Q & A

Are Paleontologists Naming Too Many Species?

Friday, March 16, 2018

Ichthyosaur skeleton Niedersächsisches Landesmuseum Lower Saxony State Museum Germany (2)

A complete new examination taking a gander at varieties in Ichthyosaurus, a typical British Jurassic ichthyosaur (maritime reptile) otherwise called ‘Ocean Dragons’, has given essential data into perceiving new fossil species.

Professor Judy Massare (SUNY College at Brockport, NY, USA) and Dean Lomax (The University of Manchester) have examined many examples of Ichthyosaurus. After their most recent research project, the pair urge caution in naming new fossil species on the basis of just a few fragmentary or isolated remains.

For their examination, Prof Massare and Lomax concentrated on one specific piece of the Ichthyosaurus skeleton, the hindfin (or back oar). The reason for existing was to assess the distinctive structures among the six-known types of Ichthyosaurus. They inspected 99 examples which could give valuable data.

Ichthyosaur skeleton Niedersächsisches Landesmuseum Lower Saxony State Museum Germany (2)

Early in their research, they found different types of hindfin that initially appeared to represent different species. However, the more specimens they examined the more ‘variation’ they uncovered, such as differences in the size and number of bones. They determined that a single hindfin alone could not be used to distinguish among species of Ichthyosaurus, but that a particular variation was more common in certain species.

Their discoveries demonstrate that with just a couple of examples, highlights can be discovered that vary significantly starting with one example then onto the next and in this way show up as though there are a few animal categories. Though, as a general rule, with a significantly bigger example measure the holes in the ‘one of a kind’ varieties are filled in, demonstrating that distinctions are essentially the aftereffect of individual variation and an absence of the full picture.

Prof Massare said: “We described a few hindfins, which might have been called a new species if they were found in isolation. Instead, we had enough specimens to determine that it was just an extreme variation of a common form.”

Scientists can be categorized as one of two camps with regards to naming species, ‘lumpers’ and ‘splitters’. The previous ‘protuberance’ gatherings of comparable examples together, though the last pick to part up examples and recognize new species. Be that as it may, in this new examination, if the group picked to part up the examples in view of the variety discovered, it would propose an immense number of animal varieties.

“On the off chance that we thought about the variety as interesting, it would mean we would name around 30 new species. This would be like what was done in the Nineteenth Century when any new fossil find, from another area or skyline, was named as another species on the off chance that it varied marginally from already known examples.

“As bunches of new fossil species are named each year, at times, for example, with fragmentary or restricted remains, the choice to name another species ought to be viewed as deliberately.”

The new study has been published today in the scientific journal, Geological Magazine.

Source: www.techexplorist.com

How Birds Followed the Way of the Dinosaurs

Saturday, February 17, 2018

Artist’s depiciton of a Sinosauropteryx Caudipteryx

The science is settled. Birds evolved from dinosaurs, according to Dr Mike Lee, who is the South Australian Museum’s Palaeontology Senior Research Scientist and is a Fellow at Flinders University.

“For about 150 years after Charles Darwin came up with the idea of evolution, the idea that dinosaurs evolved into birds didn’t have a huge amount of support either from the fossils or the scientists,” Lee says. “There was only one fossil that seemed to suggest a link between birds and dinosaurs. That was Archaeopteryx but one bird doesn’t necessarily sway scientific opinion or prove overwhelmingly any particular radical theory.

“It was only in about 1998 that the first dinosaurs with feathers, apart from Archaeopteryx, were discovered in China. Since then we’ve had about 20 different dinosaurs with feathers, which almost show a perfect gradation from dinosaurs, which are only just a little bit bird-like all the way up to dinosaurs that for all intents and purposes you can’t really separate from primitive birds.”

The problem now: where to draw the line between bird and dinosaur.

“At what point does something change from a bird-like dinosaur into a primitive dinosaur-like bird? That’s tremendously exciting and this exhibition really emphasises all the new discoveries, which conclusively proves that birds are nothing more than miniature-flighted feathered dinosaurs.”

Anyone who has seen Steven Spielberg’s 1993 movie Jurassic Park will know that the question of birds evolving from dinosaurs was debated before the 1998 discovery. Lee says that up until 20 years ago it was a vigorous debate because the evidence for the evolutionary change wasn’t overwhelming.

“We didn’t have too many intermediate fossils. Now, we’ve not only got a whole, almost like a perfect line of intermediates stretching from birds to dinosaurs and all of them have feathers. There is really no debate now because, almost like watching a time-lapse movie in the fossil record, you can see the changes happening as you go from fossil-to-fossil.”

This change from bird-like dinosaur to dinosaur-like bird occured over a period of 50 million years.

“As dinosaurs got smaller the feathers got more and more elaborate,” Lee says. “The most primitive bird, at the beginning, when dinosaurs first evolved feathers, they weren’t the feathers you see in birds today, they were just little tuffs of fuzz, which really didn’t provide any sort of flight function, they were probably more for insulation, and maybe for display. As you progress towards more bird-like dinosaurs you can see the feathers becoming more elaborate and more bird-like. Then you start getting the flight feathers on the wings. You can actually see how a radical change in body-plan can happen step by step with very small changes; it was incremental, a bit like compound interest, actually. Evolution is basically nature’s version of compound interest where you can, given time, have a massive change.”

According to Lee, this change from dinosaurs to birds epitomises evolutionary change.

“Within the space of a decade it changed from that debate [of whether dinosaurs evolved into birds] into one of the best examples of major evolutionary change. Every time somebody wants to demonstrate the realities of evolution, dinosaurs and birds are pretty much the poster child.”

Children are fascinated by dinosaurs. Why does Lee think these creatures from hundreds of millions of years ago continue to capture children’s imagination?

“I think that children are always fascinated by big, fierce scary animals. Dinosaurs tick all those boxes but what makes them much more exciting than a dragon or an orc or something like that is we know they were real. We know that they did inhabit the world and they walked the world and they dominated the world for 150 million years. So the combination of being big and scary and real living creatures really attracts the imagination and attention of children.”

And dinosaurs are a pathway for children to discover science.

“All the major concepts in biology you can teach using dinosaurs as examples: evolution, physiology and taxonomy. You can teach them using other creatures as well, bugs and birds, but if you want a particular group of creatures to teach these concepts, dinosaurs, I think, have one of the broadest appeals. For instance, taxonomy is quite a dry area of science. It’s just basically scientists as librarians naming things, when you attach it to something like a brontosaurus and attach these fairly dry, boring names to these extinct charismatic creatures, even taxonomy can appeal to kids.”

Dinosaur rEvolution
South Australian Museum
Friday, February 23 to Sunday, May 6

Source: www.adelaidereview.com.au

How Colourful and Feathery Were the Dinosaurs?

