from chimps and other primates and is thought to have first infected humans at least a century ago. However, it was first recognised only in 1981. By the end of that year, there were 270 reported cases and 121 deaths. HIV destroys the immune system, opening the door to a host of deadly infections. The virus has now mutated to a separate human-only disease. Between 1981 and 2018, the disease caused an estimated 32 million deaths worldwide.

SARS An epidemic of SARS, caused by a strain of coronavirus SARSCOV, affected 26 countries and resulted in more than 8,000 cases in 2003.

SARS-CoV is thought to have spread from bats, which, in tumn, spread to other animals (civet cats) and perhaps first infected humans in southern China in 2002.

Ebola

The 2014-2016 outbreak in West Africa was the largest Ebola outbreak since the virus was first discovered in 1976. The outbreak started in Guinea and then spread to other parts of the continent. The virus is transmitted to people from wild animals (such as chimpanzees, gorillas, monkeys, antelopes or porcupines). Human-to-human transmission happens through direct or indirect contact with the blood or bodily fluids of infected people. It is thought that fruit bats of the Pteropodidae family are natural Ebola virus hosts.

Nipah

Nipah virus (Niv) infection severely affects both animals and humans. The natural host of the virus are fruit bats. It can spread from bats to other animals to people or directly from bat to and between people. Even eating a fruit bitten by an infected bat can transfer Nipah to humans. The disease was first identified in 1998 during an outbreak in Malaysia, India has reported three NiV outbreaks in the past. The first two were in West Bengal: Siliguri in 2001 and Nadia in 2007. The third outbreak occurred in Kerala in May 2018.

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Red moles are also known as cherry angiomas. You may have them on your skin and have never realized what they are. Most of the time they will appear on the chest, back, neck or face, but can pop up anywhere on the body. It’s understandable when you are concerned about the appearance of a red mole and want to undergo red mole removal immediately, but the truth is there’s usually nothing to worry about.

Cherry angiomas get their name from their appearance. Their bright red color occurs due to the dilated capillaries.

However, cherry angiomas can be a range of colors and may also appear blue or purple. If a person applies pressure to them, they do not usually turn white, or blanch.

These angiomas can also vary in size but commonly grow to be a few millimeters (mm) in diameter. As they get bigger, the angiomas usually form round, domed shapes with smooth, flat tops.

The growths can appear anywhere on the body but grow most often on the chest, stomach, and back. Multiple cherry angiomas often appear in groups.

The causes of cherry angiomas are largely unknown, though experts believe they tend to be genetic.

Age contributes heavily, and cherry angiomas increase in number and size after 40 years of age.

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Warts are raised bumps on your skin caused by the human papillomavirus (HPV). Warts have plagued humans for thousands of years — they have been discovered on 3,000-year-old mummies and were mentioned by Shakespeare. Although warts generally aren’t dangerous, they are ugly, potentially embarrassing, and contagious. They can also be painful.

Most warts clear up without treatment. It can take from a few weeks to several years, depending on the location and number of warts. They usually disappear faster in children.

One third of children are estimated to have warts, but studies have found that 50 percent Trusted Sourceof these disappear within a year, and 70 percent are gone after 2 years.

However, if they do not disappear, or if a wart causes concern, medical help is available.

A doctor will examine the wart, they may ask about family history, and they may take some tissue for tests.

HPV viruses cause the excessive and rapid growth of keratin, which is a hard protein on the top layer of the skin.

Different HPV strains cause different warts. The wart-causing virus can be passed on by close skin-to-skin contact, and through contact with towels or shoes.

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A skin tag is a small piece of soft, hanging skin that may have a peduncle, or stalk. They can appear anywhere on the body, but especially where skin rubs against other skin or clothing.

They often go unnoticed, unless they are in a prominent place or are repeatedly rubbed or scratched, for example, by clothing, jewelry, or when shaving.

Some people may have skin tags and never notice them. In some cases, they rub off or fall off painlessly. Very large skin tags may burst under pressure.

The surface of skin tags may be smooth or irregular in appearance. They are often raised from the surface of the skin on fleshy peduncles, or stalks. They are usually flesh-colored or slightly brownish.

Skin tags start small, flattened like a pinhead bump. Some stay small, and some grow bigger. They can range in diameter from 2 millimeters (mm) to 1 centimeter (cm), and some may reach 5cm.

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Moles are very common, and most people have one or more. Moles are concentrations of pigment-producing cells (melanocytes) in your skin. People with light skin tend to have more moles.

