The lush biodiversity of South America's rainforests is rooted in one of the most cataclysmic events that ever struck Earth.
- One especially mysterious thing about the asteroid impact, which killed the dinosaurs, is how it transformed Earth's tropical rainforests.
- A recent study analyzed ancient fossils collected in modern-day Colombia to determine how tropical rainforests changed after the bolide impact.
- The results highlight how nature is able to recover from cataclysmic events, though it may take millions of years.
About 66 million years ago, a massive asteroid slammed into present-day Chicxulub, Mexico, triggering the extinction of dinosaurs. Scientists estimate the impact killed 75 percent of life on Earth. But what's remained more mysterious is how the event shaped the future of plant life, specifically tropical rainforests.
A new study published in Science explores how the so-called bolide impact at the end of the Cretaceous period paved the way for the evolution of our modern rainforests, the most diverse terrestrial ecosystems on Earth.
For the study, researchers analyzed thousands of samples of fossil pollen, leaves, and spores collected from various sites across Colombia. The researchers analyzed the samples to determine which types of plants were dominant, the diversity of plant life, and how insects interacted with plants.
All samples dated back to the Cretaceous-Paleogene boundary, some 70 million to 56 million years ago. Back then, the region's climate was mostly humid and hot, as it is today. However, the composition and structure of forests were quite different before the impact, according to the study results.
Tropical jungle with river and sun beam and foggy in the gardenSASITHORN via Adobe Stock
For one, the region's rainforests used to have a roughly equal mix of angiosperms (shrubs and flowering trees) and plants like conifers and ferns. The rainforests also had a more open canopy structure, which allowed more light to reach the forest floor and meant that plants faced less competition for light.
What changed after the asteroid hit? The results suggest the impact and its aftermath led to a 45 percent decrease in plant diversity, a loss from which the region took about 6 million years to recover. But different plants came to replace the old ones, with an increasing proportion of flowering plants sprouting up over the millennia.
"A single historical accident changed the ecological and evolutionary trajectory of tropical rainforests," Carlos Jaramillo, study author and paleopalynologist at the Smithsonian Tropical Research Institute in Panama City, told Science News. "The forests that we have today are really the by-product of what happened 66 million years ago."
Today's rainforests are significantly more biodiverse than they were 66 million years ago. One potential reason is that the more densely packed canopy structure of the post-impact era increased competition among plants, "leading to the vertical complexity seen in modern rainforests," the researchers wrote.
The extinction of long-necked, leaf-eating dinosaurs probably helped maintain this closed-canopy structure. Also boosting biodiversity was ash from the impact, which effectively fertilized the soil by adding more phosphorus. This likely benefited flowering plants over the conifers and ferns of the pre-impact era.
In addition to unraveling some of the mysteries about the origins of South America's lush biodiversity, the findings highlight how, even though life finds a way to recover from catastrophe, it can take a long time.
Ultimately, this is a fight between a giant reptile and a giant primate.
The 2021 film “Godzilla vs. Kong" pits the two most iconic movie monsters of all time against each other. And fans are now picking sides.
Even the most fantastical creatures have some basis in scientific reality, so the natural world is a good place to look to better understand movie monsters. I study functional morphology – how skeletal and tissue traits allow animals to move – and evolution in extinct animals. I am also a huge fan of monster movies. Ultimately, this is a fight between a giant reptile and a giant primate, and there are relative biological advantages and disadvantages that each would have. The research I do on morphology and biomechanics can tell us a lot about this battle and might help you decide – #TeamGodzilla or #TeamKong?
Larger than life
First it's important to acknowledge that both Kong and Godzilla are definitely far beyond the realms of biological possibility. This is due to sheer size and the laws of physics. Their hearts couldn't pump blood to their heads, they would have temperature regulation problems and it would take too long for nerve signals from the brain to reach distant parts of the body – to name just a few issues.
However, let's assume that somehow Godzilla and Kong are able to overcome these size limitations – perhaps because of their radiation exposure they have distinctive mutations and characteristics. Based on how they look on the big screen, let's explore the observable differences that might prove useful in a fight.