Saturday, February 17, 2018

Kulindadromeus: An example of a plant-eating dinosaur with feathers and scales

Dinosaurs are depicted as naked, scaly reptiles, but evidence shows they were much more bird-like

Jurassic Park (1993) featured Velociraptors hunting park visitors, depicting them as wily lizard-like predators. Time and science, however, have been unkind to the filmmakers. Velociraptors and most other dinosaurs were bird-like creatures. Even Tyrannosaurs rex is believed to have sported a plume (more “terrible emu” than “terrible lizard”).

“Over the past 10 to 15 years we have come to realise that dinosaurs possessed feathers. Not just some, but lots of them,” says Dr Maria McNamara at University College Cork. All sorts of feathered dinosaurs lived during the Jurassic – 201 to 145 million years ago (mya) – with feathers evolving first for insulation and display, not flight.

“Dinosaurs were depicted as these naked, scaly reptiles. Jurassic Park did that. But discoveries in China changed our perception. They were much more bird-like,” says palaeontologist Dr Jakob Vinther at the University of Bristol. Though there are no fossils of Velociraptors with feathers, Chinese fossils prove their relatives were covered in them.

Dinosaurs experimented with feather designs and shapes. Vinther recently re-examined fossils of a dinosaur called Anchiornis, from the Jurassic. Whereas modern birds have a long central shaft, barbs and then filaments that seal feathers together, Anchiornis was different: “[It] had a short shaft, but then long barbs coming off and bundles of filaments. It would have given the dinosaur a much fluffier appearance; more like a shaggy mammal than a bird,” Vinther says.

In 2017, lasers were used to study traces of soft tissue from Anchiornis and revealed a four-winged dinosaur with drumstick shaped legs, padded feet, a slender tail and an arm similar to a modern bird’s wing. The crow-sized dinosaur may have glided through its woodland home.


Upending science

The first bird is still seen by many as Archaeopteryx (150 mya), a famous fossil discovered in the 19th century in a limestone quarry in Germany. Dublin Zoo put a cast of an Archaeopteryx fossil in its Zoorassic World gallery where visitors can see feather impressions, teeth and a long bony tail, a hodgepodge of dinosaur and bird.

But it was discoveries in China that upended dinosaur science. “We went from a dozen specimens of Archaeopteryx to tens of thousands of feathered specimens, each of which was as amazing,” says Prof Mike Benton, senior dinosaur expert at the University of Bristol. “The level of detail just blew away the field because of the richness of data.”

At the start of his career in the 1980s, Benton was taught Archaeopteryx had about 30 features that set them apart from dinosaurs, including feathers, hallowed bones, reduction of teeth and a wish bone. “All these have been now found in dinosaurs, except one: Powered flight,” says Benton. All parts of the dinosaur family tree had feathers. At a minimum, feathers evolved with early theropod dinosaurs about 200-250 mya, two-legged flesh-eating dinosaurs that gave rise to T. rex.


Feather colour

By examining the shape of granules holding the pigment melanin, scientists such as McNamara have helped decipher the colour of feathers. The first reconstruction of colour was carried out by scientists at the University of Bristol and palaeontologist Dr Patrick Orr at University College Dublin in 2010, reported in the journal Nature. It revealed Sinosauropteryx had a feather-like covering of orange and brown and a striped white and orange tail, probably for display purposes.

In 2014, McNamara co-authored a paper in the journal Science describing a Jurassic dinosaur from Siberia that resembled a flightless bird such as an emu or ostrich (except it had a long tail). This was the first ever example of a plant-eating dinosaur with feathers and scales. Before that, it was only the flesh-eating theropods that were found with feathers. Today, palaeontologists suspect large dinosaurs lacking feathers lost them during evolution, similar to how large mammals such as elephants lost fur.

“If we didn’t have all these fossils from China, our understanding of dinosaurs would be very different today,” says Vinther. “Birds are dinosaurs.”


A land of feathered dragons

Northeast China is ground zero for a revolution in how we see dinosaurs. A huge area in Liaoning province has well-preserved fossils of feathered dinosaurs and early birds, which are remarkably widespread. “The area is huge, probably about 1,000 square kilometres,” says Benton. “It is a little unclear why the fossils are so exceptionally preserved, but lots of the sediment has volcanic ash. For some locations, it seems fossils were captured in ash, a little like Pompeii.”

Most seem to be buried in lake beds or marshes, and many people dig them out to sell to museums and collectors.

The fossils have shifted scientists’ views on how dinosaurs looked and behaved. Many apparently had bright feathers, like birds today, which could have driven sexual selection. Benton says: “There are so many species of these small theropod dinosaurs. It may be that sexual selection was spinning up the number of species.”

Source: www.irishtimes.com

Over 40% of Americans Believe Humans and Dinosaurs Shared the Planet

Saturday, February 10, 2018

Many believe that dinosaurs and humans once coexisted, but most know that current technology doesn't allow for cloning dinosaurs from fossils.

The recent release of Jurassic World broke records for the best opening weekend ever, taking in $208.8 million in North America. The film, which is a reboot of 1993's original Jurassic Park, focuses on a theme park which displays dinosaurs that have been cloned by taking the DNA from fossils.

YouGov's latest research shows that 41% of Americans think that dinosaurs and humans either 'definitely' (14%) or 'probably' (27%) once lived on the planet at the same time. 43% think that this is either 'definitely' (25%) or 'probably' (18%) not true while 16% aren't sure. In reality the earliest ancestors of humans have only been on the planet for 6 million years, while the last dinosaurs died out 65 million years ago

There is a religious split on this question. While most Americans who describe themselves as 'born again' (56%) believe that humans and dinosaurs once shared the planet, most Americans who do not describe themselves as born again (51%) think that they did not. Only 22% of born again Americans think that dinosaurs and humans did not coexist.

When asked about the science that provides the fictional basis for the Jurassic Park movies, most Americans (54%) say that it is not currently possible to create dinosaur clones from DNA found in fossils while 28% believe that it is currently possible. Half the public also say that if there were a theme park like Jurassic Park, they would not go to visit while 40% say that they would.

The Jurassic Park movies have been widely watched. 71% of Americans say that they have seen the original and at least a third of the public have seen the earlier two sequels, The Lost World (43%) and Jurassic Park III (36%).


Source: today.yougov.com (2015)

Could Modern Humans Survive an Asteroid Impact, Like What Killed the Dinosaurs?

Friday, January 19, 2018

Meteorite impact

We know that an enormous meteorite hit the Gulf of Mexico some 66 million of years ago, shooting dangerous gases, dust, and debris into the upper atmosphere, blotting out the sun, and killing off most of the plant life on Earth. Large herbivores followed and eventually the carnivores that preyed upon them. Note however that one recent, exhaustive study found that many of the dinosaurs were already in decline, way before the bolide or meteorite’s impact.

