Scientists shocked to discover new species of green anaconda, the world’s biggest snake

Shutterstock Bryan G. Fry, The University of Queensland

The green anaconda has long been considered one of the Amazon’s most formidable and mysterious animals. Our new research upends scientific understanding of this magnificent creature, revealing it is actually two genetically different species. The surprising finding opens a new chapter in conservation of this top jungle predator.

Green anacondas are the world’s heaviest snakes, and among the longest. Predominantly found in rivers and wetlands in South America, they are renowned for their lightning speed and ability to asphyxiate huge prey then swallow them whole.

My colleagues and I were shocked to discover significant genetic differences between the two anaconda species. Given the reptile is such a large vertebrate, it’s remarkable this difference has slipped under the radar until now.

Conservation strategies for green anacondas must now be reassessed, to help each unique species cope with threats such as climate change, habitat degradation and pollution. The findings also show the urgent need to better understand the diversity of Earth’s animal and plant species before it’s too late.

Scientists discovered a new snake species known as the northern green anaconda. Bryan Fry

An impressive apex predator

Historically, four anaconda species have been recognised, including green anacondas (also known as giant anacondas).

Green anacondas are true behemoths of the reptile world. The largest females can grow to more than seven metres long and weigh more than 250 kilograms.

The snakes are well-adapted to a life lived mostly in water. Their nostrils and eyes are on top of their head, so they can see and breathe while the rest of their body is submerged. Anacondas are olive-coloured with large black spots, enabling them to blend in with their surroundings.

The snakes inhabit the lush, intricate waterways of South America’s Amazon and Orinoco basins. They are known for their stealth, patience and surprising agility. The buoyancy of the water supports the animal’s substantial bulk and enables it to move easily and leap out to ambush prey as large as capybaras (giant rodents), caimans (reptiles from the alligator family) and deer.

Green anacondas are not venomous. Instead they take down prey using their large, flexible jaws then crush it with their strong bodies, before swallowing it.

As apex predators, green anacondas are vital to maintaining balance in their ecosystems. This role extends beyond their hunting. Their very presence alters the behaviour of a wide range of other species, influencing where and how they forage, breed and migrate.

Anacondas are highly sensitive to environmental change. Healthy anaconda populations indicate healthy, vibrant ecosystems, with ample food resources and clean water. Declining anaconda numbers may be harbingers of environmental distress. So knowing which anaconda species exist, and monitoring their numbers, is crucial.

To date, there has been little research into genetic differences between anaconda species. Our research aimed to close that knowledge gap.

Green anaconda have large, flexible jaws. Pictured: a green anaconda eating a deer. JESUS RIVAS

Untangling anaconda genes

We studied representative samples from all anaconda species throughout their distribution, across nine countries.

Our project spanned almost 20 years. Crucial pieces of the puzzle came from samples we collected on a 2022 expedition to the Bameno region of Baihuaeri Waorani Territory in the Ecuadorian Amazon. We took this trip at the invitation of, and in collaboration with, Waorani leader Penti Baihua. Actor Will Smith also joined the expedition, as part of a series he is filming for National Geographic.

We surveyed anacondas from various locations throughout their ranges in South America. Conditions were difficult. We paddled up muddy rivers and slogged through swamps. The heat was relentless and swarms of insects were omnipresent.

We collected data such as habitat type and location, and rainfall patterns. We also collected tissue and/or blood from each specimen and analysed them back in the lab. This revealed the green anaconda, formerly believed to be a single species, is actually two genetically distinct species.

The first is the known species, Eunectes murinus, which lives in Perú, Bolivia, French Guiana and Brazil. We have given it the common name “southern green anaconda”. The second, newly identified species is Eunectes akayima or “northern green anaconda”, which is found in Ecuador, Colombia, Venezuela, Trinidad, Guyana, Suriname and French Guiana.

We also identified the period in time where the green anaconda diverged into two species: almost 10 million years ago.

