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[Blwe_torch]

An asteroid wiped out dinosaurs: Scientists
REUTERS, Mar 5, 2010, 10.36am IST

LONDON: A giant asteroid smashing into Earth is the only plausible explanation for the extinction of the dinosaurs, a global scientific team said on Thursday, hoping to settle a row that has divided experts for decades.

A panel of 41 scientists from across the world reviewed 20 years' worth of research to try to confirm the cause of the so-called Cretaceous-Tertiary (KT) extinction, which created a "hellish environment" around 65 million years ago and wiped out more than half of all species on the planet.

Scientific opinion was split over whether the extinction was caused by an asteroid or by volcanic activity in the Deccan Traps in what is now India, where there were a series of super volcanic eruptions that lasted around 1.5 million years.

The new study, conducted by scientists from Europe, the United States, Mexico, Canada and Japan and published in the journal Science, found that a 15-kilometre (9 miles) wide asteroid slamming into Earth at Chicxulub in what is now Mexico was the culprit.

"We now have great confidence that an asteroid was the cause of the KT extinction. This triggered large-scale fires, earthquakes measuring more than 10 on the Richter scale, and continental landslides, which created tsunamis," said Joanna Morgan of Imperial College London, a co-author of the review.

The asteroid is thought to have hit Earth with a force a billion times more powerful than the atomic bomb at Hiroshima. Morgan said the "final nail in the coffin for the dinosaurs" came when blasted material flew into the atmosphere, shrouding the planet in darkness, causing a global winter and "killing off many species that couldn't adapt to this hellish environment."

Scientists working on the study analysed the work of palaeontologists, geochemists, climate modellers, geophysicists and sedimentologists who have been collecting evidence about the KT extinction over the last 20 years. Geological records show the event that triggered the dinosaurs' demise rapidly destroyed marine and land ecosystems, they said, and the asteroid hit "is the only plausible explanation for this".

Peter Schulte of the University of Erlangen in Germany, a lead author on the study, said fossil records clearly show a mass extinction about 65.5 million years ago -- a time now known as the K-Pg boundary.

Despite evidence of active volcanism in India, marine and land ecosystems only showed minor changes in the 500,000 years before the K-Pg boundary, suggesting the extinction did not come earlier and was not prompted by eruptions.

The Deccan volcano theory is also thrown into doubt by models of atmospheric chemistry, the team said, which show the asteroid impact would have released much larger amounts of sulphur, dust and soot in a much shorter time than the volcanic eruptions could have, causing extreme darkening and cooling.

Gareth Collins, another co-author from Imperial College, said the asteroid impact created a "hellish day" that signalled the end of the 160-million-year reign of the dinosaurs, but also turned out to be a great day for mammals.

"The KT extinction was a pivotal moment in Earth's history, which ultimately paved the way for humans to become the dominant species on Earth," he wrote in a commentary on the study.

http://timesofindia.indiatimes.com/home/science/An-asteroid-wiped-out-dinosaurs-Scientists/articleshow/5645545.cms

[Blwe_torch]

According to Wiki.......
"The scientific study of human evolution encompasses the development of the genus Homo, but usually involves studying other hominids and hominines as well, such as Australopithecus. "Modern humans" are defined as the Homo sapiens species, of which the only extant subspecies is known as Homo sapiens sapiens. Homo sapiens idaltu (roughly translated as "elder wise human"), the other known subspecies, is now extinct.[10] Homo neanderthalensis, which became extinct 30,000 years ago, has sometimes been classified as a subspecies, "Homo sapiens neanderthalensis", but genetic studies now suggest a divergence of the Neanderthal species from Homo sapiens about 500,000 years ago.[11] Similarly, the few specimens of Homo rhodesiensis have also occasionally been classified as a subspecies, but this is not widely accepted. Anatomically modern humans first appear in the fossil record in Africa about 195,000 years ago, and studies of molecular biology give evidence that the approximate time of divergence from the common ancestor of all modern human populations was 200,000 years ago.[12][13][14][15][16] The broad study of African genetic diversity headed by Dr. Sarah Tishkoff found the San people to express the greatest genetic diversity among the 113 distinct populations sampled, making them one of 14 "ancestral population clusters". The research also located the origin of modern human migration in south-western Africa, near the coastal border of Namibia and Angola.[17]

