Land plants older than than previously thought

This 2016 video says about itself:

Right at the beginning of the Paleozoic, there was a huge explosion of more complex life. And that’s when things started to get really interesting. This is our second installment on the history of life, but you can watch in any order you like!

From the University of Bristol in England:

Plants colonized Earth 100 million years earlier than previously thought

February 19, 2018

Summary: A new study on the timescale of plant evolution has concluded that the first plants to colonize the Earth originated around 500 million years ago — 100 million years earlier than previously thought.

For the first four billion years of Earth’s history, our planet’s continents would have been devoid of all life except microbes.

All of this changed with the origin of land plants from their pond scum relatives, greening the continents and creating habitats that animals would later invade.

The timing of this episode has previously relied on the oldest fossil plants which are about 420 million years old.

New research, published today in the journal Proceedings of the National Academy of Sciences, indicates that these events actually occurred a hundred million years earlier, changing perceptions of the evolution of the Earth’s biosphere.

Plants are major contributors to the chemical weathering of continental rocks, a key process in the carbon cycle that regulates Earth’s atmosphere and climate over millions of years.

The team used ‘molecular clock’ methodology, which combined evidence on the genetic differences between living species and fossil constraints on the age of their shared ancestors, to establish an evolutionary timescale that sees through the gaps in the fossil record.

Dr Jennifer Morris, from the University of Bristol’s School of Earth Sciences and co-lead author on the study, explained: “The global spread of plants and their adaptations to life on land, led to an increase in continental weathering rates that ultimately resulted in a dramatic decrease [of] the levels of the ‘greenhouse gas’ carbon dioxide in the atmosphere and global cooling.

“Previous attempts to model these changes in the atmosphere have accepted the plant fossil record at face value — our research shows that these fossil ages underestimate the origins of land plants, and so these models need to be revised.”

Co-lead author Mark Puttick described the team’s approach to produce the timescale. He said: “The fossil record is too sparse and incomplete to be a reliable guide to date the origin of land plants. Instead of relying on the fossil record alone, we used a ‘molecular clock’ approach to compare differences in the make-up of genes of living species — these relative genetic differences were then converted into ages by using the fossil ages as a loose framework.

“Our results show the ancestor of land plants was alive in the middle Cambrian Period, which was similar to the age for the first known terrestrial animals.”

One difficulty in the study is that the relationships between the earliest land plants are not known. Therefore the team, which also includes members from Cardiff University and the Natural History Museum, London, explored if different relationships changed the estimated origin time for land plants.

Leaders of the overall study, Professor Philip Donoghue and Harald Schneider added: “We used different assumptions on the relationships between land plants and found this did not impact the age of the earliest land plants.

“Any future attempts to model atmospheric changes in deep-time must incorporate the full range of uncertainties we have used here.”


Dinosaur age lizard footprints discovery

Scientists think that these fossilized footprints may represent the earliest evidence of a lizard running on two legs. Here, a front print (left) and a back print (right) are shown

By Helen Thompson, 1:19pm, February 15, 2018:

Fossil footprints may put lizards on two feet 110 million years ago

But the prints aren’t clear-cut, others say

Fossilized footprints from an iguana-like reptile provide what could be the earliest evidence of a lizard running on two legs.

The 29 exceptionally well-preserved lizard tracks, found in a slab of rock from an abandoned quarry in Hadong County, South Korea, include back feet with curved digits and front feet with a slightly longer third digit. The back footprints outnumber the front ones, and digit impressions are more pronounced than those of the balls of the feet. The lizard’s stride length also increases across the slab.

That’s what you’d expect to see in a transition from moseying along on four legs to scampering on two, says Yuong-Nam Lee, a paleontologist at Seoul National University who first came across the slab back in 2004. A closer examination two years ago revealed the telltale tracks.

Lee and his colleagues attribute the tracks to a previously unknown lizard ichnospecies, that is a species defined solely by trace evidence of its existence, rather than bones or tissue. Lee and his colleagues have dubbed the possible perpetrator Sauripes hadongensis and linked it to an order that includes today’s iguanas and chameleons in the Feb. 15 Scientific Reports.