The two species of green anaconda look almost identical, and no obvious geographical barrier exists to separate them. But their level of genetic divergence – 5.5% – is staggering. By comparison, the genetic difference between humans and apes is about 2%.

The two green anaconda species live much of their lives in water. Shutterstock

Preserving the web of life

Our research has peeled back a layer of the mystery surrounding green anacondas. This discovery has significant implications for the conservation of these species – particularly for the newly identified northern green anaconda.

Until now, the two species have been managed as a single entity. But each may have different ecological niches and ranges, and face different threats.

Tailored conservation strategies must be devised to safeguard the future of both species. This may include new legal protections and initiatives to protect habitat. It may also involve measures to mitigate the harm caused by climate change, deforestation and pollution — such as devastating effects of oil spills on aquatic habitats.

Our research is also a reminder of the complexities involved in biodiversity conservation. When species go unrecognised, they can slip through the cracks of conservation programs. By incorporating genetic taxonomy into conservation planning, we can better preserve Earth’s intricate web of life – both the species we know today, and those yet to be discovered.

Bryan G. Fry, Professor of Toxicology, School of the Environment, The University of Queensland

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Read More........→February 19, 2024

Think you’re good at multi-tasking? Here’s how your brain compensates – and how this changes with age

Arlington Research/Unsplash Peter Wilson, Australian Catholic UniversityWe’re all time-poor, so multi-tasking is seen as a necessity of modern living. We answer work emails while watching TV, make shopping lists in meetings and listen to podcasts when doing the dishes. We attempt to split our attention countless times a day when juggling both mundane and important tasks.

But doing two things at the same time isn’t always as productive or safe as focusing on one thing at a time.

The dilemma with multi-tasking is that when tasks become complex or energy-demanding, like driving a car while talking on the phone, our performance often drops on one or both.

Here’s why – and how our ability to multi-task changes as we age.

Doing more things, but less effectively

The issue with multi-tasking at a brain level, is that two tasks performed at the same time often compete for common neural pathways – like two intersecting streams of traffic on a road.

In particular, the brain’s planning centres in the frontal cortex (and connections to parieto-cerebellar system, among others) are needed for both motor and cognitive tasks. The more tasks rely on the same sensory system, like vision, the greater the interference.

The brain’s action planning centres are in the frontal cortex (blue), with reciprocal connections to parietal cortex (yellow) and the cerebellum (grey), among others. grayjay/Shutterstock

This is why multi-tasking, such as talking on the phone, while driving can be risky. It takes longer to react to critical events, such as a car braking suddenly, and you have a higher risk of missing critical signals, such as a red light.

The more involved the phone conversation, the higher the accident risk, even when talking “hands-free”.

Having a conversation while driving slows your reaction time. GBJSTOCK/Shutterstock

Generally, the more skilled you are on a primary motor task, the better able you are to juggle another task at the same time. Skilled surgeons, for example, can multitask more effectively than residents, which is reassuring in a busy operating suite.

Highly automated skills and efficient brain processes mean greater flexibility when multi-tasking.

Adults are better at multi-tasking than kids

Both brain capacity and experience endow adults with a greater capacity for multi-tasking compared with children.

You may have noticed that when you start thinking about a problem, you walk more slowly, and sometimes to a standstill if deep in thought. The ability to walk and think at the same time gets better over childhood and adolescence, as do other types of multi-tasking.

When children do these two things at once, their walking speed and smoothness both wane, particularly when also doing a memory task (like recalling a sequence of numbers), verbal fluency task (like naming animals) or a fine-motor task (like buttoning up a shirt). Alternately, outside the lab, the cognitive task might fall by wayside as the motor goal takes precedence.

Brain maturation has a lot to do with these age differences. A larger prefrontal cortex helps share cognitive resources between tasks, thereby reducing the costs. This means better capacity to maintain performance at or near single-task levels.

The white matter tract that connects our two hemispheres (the corpus callosum) also takes a long time to fully mature, placing limits on how well children can walk around and do manual tasks (like texting on a phone) together.

