Neanderthal Woman's DNA Reveals Ancient Inbreeding, Mysterious Human Lineage

 

LiveScience  |  By Charles Q. Choi Posted: 12/19/2013 8:51 am EST  |  Updated: 01/23/2014 1:38 am EST

 

The existence of a mysterious ancient human lineage and the genetic changes that separate modern humans from their closest extinct relatives are among the many secrets now revealed in the first high-quality genome sequence from a Neanderthal woman, researchers say.

The Neanderthal woman whose toe bone was sequenced also reveals inbreeding may have been common among her recent ancestors, as her parents were closely related, possibly half-siblings or another near relation.

Researchers have completed the first high-quality sequence of a Neanderthal genome, using a sample from the toe bone of a Neanderthal woman.

Although modern humans are the world's only surviving human lineage, others also once lived on Earth. These included Neanderthals, the closest extinct relatives of modern humans, and the relatively newfound Denisovans, whose genetic footprint apparently extended from Siberia to the Pacific islands of Oceania. Both Neanderthals and Denisovans descended from a group that diverged from the ancestors of all modern humans. [See Photos of Neanderthal Bone & Denisovan Fossils]

The first signs of Denisovans came from a finger bone and a molar tooth discovered in Denisova Cave in southern Siberia in 2008. To learn more about Denisovans, scientists examined a woman's toe bone, which was unearthed in the cave in 2010 and showed physical features resembling those of both Neanderthals and modern humans. The fossil is thought to be about 50,000 years old, and slightly older than previously analyzed Denisovan fossils.

Human interbreeding

The scientists focused mostly on the fossil's nuclear DNA, the genetic material from the chromosomes in the nucleus of the cell that a person receives from both their mother and father. They also examined the genome of this fossil's mitochondria — the powerhouses of the cell, which possess their own DNA and get passed down solely from the mother.

The investigators completely sequenced the fossil's nuclear DNA, with each position (or nucleotide) sequenced an average of 50 times. This makes the sequence's quality at least as high as that of genomes sequenced from present-day people.

The genetic analysis revealed the toe bone belonged to a Neanderthal. When compared with other Neanderthal mitochondrial DNA samples, this newfound fossil's closest known relatives are Neanderthals found in Mezmaiskaya Cave in the Caucasus Mountains about 2,100 miles (3,380 kilometers) away.

The toe bone of a Neanderthal woman was uncovered in the Denisova Cave (shown here) in southern Siberia, the same place where the first signs of the Denisovans, a relatively newfound human lineage, were found.

These findings helped the scientists refine the human family tree, further confirming that different human lineages interbred. They estimated about 1.5 to 2.1 percent of DNA of people outside Africa are Neanderthal in origin, while about 0.2 percent of DNA of mainland Asians and Native Americans is Denisovan in origin.

"Admixture seems to be common among human groups," said study lead author Kay Prüfer, a computational geneticist at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.

Intriguingly, the scientists discovered that apparently Denisovans interbred with an unknown human lineage, getting as much as 2.7 to 5.8 percent of their genomes from it. This mystery relative apparently split from the ancestors of all modern humans, Neanderthals and Denisovans between 900,000 years and 4 million years ago, before these latter groups started diverging from each other.

This enigmatic lineage could even potentially be Homo erectus, the earliest undisputed predecessor of modern humans. There are no signs this unknown group interbred with modern humans or Neanderthals, Prüferadded. [The 10 Biggest Mysteries of the First Humans]

"Some unknown archaic DNA might have caught a ride through time by living on in Denisovans until we dug the individual up and sequenced it," Prüfertold LiveScience. "It opens up the prospect to study the sequence of an archaic (human lineage) that might be out of reach for DNA sequencing."

Interbreeding took place between Neanderthals and Denisovans as well. These new findings suggest at least 0.5 percent of the Denisovan genome came from Neanderthals. However, nothing of the Denisovan genome has been detected in Neanderthals so far.

In addition, "the age of the Neanderthals and Denisovans we sequenced also doesn't allow us to say whether any gene flow from modern humans to Neanderthals or Denisovans happened," Prüfer said. The Neanderthals and Denisovans that researchers have sequenced the DNA of to date "probably lived at a time when no modern humans were around," he explained.