Bipedal running certainly would have come in handy when escaping predatory pterosaurs some 110 million to 128 million years ago, the age of the rock slab. Lizard tracks are pretty rare in the fossil record, due to the reptiles’ lightweight bodies and penchant for habitats that don’t make great fossils. Though tracks appear in older fossils from the Triassic Epoch, 200 million to 250 million years ago, those prints belong to more primitive lizardlike reptiles. The new find edges out another set from the same region as the oldest true lizard tracks in the world by a few million years, the researchers say.

Plenty of modern lizards use two legs to scurry around. Some studies have linked similarities in ancient lizard bone structure to bipedal locomotion, but it is unclear exactly when lizards developed bipedalism. Lee’s team argues that these tracks represent the earliest and only direct evidence of bipedal running in an ancient lizard.

Martin Lockley, a paleontologist at the University of Colorado Denver who studies ancient animal tracks, points to alternative explanations. S. hadongensis might have trampled over front prints with its back feet, obscuring them and giving the appearance of two-legged running. Preservation can vary between back and front footprints. And the stride lengths aren’t quite as long as what Lockley says he’d expect to see in running. “Running or ‘leaping’ lizards make for a good story, but I am skeptical based on the evidence,” he adds.

So it may take the discovery of more fossilized lizard prints to determine whether S. hadongensis’ tracks truly represent running on two legs rather than simply scurrying on four.

Beewolf wasps’ health, from dinosaur age till now

This video says about itself:

Lifecycle of the European Beewolf wasp – short story with narration

22 August 2017

A short story on the European Beewolf Wasp (Philanthus triangulum) showing how it preys on others and what it does to improve the success of its offspring.

From the Max Planck Institute for Chemical Ecology in Germany:

Beewolves have been successfully using the same antibiotics for 68 million years

The antibiotic cocktail produced by symbiotic bacteria changed very little in the course of evolution and its antipathogenic effect remained unaltered

February 14, 2018

Summary: Scientists have now found that beewolves, unlike humans, do not face the problem of antibiotic resistant pathogens. These insects team up with symbiotic bacteria which produce up to 45 different antibiotic substances to protect their offspring against mold fungi. This antibiotic cocktail has remained surprisingly stable since the symbiosis emerged, about 68 million years ago.

The discovery of penicillin about 90 years ago and the widespread introduction of antibiotics to combat infectious diseases have revolutionized human medicine. However, in recent decades, the increase in multidrug-resistant pathogens has confronted modern medicine with massive problems. Insects have their own antibiotics, which provide natural protection against germs. A team of scientists from the Johannes Gutenberg University in Mainz and the Max Planck Institute for Chemical Ecology in Jena have now found that beewolves, unlike humans, do not face the problem of antibiotic resistant pathogens. These insects team up with symbiotic bacteria which produce an antibiotic cocktail of up to 45 different substances within a single species to protect their offspring against mold fungi. The researchers not only discovered that the number of antibiotic substances is much higher than previously thought, they also proved that the cocktail has remained surprisingly stable since the symbiosis emerged, about 68 million years ago.

Beewolves are solitary digger wasps that carry paralyzed bees into their underground brood cells; these serve as a food supply for their offspring. After the larvae hatch from the eggs, they feed on the bees and then hibernate in a cocoon in the ground. While hibernating, they are constantly endangered by fast-growing mold fungi whose spores are omnipresent in the soil. To protect their young, beewolves have not only developed their own defense mechanisms, they also rely on the chemical arsenal of microorganisms. Adult females breed bacteria of the genus Streptomyces in their antennae and deposit these bacteria to the walls of the brood cells in which their larvae develop. When a larva spins its cocoon, it weaves the Streptomyces into the cocoon silk. Because the bacteria produce a cocktail of different antibiotic substances, a protective layer is formed which prevents mold fungi from entering the cocoon and infecting the larva.

