46 million year old Blood-filled mosquito fossil found.

A Unique 46-million-year-old mosquito fossil with a belly full of dried blood has been found in a Montana riverbed, US researchers say.

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“It is an extremely rare fossil, the only one of its kind in the world,” said Dale Greenwalt, lead author of the study in the Proceedings of the National Academy of Sciences, on Monday.

Cutting-edge instruments detected the unmistakable traces of iron in her engorged abdomen, but just what creature that blood came from is a mystery since DNA cannot be extracted from a fossil that old.

Greenwalt said it might have been blood from a bird, since the ancient mosquito resembles a modern one from the genus Culicidae, which likes to feed on our feathered friends.

“But that would be pure speculation,” said Greenwalt, a retired biochemist who volunteers at the Smithsonian Museum of Natural History in Washington.

Greenwalt said he became fascinated with fossilised insects several years ago.

He learned about Master’s student Kurt Constenius, who described his discoveries of fossilised insects along a remote Montana riverbed in an obscure geological journal more than two decades ago.

Greenwalt and Constenius discussed the fossil grounds, which lie near the Flathead River along the western boundary of Glacier National Park.

The fossil described in PNAS came from a collection of fossilised insects languishing in Constenius’s basement since the 1980s, and which he and his family had donated to the Smithsonian museum.

“As soon as I saw it, I knew it was different,” Greenwalt said.

The mosquito itself is only about 0.5cm in size. Somehow, the fragile creature ate its last meal, filling its abdomen until it was nearly ready to burst like a balloon.

Then, perhaps as the mosquito was flying over an algae-coated lake, it became caught in that mucus, enveloped in microbes that protected it from degrading, and eventually sank deep into the sediment of the lake.

Despite its impressive age it is far from the oldest known mosquito fossil. That honour goes to a 95-million-year-old mosquito in amber in Myanmar.

 

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Where did we come from?

 

One of the big questions is: “Where did we come from?” Well, thanks to a strange fusion of a few different sciences, we’re getting closer to finding out — and the answer is pretty surprising.

The scientists included palaeontologists (the fossil dudes), geneticists (the DNA dudes) and archaeologists (the dudes who try to understand artifacts from our human past).

So here we are today, Homo sapiens, the only species of human left. But 100,000 years ago, there were at least three different species of human, and possibly six. So, to understand this, let’s look at the timeline of our evolution.

Well, the story begins in Africa about six to eight million years ago, when there was the big split between the line that led to us, and the line that led to the chimpanzees. Around 2.6 million years, our ancestors had invented rock tools and had a brain around 400 to 500 cubic centimeters or cc.

Via evolution, the brain size gradually increased, and by around 600,000 years ago, our direct ancestor was Homo heidelbergensis. They were not that different from us — the brain was only about 100cc smaller, at around 1,200cc, and there’s very strong evidence that they had language.

Around 500,000 years ago, a group of hominins (almost certainly Homo heidelbergensis) walked out of Africa forever, heading north for Europe and Asia. By around 300,000 years ago, they had evolved into two different species.

Now, one species was the Neanderthals, who headed west, towards Europe. About 100,000 years ago, they got itchy feet and began spreading east, towards Asia. The last Neanderthals died out as recently as 30,000 years ago, in caves in Gibraltar. We’ve known about the existence of the Neanderthals for nearly two centuries.

The other species (who also descended from Homo heidelbergensis) headed east towards Asia. They are also our long-lost cousins, but we’ve known about them only since 2010, when some remains were found in a cave in the Altai Mountains. Now, these mountains are in Southern Siberia, about 2600 kilometres north of Dhaka, the capital of Bangladesh.

In the 18th century, a hermit named Denis lived in this very cave and in 2008, an archaeologist exploring this cave found a tiny 40,000 year-old bone. It was a chip of the middle section of a little finger and when DNA was analysed, there was a huge surprise — it was human, but it was not Neanderthal, and it wasn’t us, Homo sapiens. So this new species of extinct human was called Denisovan, after the hermit, Denis.

So getting back to our timeline, about a quarter-of-a-million years ago, there were at least three species of humans on the planet. There was Homo heidelbergensis, still hanging around in Africa, the Neanderthals who had gone West to Europe, and the Denisovans in the East.

Then, in Africa, by around 200,000 years ago, Homo heidelbergensis had gradually evolved into us, Homo sapiens and, about 65 to 70,000 years ago, Homo sapiens left Africa, and spread across the world. They walked into Europe, and, to a very limited degree, they interbred with the Neanderthals.

Now, by this time, the Neanderthals had walked across to the east, in fact, to that very same cave that Denis the Hermit lived in. But the Neanderthals never walked back into Africa. So, all of us, except for Africans, today carry some Neanderthal DNA. About 2.5 per cent of our DNA (excluding Africans) is Neanderthal DNA.