Modern humans' distinguishing features

It remains uncertain when modern humans, Neanderthals and Denisovans diverged from one another. The researchers currently estimate modern humans split from the common ancestors of all Neanderthals and Denisovans between 550,000 and 765,000 years ago, and Neanderthals and Denisovans diverged from each other between 381,000 and 473,000 years ago.

Genetic analysis revealed the parents of the woman whose toe bone they analyzed were closely related — possibly half-siblings, or an uncle and niece, or an aunt and nephew, or a grandfather and granddaughter, or a grandmother and grandson. Inbreeding among close relatives was apparently common among the woman's recent ancestors. It remains uncertain as to whether inbreeding was some kind of cultural practice among these Neanderthals or whether it was unavoidable due to how few Neanderthals apparently lived in this area, Prüfer said.

By comparing modern human, Neanderthal and Denisovan genomes, the researchers identified more than 31,000 genetic changes that distinguish modern humans from Neanderthals and Denisovans. These changes may be linked with the survival and success of modern humans — a number have to do with brain development.

"If one speculates that we modern humans carry some genetic changes that enabled us to develop technology to the degree we did and settle in nearly all habitable areas on the planet, then these must be among those changes," Prüfer said. "It is hard to say what exactly these changes do, if anything, and it will take the next few years to find out whether hidden among all these changes are some that helped us modern humans to develop sophisticated technology and settle all over the planet."

Prüfer and his colleagues detailed their findings in the Dec. 19 issue of the journal Nature.

Ardipithecus ramidus, human evolution, students and schools

Gary Hurd

LA Science Education Examiner

October 2, 2009

The last two days, and we can expect for the next two weeks, news reports have been filled with the spectacular Hominid fossils discovered in Ethiopia and published today in a special issue of Science Magazine.

The fossils represent the Hominin species, Ardipithecus ramidus and were nicknamed "Ardi." This will have much greater public penetration than many scientific discoveries because the AAAS has made their special edition public, and the announcement has been coordinated with the National Geographic Society, and news organizations such as CNN. This discovery has literally traveled the globe overnight. 

Your students will have questions for you that very few K-12 teachers are prepared to answer. I'll try to anticipate a few, and I'll reply to any questions posted below.

The first will be prompted by actually misleading, or at best poorly phrased headlines. These are from some surprising sources. The National Geographic News science editor, Jamie Shreeve, used the following headline for their article on Ardi, "Oldest "Human" Skeleton Found--Disproves "Missing Link."

There are several errors in a few words. These fossils are not "human." We limit "human" to the members of our Genus Homo, collectively called Hominidae often shortened to hominins.  The great apes, including humans are collectively called Hominids. "Ardi" is not a member of our genus, and is not a human. The notion of a "missing link" is falsely claimed by creationists to mean that there was a direct intermediate between modern humans and modern apes. This was never suggested by any evolutionary scientist, all the way back to Darwin. The discoverers of the newly reported fossils do think that even some of the common shared features of Chimps and Humans evolved independently. This is called convergent evolution, and is perhaps what Shreeve was refering to as "missing link" being falsified. This same error has appeared in other reports, such as by CNN.

So, the first likely question "Was this the first Human?" is answered, "No, it was one of the many early Hominids that were ancestors of Humans." The oldest member of our genus is still Homo habilus discovered in the Olduvai Gorge of Kenya and about 1.8 million years old.

These headlines also claim this is the "Oldest Human" with the emphasis on age. This is also incorrect. These fossils are exceptionally well dated and are 4.4 million years old. There are other known Hominid species older than Ardi. These are Ardipithecus kadabba, from Ethiopia about 5.5 million years old, Orrorin tugenensis from Kenya between 6.1 and 5.8 million years old, and Sahelanthropus tchadensis discovered in Chad and about 7 million years (Ma) old. This leads to the next most likely question you might hear from a student;

"How do they know how old it is?"

Ardipithecus ramadi fossils recently reported are all from a single three meter thick sedimentary deposit that is sandwiched between two volcanic ash, or tuff, layers.  The bottom layer is the Gàala("Camel") Tuff Complex (GATC) which has a ⁴⁰Ar/³⁹Ar age of4.419 ± 0.068 Ma. The capping strata is the Daam Aatu ("Baboon") BasalticTuff (DABT), which has a ⁴⁰Ar/³⁹Ar age of 4.416 ± 0.031Ma. The maximum age range known so far for these fossils is within 40,000 years. Argon dating is a radiometric method that measures the accumulation of argon 39 produced by the radioactive decay of argon 40 (see the excellent discription of ⁴⁰Ar/³⁹Ar dating provided by our reader, Readbeard in his comment below). Since the tuff was fully melted releasing its gasses, there is no question of residual argon to complicate the dates.

