Category Biology

WHAT DID EARLY ANIMALS LOOK LIKE?

By around 500 million years ago, bacteria in the oceans had evolved into the earliest fish. These strange creatures had no jaws; they had funnel-like Sucking mouths.

The first animals – including the common ancestor of all animals today – evolved in the sea over half a billion years ago. We have no direct evidence of what they were like.

But by studying animals today, we can work out features they must have shared – small size, soft bodies, and a tendency to stay very still or creep slowly across the ocean floor.

The creatures had bodies built from multiple cells with specialised roles, like organisms before them. Now, those cells could also form sheets called epithelia, allowing structures to develop. Along with increased genetic complexity, this set the scene for big changes.

Earth’s environment was in flux during the Cambrian period, and the Ediacaran period that came before it. Sea levels rose, and chemicals washed into the ocean. In the underwater world, evolution got to work. New creatures emerged that could move further than ever before – and change their environment by burrowing and building. Soon, the new species were living in every habitat across the length and breadth of the ocean.

Credit: Natural History

Picture credit: Google

Can peacocks predict rain?

Have you watched a peacock dance? It is a beautiful sight to behold. We have heard people say that a peacock dance is an indicator of rain. How true is this? Sadly, the reality is not as cool as it sounds. The male of the Indian peafowl species is called the peacock. (The female is called the peahen and the offspring, the peachick). The stunning pattern on their metallic blue-green covert feathers (called a train), and the eye spots are something unique to the Asiatic species. (The Congo peacocks do not have the train nor the eyespots).

A peacock opens its train and dances to attract a peahen. It is part of the courtship ritual, where the male fans his tail displaying the eyespots. Peacocks moult (shed) their train at the end of every breeding season. So, what is the link between rain and their dance? Peafowls breed during the wet or rainy season. Hence, it is only a coincidence if you watched a peacock dance and you witnessed a rain soon after.

Picture Credit : Google 

What are tawny crazy ants?

One of the most incredible things about Nature must be how everything is so balanced. The interdependence and co-existence of species, for one. Of course, it’s a different story altogether that humans have singularly ruined that balance. But, now and then, comes a story to remind us that Nature will win eventually.

So, these crazy ants (really. that’s their name!), spreading in the southeastern parts of the U.S., have been living up to their name very well for the last 20 years. These ants, whose full name is tawny crazy ant, are an invasive species in Texas, and unimaginably destructive. According to a news report, when these crazy ants invade any new region in Texas, they “wipe out local insects and lizards, drive away birds, and even blind baby rabbits by spewing acid in their eyes”. Native to South America, they moved up north through ships. Ants are known for their “orderly marches”, but this one got its name because there are no orderly marches here, only “erratic, jarring movements”. In addition to ecosystems, they take over electrical systems, “causing shorts in breaker boxes, AC units and sewage pumps”.

And, looks like their days may be numbered. In a recent study, scientists discovered a naturally occurring fungus-like pathogen that can be used to reverse the rampant spread of these ants. The “fungus had already driven pockets of the invaders to extinction, and would soon be tested at environmentally-sensitive sites to protect endangered species”.

Though the pathogen’s origins aren’t clear, the study has shown that over the last eight years, “every population harboring the pathogen declined, and 60 percent of the populations went completely extinct”.

This is good news in two ways because “first, a pathogen of natural origin was selectively targeting the invasive species, limiting their ability to steamroll local ecosystems. Second, scientists can accelerate the spread of the pathogen to kill the crazy ants quicker”. But the reality is also that the process is “labor intensive, not something that could eradicate the species overnight”.

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Does deserts ‘breathe’ water vapor?

Deserts are arid ecosystems, receiving fewer than 25 cm of precipitation a year. They are hot dry and deserted. But the sand dunes aren’t just inert masses. They, in fact. “breathe” water vapor and are very much alive. Scientists have developed a super-sensitive probe that has recorded how water vapor from the surrounding air percolate between sand grains.

