AP Biology class blog for discussing current research in Biology

Tag: australia

After 50 Years, Ancient Fish Finally Named

Tiktaalik roseae life restor

The Australian Outback is one of the most hostile environments on planet earth. Covering a land mass of nearly twenty two times the size of the United Kingdom, this dry landscape is a formidable and unforgiving adversary for the species that have adapted to inhabit it. But The Outback wasn’t always as dry as it is today. Millions of years ago, it was a lush, green biome that had rivers running in all directions. A recent archeological excavation has presented a team of scientists with a unique opportunity to name a fossil fish. Dr. Brian Choo of Findlers University and a team of researchers named the fish Harajicadectes zhumini after developing a more comprehensive understanding of the species. While fragments of Harajicadectes were discovered in 1973, a nearly complete specimen was unearthed by Flinders University in 2016, when they began constructing a comprehensive profile of the species.

By observing the skeletal remains, the team was able to reconstruct a hypothesized anatomy of the animal. One of its striking features was a series of large openings at the top of its head. “These spiracular structures are thought to facilitate surface air-breathing, with modern-day African bichir fish having similar structures for taking in air at the water’s surface,” commented Dr. Choo. In light of these findings, the team began to consider how the supplementary breathing apparatuses contribute to our evolutionary heritage. “The ability to supplement gill respiration with aerial oxygen likely afforded an adaptive advantage,” added Professor Long. Harajicadectes is a member of those intrepid water dwellers who brought life to land. Elpistostegalians gave way to limbed tetrapods in the evolutionary family tree.

The evolutionary edge that supplementary breathing gave Harajicadectes is not to be underestimated. It is widely understood that oxygen sustains life, but its immense significance can only be realized when looking at the molecular level of respiration. Mitochondria are one of the most ancient organelles and, according to the endosymbiont theory, preceded eukaryotic cells as aerobic bacteria. In the final and most powerful stage of Cellular respiration – oxidative phosphorylation – oxygen plays an essential role in ensuring that ATP is churning. Oxidative phosphorylation takes place in the mitochondrial inner membrane, where proton pumps transport hydrogen protons from the mitochondrial matrix to the intermembrane space where a gradient builds. Then, through simple diffusion, protons cross through the ATP synthase complex back into the matrix where they bind with O2 molecules, forming H2O as a byproduct. If Harajicadectes didn’t have access to oxygen on land, it would have only been able to leave the water for brief periods of time. This would have greatly reduced its competitive advantage on the shores and reduced the likelihood of limbed tetrapod evolution. 

I think the field of paleontology is an underappreciated field of biology and science. Just as the field of history provides context for the problems of today, paleontology better helps modern biologists understand how, when, and why species evolve as they do. This naming of the animal has been fifty years in the making, but thanks to the team of Australian scientists, we understand our evolutionary beginnings slightly better. I find the mapping of ancient biomes fascinating, and as more advanced chemistry develops, maybe one day scientists will be able to bring these prehistoric animals back to life. 

Will Electrifying Delivery Trucks Limit the Predicted CO2 Emissions of this Decade?

The Australia Wildfires have evoked a sense of urgency concerning the climate change issue. The numbers, specifically the 500 million animals killed in the fires, are astonishing and heartbreaking. The fires have been a result of record high temperatures and low moisture in the air and earth. Climate change caused these fires, and it will continue to make them worse. Many people now are wondering what will come next? What can we do to help Australia? What will we do to prevent more events like this?

Maxine Joselow writes for the Scientific American about the impact that the commercial delivery process has on the environment. The World Economic Forum released a report in early January, 2020 on the rise of e-commerce in major cities around the world. The report showed that the number of delivery vehicles in the top 100 cities is predicted to rise 36% within the next decade, and as a result, carbon dioxide emissions will rise 32% from the delivery traffic alone; that’s 6 million tons.

My brother recently received a camera drone for Christmas, and I was immediately reminded of it while reading this article. My initial reaction was, “just replace the trucks with drones,” since I remember hearing about the new advancements in drone delivery. However, Joselow reminded me that drone technology, though very advanced, is not yet at a level in which it could be used efficiently, safely, and practically. The possibility of drone delivery in the future also depends on the area in which they would be delivering. In urban communities, there is are safety concerns surrounding air traffic and pedestrians.

The report from the World Economic Forum recommended several solutions to the carbon-emitting delivery truck problem, including replacing trucks with drones and requiring all delivery trucks to be electric. One author at the World Economic Forum Richa Sahay analyzes supply chain and transport work, and he claims that making the switch from gas to electric delivery vehicles would make the biggest dent in carbon emission levels.


This World Is On Fire

Perhaps the most striking and recent example of the extreme effects of climate change is the massive wildfires raging through Australia that continue to burn as I write this very article. Though the fact that this will only get worse as the effects of climate change escalate seems cause for hopeless nihilism, it should actually serve as the opposite: a desperate call to arms to prevent this from happening.