The closest living relatives of humans are gorillas and chimpanzees, but humans did not evolve from these apes: instead these apes share a common ancestor with modern humans.[18] Humans are probably most closely related to two chimpanzee species: Common Chimpanzee and Bonobo.[18] Full genome sequencing has resulted in the conclusion that "after 6.5 [million] years of separate evolution, the differences between chimpanzee and human are ten times greater than those between two unrelated people and ten times less than those between rats and mice". Suggested concurrence between human and chimpanzee DNA sequences range between 95% and 99%.[19][20][21][22] It has been estimated that the human lineage diverged from that of chimpanzees about five million years ago, and from that of gorillas about eight million years ago. However, a hominid skull discovered in Chad in 2001, classified as Sahelanthropus tchadensis, is approximately seven million years old, which may indicate an earlier divergence.[23]"

[Blwe_torch]

The point of posting these info-bits from history is to confirm that human beings didn't exist when the Dinosaur carnage was going on....................or even during the time, when the dinosaurs went mass-extinct.

[Blwe_torch]

Meet X-woman: a possible new species of human

    * 18:00 24 March 2010 by Ewen Callaway


The human family tree may be in for a dramatic rewrite. DNA collected from a fossilised finger bone from Siberia shows it belonged to a mysterious ancient hominid – perhaps a new species.

"X-woman", as the creature has been named, last shared an ancestor with humans and Neanderthals about 1 million years ago but is probably different from both species. She lived 30,000 to 50,000 years ago.

"This is the tip of the iceberg," says Chris Stringer, a palaeoanthropologist at the Natural History Museum in London who was not involved in the find. More hominids that are neither Neanderthal nor human are likely to be discovered in coming years, particularly in central and eastern Asia, he says.

Roaming Asia

Previously, anthropologists thought that Neanderthals and humans were the only hominids roaming Europe and Asia during the late Pleistocene. The discovery of 17,000-year-old Homo floresiensis – the "hobbit" – dispelled that notion, but many anthropologists look on H. floresiensis as an anomaly, isolated from the human–Neanderthal hegemony on the mainland.

The newly discovered creature, which probably lived in close proximity to humans and Neanderthals, suggests that things were not that simple. "The picture that's going to emerge in the next years is a much more complex one," says Svante Pääbo, a palaeogeneticist at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.

Pääbo and colleague Johannes Krause discovered the specimen in the Denisova cave in southern Siberia, and sequenced DNA from its mitochondria. It is impossible to say what the creature would have looked like based on a single pinkie bone, so Pääbo and Krause are hesitant to call it a new species.

Though the creature's sex is not known, they are for now referring to her as X-woman because mitochondria are inherited maternally. "No one really knows what she would look like," Pääbo says.

X-woman's mitochondria differ from a human's at nearly 400 DNA letters; Neanderthals show only half as many differences.

Home sweet home. DNA analysis shows a finger bone discovered in the Denisova cave, southern Siberia, may be from a previously unrecognised, extinct human species (Image: Johannes Krause, Max Planck Institute for Evolutionary Anthropology)
African ancestry

This suggests that X-woman shared an African ancestor with the two other species somewhere between 780,000 and 1.3 million years ago, before striking north and east. This expansion is distinct from the one that occurred around 500,000 years ago that gave rise to Neanderthals, and from our own species' peregrinations from about 50,000 years ago.

The split seems too recent for X-woman to be related to Homo erectus, which began moving out of Africa around 2 million years ago.