Moles are caused when cells in the skin (melanocytes) grow in clusters or clumps. Melanocytes are distributed throughout your skin and produce melanin, the natural pigment that gives your skin its color.

Most moles are harmless. Rarely, they become cancerous. Monitoring moles and other pigmented patches is an important step in detecting skin cancer, especially malignant melanoma.

Moles can develop anywhere on your body, including your scalp, armpits, under your nails, and between your fingers and toes. Most people have 10 to 40 moles. Many of these develop by age 50. Moles may change in appearance or fade away over time. Hormonal changes of adolescence and pregnancy may cause moles to become darker and larger.

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You may have come across news stories about captive-breeding programmes being successful or failures. What is captive breeding?

Captive breeding is a programme where usually animals, birds, reptiles, etc. that are extinct or nearly extinct in the wild, or those that are endangered, are bred in a controlled facility under human supervision. It is seen as a conservation effort because it strives to ensure that a species does not go extinct, and as a result, also protects the animal's habitat. Captive breeding is also viewed as part of species-survival plans that help create "large, healthy, and genetically diverse populations", thus leading to biodiversity too. There are many instances of captive breeding leading to newer populations of animals. For instance, the Arabian oryx that went extinct in the wild in the 1960s was captive bred and reintroduced into the wild in the mid-1980s.

However, the process is not without concern.

Normally, the creatures are bred in an environment different from their natural habitat. They are also in a safe environment, and are fed, which means they lack opportunities for their natural instincts to kick in or to learn survival skills. This could prove problematic or even fatal when such animals are released into the wild. Also, since only a small population is used for breeding, it can lead to in-breeding. In-breeding happens when closely related animals breed. If there are genetic problems or infections in the breeding population, this is likely to continue over generations.

Captive breeding may not always be taken up for conservation. Animals could be bred this way for zoos where they are primarily used for exhibition, often in cages under unhygenic conditions. Exotic animals can be bred to be pets or for the pet trade, or for illegal trade where they are killed for their skin, meat, etc.

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A chameleon is a very unique lizard that inhabits warm locations such as rainforests and deserts. They are known for their colour-changing abilities, long tongues, and unusual eye movements. The word chameleon comes from the Latin word chamaeleon, derived from Greek words chamai and leon, meaning ground and lion respectively. So, chameleon means lion on the ground. It is thought that the name refers to the ornate mane-shaped crests around the heads of some species.

The longest chameleon in the world is Parson’s chameleon (Calumma parsonii), which may grow up to 69.5 cm (about 27 inches) long. On the other hand, the world’s shortest chameleon, the male nano-chameleon (Brookesia nana), can be as small as 21.6 mm (about 0.9 inch) long. Most chameleons, however, are 17–25 cm (7–10 inches) long. The body is laterally compressed, the tail is sometimes curled, and the bulged eyes move independently of one another. Also, some chameleons possess helmet-shaped heads.

The chameleon’s specialized vision and a specialized tongue-projection system permit the capture of insects and even birds from a distance. The chameleon’s eyes are very good at detecting and regulating light. The lens of a chameleon’s eye is capable of focusing extremely rapidly, and it can enlarge visual images much like a telephoto lens. Although many other lizards also use the tongue to capture prey, most can expel it only a short distance. 

Credit : Britannica

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Flamingos are wading birds that are easily recognised by their long, stilt-like legs, and striking pink feathers. The bright pink colour comes from beta carotene, a red-orange pigment that's found in the algae and the shrimp that flamingos eat in their wetland environment. This flame-like appearance also gave them their name. In Portuguese and Spanish flamengo means flame-coloured. The genus name Phoenicopterus comes from the Greek word phoinikopteros, which means, "blood red-feathered".

To feed, flamingos tramp the shallows, head down and bill underwater, stirring up organic matter with their webbed feet. They eat various types of food, including diatoms, algae, blue-green algae, and invertebrates such as minute mollusks and crustaceans. While the head swings from side to side, food is strained from the muddy water with small comblike structures inside the bill. The bird’s pink colour comes from its food, which contains carotenoid pigments. The diet of flamingos kept in zoos is sometimes supplemented with food colouring to keep their plumage from fading.

Flamingos constitute the family Phoenicopteridae, which is the only family in the order Phoenicopteriformes. They are sometimes classified in the order Ciconiiformes (herons and storks) but also show similarities to anseriforms (ducks and geese), charadriiforms (shorebirds), and pelecaniforms (pelicans and cormorants).

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