In the present study, published in the Proceedings of the National Academy of Sciences, the scientists from Mainz and Jena showed that the protective symbiosis between beewolves and their bacterial partners has not only existed since the Cretaceous (see also our press release, moreover, the antibiotic protection offered by the bacteria against pathogens has changed very little since it evolved about 68 million years ago. All of the studied beewolf species use very similar mixtures of antibiotics — basically, modifications of only two structures: streptochlorine and piericidin. “We had expected that some beewolf symbionts evolved new antibiotics to complement their arsenal over the course of evolution in order to help their hosts combat new or resistant mold fungi”, Tobias Engl from Mainz University, the first author of the study, said. However, the original antibiotic cocktail must have been so effective that it did not need to change. An especially important property from the start was possibly that the mixture was effective against a wide variety of fungi, as no specialized pathogens in beewolves are known to have evolved resistance to these antibiotics.

The broad protection offered by the antibiotic cocktail against a variety of mold fungi is probably related to the large number of substances produced by the bacterial symbionts. Because most of these substances can be traced back to a single gene cluster, the scientists also studied the molecular reasons for the diversity of products. They identified several key biosynthetic steps and discovered that the enzymes of the symbiotic Streptomyces worked less selectively than those of free-living bacteria. This lack of specificity allows the enzymes to bind to different chemical precursors, which is the reason for a larger number of products. In addition, the direct end-product of the piericidin biosynthesis is modified in multiple ways. The result is a multitude of antibiotic substances which are found in varying amounts in the different beewolf species. The geographical pattern of the relative amounts of single substances suggests that the antibiotics allow beewolves to adapt to a certain degree to local mold communities.

Beewolves and their symbiont-produced antibiotics are likely exposed to different selective pressures than humans. Human pathogens gain enormous advantage by becoming resistant to common antibiotics. They can use this advantage effectively, because they are transmitted from person to person and, in our globalized world, even from country to country. They spread easily in hospitals, where many people, often with compromised immune systems, live together in close proximity. “Beewolves, in contrast, are usually found in small populations and frequently relocate, because they rely on open sandy grounds to build their burrows”, Martin Kaltenpoth, who headed a Max Planck Research Group in Jena until he became Professor of Evolutionary Ecology in Mainz in 2015, explained. “Hence resistant pathogens have little opportunity to spread within or between populations.” Perhaps this is the reason why no resistant microorganisms are known to have specialized on beewolves. It seems most important for beewolves to have a defense which is efficient against a broad and constantly changing spectrum of mold fungi. The selective process that favored broad-spectrum activity over adaptation to specialized pathogens likely influenced the development of the antibiotic cocktail and led to it remaining mostly unchanged for millions of years.


Columbian mammoth footprints discovery in Oregon, USA

This video from the USA says about itself:

9 February 2018

A video produced by Dean Walton, science and technology outreach librarian in the Allan Price Science Commons & Research Library, takes us on a journey above and along a mammoth trackway at a remote site in Lake County, Oregon. The site was discovered in 2014 by the UO’s Greg Retallack and excavated by a research team in 2017. The ancient path contains multiple footprints of Columbian mammoths that once roamed the region.

From the University of Oregon in the USA:

Ancient trail of Columbian mammoths uncovered in south-central Oregon

University of Oregon-led research team uncovers numerous footprints of adult, juvenile and infant elephants in a remote dry lake basin

February 12, 2018

A fossilized trackway on public lands in Lake County, Oregon, may reveal clues about the ancient family dynamics of Columbian mammoths.

Recently excavated by a team from the University of Oregon Museum of Natural and Cultural History, the Bureau of Land Management and the University of Louisiana, the trackway includes 117 footprints thought to represent a number of adults as well as juvenile and infant mammoths.

Discovered by Museum of Natural and Cultural History paleontologist Greg Retallack during a 2014 class field trip on fossils at the UO, the Ice Age trackway is the focus of a new study appearing online ahead of print in the journal Palaeogeography, Palaeoclimatology, Palaeoecology.