However, Clive Finlayson, a palaeoanthropologist at the Gibraltar Museum, says the idea that there were just a handful of hominid migrations out of Africa is a vast oversimplification that ignores how other species expand their range over time. "To talk about one or two expansions from a particular region doesn't make any biological sense," he says. "There were probably hundreds, thousands of migrations out of Africa."

Though there is no complete skeleton for X-woman, her lineage could mean she is related to any number of more complete specimens recovered in Asia that don't neatly fit human or Neanderthal body patterns, says Stringer. "This new DNA work provides an entirely new way of looking at the still poorly understood evolution of humans in central and eastern Asia."
Nuclear DNA

Pääbo and his team are hesitant to speculate too much about X-woman's nature until they obtain DNA sequences from the nuclear genome's 3.1 billion letters. That project is already under way, and the first results should come within months. Pääbo's team will likely want X-woman's genome to answer the same questions they are asking of the Neanderthal genome, which is due for publication soon.

For instance, humans and Neanderthals share unique mutations in a gene linked to speech and language called FOXP2. If X-woman's sequence is complete enough, they will be able to determine if it possesses the same change – and potentially the capability for language.

There is no sign in X-woman's mitochondrial genome that her kind interbred with humans or Neanderthals, but the nuclear genome will offer a far better chance of finding out.


Room with a view. X-woman's stomping ground. (Image: Johannes Krause, Max Planck Institute for Evolutionary Anthropology)

Neanderthal neighbours

Given the close proximity of Neanderthal remains dated to the same time and artefacts that appear to be human, interbreeding is not unlikely, Pääbo says. "Having in about the same time window three different forms [of hominids], increases the potential of all types of interactions, including genetic."

X-woman's mitochondrial DNA begins to paint a picture of what she was like, if only a blurry one. The protein-coding genes do not contain any surprising mutations that would cause disease.

Finlayson would love to link X-woman to other bones, and even stone technologies, though the chances of doing this may be slim. "Ideally we would like to have all that information, but we don't. The fact that we've got this genetic result is important, it's very important."

Pääbo hopes that such a connection will come through sequencing DNA from other Asian hominid fossils. But he, too, is prepared for the possibility that such bones may never turn up.

He sees in X-woman the beginning of a new way of understanding human history. "It gives another picture of our past, a molecular picture of the evolution of our genome" which he says is in some aspects even more conclusive than fossils.

Journal reference: Nature, DOI: 10.1038/nature08976
http://www.newscientist.com/article/dn18699-meet-xwoman-a-possible-new-species-of-human.html

[Blwe_torch]

Ancient 'X-Woman' discovered as man's early ancestors are pictured together for the first time

By Daily Mail Reporter

A mysterious species of ancient human has been discovered in a cave in southern Siberia.

Nicknamed X-Woman, scientists say the human lived alongside our ancestors tens of thousands of years ago.

The discovery, which could rewrite mankind's family tree, was made after analysis of DNA from a fossilised finger bone.


Back in the beginning: Living 6.8million years ago this is Sahelanthropus tchadensis. Parts of its jaw bone and teeth were found nine years ago in the Djurab desert, Chad, and from this scientists created this model head.



This young woman lived between 100,000 and 90,000 years ago. Her skull and mandible were found in a cave in Israel in 1969 along with the remains of 20 others. The size of their skulls was higher than that of the average person today

Experts believe the finger belonged to a child who died 48,000 to 30,000 years ago.

It was thought only two species of early humans lived at that time - the ancestors of modern man and the Neanderthals, who died out soon afterwards.

But the DNA evidence published in the journal Nature reveals a third species.

The latest study was based on an analysis of 'mitochondrial' DNA - a genetic code passed from mothers to children.

Researcher Dr Svante Pääbo said the code was different from that of Neanderthals and modern humans and was 'a new creature that's not been on our radar screens so far'.

The scientists are unable to say what X-Woman looked like and are even unsure if the finger belonged to a male of female, but Dr Pääbo said they named her X-Woman 'because its mitochondrial and we want to take a feminist tack on this'.