And the follow-up question is, "How do they know that radiometric dating works?"

We know this because electric lights work. We know this because any change in the universal physical constants great enough to affect dating results would necessarily have caused the earth to have recently melted, and penetrated with so much radiation that it would glow. We know this because radiometric dates agree with simple counting of annual events that accumulate in lakes, glaciers, and the ocean bottom. Radiometric dates also match with yearly events like tree rings.

Many students are influenced by creationism through their churches. Excellent resources for teachers on evolution are The National Center for Science Education, and Understanding Evolution

 

Ardipithecus ramidus Illustration courtesy J. H. Matternes via Science/AAAS

Fossils radically alter ideas about the look of man's earliest ancestors

 

Analysis of a near-complete skeleton of a human ancestor found in Ethiopia changes scientists' thinking about the appearance and behavior of our distant forebears.

By Thomas H. Maugh II

October 2, 2009

A treasure trove of 4.4-million-year-old fossils from the Ethiopian desert is dramatically overturning widely held ideas about the early evolution of humans and how they came to walk upright, even as it paints a remarkably detailed picture of early life in Africa, researchers reported Thursday.

The centerpiece of the diverse collection of primate, animal and plant fossils is the near-complete skeleton of a human ancestor that demonstrates our earliest forebears looked nothing like a chimpanzee or other large primate, as is now commonly believed. Instead, the findings suggest that the last common ancestor of humans and primates, which existed nearly 2 million years earlier, was a primitive creature that shared few traits with modern-day members of either group.

Graphic: Graphic: Dramatic addition to human evolutionary tree

The findings, analyzed in a large group of studies published Thursday in the journal Science, also indicate that our ancestors began walking upright in woodlands, not on grassy savannas as prior generations of researchers had speculated.

The discovery of the specimen called Ardipithecus ramidus "is one of the most important discoveries for the study of human evolution," said paleoanthropologist David Pilbeam of Harvard University, who was not involved in the research. "The find itself is extraordinary, as were the enormous labors that went into the reconstruction of a skeleton shattered almost beyond repair," he said in an e-mailed statement.

"It is so rare to get a more or less complete skeleton," said paleoanthropologist Andrew Hill of Yale University. "In the entire course of human evolution, at least until you get to Neanderthals, there are only three to four available. We can always tell so much more from a skeleton" than from the jawbones and skulls that are more commonly found.
The fossils described in the new studies were found 15 years ago in the Afar Triangle of Ethiopia by a team led by paleoanthropologist Tim White of UC Berkeley. But White and his team have been relatively closemouthed about the fossils, and other researchers -- some of whom have accused him of hoarding the fossils for his own use -- have been eagerly awaiting more information.

Today, they are getting a surfeit: Eleven papers by 47 authors, and a similar number of short summaries prepared by each paper's authors.

The fossils were found in a layer of sediment sandwiched between two layers of volcanic ash, each dating from 4.4 million years ago -- indicating that the fossils are also of that age.

In addition to the nearly complete fossil specimen of the female primate, which investigators have dubbed Ardi, the team found more than 100 fossils from 36 other members of the same species.

"These fossils are much more important than Lucy," the 3.2-million-year-old specimen of Australopithecus afarensis that was found in the Afar desert in the 1970s, said paleoanthropologist Alan Walker of Pennsylvania State University, who was not involved in the research. "The reason is that when Lucy was found, we already knew the major features of Australopithecus from fossils found in the 1940s. . . . These fossils are of a completely unknown creature, and are much stranger and more primitive than Australopithecus."

The White team also found fossils of 29 species of birds, primarily small ones like doves, lovebirds, mousebirds, passerines and swifts, as well as several that were previously unknown. Animal fossils included 20 new species of small mammals, including shrews, bats, rodents, hares and small carnivores, as well as larger animals, including baboons, colobus monkeys and spiral-horned antelopes.