Retallack returned to the site with the study’s coauthors, including UO science librarian Dean Walton, in 2017. The team zeroed in on a 20-footprint track, dating to roughly 43,000 years ago, that exhibited some intriguing features.

“These prints were especially close together, and those on the right were more deeply impressed than those on the left-as if an adult mammoth had been limping,” said Retallack, also a professor in the UO Department of Earth Sciences and the study’s lead author.

But, as the study reveals, the limping animal wasn’t alone: Two sets of smaller footprints appeared to be approaching and retreating from the limper’s trackway.

“These juveniles may have been interacting with an injured adult female, returning to her repeatedly throughout the journey, possibly out of concern for her slow progress”, Retallack said. “Such behavior has been observed with wounded adults in modern, matriarchal herds of African elephants.”

The tracks were made in a layer of volcanic soil at Fossil Lake, a site first excavated by UO science professor Thomas Condon in 1876 and today administered by the Bureau of Land Management.

“America’s public lands are some of the world’s greatest outdoor laboratories. Localities such as this mammoth tracksite are unique parts of America’s heritage and indicate that there are many special sites still to be discovered,” said study co-author Brent Breithaupt, a paleontologist in the Wyoming State Office of the Bureau of Land Management.

Specimens from the 1876 Fossil Lake excavation-along with the rest of Condon’s extensive assemblage of fossils and geologic specimens-were donated to UO in the early 1900s and form the core of the museum’s Condon Fossil Collection, now under Retallack’s direction and boasting upwards of 50,000 fossil specimens.

Last month a new state law went into effect, making the UO museum Oregon’s default repository for fossils found on state lands. The museum is also a designated repository for artifacts and paleontological specimens collected from BLM-administered lands in Oregon, ensuring they are available to future generations for education and research.

As part of the 2017 study, Neffra Matthews of the BLM’s National Operations Center in Denver, helped survey, map and document the trackway using photogrammetry, which helps scientists perform accurate measurements based on land-based or aerial photographs.

“There is a vast storehouse of natural history found on BLM-managed land, and it’s exciting to work with researchers like Professor Retallack in capturing 3D data on fragile paleontological resources,” she said.

Retallack said that trace fossils such as trackways can provide unique insights into natural history.

“Tracks sometimes tell more about ancient creatures than their bones, particularly when it comes to their behavior,” he said. “It’s amazing to see this kind of interaction preserved in the fossil record.”

Elephants once roamed across much of North America. Woolly mammoths (Mammuthus primigenius) were common in Canada and Alaska. Columbian mammoths (Mammuthus columbi) occupied the region that became Washington state to South Dakota and south into Mexico. Most mammoths went extinct about 11,500 years ago, but some isolated Arctic island populations of woolly mammoth persisted until 4,000 years ago.


Grass snakes survived Ice Age

This video from Britain says about itself:



These reptiles had been huddling together for warmth and are waking up.

From the Senckenberg Research Institute and Natural History Museum in Germany:

Cool Snake – Warmth-loving Grass Snake survived the Ice Age in Central Europe

February 9, 2018

Using genetic analyses, Senckenberg scientists have discovered that not all Grass Snakes retreated to warm southern refugia during the last Central European Ice Age. Together with a colleague from Spain, they offer first evidence for the survival of a warmth-loving, egg-laying reptile during this cold period. The study was recently published in the journal Scientific Reports.

Among the warmth-loving reptiles, the Grass Snake is generally considered a “cool” representative: Its present distribution even extends to the Siberian permafrost soils and the area around the Finnish-Russian Lake Ladoga. “However, it came as a complete surprise to all of us that this thermophilic snake actually ‘overwintered’ in Central Europe during the Pleistocene Ice Age”, explains Professor Dr. Uwe Fritz, director of the Senckenberg Natural History Collections in Dresden.