The discovery of the 'X-Woman' comes as scientists revealed images of what man looked like millions of years ago.

Gathering bone fragments from across the globe, paleoanthropologists used sophisticated research methods to form the 27 model heads, which are on show at the Senckenberg Natural History Museum in Frankfurt, Germany.

The exhibition goes back seven million years to sahelanthropus tchadensis and traces the numerous stages of man culminating with modern-day homo sapiens.

Each of the heads is used to tell its story: where they lived; what they ate; and what killed them.

It shows how researchers today use satellite image analysis and computer tomography.

There is little doubt that Africa is the cradle of humanity and this is where the most ancient of the remains were unearthed. But clues to other pre-human species have been found in the Middle East and Far East.

Only a few thousand fossils of pre-human species have ever been discovered and entire sub-species are sometimes known only from a single jaw or fragmentary skull.

Experts are often forced to resort to educated guesswork to fill in the gaps in research to come up with images of human ancestors.

Each new discovery means paleoanthropologists have to rethink the origins of man's ancestors.

The previously held concept of primitive man - characterised by a large brain and the ability to manufacture tools - has had to be changed by researchers.

European natives of primitive man, homo heidelbergensis, are believed to have been able to make perfect javelins from wood 400,000 years ago and are also thought to have had the ability to plan for the future.

Neanderthals are also now thought to have had far more culture and craft skills than earlier research indicated.

Read more here:
http://www.dailymail.co.uk/sciencetech/article-1260294/X-Woman-Species-ancient-human-Siberia.html#ixzz0jSyDiJZn

[vincent]

The point of posting these info-bits from history is to confirm that human beings didn't exist when the Dinosaur carnage was going on....................or even during the time, when the dinosaurs went mass-extinct.

And you thought humans existed 60 million years ago?

The extinction of Dinosaurs lasted for 10,000 years about the time the current human civilization exists. The only living creatures (on the land that is) that survived the "holocaust" were the Ants who are also,relatively,the most intelligent creatures on earth today.

[Cover Point]

The point of posting these info-bits from history is to confirm that human beings didn't exist when the Dinosaur carnage was going on....................or even during the time, when the dinosaurs went mass-extinct.

It is infact confirmed that the humans did not exist THOUGH even those days of more than 60 millions years ago dinosaurs in a land area which confirms to current day Bengal were known to support a weak and slow dinosaur named Gangusaurus. It was known that even in those days the followers of Gangusaurus would blame everyone else (particularly a brave and accomplished dinosaur named chappelsaurus) when Gangusaurus failed to finish any dinosaur race (which was usually the case)

[dhruvdeepak]

now if only an asteroid could wipe out scientists, the world might become an even better place

[Blwe_torch]

Another tiny dino..........still roams the earth.
The unheralded Chippynodon.....found scurrying across the streets of Windy City.....................as big as a garden lizard, is often mistaken as a garden-lizard.......which actually, it is.
This is the only dino with a thinking brain.............although the thought -process, it has been studied, belongs to the paleolithic age.
It also bears the trauma of the asteroid-hit even today......and hence keeps hiding into his holes fearing someone may 'asteroid' him.
It is an unique species....not available in any zoo( so, plz don't disturb the zoo authorities).

[Blwe_torch]

The point of posting these info-bits from history is to confirm that human beings didn't exist when the Dinosaur carnage was going on....................or even during the time, when the dinosaurs went mass-extinct.

And you thought humans existed 60 million years ago?

The extinction of Dinosaurs lasted for 10,000 years about the time the current human civilization exists. The only living creatures (on the land that is) that survived the "holocaust" were the Ants who are also,relatively,the most intelligent creatures on earth today.

Actually I wasn't sure..............anytime beyond a few million years become so fuzzy, that one never knows.
That's why I have attempted to document this, once and for all....
It is interesting to note that there were 3 different species of human beings that existed almost at the same period.......initially.