Researchers at Cornell University, New York, and University of Nantes, France, developed over a decade a new form of instrumentation called capacitance probes. to study the moisture content in sand dunes to better understand the process by which agricultural lands turn to desert. The probe uses multiple sensors to record everything from solid concentration to velocity to water content, all with unprecedented spatial resolution. It is so sensitive to moisture that it can pick up tiny films of water on a single grain of sand!

Conducting the research at Qatar, they combined data on wind speed and direction as well as ambient temperature and humidity. The study revealed just how porous sand is, with a tiny amount of air seeping through it.

When wind flows over the dune, it creates imbalances in the local pressure. This forces air to go into and out of the sand. “So, the sand is breathing, like an organism breathes,” the researchers note. This breathing could be the reason behind how microbes live deep in sand dunes, even when no liquid water is available. The researchers also found that at the surface of the dune, the probe measured less evaporation than scientists were predicting. This shows that the leaching of moisture from the sand dune to the atmosphere is a slow chemical process.

The team’s paper has been published in the Journal of Geophysical Research-Earth Surface. Probes that can sensitively measure moisture within sand could help experts find invisible signs of water, say, on Mars.

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Six environmental issues and how to solve them?

Earth has undergone many environmental changes in its history. But the current ones are being caused by one species: humans. Our activities contribute to global warming, climate change, extreme weather events, species extinction, resource depletion, and what not. Let’s take a closer look at six of them to mark Earth Day, observed on April 22.

1. POLLUTION

Since the industrial revolution, environmental pollution has been on the rise. Pollution is the introduction of harmful contaminants into the environment that negatively alters our surroundings. While pollution can take several forms, such as light and noise, the three major types are air, land, and water pollution. Humans contribute to each of these every day. Pollution affects biodiversity, ecosystems, and human health worldwide. Air pollution is attributed to 11.65% of deaths globally, for instance. Vehicular and industrial emission, and basically, our dependence on fossil fuel for energy, is the chief cause of air pollution. While water pollution comes from sewage, chemicals, agricultural runoffs, etc. land pollution is caused by indiscriminate dumping of garbage, toxic materials, and industrial waste. Not to mention the harm caused by plastic pollution to marine and terrestrial life. As economies and population grow, pollution too increases at an alarming rate globally.

 2.GLACIER MELT AND SEA-LEVEL RISE

Nineteen of the warmest years in the recorded history of the planet has occurred since 2000. Models predict that as the world consumes more fossil fuel, greenhouse gas concentrations will continue to rise, and Earth’s average surface temperature will rise with them. Average surface temperatures could rise between 2°C and 6°C by the end of the 21st Century. A warmer atmosphere causes glaciers and polar ice sheets to melt rapidly. Glacial melt has a direct impact on freshwater flow because glaciers store water in the form of ice during the colder seasons and release it during warmer seasons by way of melting. This serves as a water source for humans, animals, and vegetation. Glacier melt also contributes to unusual rise in sea level. The impact of sea-level rise includes flooding of coastal areas, increased soil erosion, disappearance of some low-lying islands, saltwater intrusion, and habitat destruction in coastal areas, which, in turn, can affect coastal ecosystems.

What can you do?

A few tips on how we can reduce our impact on global warming: 1. Urge your parents to switch to renewable sources such as solar to power your home.

2. Use energy-efficient appliances at home and school

3. Support local businesses that use and promote sustainable, climate-smart practices

3. DEFORESTATION

Deforestation is the destruction of forests in order to make the land available for other uses. Earth loses 18.7 million acres of forests per year, which is equal to 27 football fields every minute, according to the World Wildlife Fund. Farmers clear forests to use the land for agriculture. Trees are cut for mining. for use as fuel. housing, and urbanisation, contruction of dams and infrastructual projects, and for making furniture. Deforestation is considered to be one of the contributing factors to global warming and climate change. Trees absorb not only the carbon dioxide that we exhale, but also the other heat-trapping greenhouse gases that human activities emit. With increase in deforestation, larger amounts of these gases will enter the atmosphere and global warming will increase further. As much as 70 % of the world’s plants and animals live in forests. They are losing their habitats due to deforestation. Loss of habitat can lead to species extinction.

What can you do?