Until now it had been assumed that thermophilic reptiles survived the Ice Ages only on the southern peninsulas of Europe and spread northward once the temperatures rose again during the Holocene and the interglacial periods. Using genetic methods, Fritz, his doctoral student Carolin Kindler, and their Spanish colleague, Eva Graciá now discovered that not all of the snakes, which are widespread across Europe today, retreated to warmer, Mediterranean regions.

The team examined a total of 1,372 genetic samples of these harmless reptiles. “We closely studied different genetic lineages of the Barred Grass Snake (Natrix helvetica) and the Eastern Grass Snake (Natrix natrix)”, explains Kindler and continues, “One of the lineages of Natrix natrix survived the Ice Age in two separate refugia: one was located in the Southern Balkans, the other — unexpectedly — in Central Europe.”

As evidence, the scientists from Dresden highlight the much higher genetic diversity — compared to their more southerly relatives — of the Grass Snakes in Northern Germany and Scandinavia.

“This means that we need to rethink the model of ‘southern warm refugia’ — areas of retreat in the Mediterranean region — during the Ice Ages. It is quite possible that other heat-loving animals also withstood the cold temperatures directly ‘at home'”, adds Fritz in summary.


Humans better at visual arts than Neanderthals. why?

This video says about itself:

CARTA: Evolutionary Origins of Art and Aesthetics: Art in Neanderthal and Paleolithic Cultures

Did our early ancestors produce art? Or do modern humans only think they did? In this episode of the CARTA series Evolutionary Origins of Art and Aesthetics, join renowned scientists Jean-Jacques Hublin and Randall White in an exploration of the notions of creativity and aesthetics as seen in Neanderthal and Paleolithic cultures. Series: CARTA – Center for Academic Research and Training in Anthropogeny [6/2009]

From the University of California – Davis in the USA:

Neanderthals‘ lack of drawing ability may relate to hunting techniques

Spear-throwing gave Homo sapiens better eye-hand coordination, smarter brains

February 9, 2018

Visual imagery used in drawing regulates arm movements in manner similar to how hunters visualize the arc of a spear. Neanderthals had large brains and made complex tools but never demonstrated the ability to draw recognizable images, unlike early modern humans who created vivid renderings of animals and other figures on rocks and cave walls. That artistic gap may be due to differences in the way they hunted, suggests a University of California, Davis, expert on predator-prey relations and their impacts on the evolution of behavior.

Neanderthals used thrusting spears to bring down tamer prey in Eurasia, while Homo sapiens, or modern humans, spent hundreds of thousands of years spear-hunting wary and dangerous game on the open grasslands of Africa.

Richard Coss, a professor emeritus of psychology, says the hand-eye coordination involved in both hunting with throwing spears and drawing representational art could be one factor explaining why modern humans became smarter than Neanderthals.

In an article recently published in the journal Evolutionary Studies in Imaginative Culture, Coss examines archaeological evidence, genomics, neuroscience studies, animal behavior and prehistoric cave art.

New theory of evolution

From this, he proposes a new theory for the evolution of the human brain: Homo sapiens developed rounder skulls and grew bigger parietal cortexes — the region of the brain that integrates visual imagery and motor coordination — because of an evolutionary arms race with increasingly wary prey.

Early humans hunted with throwing spears in sub-Saharan Africa for more than 500,000 years — leading their increasingly watchful prey to develop better flight or fight survival strategies, Coss said.

Some anthropologists have suggested that throwing spears from a safe distance made hunting large game less dangerous, he said. But until now, “No explanation has been given for why large animals, such as hippos and Cape buffalo, are so dangerous to humans”, he said. “Other nonthreatening species foraging near these animals do not trigger alert or aggressive behavior like humans do.”

Drawn from earlier research on zebras

Coss’ paper grew out of a 2015 study in which he and a former graduate student reported that zebras living near human settlements could not be approached as closely before fleeing as wild horses when they saw a human approaching on foot — staying just outside the effective range of poisoned arrows used by African hunters for at least 24,000 years.

Neanderthals, whose ancestors left Africa for Eurasia before modern human ancestors, used thrusting spears at close range to kill horses, reindeer, bison, and other large game that had not developed an innate wariness of humans, he said.