[Cover Point]

The point of posting these info-bits from history is to confirm that human beings didn't exist when the Dinosaur carnage was going on....................or even during the time, when the dinosaurs went mass-extinct.

And you thought humans existed 60 million years ago?

The extinction of Dinosaurs lasted for 10,000 years about the time the current human civilization exists. The only living creatures (on the land that is) that survived the "holocaust" were the Ants who are also,relatively,the most intelligent creatures on earth today.

Actually I wasn't sure..............anytime beyond a few million years become so fuzzy, that one never knows.

though u still remember ganguly's innings from that long ago

[Cernunnos]

The point of posting these info-bits from history is to confirm that human beings didn't exist when the Dinosaur carnage was going on....................or even during the time, when the dinosaurs went mass-extinct.

It is infact confirmed that the humans did not exist THOUGH even those days of more than 60 millions years ago dinosaurs in a land area which confirms to current day Bengal were known to support a weak and slow dinosaur named Gangusaurus. It was known that even in those days the followers of Gangusaurus would blame everyone else (particularly a brave and accomplished dinosaur named chappelsaurus) when Gangusaurus failed to finish any dinosaur race (which was usually the case)

Did blwe post your pictures from a DG meet on this thread?

 

[Cover Point]

The point of posting these info-bits from history is to confirm that human beings didn't exist when the Dinosaur carnage was going on....................or even during the time, when the dinosaurs went mass-extinct.

It is infact confirmed that the humans did not exist THOUGH even those days of more than 60 millions years ago dinosaurs in a land area which confirms to current day Bengal were known to support a weak and slow dinosaur named Gangusaurus. It was known that even in those days the followers of Gangusaurus would blame everyone else (particularly a brave and accomplished dinosaur named chappelsaurus) when Gangusaurus failed to finish any dinosaur race (which was usually the case)

Did blwe post your pictures from a DG meet on this thread?

 

no. though he did post a story of the missing gangulians from today's game thread.

[Cernunnos]

The point of posting these info-bits from history is to confirm that human beings didn't exist when the Dinosaur carnage was going on....................or even during the time, when the dinosaurs went mass-extinct.

It is infact confirmed that the humans did not exist THOUGH even those days of more than 60 millions years ago dinosaurs in a land area which confirms to current day Bengal were known to support a weak and slow dinosaur named Gangusaurus. It was known that even in those days the followers of Gangusaurus would blame everyone else (particularly a brave and accomplished dinosaur named chappelsaurus) when Gangusaurus failed to finish any dinosaur race (which was usually the case)

Did blwe post your pictures from a DG meet on this thread?

no. though he did post a story of the missing gangulians from today's game thread.

Ok. Blwe was only having a harmless discussion on dinosaurs, which made you pour vitriol - I was trying to see what the "missing link" was ..

[Blwe_torch]

The point of posting these info-bits from history is to confirm that human beings didn't exist when the Dinosaur carnage was going on....................or even during the time, when the dinosaurs went mass-extinct.

And you thought humans existed 60 million years ago?

The extinction of Dinosaurs lasted for 10,000 years about the time the current human civilization exists. The only living creatures (on the land that is) that survived the "holocaust" were the Ants who are also,relatively,the most intelligent creatures on earth today.

Just check this post below-:

Anatomically modern humans first appear in the fossil record in Africa about 195,000 years ago, and studies of molecular biology give evidence that the approximate time of divergence from the common ancestor of all modern human populations was 200,000 years ago. Suggested concurrence between human and chimpanzee DNA sequences range between 95% and 99%. It has been estimated that the human lineage diverged from that of chimpanzees about five million years ago, and from that of gorillas about eight million years ago. However, a hominid skull discovered in Chad in 2001, classified as Sahelanthropus tchadensis, is approximately seven million years old, which may indicate an earlier divergence


Modern human beings existed much longer back and not just 10000 yrs, as you are suggesting ( that is the inference I am drawing from your post).