1. Plant saplings

2. Go paperless

3. Go for used-furniture instead of buying new ones every time.

4.WATER CRISIS

If global temperatures continue to rise, rainfall will increasingly become a thing of extremes: long dry spells here. dangerous floods there and in some places, intense water shortages. This will also affect agriculture. Worldwide, farmers are struggling to keep up with shifting weather patterns and increasingly unpredictable water supplies. Extreme weather patterns also destroy life, property. and livelihood. The rapid increase in population and the massive growth in the industrial sector have increased the demand for water multifold. Overexploitation and wastage of water are major issues, especially in urban areas. A UN report says that at least two billion people live in countries with high water stress. That is more than a quarter of the world population. Ecosystems and biodiversity are threatened by the scarcity of water resources. Water crisis can also lead conflict between States that share water sources such as river.

What can you do?

1. Do not waste water

2. Fix leaking tap and try to reuse water wherever possible

3. Urge your parents to install rainwater harvesting facility

4. Don’t pollute water: Do not dump household solid waste or oil and chemicals into the drainage system. Do not litter. They are likely to end up in a waterbody.

5.WILDFIRE

As warmer temperatures increase evaporation, the land becomes drier and drier, enhancing the chances of wildfires. The intense, destructive fires that have dominated headlines in recent years are expected to become more frequent, even in places such as the Arctic. Extreme fires are projected to rise up to 14% by 2030 and 30% by mid-century, according to a new report by the UN Environment Programme.

Wildfires not only destroy forests and cause loss of life, they emit large amounts of greenhouse gases such as CO2, methane, and carbon monoxide. The smoke from burning vegetation can pose serious risks to respiratory health. Animals are directly impacted by wildfire. They lose their life or their home and food source.

What can you do?

1. Build your campfire in an open location and far from flammables

2. Do not contribute to global warming

3. Avoid burning wastes around dry grass.

6. WILDLIFE TRADE

Wildlife trade is a big business, run by international networks. Animals and birds are trafficked across the globe for meat, skin, bone, fur, and other body parts. In addition, many species are sold as pets. Experts at TRAFFIC, the wildlife trade monitoring network, estimate that the illegal wildlife commerce runs into billions of dollars. Wildlife trafficking threatens the survival of some of the Earth’s most iconic species: tiger, elephant, rhinoceros, pangolin, etc. It affects food chain and threatens the local ecosystem. Wildlife trade also increases the chances of human-animal contact, putting humans at the risk of contracting diseases. COVID-19 was linked to wildlife trade and eating of wildlife. People who handled, killed, and sold wild animals made up nearly 40 % of the first cases of SARS. Poorly regulated wet markets and illegal wildlife trade offer a unique opportunity for viruses to spill over from wildlife hosts into the human population.

What can you do?

1. Create awareness among the public about wildlife trade.

2. Say no to exotic pets. They may have been trafficked and kept in unsafe conditions before being sold.

3. Avoid buying things made from ivory, horns, and leather. This discourages illegal trading.

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Can seaweed clean your teeth?

NEWCASTLE University scientists claim that an enzyme isolated from marine bacterium Bacillus licheniformis cuts through plaque on teeth and cleans hard-to-reach areas. Dr Nicholas Jakubovics of the university’s School of Dental Sciences said: “Plaque is made up of bacteria which join together to colonize an area in a bid to push out any potential competitors. Traditional toothpastes work by scrubbing off the plaque containing the bacteria. But that’s not always effective which is why people who religiously clean their teeth can still develop cavities.” When bacterial cells die, the DNA inside leaks out and creates a biofilm that sticks to teeth, protecting the bacteria from brushing, chemicals or even antibiotics. Bacillus licheniformis, found on the surface of seaweed, releases an enzyme which breaks up the biofilm and strips away harmful bacteria.

Researcher Prof. Burgess said: “The zyme breaks up and removes the bacteria esent in plaque and importantly, prevents build-up of plaque too. If we can contain it with’n toothpaste we would be creating a product which could prevent tooth decay. The enzyme also has huge potential in he ping keep clean medical implants such as artificial hips and speech valves which also suffer from biofilm infection.”

Picture Credit : Google