Kong: the best of ape and human
At first glance, Kong is a colossal primate - but he's not simply a giant gorilla.
Cliff/Wikimedia Commons, CC BY
One of the most striking things about Kong is his upright, bipedal stance – he mostly walks on two legs, unlike any other living nonhuman apes. This ability could suggest close evolutionary relationship to the only living upright ape, humans – or his upright stance could be the result of convergent evolution. Either way, like us, Kong has thick muscular legs geared toward walking and running, and large free arms with grasping hands, enabling him to use tools.
Humanity's bipedal, upright posture is unique in the animal kingdom and provides a slew of biomechanical abilities that Kong might share. For example, human torsos are highly flexible and particularly good at rotation. This feature – in addition to our loose shoulder girdle – makes humans the best throwers in the animal kingdom. Throwing is helpful in a fight, and Kong could probably throw with the best of them.
Kong is also, of course, massive. He absolutely dwarfs the largest known primate, an extinct orangutan relative called Gigantopithecus that was a bit bigger than modern gorillas.
Kong does have many gorillalike attributes as well, including long muscular arms, a short snout with large canine teeth, and a tall sagittal crest – a ridge of bone on his head that would be the anchor point for some exceptionally strong jaw muscles.
Strong, agile, comfortable on land and with the unparalleled ability to use tools and throw, Kong would be a brutal force in a fight.
Kenneth Carpenter/Wikimedia Commons, CC BY-SA
Godzilla: An aquatic lizard to be reckoned with
Godzilla appears to be a giant, semiaquatic reptile. Like Kong, Godzilla has the traits of a few different species.
Recent Godzilla movies show him decently mobile on land, but seemingly much more comfortable in the water despite his lack of overt aquatic features. Interestingly, Godzilla is depicted with gills on his neck – a trait that land vertebrates lost after they emerged from the sea about 370 million years ago. Given Godzilla's terrestrial features, it's likely that his species has land-dwelling reptile ancestors and reevolved a mostly aquatic lifestyle – kind of like sea turtles or sea snakes, which can actually absorb oxygen through their skin in water. Godzilla may have uniquely reevolved gills.
Godzilla's tail is what really separates him from Kong. It is massive, and anchored and moved by huge muscles attached to his legs, hips and lower back. Dinosaurs like Tyrannosaurus rex stood horizontally and used their tails for balance and to help them walk and run. Godzilla, in contrast, stands vertically and keeps his tail low to the ground, probably for a different type of balance. This vertical posture is unique for a two-legged reptile and more resembles a standing kangaroo. Godzilla stands on two muscular, pillarlike legs similar to those of a sauropod dinosaur. These would provide stability and help support his gargantuan mass but would also bolster the strength of his tail.
In addition to his powerful tail, Godzilla carries three rows of sharp spikes going down his back, thick scaly skin, a relatively small head full of carnivorous teeth and free arms with grasping hands, all built onto a muscular body. Taken together, Godzilla is a terrifying and intimidating adversary.
Tim Simpson/Flickr, CC BY-NC
So now that we've looked a little closer at how Godzilla and Kong are built, let's imagine who might emerge victorious in battle.
Though Kong is a little bit smaller than Godzilla, both are more or less comparably massive in size and neither has a clear advantage here. So what about their fighting abilities?
Godzilla would likely favor his robust tail for both offense and defense – much like modern-day large lizards that use their strong tails as whips. Scale up that strength to Godzilla's size, and that tail becomes a lethal weapon – which he has used before.
However, Kong is more comfortable on land, faster and more agile, can use his strong legs to jump, and possesses much stronger arms than Godzilla – Kong probably packs a walloping punch. And as an ape, Kong would also likely use tools to some degree and might even capitalize on his throwing ability.
Both would have a gnarly bite, with Kong likely getting a slight advantage. However, Godzilla's bite is by no means weak, and all of his teeth are flesh-piercing, similar to crocodile and monitor lizard teeth.
On defense, Godzilla has the edge, with thick scaly skin and sharp spikes. He might even act like a porcupine, turning his back to a rapidly approaching threat. However, Kong's superior agility on land should be able to offer him some protection as well.