Had the asteroid hit just 30 seconds later (or sooner), landing more in the Atlantic or Pacific, rather than just off the coast of Mexico, we may have had more, non-avian dinosaurs running around today. Instead, the bolide smashed into the Earth with a force equivalent to ten billion nuclear bombs.

Our ancient, tiny mammalian ancestors survived, their rodent-like bodies cowering as they witnessed one of the greatest mass extinction events ever to occur on our planet. Of course, they probably didn’t have brains developed enough to fully comprehend it. Besides the stench of death filling the air and the massive bodies piling up hither and yon, acid rain fell and volcanic eruptions shook the Earth, sullied the air, and scarred the landscape.

Smallness and requiring little food helped our ancient, shrew-like ancestors survive, which begs the question, could we modern humans make out okay if such an event happened today? Research surrounding another, similar incident suggests so, but it’s complicated. Around 790,000 years ago another asteroid about a kilometer (approx. 0.62 mi) long struck the Earth with such a force that it sent debris hurtling into the atmosphere, which ended up covering one tenth of the Earth’s surface. The crater has yet to be found. Scientists say it would be about 40–100 km (approx. 24-62 mi) in diameter.

Barringer crater: The impact site of the meteorite that struck nearly 800,000 years ago hasn’t been found. Credit: By USGS/D. Roddy.

What’s been unearthed are these glassy rocks called tektites. Larger varieties can weigh up to 20 kilograms (44 lbs.).  Scientists recently analyzed these stones. Their findings were published in the journal Geology. This was the largest such event to occur during the time when humans were known to be on Earth and evolving (as they always are). Researchers say the event gives us clues as to whether modern humans could survive a dinosaur-size cataclysm today. The answer is yes, but it would be difficult.

So far, tektites have been found in Australia, Asia, and Antarctica. In this study, astrobiologist and geochemist Aaron Cavosie of Curtin University in Australia, along with colleagues, looked into the chemical makeup of three tektites found in Thailand. Researchers studied minute crystals of zircon, each about the width of a human hair, within the tektites.

These showed signs of the rare mineral reidite, which disappears seconds after being formed. “Reidite requires substantially higher shock pressures to form,” Cavosie said. High temperatures are needed as well. The orientation of the zircon in the tektites points to an impact occurring somewhere in Southeast Asia, probably near Thailand. Though these samples tell a lot, what’s missing is the exact location of the impact site. It’s mind-boggling that such a large crater has yet to be found.

Tektite found in the Libyan Desert. Credit: James St. John. Flickr.

“Our not-too-distant ancestors witnessed this impact,” Cavosie said. “They might have been dragging their knuckles, but an event like the formation of a 50- to 100-kilometer-diameter impact is sure to have gotten their attention.” Further studies examining tektites may yet reveal the crater’s location.

Even though this was a catastrophic event, our ancestors were able to survive and thrive, as the debris shot up into the atmosphere must've caused significant changes to the climate. How this influenced our ancestors and perhaps changed the course of human evolution is difficult to discern, though more clues may help us get a better understanding of that.

So what if a comet or a serious asteroid collided with the Earth? Most scientists say our planet is threatened by such an asteroid about every million years or so. We’re not due for one any time soon. Most of the asteroids out there lie between Mars and Jupiter and won’t threaten Earth ever.

There are thousands though which could potentially hit us. Most are the size of a compact car or smaller and burn up in the atmosphere. A few are a bit larger and could do great damage to say a house or even a city, depending on the size, but wouldn’t threaten all life on Earth or anything.

NASA’s Planetary Defense Coordination Office (PDCO) tracks near-Earth objects (NEOs) of significant size with the potential to hit our planet. It’s a collaborative effort involving observatories and universities all over the world. The perennial question is whether or not an asteroid looks as if it’s inside the “keyhole,” meaning it has the potential to make impact with Earth.

Besides a collision, a sizeable object passing close by the Earth could throw the planet’s orbit off. So far, deflection strategies haven’t been decided upon. Planting a nuclear bomb inside a potentially hazardous asteroid, or nudging it off course with rockets or a solar sail, are some other the methods that have been proposed.

Should we fail and a large asteroid once again crash into our world, causing a long-term impact winter, most of the plant life would die off within weeks. Large trees could last decades due to a buildup of sugar in their systems and a slow metabolism. Not much life would exist beyond that, save for microbes and small creatures.

Humans could survive if they went deep underground to take advantage of heat found there, or if we built isolated habitats inside domes. Of course, it’s best to safeguard our precious planet. And although attaching a solar sail to an asteroid may sound fantastical, most scientists believe it’s feasible, using technology that’s already available today.

Source: http://bigthink.com

Is the Dinosaur Family Tree Becoming a Dinosaur?

Saturday, November 11, 2017

Dinosaur Family Tree

The division of dinosaurs into two groups, a taxonomy that dates back to the Victorian era, is looking increasingly shaky to some paleontologists in light of a wealth of new fossil discoveries.

The dinosaur family tree has two main branches: the bird-hipped dinosaurs and the lizard-hipped dinosaurs. Paleontologists have built upon this idea for nearly 130 years. Textbook writers know it. Museum curators know it. Even children know it.

But what if it’s wrong? What if the established dinosaur family tree is, well, a dinosaur?

That question has sparked a heated debate among paleontologists. The Victorian-era model now has a formidable rival.

The debate reverberates beyond paleontology, as learning about dinosaurs often marks our first interaction with evolutionary biology. So as the scientists delve into the data, they open a window for the public to view how scientific models change.

“Just because we grew up with these ideas doesn’t mean that that’s set in stone,” says Peter Makovicky, associate curator at the Field Museum in Chicago. “We have to continuously revisit the evidence.”

It began in March. With all the new dinosaur fossils – just last year saw 36 new species described – it’s time to rethink the structure of the dinosaur family tree, according to Matthew Baron, who was a PhD student at the University of Cambridge at the time. After examining a massive dataset of dinosaur fossils, Dr. Baron and his advisors proposed a new model, placing the typically two-legged lizard-hipped theropods (like Tyrannosaurus) on a branch with the bird-hipped dinosaurs (like Stegosaurus and Triceratops), and the four-legged lizard-hipped, long-necked sauropods (like Brontosaurus) off on their own branch.

That shake-up of the dinosaur family tree set off a whirlwind of press activity and a flurry of exchanges among paleontologists. But we shouldn’t rewrite the textbooks just yet, say another group of paleontologists, in a paper published Wednesday in the journal Nature. This team, led by Max Langer of the Universidade de São Paulo in Brazil, reexamined the data underpinning the Baron et al. paper and concluded that the traditional dinosaur family tree should still stand – at least for now.

But the debate is still far from settled. This responding study actually found support for both models. The difference was “statistically indistinguishable,” says study co-author Steve Brusatte of the University of Edinburgh, although the results slightly leaned toward the traditional model.