Early Homo sapiens, when they left Africa, about 65 to 70,000 years ago, also went East and West. To a limited degree, the early Homo sapiens interbred with the Denisovans. So today, in the Melanesians of Papua New Guinea and of Bougainville, and in the Australian Aborigines, there’s some Denisovan DNA — up to five per cent.

But these answers, of course, lead to more questions.

First, if our Homo sapiens ancestors bred with the Denisovans, you can see how the Australian Aborigines and the Melanesians could have some Denisovan DNA. But how come hardly anybody else in Asia has any Denisovan DNA?

Second, we know that there were a few other species of humans around in the past — such as the Neanderthals and the Denisovans, and almost certainly Homo floresiensis. Why did they die out?

We don’t know.

But, this cave, now it was home to the Neanderthals and the Denisovans and to us Homo sapiens and, not to mention, Denis the Hermit. Here’s the big question: What’s so great about this cave?

Thanks to Dr Karl

PERFECTLY PRESERVED 15 YEAR OLD INCA GIRL FROZEN FOR 500 YEARS GIVES NEW INSIGHT INTO DISEASES OF THE PAST!

A 500-year-old frozen Incan mummy known as ‘The Maiden’ was suffering from a bacterial infection when she died – and being able to ‘diagnose’ the disease could lead to new insights into diseases of the past.

The discovery could help defend against new illnesses – or the re-emergence of diseases of the past.

The mummy was suffering from an illness similar to tuberculosis when she was sacrificed on the Argentinian volcano Llullaillaco, 22,100 feet above sea level.
The find – using a new technique of swabbing the lips and comparing the swabs with those of current patients – is the first time a disease has been ‘diagnosed’ in such an ancient body.

‘Pathogen detection in ancient tissues isn’t new, but until now it’s been impossible to say whether the infectious agent was latent or active,’ says Corthals.

‘Our technique opens a new door to solving some of history’s biggest mysteries, such as the reasons why the flu of 1918 was so devastating. It will also enhance our understanding of our future’s greatest threats, such as the emergence of new infectious agents or re-emergence of known infectious diseases.’

The analysis was possible because of the incredible preservation of the mummy, which is so well-preserved there were still lice in her hair.

The team swabbed the lips of two Andean Inca mummies, buried at 22,000-feet elevation and originally discovered in 1999, and compared the proteins they found to large databases of the human genome.

They found that the protein profile from the mummy of a 15-year old girl, called ‘The Maiden,’ was similar to that of chronic respiratory infection patients, and the analysis of the DNA showed the presence of probably pathogenic bacteria in the genus Mycobacterium, responsible for upper respiratory tract infections and tuberculosis.

In addition, X-rays of the lungs of the Maiden showed signs of lung infection at the time of death.

The mummies were found in 1999.

‘The doctors have been shaking their heads and saying they sure don’t look 500 years old but as if they’d died a few weeks ago,’ said U.S. archaeologist and expedition member Johan Reinhard at the time. And a chill went down my spine the first time I saw her hands because they look like those of a person who is alive.’

It’s thought that the children were chosen by the Incas for their beauty and sacrificed in a ceremony called a capacocha.

‘The Incas didn’t do this very often,’ according to Reinhard.

‘The sacrifices were children because they were considered to be the most pure.’
They were not sacrificed to feed or appease the gods but, rather, ‘to enter the realm of the gods and live in paradise with them. It was considered a great honour, a transition to a better life from which they would be expected to remain in contact with the community through shamans (holy men)’.

The Incas believed that by scaling the snow-topped heights of the mountains they could get closer to the heavens and communicate better with the gods.

Detecting diseases in ancient remains is often fraught with difficulty, especially because of contamination.

Techniques based on microbe DNA can easily be confused by environmental contamination, and they can only confirm that the pathogen was present, not that the person was infected, but the researchers behind the study, led by Angelique Corthals of the John Jay College of Criminal Justice, City University of New York, found a way around this problem.

They used proteomics, focusing on protein rather than DNA remains, to profile immune system response from degraded samples taken from 500 year-old mummies.
Proteomics, DNA, and x-rays from another mummy found together with the Maiden did not show signs of respiratory infection.

‘Our study is the first of its kind since rather than looking for the pathogen, which is notoriously difficult to do in historical samples, we are looking at the immune system protein profile of the ‘patient’, which more accurately tells us that there was indeed an infection at the time of death.’ or

‘Our study opens the door to solving many historical and current biomedical and forensic mysteries, from understanding why the plague of 1918 was so lethal, to finding out which pathogen is responsible for death in cases of multiple infections.’