My Science School

Our planet is indeed a wonderland with zillions of creatures inhabiting it, each having its own unique way of adapting to its habitat. Among these, there are some creatures that have developed some bizarre defence mechanisms. Let's read up on some of these animal species.

IBERIAN RIBBED NEWT

Imagine ribs that you can use as poisonous spikes. The iberian ribbed newt is capable of pushing its ribs outside its skin when attacked. These form spikes which the newt uses to defend itself. The animal does this by moving its ribs away from the spine and increasing their angle by 50 degrees. The tips of the ribs then stick outside the animal's body, like a set of spines. At the same time, the newt is capable of producing a poisonous milky substance on its body surface. This coupled with its protruding ribs acts as its stinging tool.

GOLDEN POISON FROG

The golden poison frog is one of the most toxic animals on Earth. It is known for its vibrant colours and the potent poison produced by its skin. While its bright colour is itself a warning sign to predators, the frog takes its defence one notch higher by producing toxins such as steroidal alkaloids batrachotoxin, homobatrachotoxin, and batrachotoxin A. These compounds can cause arrhythmias, fibrillation, and cardiac failure in humans.

TEXAS HORNED LIZARD

Here is a lizard that shoots blood from its eyes. When under threat, the Texas horned lizard sprays out pressurised blood from the corners of its eyes at its attacker. In biology, this is called autohaemorrhaging or reflex bleeding. The animal resorts to this when all its other defences such as camouflage fail. This is carried out by the lizard by rupturing its own sinus membranes.

MOTYXIA MILLIPEDE

While the most common defence mechanism is to display vibrant colours to ward off predators, there are some animals that use their bioluminescence as a warning. A genus of millipedes that is endemic to California called the Motyxia uses its bioluminescence to warn off predators. But the most unusual ability this creature possesses is that it can produce and ooze cyanide from the pores on its body. The cyanide is toxic for the predators of this species such as rodents, centipedes, and beetles.

MALAYSIAN ANT

Imagine a defence strategy that kills your predator but you end up getting the raw deal as well. These are the ants that will destroy themselves to defend their colony when under attack. These exploding ants are called the Malaysian ants. Whenever their nest is invaded, they will "blow" up (rupture) their abdomens. The ants have poison glands that get burst when they flex their body, releasing the poisonous substance onto their predator. This can either kill the enemy or incapacitate it.

HAIRY FROG

Meet the "Wolverine" in the wild. When threatened, this frog can crack its own finger bones and pierce them through its skin. These are then used as claws. On one end of the bone, there is a muscle that the frog can use to contract and thereby break a fragment of bone and push it outwards.

Picture Credit : Google 

What makes us humans different from our ape cousins? Well, our brain power. And, that came about through tweaks in the genes, according to an ambitious project, whose results were published recently. Come, let's find out more about this, and also how we are similar to and different from other mammals.

The Zoonomia Project compared the genomes (the genetic material that makes up a living organism) of 240 mammal species, including humans, to trace evolutionary changes over 100 million years. It studied a wide variety of mammals-from the huge North Pacific right whale (59 feet long) to the tiny bumblebee bat, just 3 cm long. It also included our closest evolutionary relatives - chimpanzees and bonobos. Do you know what startling result the study threw up? "The researchers identified genomic elements- 4,552 in all - that were pretty much the same across all mammals and were identical in at least 235 of the 240 species, including people." It means that certain parts of genomes have remained unchanged across all mammal species, humans included, over millions of years of evolution.

As for how humans are different from other mammals, the study points to areas "associated with developmental and neurological genes". It suggests that when Homo sapiens evolved, it involved changes in how the nervous system genes were "regulated". And these were just tweaks rather than any dramatic and major changes to the genes themselves. This explains why we still share a large part of our genetic makeup with our ape cousins.

And, genes are also responsible for traits unique to some mammals. For instance, hibernation and the sense of smell. While some mammals have a keen sense of smell, others have almost none. Humans are "somewhat average". The study also saw changes in genetic sequences in some species "in relatively short periods of time", indicating how they are adapting to their environments.

While the findings are fascinating by themselves. scientists believe they "could inform human therapeutics, critical care and long-distance space flight", and "also can help identify genetic mutations that lead to disease".

In a study, researchers identified genomic elements - 4,552 in all-that were pretty much the same across all mammals and were identical in at least 235 of the 240 species, including people. It means that certain parts of genomes have remained unchanged across all mammal species, humans included, over millions of years of evolution.

Picture Credit : Google 

When the Indian government brought the big cat to India last September, there was palpable excitement. However, in a matter of months, at least three adults - and a few cubs born in India - have died, turning the focus once again on the viability of such an ambitious project. In five points, here's a quick look at all that's been happening

1. Cheetah goes extinct

India has been a proud host to several big cat species, including the Asiatic lion, the Bengal tiger, and the snow leopard. More than seven decades earlier, it was also home to the Asiatic cheetah, found in the wild today only in Iran. Plagued by hunting habitat loss, and reduction in prey base, their numbers plunged dramatically over the years; the last of this carnivore died way back in 1947. Five years later it was declared officially extinct in our country - "the only large mammal to become extinct since independence".

2. Bringing the big cat home

For decades, India had considered bringing the Asiatic cheetah from Iran. However, since Iran itself was host to only a small number of this animal, India could not move ahead with that plan. (Today, the number of Asiatic cheetahs in Iran stands at a paltry 12: the country recently lost a 10-month-old cub born in captivity.) Meanwhile, the idea of 'African Cheetah Introduction Project in India' shaped up in 2009, but it failed to take off for over a decade. When it appeared as if it could come to fruition after 2019, the COVID-19 pandemic set in, delaying it further. The wait finally ended in 2022, when the world's fastest land animal came to our country.

3. The reintroduction begins

With great fanfare, as many as eight cheetahs arrived from Namibia last September. A few months later, 12 more arrived from South Africa. (It is said that the plan is to bring a total of 50 in the next five to 10 years.) They reached an enclosure at Kuno National Park in Madhya Pradesh. Since they arrived from a different country (and even a continent), they need time for acclimatisation (getting used to their new surroundings). So, gradually over a period of time they are to be released into the wild from their enclosures. But, it seems, not all 20 will survive the relocation.

4. Births and deaths

In March, a female cheetah brought in from Namibia died, possibly due to kidney ailment. That would be the first of a few more deaths to follow. In April, a male, belonging to the batch from South Africa, died, due to cardiac failure. In May, a female cheetah from South Africa died, believed to be from injuries during mating. Meanwhile, just a couple of days after the death of the first cheetah, a female from Namibia gave birth to four cubs. But that joy was to be short-lived - in May, at least three of them died due to reasons such as weakness and dehydration.

5. Hope and reality

The government and the supporters of the project have hoped the reintroduction is a chance to restore the biodiversity link that was broken due to the animal's extinction. Viewing it as a step towards wildlife education and conservation awareness, they also believe that the species can revive the grasslands it once roamed. However, many conservationists and critics have all along said that the project is unviable due to several reasons. One of them is that Kuno has neither enough space nor prey for the big cat. In fact, following the deaths of the cheetahs, the Supreme Court itself has come down heavily on the government, urging it to home some of these carnivores in other States, including Rajasthan. While stating that such deaths are not unusual, the government has said it would explore other places for the animal's release into the wild.

Picture Credit : Google