Fossilized wood, seed and other plant remains indicate the presence of hackberry, fig and palm trees. Collectively, these finds indicate that the environment was more humid and cooler than it is today, and contained grassy woodland with forest patches.
Today, the Afar is a desert. But go back in a time machine and "4.4 million years ago, this was really a different world," White said. "We look up in the trees and we see that they are full of monkeys. We look around on the ground and we see that there are a lot of kudus. And we see an occasional hyena. And we see elephants and we see lots of small mammals."

This whole collection of data "gives us information we have never had before about human evolution," said paleoanthropologist C. Owen Lovejoy of Kent State University, one of the primary authors of the papers. "The whole savanna theory goes out the window in terms of it being the explanation for upright walking. . . . And the idea that we evolved from something like a chimpanzee also goes out the window."

Ardi stood about 47 inches tall and probably weighed 110 pounds. Many researchers previously believed that such an early ancestor would, like modern chimps, be a knuckle-walker, using the knuckles for support while moving on all fours. Instead, Ardi appears to have climbed on all fours on branches, but walked upright on the ground. Her feet, like those of monkeys but not chimps, were designed more for propulsion than for grasping.
Her face had a projecting muzzle, giving her an ape-like appearance, but many features of her skull, such as the ridge above the eye socket, are quite different than those of chimpanzees. Her brain is about the same size as Lucy's.

Her hands lacked many of the specializations that allow modern-day African apes to swing, hang and easily move through trees. Those specializations apparently evolved in large primates after they separated from the last common ancestor with humans more than 6 million years ago. (Few fossils of such primates are available because they lived primarily in forests, which are not conducive to preservation of bone.)
The finds "are turning evolution on its head," Lovejoy said.

The most controversial aspects of the papers involve the authors' -- particularly Lovejoy's -- interpretations of what the fossils say about behavior. Of particular importance, he said, is that the sizes of males and females were about the same, and that the specimens do not have large, sharp canine teeth. Both findings suggest that the fierce, often violent competition among males for females in heat that characterizes gorillas and chimpanzees was absent in Ardipithecus.

That implies, Lovejoy concluded, that the males were beginning to enter into monogamous relationships with females and devoted more time to caring for their young than did earlier ancestors.

"This is a restatement of Owen Lovejoy's ideas going back almost three decades, which I found unpersuasive then and still do," Pilbeam said.
Hill was more blunt, calling Lovejoy's speculation "patent nonsense."

thomas.maugh@latimes.com

http://www.latimes.com/news/nationworld/nation/la-sci-fossils2-2009oct02,0,3420742.story#ixzz2tV4kMLzY

Ten facts about Ardipithecus ramidus, Ardi

Kathryn Siranosian

Science & Nature Examiner

 

 

October 1, 2009

Ardipithecus ramidus is an archaelogical specimen that has been described as "one of the most important discoveries for the study of human evolution."

The skeleton fossils were found 15 years ago in the Afar Triangle of Ethiopia by an archaelogical team led by paleoanthropologist Tim White of UC Berkeley. The team found a nearly complete fossil specimen of a female primate, plus more than 100 fossils from 36 other members of the same species.

After 15 years of analysis, the researchers released their findings today. The findings are contained in a total of 11 papers by 47 authors.

Scientists call Ardipithecus ramidus "Ardi" for short.

Ardi lived 4.4 million years ago in what is now Ethiopia.

She lived in woodland conditions more than a million years before the famous "Lucy" fossil (Australopithecus afarensis).

Ardi walked upright. She stood about 47 inches tall and weighed about 110 pounds.

Even though she walked upright, her feet were well adapted to grasping, and so researchers think she was able to climb trees. The structure of Ardi's feet, pelvis, legs and hands suggest that she was a biped on the ground, but a quadruped in the trees.

What's more, her teeth resemble modern human teeth more closely than they do those of a chimpanzee.

It's this unexpected mix of advanced characteristics and primitive traits that has scientists so intrigued.Ardi appears to be a transitional fossil that fits somewhere between a more ape-like ancestor and the bipedal hominid Lucy.

http://www.examiner.com/article/ten-facts-about-ardipithecus-ramidus-ardi

After reading this, you’ll never look at a banana in the same way again

January 26, 2014 2:44 pm

This is interesting. After reading this, you’ll never look at a banana in the same way again.