In order to understand why these fires can destroy at such a large scale, it is crucial to look to the source of these fires — drought through the Indian Ocean Dipole. Fires become much more destructive during a drought not just because of a lack of rain, but also because dead foliage makes it much easier for fire to spread. When put into conjunction with the lack of rain, these wildfires become an almost never-ending cycle of devastation due to the sheer scale of the fires. “Sustained changes in the difference between sea surface temperatures of the tropical western and eastern Indian Ocean are known as the Indian Ocean Dipole or IOD” (Australia Bureau of Metereology). In its positive phases, water moves away from Australia and to Africa and the temperatures rise in Australia. The positive phases of the Indian Ocean Dipole directly influence and have influenced wildfires, as “every major bushfire was preceded by [a positive ocean dipole]” and these positive phases are likely to grow threefold by 2100.

Although the current wildfire sets records for its scale and impact, the emphasis of this event should be on what we can now do with this information. The article directly points to the limit of carbon/greenhouse emissions as an efficient method of controlling the Indian Ocean Dipole. Above simply a horrible event for the environment, this fire has taken and continues to take the lives and homes of animals and people. The effects of climate change always affects those who cannot protect themselves: those without the resources to recreate their lives, those animals who cannot adapt to human-caused disasters, those entire biomes set years behind due to wildfires. Climate change is a human issue.

Rampant Roos: The Problematic Kangaroo Overpopulation

Kangaroos, the poster-animal of Australia, find themselves a topic of controversy due to its massively increasing population. Though adorable, the impact of kangaroos raise the question of whether its destruction on neighboring native species warrants the question of whether it is justified to increase kangaroo control.

Though an area may be protected, the rapid growth of herbivores due to the decrease of predators lead to the massive imbalance of an ecosystem. 

According to West Australian Environment Minister Stephen Dawson, the red kangaroo population has (insert hyperlink) increased over 345.94% from 409,422 in 2014 to 1,825,760 in 2018, and the Western Grey population has increased about 94% from 1,246,870 in 2014 to 2,423,800 in 2018 in West Australia alone. Throughout Australia, the numbers are just as gigantic: the graph below depicts the tremendous population growth over the last few years in South Australia.

Ironically, the protected areas are finding themselves lacking the ability to properly maintain biodiversity due to the ecological imbalance of herbivores. Though they lack the threat of human clearing,  the herbivores’ rabid consumption still endanger other native species. 

In addition to harming the protected areas, farmers find themselves asking “what is the best way to deal with the kangaroo problem?” According to the vice president of the Pastoralists and Graziers Association of West Australia, Digby Stretch, kangaroos should be used for pet and human consumption – thus killing two birds with one stone. Kangaroos cannot be simply fenced off farm land, and make the creation of grazing pastures and the planting of perennial species unrealistic. 

Personally, the control of kangaroos seems like a necessity due to the threat it poses on other native species. Even though it may seem inhumane to kill animals of a native species, controlling the kangaroo population better allows the balance to return between the other species instead of leaving the area barren. Extinction rates are rising in Australia, and with it, the solutions must also rise and adapt. Attempting to simply protect a singular species won’t fix an issue with a whole ecosystem. Moving forward, the conservation of biodiversity needs to adapt and evolve along with the specific problems of an ecosystem.

i-motif: A new form of DNA discovered

Australian researchers have discovered a new structure of DNA called i-motif. This form of DNA is in the shape of a twisted knot, vastly different from the conventional double helix model. i-motif basically looks like a four-stranded knot of DNA. In the i-motif form, the C bases on the same strand of DNA bind to each other instead of their complementary pairs.


(Photo: Wikimedia Commons)

How did scientists discover i-motif?

i-motif previously haven’t been seen before, apart from in in-vitro (which means under laboratory conditions and not in the natural world) To detect i-motif, scientists used a tool made up of a fragment of an antibody molecule. This antibody could recognize and attach to i-motifs. Researchers showed that the i-motif structures mostly formed at the G1 phase -when mRNA is synthesized- in a cells life cycle. The i-motifs show up in promoter regions and in telomeres in the chromosome.

While scientists aren’t really sure the actual reason for their existence, some researchers suggest that they are there to help switch genes on and off and affect whether or not a gene is actively read.

Whatever the reason for their existence, they have potential to play an important role in how and when DNA is read. Prof Marcel Dinger at the Garvan Institute for Medical Research says, “It’s exciting to uncover a whole new form of DNA in cells — and these findings will set the stage for a whole new push to understand what this new DNA shape is really for, and whether it will impact on health and disease.”

Smallest Komodo Dragon Out There.