I will admit I am #TeamGodzilla, but it's very close. I may give a slight edge to Kong in broad terrestrial battle ability, but Godzilla's general mass, defense and tail would be hard to overpower. And lest we forget, the tipping point for Godzilla is that he has atomic breath! Until researchers find evidence of a dinosaur or animal with something like that, though, I will have to reserve my scientific judgment.
Regardless of who emerges victorious, this battle will be one for the ages, and I am excited as both a scientist and monster movie fan.
This article has been updated to use more inclusive language.
Kiersten Formoso, PhD Student in Vertebrate Paleontology, USC Dornsife College of Letters, Arts and Sciences
Awareness of one's own heartbeat has some positive effects.
The heart is more than just a pump that pushes blood through our veins. It's also an organ that affects our thinking, feelings, perception and identity.
The human heart is usually the size of one's fist, sometimes a little larger.
It's made of two parts – the left and the right – that are not directly connected to one another. This is why sometimes they are called the left heart and the right heart.
The right heart pumps blood to the lungs. Then, oxygen-rich blood travels to the left heart.
The left heart pumps blood to the entire body, which is why it's a little larger than the right one.
Then blood comes back to the right heart, which pumps it into the lungs again.
The heart has its own automatism, meaning that it can work without being managed by the brain. It controls its contractions itself.
Cardiac contractions are induced by the electrical conduction system of the heart. This system is independent of the nervous system, which can only slow the contractions down or speed them up.
The cells of the electrical conduction system are capable of generating cyclical electric impulses. Those electrical impulses originate in the wall of the right atrium, in the sinus node of the heart, and from there, they travel to other cells in the system.
The electrical activity of the heart is measured during an ECG.
In a very simplified way, the heart's work can be divided into two phases: systole, when it contracts to pump the blood, and diastole, when the heart relaxes and fills with blood.
The sounds of the typical healthy heart resemble the syllables 'lub' and 'dub'. The first opens the contraction sequence and the latter closes it.
During contraction, pain is felt less acutely, and our reflexes and perception are numbed. According to the results of experiments carried out by Sarah Garfinkel from Brighton and Sussex Medical School, tiny stimuli (such as pinpricks) could go unnoticed.
Awareness of one's own heartbeat has some positive effects. People who can feel their own heartbeat are more intuitive and better at estimating risks accurately. Research by the British scientists Narayanan Kandasamy, Sarah Garfinkel and Lionel Page suggests that such people make better stockbrokers.
Meanwhile, people who cannot clearly feel their heartbeat are less apt at reading the emotions of others, following research by Oxford neurobiologist Geoff Bird.
The rhythm of the heart's systole and diastole cycle leaves its mark on our cerebral activity, the so-called heartbeat-evoked potential (HEP) – the brain's electrical activity that is synchronized with our heartbeat.
The stronger the HEP, the clearer we can register our heartbeat.
Various experiments have shown that people with strong HEP are better at noticing visual details. According to the results of Catherine Tallon-Baudry's experiments at the French Centre National de la Recherche Scientifique, these people are also more consistent and confident in their decision making.
Some scientists – including Olaf Blanke and Hyeongdong Park from the École Polytechnique Fédérale de Lausanne – claim that the HEP phenomenon is key to our identity building. They even say that the rhythm of our heartbeat gives us a sense of the continuity of the self.
It's also worth mentioning that HEP can be improved with the right training.
The human heart beats an average of 70 times per minute. Each time, it expels about 72 millilitres of blood. This makes for about 100,000 heartbeats and over 7200 litres of blood pushed through the heart each day.
During the average 78 years of the human lifespan, the heart beats 2.8 billion times, pumping 200 million litres of blood, an amount equal to 60 Olympic-sized swimming pools.
During physical exertion, the heartbeat rate is raised, but regular exercise lowers our blood pressure because the heart – like any other muscle – can be strengthened and made more efficient.
Sometimes it is claimed that every person has a finite number of heartbeats to use up in their lifetime. This is not true – the equation is not so simple. But it is true that those with a slower heartbeat tend to live longer.
As for animals, the ones with a slower pulse (such as whales – 20 heartbeats per minute) tend to live longer than those with fast-beating hearts (such as hamsters – 450 beats per minute).