The Victorian model

That family tree traces its roots back to 1888, when a British paleontologist, Harry Seeley, proposed that the distinction between dinosaur groups hinged on the hips. Seeley noted that all the dinosaur hip fossils on hand could easily be sorted into two groups determined by whether their pubic bones pointed forward or backward. Those that pointed forward resembled the hips of lizards, so Seeley dubbed that group saurischians (“lizard-hipped”). Likewise, the ornithischians (“bird-hipped”) had backward pointed pubic bones resembling those seen in birds.

Left: The traditional dinosaur family tree, with sauropods and theropods (both considered “lizard-hipped” dinosaurs) more closely related than ornithischians (“bird-hipped” dinosaurs). Right: The dinosaur family tree proposed by Baron et al. in March, 2017. Here, ornithischians (like Stegosaurus, Triceratops, Iguanodon) share a branch with theropods (like Tyrannosaurus). The long-necked sauropods (like Diplodocus) have their own branch. Courtesy of the University of Cambridge

So what does it take to overthrow a scientific model?

“Right now we’re at a point where we don’t really know with a lot of confidence” what the best model is, Dr. Brusatte says. “There have been so many new fossils, and now there are new datasets and some new techniques that are being used, and it’s thrown everything up into the air.”

What’s a paleontologist to do? The dinosaur family tree, or phylogeny, as scientists call it, underpins the major questions about how these creatures came to rule the Earth millions of years ago. And toppling an established scientific model is no easy feat.

“When you propose such a radical change to a well-established idea, you need very strong evidence,” Dr. Langer writes in an email. “The evidence they were putting forward in support of their model was not as strong as necessary to overthrow decades of studies pointing to another direction.”

Baron and his colleagues penned a rebuttal to the new paper. Still, Baron hopes that the debate will ultimately transcend the back-and-forth of papers and that all the scientists will find a consensus as a team.

For living animals, building phylogenies can be a bit less controversial, because the animals’ genomes are available. And that foundation can reveal surprising relationships. For example, genetic research in 2014 revealed that a tiny shrew that lives in Namibia is actually closely related to elephants.

But when it comes to dinosaurs, all paleontologists have to work with is appearance. DNA degrades too quickly to have lasted the millions of years that have elapsed since the dinosaurs went extinct (sorry, “Jurassic Park” fans). And bones and footprints can be ambiguous.

“It doesn’t mean that we’re making it up,” Brusatte says. “It just means that it’s going to be different depending on which human is looking at these bones and trying to make sense of them.”

With so many dinosaur fossils turning up around the globe, paleontologists have to rely heavily on each others’ descriptions of a new specimen to classify where the species fits in. And that’s where the disagreements come in, right at the root of the discussion.

For more than a century, paleontologists largely sought to place each new find somewhere on the tree that grew out of Seeley’s categorizations. Baron says that when a fossil wasn’t a perfect fit, “we always tried to shoehorn the new find into the old model somehow.”

A ‘Rosetta Stone’ fossil

Could there be some sort of Rosetta Stone fossil that sits just at the right point in the Triassic period, when dinosaurs first emerged, that could resolve the debate? Possibly, says Brusatte. If that animal had a mix of features distinctive of both ornithischians and theropods, then that would be evidence that Baron and his colleagues are correct.

But evolution itself could confound such a revelatory find. Sometimes two unrelated species can undergo convergent evolution, a process by which two different animals independently evolve a similar trait. For example, birds have backward oriented pubic bones (aka bird hips), and they’re dinosaurs. But they are not ornithischians (“bird-hipped” dinosaurs). Birds actually evolved from the theropod lineage, which is one of the two main groups classified as “lizard-hipped.”

Furthermore, evolution isn’t linear, it’s bushy and has many dead ends. In other words, a fossil with features of two different groups might not be in the middle of a transition from one to the other. And because not every organism is preserved in the fossil record, determining what is and is not a dead end can be tricky.

“There’s a lot of gray areas and a lot of debates, and there’s a lot of things that we just don’t know. It’s not because we have no evidence. It’s not because we’re not looking. It’s because we have so much evidence that it’s kind of conflicting, and we have to find a path through that chaos.” says Brusatte. “At the end of it all, something might emerge, some kind of consensus, but it might not be for a while.”

Despite the dramatic headlines, a new dinosaur family tree might not actually be a scientific revolution, says Derek Turner, a philosopher of science at Connecticut College. “I do think it would be a pretty significant change if the new model catches on,” he says, as it will open up new questions about dinosaur evolution. “But I think a lot of the upheaval would be more on the public understanding side.”

Dr. Makovicky, who was not an author on either paper, agrees. For many children, this is the first evolutionary family tree they learn about from the deep past, he says. And that divide between bird-hipped and lizard-hipped dinosaurs is deeply entrenched in books and museum displays.

But just as dinosaurs have long helped engage children and adults alike with science, this debate can help communicate a key piece of how science works. “Science is not just pushing the boundaries of what we can call new knowledge,” Makovicky says. “A big part of science is actually self-correction and revising things that we assumed we knew.”

Source: NatGeo.com

Which Dinosaur Was the Biggest?

Thursday, October 19, 2017

Which Dinosaur Was the Biggest?

How big was the biggest dinosaur?

Previously, three different species had claim to the biggest dinosaur. The Supersaurus vivianae was the longest at 111 feet. The Sauroposeidon proteles was the tallest at 55 feet, and the Argentinosaurus was the heaviest at 60 tons. A recently discovered dinosaur beats all of these records and holds the title for all three categories!

This dinosaur, the Patagotitan mayorum, was discovered by a farmer in Argentina when he stumbled upon the fossils in 2014. After excavating and studying the fossils of seven individuals, the paleontologists published their results this summer.

They estimated that the Patagotitan weighed between 65-77 tons. That’s heavier than a Boeing 737 airplane and about as much as 12 African elephants. It also beats the height and length records, standing 65 feet tall and over 120 feet from head to tail. One of the fossils found, a femur, was eight feet long, which is taller than a man!

The fossils found for the Patagotitan are more complete than any other titanosaur, a group of massive dinosaurs. This allowed the palaeontologists to make more accurate predictions about the size of the dinosaur.

Fun fact: The Patagotitan was an herbivore and possibly ate up to 2,000 pounds of food daily because it was so large!

Source: columbiatribune.com

What if Dinosaurs Hadn’t Died Out?

Tuesday, September 19, 2017

What if Dinosaurs Hadn’t Died Out?

Imagine a world where an asteroid hadn’t wiped out the dinosaurs. What would have happened afterwards – and how might their presence have affected mammals like us?

 It was the kind of cataclysm that we can scarcely imagine. When an asteroid 15km-wide (nine miles) slammed into planet Earth 66 million years ago, it struck with a force equivalent to about 10 billion Hiroshima bombs. A radioactive fireball seared everything for hundreds of miles in every direction and created tsunamis that sped halfway around the globe. Even the atmosphere may have started to burn, and no land animal more than 25kg (55lb) would survive; in fact, around 75% of all species became extinct. The so-called ‘non-avian’ dinosaurs didn’t have a hope, and only the small, feathered flying dinosaurs we know today as birds would make it through.