Bananas contain three natural sugars – sucrose, fructose and glucose combined with fiber. A banana gives an instant, sustained and substantial boost of energy.
Research has proven that just two bananas provide enough energy for a strenuous 90-minute workout. No wonder the banana is the number one fruit with the world’s leading athletes.
But energy isn’t the only way a banana can help us keep fit. It can also help overcome or prevent a substantial number of illnesses and conditions, making it a must to add to our daily diet.

DEPRESSION
According to a recent survey undertaken by MIND amongst people suffering from depression, many felt much better after eating a banana. This is because bananas contain tryptophan, a type of protein that the body converts into serotonin, known to make you relax, improve your mood and generally make you feel happier.
PMS:
Forget the pills – eat a banana. The vitamin B6 it contains regulates blood glucose levels, which can affect your mood.

ANEMIA
High in iron, bananas can stimulate the production of hemoglobin in the blood and so helps in cases of anemia.
BLOOD PRESSURE:
This unique tropical fruit is extremely high in potassium yet low in salt, making it perfect to beat blood pressure So much so, the US Food and Drug Administration has just allowed the banana industry to make official claims for the fruit’s ability to reduce the risk of blood pressure and stroke.

BRAIN POWER
200 students at a Twickenham school ( England ) were helped through their exams this year by eating bananas at breakfast, break, and lunch in a bid to boost their brain power. Research has shown that the potassium-packed fruit can assist learning by making pupils more alert.

CONSTIPATION
High in fiber, including bananas in the diet can help restore normal bowel action, helping to overcome the problem without resorting to laxatives.

HANGOVERS
One of the quickest ways of curing a hangover is to make a banana milkshake, sweetened with honey. The banana calms the stomach and, with the help of the honey, builds up depleted blood sugar levels, while the milk soothes and re-hydrates your system.

HEARTBURN
Bananas have a natural antacid effect in the body, so if you suffer from heartburn, try eating a banana for soothing relief.

MORNING SICKNESS
Snacking on bananas between meals helps to keep blood sugar levels up and avoid morning sickness.
MOSQUITO BITES:
Before reaching for the insect bite cream, try rubbing the affected area with the inside of a banana skin. Many people find it amazingly successful at reducing swelling and irritation.

NERVES
Bananas are high in B vitamins that help calm the nervous system..
Overweight and at work? Studies at the Institute of Psychology in Austria found pressure at work leads to gorging on comfort foodlike chocolate and chips. Looking at 5,000 hospital patients, researchers found the most obese were more likely to be in high-pressure jobs. The report concluded that, to avoid panic-induced food cravings, we need to control our blood sugar levels by snacking on high carbohydrate foods every two hours to keep levels steady.

ULCERS
The banana is used as the dietary food against intestinal disorders because of its soft texture and smoothness. It is the only raw fruit that can be eaten without distress in over-chroniclercases. It also neutralizes over-acidity and reduces irritation by coating the lining of the stomach.

TEMPERATURE CONTROL
Many other cultures see bananas as a ‘cooling’ fruit that can lower both the physical and emotional temperature of expectant mothers. In Thailand , for example, pregnant women eat bananas to ensure their baby is born with a cool temperature.
So, a banana really is a natural remedy for many ills. When you compare it to an apple, it has FOUR TIMES the protein, TWICE the carbohydrate, THREE TIMES the phosphorus, five times the vitamin A and iron, and twice the other vitamins and minerals.. It is also rich in potassium and is one of the best value foods around So maybe its time to change that well-known phrase so that we say, ‘A BANANA a day keeps the doctor away!’

http://worldobserveronline.com/2014/01/26/reading-youll-never-look-banana-way/?utm_source=taboola&utm_medium=referral

NASA technique to scan space dust for proof of life

 

Tuesday, February 4, 2014 - 18:32 IST | Agency: IANS

In a latest bid to unravel the mysterious origin of life, a team of researchers has invented an advanced technology to inspect extremely small meteorite samples for the components of life.

This technology would enable scientists to investigate other small-scale extraterrestrial materials such as micrometeorites, interplanetary dust particles and cometary particles in future studies.

According to scientists, despite their small size, interplanetary dust particles may have provided higher quantities and a steadier supply of extraterrestrial organic material to early earth.

"Unfortunately, there have been limited studies examining their organic composition, especially with regards to biologically relevant molecules that may have been important for the origin of life owing to the miniscule size of these samples," explained Michael Callahan of NASA's Goddard Space Flight Centre in Greenbelt, Maryland.