Translated from the Polish by Aga Zano
The retraction crisis has morphed into a citation crisis.
- Even after scientific papers are retracted, hundreds of studies cite them as evidence.
- Roughly four retractions occur per 10,000 publications, mostly in medicine, life sciences, and chemistry journals.
- Journals should implement control measures that block the publication of papers that cite retracted papers.
Andrew Wakefield's 1998 study linking vaccines with autism was riddled with holes. All 12 children involved were handpicked, which is antithetical to clinical research. The now-deregistered physician falsified results. Wakefield used microscopic-level stains to make his case; a more reliable molecular method found no evidence of a link between vaccines and autism.
Add to this the fact that parents of study subjects, some with their own agendas (such as litigation), kept changing the timeline of their child's conditions. During all this time when Wakefield was raging against the vaccine, he filed for two patents on single measles shots. It was a money play from day one.
Twenty-three years later, the vaccine-autism myth remains in circulation despite decades of contrary evidence. Six years after the study was published, 10 of the 13 authors of their paper retracted their findings. It took The Lancet a few more years; in 2010 the publication finally retracted the paper. Journalist Brian Deer documented Wakefield's scam for years. Still, the lie persists.Science's replication crisis is well-known. But the research community is suffering from another serious problem, one ill-fated for the social media age: the retraction crisis.
Will America’s disregard for science be the end of its reign? | Big Think
As science journalist (and former marine biologist) Fanni Daniella Szakal recently pointed out, retracted papers are still being cited and used as gospel even when—sometimes it seems especially when—data are intentionally fabricated. Currently, roughly four retractions occur per 10,000 publications, with the highest percentages being in medicine, life sciences, and chemistry journals.
That overall number might not seem high yet those retracted studies have an outsized influence. Wakefield claiming the MMR vaccine causes autism as a ruse to patent his own vaccine is the most infamous example, but there are others.
- A 2005 paper touting omega-3 polyunsaturated fatty acids as having anti-inflammatory effects was retracted in 2008 after it was discovered that one author intentionally falsified data. After 2008, however, 96 percent of papers that cited the study never mentioned that it had been retracted.
- German anesthesiologist Joachim Boldt has a whopping 103 retractions credited to his name. Considered the greatest fraud in medicine since Wakefield, his studies, including influential work on the role of hydroxyethyl starch, continues to be cited today.
- Two COVID-19 studies published in reputable journals were retracted after their findings were deemed to be suspect. The researchers relied on a combination of big data and AI to replace randomized controlled clinical trials, leading to false results. Still, the retracted papers were cited in other prestigious journals and have been, in part, seized upon by anti-vaxxers that point to a nefarious medical industry trying to confuse us with conflicting evidence.
Gastroenterologist Dr Andrew Wakefield arrives with his wife Carmel flanked by supporters on July 16, 2007 in London, England.
As Szakal notes, a solid grasp of science matters considering research drives policy and healthcare decisions. We can't possibly expect every paper to get it right, but unfortunately, we also have to factor in biased researchers pushing forward their agendas. While the publication of such research is troublesome, Szakal takes particular issue with the authors and publications that continue to cite them after they've been retracted.
More than just a critique, however, Szakal suggests a path forward.
"In each and every publication, author guidelines should include that the author is needed to check all citations for possible retractions. Today numerous citation software are available to do this with ease; such as Zotero, scite.ai, and RedacTek alert users for any retracted papers in the reference list. As well as more care from authors, preventing post-retraction citations is a responsibility of publishers too. Along with double-checking the reference list of papers to be published, they should also make sure that retraction notices appear on all platforms where the study is available."
The past year has proven how dangerous scientific misinformation (and, even more disturbingly, disinformation) is to public health measures. The frantic urgency of social media platforms and the speed with which we consume headlines without reading articles makes teaching good science even more daunting. At the very least, we need the gatekeepers to take more responsibility for their publication process. Being the first to break bad science is way more socially damaging than being the tenth to publish science worth repeating.
Stay in touch with Derek on Twitter and Facebook. His most recent book is "Hero's Dose: The Case For Psychedelics in Ritual and Therapy."