But what if history had taken a different course? What if the asteroid had missed or arrived a few minutes earlier? That is the scenario suggested by researchers featured in The Day the Dinosaurs Died, a recent BBC documentary. These scientists – including geologist Sean Gulick of the University of Texas – argue that if the asteroid had arrived mere moments earlier or later, rather than hitting the shallow waters of Mexico’s Yucatan Peninsula, it would have plunged into the deep sea of the Pacific or Atlantic oceans, absorbing some of the force and limiting the expulsion of sulphur-rich sediments that choked the atmosphere for the months or years ahead.

Had that been the case, there would still have been a catastrophe and extinctions, but some larger dinosaurs may have survived. Pondering the course of this alternative timeline is an intriguing thought experiment that dinosaur scientists are only too enthusiastic to speculate about. Would dinosaurs be here today? What new dinosaurs might have appeared? Would dinosaurs have developed human-like intelligence? Would mammals have remained in the shadows? Would humans have evolved and – as depicted in Disney’s 2015 film The Good Dinosaur – found a way to survive alongside them?

Giant pterosaurs with enormous wingspans could dominate the skies (Credit: Getty Images)

Some researchers argue that, even without the asteroid, the reign of the dinosaurs may already have been ending. “I take a slightly unorthodox view that dinosaurs were doomed anyway because of cooling climates,” says Mike Benton, a palaeontologist at the University of Bristol in the UK. “They had just about held their own to the end of the Cretaceous, but we know that mammals were diversifying… [and] dinosaurs had already been declining for 40 million years.” Benton believes mammals would still have replaced the dinosaurs. He is an author of a 2016 paper suggesting dinosaurs were slower than mammals at replacing extinct species.

Other experts take a very different view. Carnivorous dinosaur researcher Tom Holtz at the University of Maryland in College Park, US, agrees there would have been some extinctions 66 million years ago anyway, due to eruptions and massive lava flows at the Deccan Traps in India – but he says “there’s nothing otherwise, once you’re into the Palaeocene and Eocene, that would have affected general dinosaur biology. It would be a world that Cretaceous dinosaurs would still be comfortable in.”

Stephen Brusatte of the University of Edinburgh adds that dinosaurs had survived well, doing a great diversity of things, through changing climates, for 160 million years. “Dinosaurs were still very adaptable at the end of the Cretaceous, that’s not the sign of a group that’s wasting away to extinction, just waiting for some asteroid to knock them off. It’s the sign of a group that still has a lot of evolutionary potential.”

Assuming dinosaurs had survived, what factors might have shaped their evolution? Climate change might have perhaps been the first big hurdle. An event known as the Palaeocene-Eocene Thermal Maximum, 55 million years ago, saw average global temperatures reach 8C hotter than today, and rainforests spanning much of the planet.

Triceratops (Credit: SPL)

In this hothouse world with abundant vegetation perhaps many long-necked sauropods might have grown more rapidly, breeding at a younger age and shrinking in size; several ‘dwarf’ sauropods (some little bigger than a cow) were already known from European islands in the late Cretaceous. The largest titanosaurs of mid-Cretaceous South America – 40m-long (131ft) creatures heavier than two jet aircraft – were already long gone.

Another trend in the later Cretaceous was the rise of flowering plants or angiosperms. During the Jurassic, most plants were ferns and gymnosperms (which include ginkgoes, cycads and conifers). These tend to be less nutritious than angiosperms, and the huge size of sauropods may have been driven by the processing time and gut size needed to digest them efficiently.

“If plant evolution continued as it has in our modern world, the herbivorous dinosaurs would almost certainly have had a diet primarily of flowering plants,” notes Matt Bonnan a palaeontologist at Stockton University in New Jersey. “Given that they are somewhat easier to digest, perhaps we would have seen an overall decrease in body size… the gigantic sizes of Mesozoic dinosaurs might have disappeared.”

Along with flowering plants came fruit, which co-evolved with mammals and birds to help plants disperse seeds. Might monkey-like dinosaurs have evolved to take advantage of this resource, just as primates did in our timeline? “Many birds eat fruit. So, there may also have been non-bird dinosaurs adapted to a frugivorous diet,” says Bonnan.

Brusatte agrees that some “small, feathered dinosaurs might have gone the route of primates,” as some were already scampering about in the branches. Others may have become nectar-drinkers, spreading pollen from flower to flower in the process.

Tyrannosaurs might have hung on until the present day (Credit: Getty Images)

Another major event, about 34 million years ago at the Eocene-Oligocene boundary, was the separation of South America and Antarctica. This caused a circumpolar current to develop, leading to the formation of the Antarctic ice cap and cooling and drying the world. During the Oligocene, and later the Miocene, grasslands then spread across great swathes of the planet.

“Slender-legged, fast-running, herbivorous mammals became common – in the past you could amble or leap off and hide, but you can’t hide in the open grasslands,” Holtz says. This is when, in our history, we started to see a burst in the diversity of hoofed, grazing animals and the carnivores that preyed upon them.

Darren Naish, a vertebrate palaeontologist in Southampton, UK, says that perhaps in our alternative timeline the speedy, grass-mowing dinosaur equivalents would be descendants of horned relatives of Triceratops or bipedal, beaked herbivores akin to Hypsilophodon.

“Dinosaurs already come with a huge set of evolutionary advantages that it took mammals a long time to evolve,” he adds, and would have a head start at adapting to grasslands. Duck-billed hadrosaurs had ‘batteries’ of up to 1000 teeth in their jaws, as opposed to the 40-odd teeth a horse has, so could have made short work of grinding grasses.

Dinosaurs also had better eyesight than mammals, with increased colour vision, and may have been more adept at spotting danger. Horses and cows have flattened muzzles useful for cropping tough, low-lying vegetation, so duck-bills and sauropods might also have developed squared off snouts, and sauropod necks might have shortened to aid grazing at their feet.

Even closer to the present day, dinosaurs would have had to deal with the various ice ages of the past 2.6 million years. But we know that Cretaceous dinosaurs were living above the Arctic Circle. “Maybe in cooler places you would see things with thick and elaborate pelts, covered in fuzz and feathers all the way down to the tips of their toes and tails,” says Naish.

“It wouldn’t have been difficult for a ‘woolly’ tyrannosaurus or dromaeosaur relatives of Velociraptor to evolve,” adds armoured dinosaur expert Victoria Arbour of the Royal Ontario Museum in Canada. “Maybe we could have even had shaggy and woolly ceratopsians, ankylosaurs, or hadrosaurs.”