The team found amino acids in a 360 microgram sample of the 'Murchison' - a well-studied meteorite.

This sample size is 1,000 times smaller than the typical sample size used.

"Murchison is a well-studied meteorite. We got the same results looking at a very small fragment as we did a much larger fragment from the same meteorite," said Callahan.

The team used a nanoflow liquid chromatography instrument to sort the molecules in the meteorite sample.

It then applied nanoelectrospray ionisation to give the molecules an electric charge and deliver them to a high-resolution mass spectrometer instrument, which identified the molecules based on their mass.

"We are pioneering the application of these techniques for the study of meteoritic organics," said Callahan in a study available in the Journal of Chromatography A.

"This technology would also be extremely useful to search for amino acids and other potential chemical biosignatures in samples returned from Mars," added Daniel Glavin from Goddard's astrobiology analytical laboratory.

Till date, researchers have analysed carbon-rich meteorites (carbonaceous chondrites) and found amino acids, which are used to make proteins.

Proteins are among the most important molecules in life, used to make structures like hair and skin, and to speed up or regulate chemical reactions.

The 'first true scientist'

By Professor Jim Al-Khalili
University of Surrey

An artist's impression of al-Hassan Ibn al-Haytham

Isaac Newton is, as most will agree, the greatest physicist of all time.

At the very least, he is the undisputed father of modern optics,­ or so we are told at school where our textbooks abound with his famous experiments with lenses and prisms, his study of the nature of light and its reflection, and the refraction and decomposition of light into the colours of the rainbow.

Yet, the truth is rather greyer; and I feel it important to point out that, certainly in the field of optics, Newton himself stood on the shoulders of a giant who lived 700 years earlier.

For, without doubt, another great physicist, who is worthy of ranking up alongside Newton, is a scientist born in AD 965 in what is now Iraq who went by the name of al-Hassan Ibn al-Haytham.

Most people in the West will never have even heard of him.

As a physicist myself, I am quite in awe of this man's contribution to my field, but I was fortunate enough to have recently been given the opportunity to dig a little into his life and work through my recent filming of a three-part BBC Four series on medieval Islamic scientists.

Modern methods

Popular accounts of the history of science typically suggest that no major scientific advances took place in between the ancient Greeks and the European Renaissance.

But just because Western Europe languished in the Dark Ages, does not mean there was stagnation elsewhere. Indeed, the period between the 9th and 13th Centuries marked the Golden Age of Arabic science.

Great advances were made in mathematics, astronomy, medicine, physics, chemistry and philosophy. Among the many geniuses of that period Ibn al-Haytham stands taller than all the others.

Ibn-al Haytham conducted early investigations into light

Ibn al-Haytham is regarded as the father of the modern scientific method.

As commonly defined, this is the approach to investigating phenomena, acquiring new knowledge, or correcting and integrating previous knowledge, based on the gathering of data through observation and measurement, followed by the formulation and testing of hypotheses to explain the data.

This is how we do science today and is why I put my trust in the advances that have been made in science.

But it is often still claimed that the modern scientific method was not established until the early 17th Century by Francis Bacon and Rene Descartes.

There is no doubt in my mind, however, that Ibn al-Haytham arrived there first.

In fact, with his emphasis on experimental data and reproducibility of results, he is often referred to as the "world's first true scientist".

Understanding light

He was the first scientist to give a correct account of how we see objects.

It is incredible that we are only now uncovering the debt that today's physicists owe to an Arab who lived 1,000 years ago

Prof Jim Al-Khalili

He proved experimentally, for instance, that the so-called emission theory (which stated that light from our eyes shines upon the objects we see), which was believed by great thinkers such as Plato, Euclid and Ptolemy, was wrong and established the modern idea that we see because light enters our eyes.

What he also did that no other scientist had tried before was to use mathematics to describe and prove this process.

So he can be regarded as the very first theoretical physicist, too.

He is perhaps best known for his invention of the pinhole camera and should be credited with the discovery of the laws of refraction.

He also carried out the first experiments on the dispersion of light into its constituent colours and studied shadows, rainbows and eclipses; and by observing the way sunlight diffracted through the atmosphere, he was able to work out a rather good estimate for the height of the atmosphere, which he found to be around 100km.

Enforced study

In common with many modern scholars, Ibn-al Haytham badly needed the time and isolation to focus on writing his many treatises, including his great work on optics.