The new treatment targets the underlying genetic cause of the disease.
- Progeria is an "accelerated aging" disease that causes children to die of "old age" at around 13 to 15 years.
- There are only two existing treatments, and both have unpleasant side effects.
- A promising new therapy based on biotechnology increases the lifespan of mice by over 60% and is ready for human clinical trials.
Progeria is an extremely rare genetic disorder that causes children to present with symptoms that resemble "accelerated aging." A child with the condition takes on the appearance of an elderly person, including hair loss and thin skin. Surviving on average merely 13 to 15 years, these children often die from a heart attack or stroke, diseases that are generally associated with advanced age.
The underlying genetic cause is complex. It is the result of a single point mutation (that is, a single "letter" in the DNA is changed from G to C), and it yields an unexpected and catastrophic outcome. To understand why, an explanation of the genetics of higher organisms (like plants and animals) is in order.
Genes contain the information to encode proteins. The first step in the process of converting the information in a gene to a protein product is to transcribe ("photocopy") the gene into a molecule known as messenger RNA (mRNA). The trouble with mRNA in higher organisms is that it is riddled with garbage sequences, known as "introns," that need to be removed. The protein-encoding sequences, known as "exons," are then strung together. The process of removing introns from mRNA for the purpose of stringing together exons is called splicing. When the splicing process is complete, the mature mRNA is translated to protein.
In plants and animals, mRNA "splicing" removes the introns and strings together the exons. Credit: Genomics Education Programme via Flickr
As with all biological processes, splicing can go wrong. Typically, splicing occurs only at the ends of exons, so that the end of one exon is spliced to the beginning of the subsequent exon. In progeria, something very strange happens. The G to C point mutation mentioned above occurs in a gene called LMNA and reveals a cryptic splicing site in an inappropriate location. The outcome is the removal of a crucial exon (see "exon 11" in the figure below), which results in a deformed protein called progerin. (The normal protein, which contains exon 11, is called Lamin A.)
A mutation in a gene called LMNA results in inappropriate mRNA splicing. This is the underlying genetic cause of Hutchinson-Gilford progeria syndrome. Credit: Michael R. Erdos et al., Nature Medicine, 2021.
Now, a team of researchers led by Michael Erdos and Francis Collins (the current director of the National Institutes of Health) has devised a highly precise potential treatment that targets the underlying genetic cause of Hutchinson-Gilford progeria syndrome. The results are reported in Nature Medicine.
Existing treatments are not ideal, as they both have serious side effects. The drug lonafarnib causes gastrointestinal problems, and the drug everolimus causes immunosuppression. A more targeted approach, therefore, is needed.
Erdos and his colleagues have identified a potential candidate, which comes from a class of drugs called "antisense peptide-conjugated phosphorodiamidate morpholino oligomers" (PPMOs). Essentially, it's a molecule similar to DNA or RNA with a tiny protein attached. The PPMO can be designed to recognize a very specific mRNA sequence, and in this case, it can be engineered to recognize and bind to the cryptic splice site next to exon 11. This physically blocks the cell from inappropriately splicing out exon 11 and allows it to produce a normal version of the protein (Lamin A).
Using mice that were genetically modified to mimic progeria, the researchers showed that their PPMO drug helped prevent the onset of progeria symptoms and extended the lives of the mice by nearly 62%.
Treatment of mice genetically modified to mimic progeria helped prevent symptom onset.Credit: Michael R. Erdos et al., Nature Medicine, 2021.
Treatment of mice genetically modified to mimic progeria helped extend their lives by nearly 62%.Credit: Michael R. Erdos et al., Nature Medicine, 2021.
The authors believe this evidence justifies proceeding to human clinical trials. Of course, just because a drug works in a mouse does not mean it will work in a human. But this potential new treatment provides hope for those suffering from one of the world's most devastating genetic diseases.
Source: Michael R. Erdos, et al. "A targeted antisense therapeutic approach for Hutchinson–Gilford progeria syndrome." Nature Medicine. Published online: 11-Mar-2021. DOI: 10.1038/s41591-021-01274-0