South American rodent evolution, new study


This video says about itself:

Today the largest land mammals in South America are wild camelids, tapirs, jaguars, and capybaras.

Yet, as recently as 10,000-17,000 years ago the landscape of South America contained remarkable beasts—massive mammals that dominated their environment, many of which have no modern analog for comparison. These enigmatic animals were decimated during the Quaternary—all South American mammal species larger than 100 kg were lost.

The mystery surrounding their extinction has yet to be fully resolved, and is a topic of considerable debate.

List of these giants vanished forever is very large but here is the mention of 10 such beasts which roamed in South America until recently when earlier humans reached these lands and made interactions with them.

1- Megatherium 2- Macrauchenia 3- Cuvieronius 4- Doedicurus clavicaudatus 5- Hippidion 6- Toxodon 7- Notiomastodon 8- Arctotherium 9- Smilodon populator 10- Terror Birds

From Florida State University in the USA:

Family of rodents may explain how some groups of animals become so diverse

October 3, 2018

Summary: Scientists have developed a new model that shows how geography can play a major role in how families of animals evolve and result in many species.

How did a single species of rodent invade South America and then quickly branch off into 350 new species?

The answer is simple — the rodents were able to move quickly across the continent unencumbered by geographic boundaries that can’t be easily crossed such as an ocean.

FSU Professor of Biological Science Scott Steppan and his former postdoctoral researcher John Schenk, now at Georgia Southern University, developed a new model that shows how geography can play a major role in how families of animals evolve and result in many species. The research was part of a $500,000 grant from the National Science Foundation to understand why the superfamily Muroidea (which includes the subfamily Sigmodontinae) is the most diverse branch of the mammal family tree.

The research is published in the journal American Naturalist.

“Biologists have long been fascinated by the process of adaptive radiations, which occurs when a lineage undergoes rapid speciation that is correlated with variation in habitats that species evolve into, resulting in numerous species that differ in the environments in which they live”, Schenk said. “Our study was the first to directly measure how movement across the landscape facilitated the speciation process.”

Scientists in the past had believed that when species evolved in a short period of time they diverged because of different ecological niches, not necessarily because of the ability to cross geographic boundaries.

Schenk and Steppan found that the … Sigmodontinae moved into South America and quickly diversified across all the regions within the continent. In about 8 million years, they diversified into about 400 new species that covered South America.

“That’s really fast”, Steppan said. As time passed, the movement between regions and diversification slowed because the regions and their associated ecological niches were essentially full.

“This [geography] largely tracks with what speciation is doing,” Steppan said. “After that initial burst, it slows down.”

Steppan studies evolutionary biology and has always been interested in how species diversify. Most studies of species diversification involve islands where different groups of terrestrial species are walled off from competing interests by ocean water allowing for animals to diversify based simply on the ecology of the island.

But little is known about how species diversify across the continuous geography of a continent.

Steppan said that he and Schenk are looking at several possibilities for follow-up studies that focus on DNA work and measuring other aspects of the rodents, such as the structure of their limbs and skulls, to see how these structures adapted to new environments over time. Steppan said.

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Leonardo da Vinci’s caricatures exhibited in Dutch Haarlem


Caricature by Leonardo da Vinci. Royal Collection Trust / © Her Majesty Queen Elizabeth II 2018

Translated from Annephine van Uchelen in the Netherlands today:

Astonishment, joy and blind anger: it can all be seen on the dozens of sketches of faces made by Leonardo da Vinci. He drew the faces as ‘mirrors of the soul’. And sometimes he also took ‘revenge with the pen’ on those who mocked him because he was ‘different’.

The works can be seen from this Friday on in the Teylers Museum in Haarlem, which takes an advance with this exhibition on the international Da Vinci year 2019. It is striking that the Netherlands kicks off and not Italy. While Da Vinci still counts as one of the best export products in the cultural field in his native country.

When Italian merchants of death corporation Finmeccanica, linked to convicted criminal racist mafia crony politician Silvio Berlusconi, was entangled in its umpteenth corruption scandal, these war profiteers whitewashed themselves by changing the corporation name to ‘Leonardo’. The real Leonardo hated money-grabbers.

Caricature by Leonardo da Vinci. Royal Collection Trust / © Her Majesty Queen Elizabeth II 2018

The land of Rembrandt and Van Gogh is very much ahead of the troops, some countries think. But the exhibition goes ahead – also in the context of 500th anniversary of the artist’s death. …

This exhibition is unique and will not be seen again soon in the Netherlands for the next forty years. …

Leonardo da Vinci was born in 1452 in Anchiano, near Florence. He is seen as all-rounder: he was, among other things, a visual artist, inventor, architect, philosopher, physicist and chemist.

Someone who has seen Da Vinci’s most famous painting, the lovely Mona Lisa, may have to get used to the sketches. The deformed faces and tronies would not be out of place as illustrations in a horror story: toothless men with sunken mouths and hook noses, curious headgear, beaked mouths and faces expressing blind fury.

“You would like to call Da Vinci the inventor of the caricature, but unfortunately we have never been able to link his work to famous names and people”, says guest curator Michael Kwakkelstein.

Caricature by Leonardo da Vinci. Royal Collection Trust / © Her Majesty Queen Elizabeth II 2018

“Unique for that time was that he also incorporated emotions, sometimes he went to the city gate to study the faces of tramps and travelers in preparation for his sketches.” …

“He was an illegitimate child“, says Kwakkelstein. “And he was not taken seriously by other scientists, because he did not do university studies and did not know Latin, and he was almost certainly homosexual.”