He was given an unwelcome opportunity, however, when he was imprisoned in Egypt between 1011 and 1021, having failed a task set him by a caliph in Cairo to help solve the problem of regulating the flooding of the Nile.

While still in Basra, Ibn al-Haytham had claimed that the Nile's autumn flood waters could be held by a system of dykes and canals, thereby preserved as reservoirs until the summer's droughts.

But on arrival in Cairo, he soon realised that his scheme was utterly impractical from an engineering perspective.

Yet rather than admit his mistake to the dangerous and murderous caliph, Ibn-al Haytham instead decided to feign madness as a way to escape punishment.

This promptly led to him being placed under house arrest, thereby granting him 10 years of seclusion in which to work.

Planetary motion

He was only released after the caliph's death. He returned to Iraq where he composed a further 100 works on a range of subjects in physics and mathematics.

While travelling through the Middle East during my filming, I interviewed an expert in Alexandria who showed me recently discovered work by Ibn al-Haytham on astronomy.

It seems he had developed what is called celestial mechanics, explaining the orbits of the planets, which was to lead to the eventual work of Europeans like Copernicus, Galileo, Kepler and Newton.

It is incredible that we are only now uncovering the debt that today's physicists owe to an Arab who lived 1,000 years ago.

Professor Jim Al-Khalili presents Science and Islam on BBC Four at 2100GMT on Monday 5, 12 & 19 January

 

The Language of Science

Episode 1 of 3

Duration: 59 minutes

Physicist Jim Al-Khalili travels through Syria, Iran, Tunisia and Spain to tell the story of the great leap in scientific knowledge that took place in the Islamic world between the 8th and 14th centuries.

Its legacy is tangible, with terms like algebra, algorithm and alkali all being Arabic in origin and at the very heart of modern science - there would be no modern mathematics or physics without algebra, no computers without algorithms and no chemistry without alkalis.

For Baghdad-born Al-Khalili this is also a personal journey and on his travels he uncovers a diverse and outward-looking culture, fascinated by learning and obsessed with science. From the great mathematician Al-Khwarizmi, who did much to establish the mathematical tradition we now know as algebra, to Ibn Sina, a pioneer of early medicine whose Canon of Medicine was still in use as recently as the 19th century, he pieces together a remarkable story of the often-overlooked achievements of the early medieval Islamic scientists.

 

The Empire of Reason

Episode 2 of 3

Duration: 1 hour

Physicist Jim Al-Khalili travels through Syria, Iran, Tunisia and Spain to tell the story of the great leap in scientific knowledge that took place in the Islamic world between the 8th and 14th centuries.

Al-Khalili travels to northern Syria to discover how, a thousand years ago, the great astronomer and mathematician Al-Biruni estimated the size of the earth to within a few hundred miles of the correct figure.

He discovers how medieval Islamic scholars helped turn the magical and occult practice of alchemy into modern chemistry.

In Cairo, he tells the story of the extraordinary physicist Ibn al-Haytham, who helped establish the modern science of optics and proved one of the most fundamental principles in physics - that light travels in straight lines.

Prof Al-Khalili argues that these scholars are among the first people to insist that all scientific theories are backed up by careful experimental observation, bringing a rigour to science that didn't really exist before.

 

The Power of Doubt

Episode 3 of 3

Duration: 1 hour

Physicist Jim Al-Khalili tells the story of the great leap in scientific knowledge that took place in the Islamic world between the 8th and 14th centuries.

Al-Khalili turns detective, hunting for clues that show how the scientific revolution that took place in the 16th and 17th centuries in Europe had its roots in the earlier world of medieval Islam. He travels across Iran, Syria and Egypt to discover the huge astronomical advances made by Islamic scholars through their obsession with accurate measurement and coherent and rigorous mathematics.

He then visits Italy to see how those Islamic ideas permeated into the West and ultimately helped shape the works of the great European astronomer Copernicus, and investigates why science in the Islamic world appeared to go into decline after the 16th and 17th centuries, only for it to re-emerge in the present day.

Al-Khalili ends his journey in the Royan Institute in the Iranian capital Tehran, looking at how science is now regarded in the Islamic world.

http://news.bbc.co.uk/2/hi/science/nature/7810846.stm

http://www.bbc.co.uk/programmes/b00gksx4