For a child or adult with motor skill difficulties, or developmental coordination disorder, multi-tastking errors are more common. Simply standing still while solving a visual task (like judging which of two lines is longer) is hard. When walking, it takes much longer to complete a path if it also involves cognitive effort along the way. So you can imagine how difficult walking to school could be.

What about as we approach older age?

Older adults are more prone to multi-tasking errors. When walking, for example, adding another task generally means older adults walk much slower and with less fluid movement than younger adults.

These age differences are even more pronounced when obstacles must be avoided or the path is winding or uneven.

Our ability to multi-task reduces with age. Shutterstock/Grizanda

Older adults tend to enlist more of their prefrontal cortex when walking and, especially, when multi-tasking. This creates more interference when the same brain networks are also enlisted to perform a cognitive task.

These age differences in performance of multi-tasking might be more “compensatory” than anything else, allowing older adults more time and safety when negotiating events around them.

Older people can practise and improve

Testing multi-tasking capabilities can tell clinicians about an older patient’s risk of future falls better than an assessment of walking alone, even for healthy people living in the community.

Testing can be as simple as asking someone to walk a path while either mentally subtracting by sevens, carrying a cup and saucer, or balancing a ball on a tray.

Patients can then practise and improve these abilities by, for example, pedalling an exercise bike or walking on a treadmill while composing a poem, making a shopping list, or playing a word game.

The goal is for patients to be able to divide their attention more efficiently across two tasks and to ignore distractions, improving speed and balance.

There are times when we do think better when moving

Let’s not forget that a good walk can help unclutter our mind and promote creative thought. And, some research shows walking can improve our ability to search and respond to visual events in the environment.

But often, it’s better to focus on one thing at a time

We often overlook the emotional and energy costs of multi-tasking when time-pressured. In many areas of life – home, work and school – we think it will save us time and energy. But the reality can be different.

Multi-tasking can sometimes sap our reserves and create stress, raising our cortisol levels, especially when we’re time-pressured. If such performance is sustained over long periods, it can leave you feeling fatigued or just plain empty.

Deep thinking is energy demanding by itself and so caution is sometimes warranted when acting at the same time – such as being immersed in deep thought while crossing a busy road, descending steep stairs, using power tools, or climbing a ladder.

So, pick a good time to ask someone a vexed question – perhaps not while they’re cutting vegetables with a sharp knife. Sometimes, it’s better to focus on one thing at a time.

Peter Wilson, Professor of Developmental Psychology, Australian Catholic University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Read More........→January 02, 2024

If humans disappeared, what would happen to our dogs?

Shutterstock Bradley Smith, CQUniversity Australia and Mia Cobb, The University of MelbourneFor many of us, dogs are our best friends. But have you wondered what would happen to your dog if we suddenly disappeared? Can domestic dogs make do without people?

At least 80% of the world’s one billion or so dogs actually live independent, free-ranging lives – and they offer some clues. Who would our dogs be if we weren’t around to influence and care for them?

What are dogs?

Dogs hold the title of the most successful domesticated species on Earth. For millennia they have evolved under our watchful eye. More recently, selective breeding has led to people-driven diversity, resulting in unique breeds ranging from the towering Great Dane to the tiny Chihuahua.

Today’s diverse dog breeds are a result of the modern approach to selective breeding. Shutterstock

Humanity’s quest for the perfect canine companion has resulted in more than 400 modern dog breeds with unique blends of physical and behavioural traits. Initially, dogs were bred primarily for functional roles that benefited us, such as herding, hunting and guarding. This practice only emerged prominently over the past 200 years.

Some experts suggest companionship is just another type of work humans selected dogs for, while placing a greater emphasis on looks. Breeders play a crucial role in this, making deliberate choices about which traits are desirable, thereby influencing the future direction of breeds.

Are we good for dogs?