There are other adaptations common today but rare in dinosaurs. Burrowing for example, says Paul Barrett, a palaeontologist at the Natural History Museum in London. “It’s odd that dinosaurs didn’t really do it, as it’s a common way of life among lizards and snakes.” Given more time, some dinosaurs might have become subterranean specialists – the scaly or feathery equivalent of mammalian moles.

Model dinosaur surrounded by people (Credit: Getty Images)

The oceans are another realm little explored by dinosaurs. Species such as Spinosaurus were dabbling in estuarine and river environments, and armoured ankylosaurs are often found as fossils in marine sediments and were living along coastlines. Could spinosaurs or ankylosaurs have followed the path of mammalian whales and evolved to live entirely at sea? They might have returned to land to lay eggs or could have eventually given birth to live young at sea, as ichthyosaurs and plesiosaurs did.

In a world that never lost the dinosaurs on land, pterosaurs in the sky and ichthyosaurs and mosasaurs at sea, what would have been the fate of birds and mammals?

Birds were already diverse in the late Cretaceous. “Pterosaur diversity had been really knocked back,” says Holtz, perhaps because of this. Remaining pterosaurs included the massive, toothless azhdarchids, some of which were the size of biplanes with wingspans of 12m (40ft). There is already a debate about whether some azhdarchids were flightless, and you can imagine a world where islands, such as Madagascar, Mauritius and New Zealand, are dominated by strange terrestrial pterosaurs, much as in our timeline they were once the province of flightless elephant birds, dodos and giant moas.

Naish argues that a dinosaur world might still have much of the present diversity of modern birds. Mammals, however, are a different story. Though they had already been around for perhaps 160 million years when the asteroid struck, they were still “marginal, shadowy little creatures” says Brusatte, diverse but typically small and restricted to specific niches. “It was only the shock of the asteroid knocking off the incumbent dinosaurs that allowed them to break free,” he says.

Others disagree, accepting that large megafauna might not have had a chance, but bats, rodents, small carnivores and climbing primates and possums could all have been plentiful. If marmosets, langurs and gibbons had swung through the branches while dinosaurs browsed around them, might not something akin to hominids also have evolved?

“Some of the mammal lineages were already evolving before the extinction event,” says Naish. “In view of that, you’d probably still get primates and… [perhaps] a version of humanity. Given that we evolved in a world full of giant mammals, it’s plausible.”

Holtz agrees it’s a possibility: “You could have had some tree-dwelling primates that, as grasslands expand, they move into that habitat and become the pseudo-humans of this alternative universe. And just as our ancestors had to deal with sabretooth cats and big antelope, these guys would have to deal with the dromaeosaurs and abelisaurs.”

Natural History Museum dinosaur skeleton (Credit: SPL

People would have had to create protected places, which Naish admits has a One Million Years BC spin to it”, but he points to the fact that our own ancestors lived alongside large dangerous animals and had to come up with strategies to survive. “People think the Mesozoic world was a continual bloodbath, where you get ripped to shreds within seconds, but a lot of the time big predators are sparsely distributed and the world is relatively safe if you stay out of their way.”

Given that intelligent mammals are possible, could sentient dinosaurs also have evolved? In 1982, Dale Russell – then at the Canadian Museum of Nature in Ottawa – published a paper proposing that an intelligent ‘dinosauroid’ might one day have evolved. He commissioned a life-sized model, which today looks like an alien from a dated sci-fi show, with green skin and huge eyes. His theory was that the carnivorous dinosaur Troodon had an unusually large brain and might have been the lineage from which brainy dinosaurs evolved.

“Dinosaurs equivalent to crows, parrots or primates, with very complex brains and problem-solving abilities might have evolved,” agrees Holtz, but he doesn’t believe dinosaurs could ever have looked like humans. “The pathway to humans was really odd and involved hanging in trees and so forth… dinosaurs got to bipedality and manipulative hands in a much more reasonable approach.”

“I don’t think you would get anything approaching human-level intelligence,” says Naish. “You might get big-brained, intelligent dinosaurs, but they would still look like dinosaurs… It’s anthropomorphic to assume that other kinds of human-like intelligence would have evolved.”

Assuming dinosaurs did make it through to the last few hundred thousand years, and lived alongside humans, could they have survived to the present day? The answer seems to be yes. But just as humans hunted mammoths and other megafauna to extinction, our population growth and hunting technologies would inevitably have taken a toll on big dinosaurs as we spread across the globe. “There could have been a Pleistocene dinosaur megafaunal extinction event, as the humans migrate out of whatever corner of the world they came from,” Holtz says.

In the present day in this alternative timeline, perhaps a few species of large herbivorous sauropods, and even carnivores similar to T. rex, might hang on in protected wildernesses and national parks vast enough to fit their home ranges. They would have to be truly vast wildernesses though, with little human development, in places like outback Australia and Alaska. Maybe some of the smallest non-avian dinosaurs would have adapted to urban environments, thriving alongside people in the cities, as pigeons, rats and seagulls have in our world.

Though in our own past, large mammals were mostly wiped out, a few, such as elephants and rhinos hang on, so perhaps it’s not too much of stretch to imagine a parallel world where today you could hop on a dinosaur safari, Jurassic Park-style, and enjoy spotting some of them, cameras and binoculars at the ready.

John Pickrell is the author of Flying Dinosaurs and Weird Dinosaurs.

Source: bbc.com

10 Common Myths About Evolution

Sunday, September 10, 2017

Evolution is the single most important concept in all of biology. It is absolutely vital for understanding both the history of life on earth and why our modern organisms have their current traits and behaviors. Nevertheless, it is also one of the most misunderstood concepts in modern science. Much of the confusion stems from creationists’ faulty arguments, but even those who accept evolution often don’t really understand it. Therefore, I am going to describe and debunk ten of the most common myths and misconceptions about evolution.


Myth 1: Evolution is just a theory

This is arguably the most common myth about evolution, and it is probably creationists’ most well worn trope. It is also a fundamental misunderstanding of how science works. Briefly, evolution is both fact and theory depending on exactly what we are talking about. The idea that all modern organisms (including humans) evolved from a single celled organism over a period of millions of years is a scientific fact. It has been confirmed by the fossil record, genetics, biogeography, etc. Like it or not, it’s a fact, but there is also a theory component. You see, theories explain facts. So, the theory of evolution by natural selection states that natural selection has been the dominant mechanism causing species to evolve. In other words, it is a fact the evolution occurred, and the theory of evolution by natural selection explains how that evolution occurred. Indeed, it is a common misconception that Charles Darwin came up with the idea of evolution. In reality, many scientists before him thought that organisms evolved, but they couldn’t figure out how or why they evolved. So, what Darwin (along with Alfred Russel Wallace) did that was so extraordinary, was to provide a mechanism that drove evolutionary change (i.e., natural selection).