Most everyone knows that Komodo Dragons are the largest lizards on the planet. Surprisingly, humans have only known about these lizards for about 100 years. But thats nothing compared to the newest discovery of a very very small relative of the Komodo dragon. (original article)

These lizards, about the length of a human hand and very skinny, are about as small as the Komodo’s are big. They are even smaller than the pygmy goanna (the short-tailed monitor, V. brevicauda), which, until now, was believed to be the smallest relative of the Komodo Dragon. These new tiny dragons are shorter, thinner, and more boldly colored than the pygmy goanna. It is believed that around the same time chimpanzees and humans begun to separately evolve (between six million and seven million years ago) the pygmy and the newest lizard edition began to evolve separately. Gillenibaumann_01

These little lizards were discovered in Australia, the home of their slightly pygmy goanna larger relatives. Some females can now be seen in the Western Australian Museum in Welshpool. These lizards have yet to be named, but have been nicknamed “Pokey”.

It’s the little discoveries like these that make us realize how much more we still have to learn and discover about our planet. The planet is so vast that in our relatively short period of time here, there is no way we have a full understanding of the creatures we share the earth with!

Recently discovered mammal suffers from parenthood…

For a recently discovered species of marsupials, the Black-tailed Antechinus, it seems that parenthood is the highest cause of death. The Black-tailed Antechinus was discovered in Queensland’s Springbrook National Park, Australia by Dr. Andrew Baker. He laid 300 traps of oats and peanut-butter to catch the marsupial. After putting the marsupials through a multitude of tests they found that all the males died after mating. The stress hormone levels in the males, post mating, would steadily increase until eventually the males bodies would simply shut down. In this species of marsupials the males never live to see their young be born.

Turtle Telepathy

Photo Credit: Me


Have you ever heard of twin telepathy? Ever wished that you could communicate telepathically? Well, Australian River Turtles have their own form of telepathy. Female turtles dig a hole in the sand of a beach to lay their eggs. They then cover the hole with sand to protect against predators and leave their eggs to mature. The baby turtles mature on their own without the help of a parent, obviously they develop a special bond because the eggs wait until everyone is ready to hatch.


When the eggs are in the hole in the sand, the eggs on the bottom are colder in temperature than the eggs above them. Therefore, the eggs on top mature faster than the eggs on the bottom. However, if some eggs mature faster than others, then why do all of the eggs hatch at the same time? The answer is that they wait for each other. The turtles communicate with each other while they are still in their eggs through the levels of oxygen and carbon dioxide in the hole. When the eggs on top are more mature, they breath more, raising the level of carbon dioxide in the hole. The increase in carbon dioxide triggers a metabolic response in the underdeveloped eggs; it speeds up their metabolism. Ricky-John Spencer in Sydney, Australia believes that this communication can be attributed to evolution because if all of the turtles hatch and head to the ocean together, they have a lesser chance of being eaten by predators. Therefore, the eggs that hatched in a batches or around the same time had a higher chance of living than the eggs that hatched at all different times.

Koala Chlamydia

Photo Credit: Jonathon D. Colman

For generations the koala bear has been a cuddly mascot from down under, bringing in approximately $1 billion in tourism to the Australian economy a  year, but the species is being plagued by a heinous disease: Chlamydia. Yes, that’s right, Chlamydia. Studies show that between 50 to 80% of koala bears are infected with the bacterial infection which causes conjunctivitis, incontinence, prostatitis, infertility, and kidney damage.

According to recent reports, the sexually transmitted disease has caused serious population damage over the last decade. In 2003, studies showed that the koala population was at approximately 100,000, but the 2009 survey reported a drop to as few as 43,000 koalas in the wild. Experts fear that if these numbers continue to fall at the current rate, the koala will reach extinction within a mere 30 years.

And, with the disease spreading faster than ever, there is little conservationists can do to treat the infected population due to the absence of a vaccine. Unfortunately, however, a small percent of koalas is being treated with long-term antibiotics and anti-inflammatories in order to provide temporary relief to the suffering animals. But as the disease continues to run rampant, there seems to be little hope for the koala bear’s survival, which raises the question: why now?

Some experts believe for the combination of climate change and human development of koala bear natural habitat have increased the disease’s ability to spread among individuals. Climate change has caused heat waves and drought to sweep across much of the eucalyptus forests where koalas live and has resulted in the overall weakening of many koala populations unable to cope with such temperatures. In recent years, the species has also lost inordinate amounts of their habitat to human development which pushes them into a smaller and smaller region. This encroachment forces koalas into closer quarters, which, along with their already weakened state caused by climate change, results in the extremely rapid spread of Chlamydia among individuals.

But if the extinction is so pressing and the situation is so bad, why hasn’t the Australian government stepped in? Well until recently Australia officials have been avoiding taking action, but just this summer the Australian senate has finally agreed to address the problem and evaluate whether or not the koala bear should be an endangered animal under the protection of national law. Unfortunately, the process is taking longer than anticipated. A decision was supposed to be in by August, but here we are in mid-October and the koala bears are still unprotected by the government. How many more koala’s will have to die before the Australian senate takes action? And if they do take action, will it be too late to save the iconic marsupial from down under?


For more information on the current situation go to:

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