Hunting relates to drawing

“Neanderthals could mentally visualize previously seen animals from working memory, but they were unable to translate those mental images effectively into the coordinated hand-movement patterns required for drawing”, Coss writes.

Coss, who taught drawing classes early in his academic career and whose previous research focused on art and human evolution, used photos and film to study the strokes of charcoal drawings and engravings of animals made by human artists 28,000 to 32,000 years ago in the Chauvet-Pont-d’Arc Cave in southern France.

The visual imagery employed in drawing regulates arm movements in a manner similar to how hunters visualize the arc their spears must make to hit their animal targets, he concludes.

These drawings could have acted as teaching tools. “Since the act of drawing enhances observational skills, perhaps these drawings were useful for conceptualizing hunts, evaluating game attentiveness, selecting vulnerable body areas as targets, and fostering group cohesiveness via spiritual ceremonies”, he writes.

As a result, the advent of drawing may have set the stage for cultural changes, Coss said. “There are enormous social implications in this ability to share mental images with group members.”


Carboniferous-Permian plant extinction harmed amphibians, helped reptiles

This video says about itself:

30 March 2015

Dave and Palaeo After Dark’s James explore the Carboniferous forests in the ‘Carboniferous Forest Simulator‘!

This fantastic software is free for educational, museum or personal use. We really need to get our full support behind this project!

The programme, in its ‘alpha testing’ stage can be downloaded here.

Details of the development of the project can be found here.

From the University of Birmingham in England:

Rainforest collapse 307 million years ago impacted the evolution of early land vertebrates

February 7, 2018

Researchers at the University of Birmingham have discovered that the mass extinction seen in plant species caused by the onset of a drier climate 307 million years ago led to extinctions of some groups of tetrapods, the first vertebrates to live on land, but allowed others to expand across the globe. This research is published today (7th February 2018) in the journal Proceedings of the Royal Society B.

The Carboniferous and Permian periods (358 — 272 million years ago) were critical intervals in the evolution of life on land. During the Carboniferous Period North America and Europe lay in a single land mass at the equator which was covered by dense tropical rainforests. These rainforests flourished because of the warm humid climate, providing an ideal habitat for early tetrapods (vertebrates with four limbs), allowing them to diversify into a variety of species.

But towards the end of this period a major global environment change took place — just as the number of tetrapod species began to increase, the rainforests started to disappear. The climate became much drier causing the mass extinction of many species within the dominant plant groups, such as horsetails and club mosses. Despite this being a catastrophic event for plants, it has been unclear how this affected the early tetrapod community.

Previous attempts to estimate the diversity changes during this period have been hindered by the fossil record, which has not been sampled equally in different time intervals or geographic areas. To fill these gaps in the data, the Birmingham researchers compiled a new dataset from the Paleobiology Database and used advanced statistical methods to estimate diversity and biogeographic changes.

The results of the study show that tetrapod diversity decreased after the rainforest collapse and the onset of drier conditions, largely due to the reduction in suitable habitats for amphibians which needed wet environments to survive.

However they also found that after the rainforest collapse surviving tetrapod species began to disperse more freely across the globe, colonising new habitats further from the equator. Many of these survivors were early amniotes, such as early reptiles, whose generally larger size relative to early amphibians allowed them to travel longer distances, and their ability to lay eggs meant they were not confined to watery habitats.

Emma Dunne, from the University of Birmingham’s School of Geography, Earth and Environmental Sciences, said: ‘This is the most comprehensive survey ever undertaken on early tetrapod evolution, and uses many newly developed techniques for estimating diversity patterns of species from fossil records, allowing us greater insights into how early tetrapods responded to the changes in their environment.’

Dunne continued: ‘We now know that the rainiforest collapse was crucial in paving the way for amniotes, the group which ultimately gave rise to modern mammals, reptiles and birds, to become the dominant group of land vertebrates during the Permian period and beyond.’