Finally, it is worth noting that theories are actually among our highest forms of scientific certainty. They have been rigorously tested and consistently make accurate predictions. So gravity (i.e., the theory of universal gravity), the idea that all matter is made of atoms (i.e., atomic theory), the idea that all living things are made of cells (i.e., cell theory), the idea that bacteria make you sick (i.e., the germ theory of disease), etc. are all “just theories.”


Myth 2: We evolved from monkeys/apes

We did not evolve from modern apes, but we share a common ancestor with them. In other words, if we back the clock up a few million years, we will find an ape-like ancestor whose populations split, and different groups went down different evolutionary paths. One group evolved into us, and another group evolved into chimps. So we and chimps share a great, great, great…great grandparent who went extinct a few million years ago, but we did not evolve from chimps, monkeys, or modern apes.


Myth 3: Evolution conflicts with the second law of thermodynamics

People often describe the second law of thermodynamics as, “the disorder of a system always increases,” which leads people to erroneously claim that evolution violates the second law because it says that overtime life becomes more organized. The problem is that the above definition is a terrible one which misrepresents the law and overlooks several key components.

The best way to understand the second law is in conjunction with the first law. The first law (also known as the law of the conservation of energy) states that energy cannot be created or destroyed, but it can change forms (e.g., it can go from potential energy to kinetic energy). The second law then describes the natural flow of energy within a system (i.e., the direction in which the changes take place). Both of these are dealing with energy states, and taken together, they say that a system cannot go from a low energy state to a high energy state without the input of additional energy. The classic example of this is a diving board. Someone standing on a tall diving board is in a higher energy state (i.e., they have more potential energy) than someone standing at the bottom of the ladder. So, to a physicist, the person at the bottom is more “disorganized” than the person at the top, because the person at the top has more potential energy. In technical terms, this concept of disorganization is known as entropy, and the person at the top of the board would have less entropy than the person at the bottom.

Notice, these laws do not state that it is impossible for systems to go from a low energy state to a high energy state. Rather, they say that the transition cannot take place without the input of additional energy. In other words, it is completely possible for the person at the bottom of the ladder to climb up onto the board and reach a higher energy state (i.e., become more organized/have less entropy), but doing so requires an input of energy (i.e., they have to use energy to move their muscles and climb the ladder). Another way to describe this is to say that a closed system cannot become more organized, at least in the long term (a closed system is one that receives no energy from outside sources). These laws do not, however, state that an open system cannot become more organized (an open system is one that does receive energy from outside sources).

Now, let’s apply all of that to evolution. The earth is most definitely an open system. It is constantly receiving energy from the sun. In fact, the sun drives nearly all life on earth. So, since the earth is an open system, there is no conflict between evolution and the thermodynamics. Let me use an example to prove that. I think we can all agree that a tree is more organized (has a higher energy state) than a seed. So, if thermodynamics worked the way that creationists claim, it should be impossible for a seed to grow into a tree, but it clearly is possible for seeds to grow. Why? Quite simply, because the earth is an open system. Even so, it is entirely possible for life to become more organized because organisms are constantly receiving energy from the sun (or from food which grew because of energy from the sun). So there is no conflict between evolution and thermodynamics.


Myth 4: We haven’t found any “missing links”

In each of those cases, we have multiple fossils that are exactly what we would expect if evolution was true, and the only way that you would reject the notion that these are intermediates is if you were already convinced that intermediates don’t exist. This is the fundamental problem with creationism (and a big part of why it is pseudoscience). Creationists have determined ahead of time that no intermediates exist, so no matter how perfect a transitional fossil may be, they will always claim that it is just a unique species that happens to look like a transitional. The term “missing link” is a misnomer because they aren’t missing. We have hundreds of fossils that clearly represent transitions between two groups of organisms. Creationists invariably claim that these fossils are simply uniquely created organisms that happen to look like transitions, but this is a clear and enormous ad hoc fallacy because evolution predicted the existence of these fossils. If, for example, I asked you to describe what an intermediate between a turtle and its lizard-like ancestor would look like, you would inevitably describe a creature with half the features of a lizard and half the features of a turtle (e.g., a partially formed shell, a turtle like skull that still retains lizard like teeth, a somewhat specialized neck, etc.). Well guess what, that’s exactly what we see in the fossil record with species like Odontochelys and Pappochelys which have some lizard features and some turtle features. Similarly, if I asked you to describe an intermediate between a dinosaur and a bird, you would probably describe a featured dinosaur with partially formed wings and some skeletal modifications like an enlarged breastbone, but which still retains some dinosaur features like teeth. Indeed, the creature that you are imagining closely matches fossils like ArchaeopteryxConfuciusornis, and Jeholornis. The same is true for the transition for fish to amphibians, amphibians to reptiles, reptiles to mammals, etc.

Myth 5: Evolution isn’t science because it hasn’t been observed/repeated

First, we have to specify what we mean by “evolution.” You see, evolution on a small scale has been observed numerous times. Bacteria evolving resistance to antibiotics is the most well-known example of this, but there are many others. For example, we have been able to observe finches on the Galapagos evolve and change their beak sizes in response to droughts (Grant and Grant 2002). We have even been able to observe entirely new species form.

Nevertheless, when most people make this claim, there are generally referring to evolution over a long period of time. In other words, they are saying that we have not observed or repeated something like a relative of the T. rex evolving into a chicken. First, it is important to realize that there is no real difference between “microevolution” and “macroevolution.” Macroevolution is just an accumulation of microevolutionary steps. So if evolution on a small scale occurs (as has been observed and experimentally demonstrated) then ipso facto, evolution on a large scale occurs. One inevitably leads to the other.

Finally, the idea that we have to directly observe something and repeat the event itself in order for it to be science is a fundamental misunderstanding of science. Most science is not based on direct observation of the actual event of interest. Rather, we observe clues that are left behind by the event, and we infer information about the event from them. For example, no one has directly observed two hydrogen atoms joining an oxygen atom to form a water molecule, but we know that it happens because we can conduct chemistry experiments which give observable results that we can use to infer the sharing of electrons that lets those atoms combine. Similarly, we constantly solve crimes without either observing or repeating them because there are clues left behind that we can use to infer who committed the crime (this is known as forensic science). Even so, we do not need to observe a dinosaur evolving into a bird to know that it happened because there are clues left behind in the fossils, DNA, etc., which we use to infer evolution. There is nothing unscientific about that, and, in fact, it is how most science works. We make predictions like, “if and only if birds evolved from reptiles, then birds should share more DNA with reptiles than any other group.” We then test those predictions, and when they consistently come true, we conclude that our hypothesis is most likely correct. That is the scientific method at its finest.


Myth 6: Individuals evolve

Populations evolve not individuals. Evolution is just a change in the genetic composition of a population over time, so, since individuals cannot change their genetic composition, they cannot evolve. For example, if a drought comes along and destroys all seed-bearing plants except for ones with very large seeds, an individual bird with a small bill cannot evolve in response to that drought. In other words, it cannot change its genetic makeup and alter its bill size to eat the large seeds. In biological terms, it cannot adapt. As a result, the birds that have small bills will get less food and produce less offspring than the birds with large bills. This means that there will be more genes for large bills in the next generation. So the population will evolve and adapt to the drought, but the individuals will not evolve.