According to Kwakkelstein, some sketches seem to be a reckoning with his critical fellow men and impatient clients. “He has mocked them by deforming their features.”

Caricature by Leonardo da Vinci. Royal Collection Trust / © Her Majesty Queen Elizabeth II 2018

The museum did not get Da Vinci’s works without a struggle. Kwakkelstein: “Teylers Museum does not have any Da Vinci sketches in its collection, which is not an easy basis to ask for the already fragile works on loan, let alone from the Royal Collections of Windsor Castle, where most of the sketches come from.”

The fact that the British Queen Elizabeth gave permission has to do with earlier exhibitions by Teylers about the two other Renaissance figures Michelangelo (2005) and Raphael (2012). The Haarlem museum does have a large collection of their work, which is world-famous.

The exhibition can be seen from October 5 in Teylers Museum in Haarlem. Due to the expected crowds, a ticket must be booked online in advance.

An eye disorder may have given Leonardo da Vinci an artistic edge. A neuroscientist offers evidence that the artist had exotropia, in which one eye turns outward. By Amanda B. Keener, 6:00am, October 22, 2018.

Alpacas helping to fight cancer?


Strategy to obtain and evaluate specific nanobodies against human EGF. Credit: Salvador Guardiola and Monica Varese, IRB Barcelona

From the Institute for Research in Biomedicine (IRB Barcelona) in Spain:

The immune system of the alpaca reveals a potential treatment for cancer

October 2, 2018

The natural world often provides the answer to unsolved medical problems. On this occasion, the solution to a challenge posed by cancer has come about from the immune system of camelids. A study headed by the Institute for Research in Biomedicine (IRB Barcelona) and the Vrije Universiteit Brussel (VUB), in Belgium, describes a number of therapeutic tools that have the capacity to block the activity of EGF, a growth factor that is dysregulated in cancer cells.

EGF (Epidermal Growth Factor) is a therapeutic target in cancer; however, no inhibitors have been found for it to date. The team of researchers is the first to identify a family of nanobodies — antibodies that are exclusive to camelids — derived from alpacas that are effective against EGF. In this regard, they have described the molecular mechanisms underlying the affinity and selectivity of these nanobodies in an article published in the scientific journal Angewandte Chemie.

“In spite of advances in treatments against the EGR receptor (EGFR) in patients, their efficacy decreases over time because patients develop resistance”, explain Monica Varese and Salvador Guardiola, co-authors of the study and postdoctoral researchers at IRB Barcelona. “By taking advantage of an emerging biotech tool, nanobodies, we have been able to synthesise the first inhibitors with high affinity for EGF”, they say.

Immune response

IRB Barcelona produced the EGF protein and their Belgian colleagues administered it to alpacas. The immune response of these animals to this strange antigen produced a series of nanobodies, and the researchers identified a family of these molecules as potential inhibitors of EGF. The IRB Barcelona team, which has extensive expertise in molecular recognition between proteins, observed that some of the ligands showed high affinity and selectivity towards EGF, and, using a range of biophysical techniques, they characterized the interactions in cells in vitro and in human cancer cells.

“By injecting EGF into the alpaca we have challenged nature to find a molecule capable of binding tightly and with high selectivity to EGF, and it has come up with two very different but equally effective solutions for such a small and difficult antigen as EGF,” says Ernest Giralt, head of the Peptide and Proteins Lab at IRB Barcelona and senior professor at the University of Barcelona, who has led the study.

These drugs could be useful for patients who develop resistance to the EGFR inhibitors currently on the market. The first step is now to evaluate the pharmacological effect of these new nanobodies in cell and animal models of cancer.

Nazi candidates at Belgian elections


Nazi supporting Vlaams Belang candodates of Belgian elections

Translated from Belgian daily Het Laatste Nieuws, 2 October 2018:

We discovered fifteen [candidates of the far-right Vlaams Belang party for the 14 October 2018 local elections with nazi sympathies] – only by looking at what appears publicly on Facebook. That goes from likes for Adolf Hitler to statements of support to a terrorist who planned murders to keep Flanders white.

More nazi supporting Vlaams Belang candidates

On Saturday 13 October, literally on the eve of the elections, a concert is planned in Lierde in East Flanders. Not in the cultural center, but in a shabby hangar in a private area. …

On Facebook, 72 people have already indicated that they will be there. One of them is Alexandra Remory, number one candidate for Vlaams Belang in neighboring municipality Geraardsbergen. She is in the company of guys who are fond of organizations like Blood & Honour and lavish with swastikas, and also with the organizers these feelings are not far away. “Fifty years ago [the 1940s, when Belgium was occupied by nazi Germany] such an Untermensch would have been crushed to death”, one of them writes about asylum seekers. “Now all European governments are handing out subsidies to let such lowly animal species do their thing!”

Even if the Vlaams Belang national executive would like to remove Ms Remory and her fellow Adolf Hitler lovers as candidates because of bad public relations, then that would be impossible: the ballots have already been printed.

Desert island prickly saltwort plant, photo


Prickly saltwort, 8 September 2018

This 8 September 2018 photo comes now in this a P.S. to my earlier blog post on the desert islands Engelsmanplaat and Het Rif.

On the low sand dunes of Het Rif, a few plant species grow. One of them is prickly saltwort, depicted on the photo.

This is a rare species, on the Red List in the Netherlands.

A great skua flying that day at Het Rif.