We know certain features that appeal to people have serious impacts on health and happiness. For instance, flat-faced dogs struggle with breathing due to constricted nasal passages and shortened airways. This “air hunger” has been likened to experiencing an asthma attack. These dogs are also prone to higher rates of skin, eye and dental problems compared with dogs with longer muzzles.

Flat-faced dogs such as pugs and bulldogs often aren’t comfortable in the bodies we’ve bred them for. Shutterstock

Many modern dogs depend on human medical intervention to reproduce. For instance, French Bulldogs and Chihuahuas frequently require a caesarean section to give birth, as the puppies’ heads are very large compared with the mother’s pelvic width. This reliance on surgery to breed highlights the profound impact intensive selective breeding has on dogs.

And while domestic dogs can benefit from being part of human families, some live highly isolated and controlled lives in which they have little agency to make choices – a factor that’s important to their happiness.

Dogs without us

Now imagine a world where dogs are free from the guiding hand of human selection and care. The immediate impact would be stark. Breeds that are heavily dependent on us for basic needs such as food, shelter and healthcare wouldn’t do well. They would struggle to adapt, and many would succumb to the harsh realities of a life without human support.

That said, this would probably impact fewer than 20% of all dogs (roughly the percentage living in our homes). Most of the world’s dogs are free-ranging and prevalent across Europe, Africa and Asia.

Many dogs live independently around people, like these dogs seen on the street in India. Shutterstock

But while these dogs aren’t domesticated in a traditional sense, they still coexist with humans. As such, their survival depends almost exclusively on human-made resources such as garbage dumps and food handouts. Without people, natural selection would swiftly come into play. Dogs that lack essential survival traits such as adaptability, hunting skills, disease resistance, parental instincts and sociability would gradually decline.

Dogs that are either extremely large or extremely small would also be at a disadvantage, because a dog’s size will impact its caloric needs, body temperature regulation across environments, and susceptibility to predators.

Limited behavioural strategies, such as being too shy to explore new areas, would also be detrimental. And although sterilised dogs might have advantageous survival traits, they would be unable to pass their genes on to future generations.

Rearing puppies without human support happens successfully around the world. Shutterstock

No more designer breeds

Ultimately, a different type of dog would emerge, shaped by health and behavioural success rather than human desires.

Dogs don’t select mates based on breed, and will readily mate with others that look very different to them when given the opportunity. Over time, distinct dog breeds would fade and unrestricted mating would lead to a uniform “village dog” appearance, similar to “camp dogs” in remote Indigenous Australian communities and dogs seen in South-East Asia.

These dogs typically have a medium size, balanced build, short coats in various colours, and upright ears and tails. However, regional variations such as a shaggier coat could arise due to factors such as climate.

In the long term, dogs would return to a wild canid lifestyle. These “re-wilded” dogs would likely adopt social and dietary behaviours similar to those of their current wild counterparts, such as Australia’s dingoes. This might include living in small family units within defined territories, reverting to an annual breeding season, engaging in social hunting, and attentive parental care (especially from dads).

This transition would be more feasible for certain breeds, particularly herding types and those already living independently in the wild or as village dogs.

What makes a good life for dogs?

In their book A Dog’s World, Jessica Pierce and Marc Bekoff explore the idea of “doomsday prepping” our dogs for a future without people. They encourage us to give our dogs more agency, and consequently more happiness. This could be as simple as letting them pick which direction to walk in, or letting them take their time when sniffing a tree.

As we reflect on a possible future without dogs, an important question arises: are our actions towards dogs sustainable, in their best interests, and true to their nature? Or are they more aligned with our own desires?

By considering how dogs might live without us, perhaps we can find ways to improve their lives with us.

Providing a good life for dogs requires thinking about their mental well-being, health and environment. Shutterstock

Bradley Smith, Senior Lecturer in Psychology, CQUniversity Australia and Mia Cobb, Research Fellow, Animal Welfare Science Centre, The University of Melbourne

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Read More........→December 07, 2023