Myth 7: Evolution has a direction or goal

People often talk about evolution “trying to accomplish” something, or they may describe primates and other mammals as being “more evolved” than other animals, but statements like that are extremely problematic because they inherently imply that evolution has a direction or goal, which it doesn’t. Biologist often like to say that, “evolution is blind.” All that evolution can do is adapt an organism for its current environment and way of life (I’m talking specifically about evolution by natural selection here). Evolution has no foresight, and it is completely incapable of predicting what will be useful in the future, so a trait that has been selected for thousands of generations may suddenly become harmful if the environment changes.

Because evolution just adapts organisms to their current environment and way of life, it doesn’t really make sense to describe one species as “more evolved” than the other. For example, a monkey is not “more evolved” than the fly that gets its moisture from the monkey’s poop. The monkey is certainly more complex, but it’s not really more evolved because both the monkey and the fly are extremely well suited to their way of life. If you try to say that the monkey is more evolved than the fly, then you are implying that evolution has a direction, which it doesn’t.

Finally, this explains the common creationist criticism that certain species have “evolved backwards” (e.g., penguins lost the ability to fly, whales went back into the ocean, etc.). This again assumes that evolution has a direction or goal, when in reality, it’s just adapting organisms to their current environment. So, at one point in time, flight was useful so evolution selected for it and produced flying birds, but as those birds invaded the antarctic, the ability to fly was not as important as the ability to swim and stay warm, so evolution selected against adaptations for flight and produced penguins.


Myth 8: Some systems are too complex to evolve

This is one of the oldest criticisms of evolution, and it has recently resurfaced under the moniker “irreducible complexity.” The basic idea is that some systems are too complex to evolve because they aren’t functional until all of the parts are in place. For example, an eye that is missing a single piece no longer sees, and a bacterial flagellum that is missing a single protein can no longer act as a flagellum. So the argument claims that these systems could not have evolved because there would have been steps that served no useful function, and nature could not have selected for those steps. The problem is that this argument ignores the fact that evolution is blind. Traits don’t need to function for some ultimate final product in order to be selected for. Rather, if they provide any useful function at all, nature will select them. Indeed, no one has ever been able to find a truly irreducible system, and we have evolutionary pathways that explain how complex systems evolve. For example, an early precursor of the eye would have simply involved a few light sensitive cells (much like some flatworms have). They don’t function as an eye, but they still function, so nature will select for them. Similarly, the proteins that make up a flagellum all serve other functions in the cell, and we have even figured out a step-wise series of events that would form a flagellum with each step serving a useful function for the cell, even though only the final step actually serves as a flagellum. So there is just no truth to the notion that some systems are too complex to evolve.


Myth 9: Evolution describes the formation of the universe/the first cell

I often hear people argue that, “evolution isn’t true because blah, blah, blah…big bang” or some nonsense about how we haven’t figured out how the first cell formed. Beyond the specific issues with those arguments (which I won’t go into here), those arguments are totally irrelevant to evolution. The big bang theory deals with the formation of the universe, and abiogenesis deals with the formation of life. Evolution only comes into play after life formed. So, even if you managed to disprove the big bang or disprove abiogenesis, you would not have in any way shape or form disproved evolution. Indeed, there are some people who think that God created the first cell, then let evolution take its course. In other words, they reject abiogenesis but accept evolution (to be clear though, there is no good scientific reason to reject abiogenesis or the big bang).


Myth 10: Evolution is faith based

To anyone who makes this claim, I would like to know which part exactly you think is faith based. As I explained in #5, the fact that we did not directly observe millions of years of evolution doesn’t disqualify it as science. In fact, evolution is one of the most well supported ideas in all of science, and if you actually read Origin of the Species it is packed with evidence. Further, Darwin was an exceptional scientist and made clear predictions about what future researchers should find if his theory was correct. For example, he explicitly stated that we should find intermediate fossils, and we have (see #4). Think about that for a second. Evolution predicted the existence of organisms decades before we found them. That is an utterly incredible feat. Similarly, evolution predicted a strong agreement between the fossil record and genetics, and, once again, its predictions have come true with remarkable consistency. So if you are going to claim that evolution is based on faith, I want to know precisely what part of it you think is faith based, because there is no aspect of it which I cannot back up with empirical data.

Finally, it is worth noting that, contrary to popular perception, evolution is not inherently atheistic, rather, it is a scientific fact which is supported by an insurmountable mountain of evidence.

Source: sciencetoday.com

How Intelligent Were Dinosaurs?

Sunday, August 13, 2017

It is difficult to know how smart dinosaurs were because their brains rarely survive as fossils. Casts taken from the inside of fossil skulls show that some dinosaurs had large brains, while others had small ones. A big brain does not necessarily mean higher intelligence. Scientists look at the size of the brain in relation to the animal’s total body weight. They also take into account the animal’s behavior. A dinosaur’s intelligence was suited to its lifestyle and the tasks it needed to perform.

As smart as a cassowary?

Troodon was a keen-eyed hunter. It grew to 2 m (7 ft) long, and for its size, it had a large brain. This may have given it the mental capacity and sophistication to trap its prey. The cassowary has a similar build and brain size to Troodon, so it is possible the speedy dinosaur had the same level of intelligence as the modern bird.

Brain to body weight

Dinosaurs had smaller brains relative to their size than birds or mammals. Diplodocus had a brain weighing 100,000 times less than its body weight. Compare this with a small bird’s brain, which is only 12 times lighter than its overall weight. The brain of an adult human is about 40 times lighter than its body. This is about the same ratio as the brain to body weight of a mouse. These comparisons alone should not be used to indicate intelligence, which must also be judged on how animals behave in comparison with other animals in their environment.

If we can compare to mammals, T. rex intelligence is greater than a cat...

Dinosaur brain power relative to a crocodile’s

The Encephalization Quotient (EQ) is the ratio of the brain weight of an animal to the brain weight of a similar animal of the same body weight. The scale is designed so that the expected score for an animal is one. Anything above this figure indicates a larger than predicted brain size. The EQ number can be used to compare extinct and living animals and may be helpful in suggesting how smart an animal was.

This diagram plots the range of EQ scores for different groups of dinosaurs (shown by the coloured bands). These scores are compared to the scores for their living relatives, the crocodiles. The diagram shows the sauropods had low EQs. They have a narrow range of scores because the body weights and brain sizes of the dinosaurs in this group were quite uniform. The carnosaurs had scores between about 1 and 1.9. This group had a variety of body weights and brain sizes, and these account for the wide EQ range. The troodontids were the smartest dinosaurs with an EQ of around 5.8.


Source: NatGeo.com