The origin of the ancient Dembeni people of the Comoros Islands.

When the first Europeans reached the Comoros Islands in the late fifteenth century, they found a group of small independent city-states forming part of the 'Swahili Corridor', a system of small island and port-city states which stretched up the east coast of Africa, also including cities on Madagascar and the coasts of what today are Mozambique, Tanzania, and Kenya. These states were bound together by a common language, Swahili, and a common religion, and traded slaves and African goods with the Middle East and other areas of the Indian Ocean rim. Local legend had it that the people of the Comoros were descended from King Solomon and the Queen of Sheba, and that upon hearing of the Profit Mohammed, an emissary was sent from the islands, who returned bringing with him the Islamic faith, and built the first mosque in the archipelago on the island of Ngazidja. European ethnologists concluded that the Swahili culture came about as Arab traders moved down the coast of East Africa, taking local women as wives (or, in more lurid accounts, concubines). 

The position of the Comoros Islands in the Mozambique Channel. The island of Ngazidja is now more commonly known as 'Grand Comoros', and is home to Moroni, the capital of the Union of the Comoros, which gained independence from France in 1979 as the 'Federal Islamic Republic of Comoros', adopting its current name in December 2001. The island of Moare remained a French possession, now forming the Department of Mayotte. Wright (1975).

In the 1970s and 80s a series of archaeological digs were carried out in the Comoros. The earliest culture uncovered by these excavations was identified as the 'Dembeni Phase', in reference to the location where it was first discovered, close to the village of Dembeni on the island of Moare (now the French department of Mayotte). Overlying this in places were layers assigned to the more widespread 'Hanyundru Phase', which can be clearly associated with medieval Swahili culture, with buildings made from stone or coral and cement, and imported Middle Eastern Glassware.

Six sites were associated with the Dembeni Phase, Dembeni itself plus Old Sima on the island of Ndzuwani (now more commonly known as Anjouan), M'Bachile, Dzindani, and M'Beni, on the island of Ngazidja (now usually referred to Grand Comoros), and M'Ro Deoua on Mwali (now usually Mohéli). The Dembeni people built small-to-medium sized villages, comprising houses built from wooden posts with a mud covering, on beaches or ridge-tops, always close to lagoons, and with access to freshwater streams. They consumed significant amounts of seafood (Fish, Shellfish, and Turtles), and kept Carrle and Goats, and farmed crops such as Rice, Millet, and Coconuts, which are still common across the region today.

The Dembini people produced distinctive pottery, with two distinct styles found on the islands and thought to have been made locally. The first of these is plain, with a smooth exterior and a burnished interior, sometimes embellished with a band of incisions or shell imprints. The second is covered with a red slip, either on the interior or the exterior, or both, and is typically burnished and decorated with graphite. In both cases the clay used was course and contained particles of red, grey, and white grit, although the former was typically courser. This courser, plainer style was used to make jars and pots, many of which show signs of being used for cooking. The finer, more decorated, style was used to make shallow bowls, possibly for serving food. A single bead made from local pottery was found at Dembeni,

Examples of 'plain' Dembeni-ware pottery from (a) Dembeni, (b) Sima, (c) M'Ro Deoua, (d) Dembeni, (e) Sima, (f) Dembeni, (g) M'Beni, (h) Dembeni, (i) Dembeni, (j) Dembeni, (k) Dembeni, (l) M'Bachile, (m) M'Bachile, and (n) Sima. Carla Sinopoli in Wright (1984).

Dating of the Dembeni sites was difficult with the technology available in the 1970s and 80s. Attempts were made to obtain carbon¹⁴ dates from several items. A shell collected from a midden at Sima yielded a carbon¹⁴ date of 1550±70 years before the present. Since it was understood by this time that it was necessary to adjust dates from shells to take into account for the carbon¹⁴ content of the atmosphere and the ocean in which the shell had formed, this was interpreted as indicating a date of about 910 AD, with a 96% probability of a date between 785 and 1040 AD. A piece of charcoal from M'Bachile yielded a carbon¹⁴ date of 1140±60 years before the present, with a 96% chance of a date between 470 and 650 AD, while a second piece of charcoal from Sima yielded a carbon¹⁴ date of 1960±70 years before the present, with a 96% chance of a date between 155 BC and 215 AD. At first sight, these dates seem incompatible, sine the Dembeni culture is not thought to have persisted for many centuries, but dates obtained from charcoal represent the age of the original wood from which the charcoal was made, and if this wood came from the interior of a tree, may be much older than the burning event.

Another way to determine the age of archaeological sites is by comparing goods from them to similar items from other sites with known chronologies. Although the majority of the recovered material from the Dembeni sites appears to have been local in origin, items from further afield were found at all locations, together representing about 4% of the recovered ceramics. 

Among the items found at M'Ro Deoua were several large basins and the neck of a large pithoi (large storage jar) made from an oxidised yellow-green clay. These items were made from a base-material which contained fragments of older pottery and fragments of igneous rock, and were decorated with chopped-grass impressions. Smaller fragments of the same material were also found at Dembeni and Sima. This pottery resembled similar material known from several sites in the Near East, at sites dated to between the eighth and tenth centuries AD, although this pottery had never been the subject of any detailed study.

A second type of non-local pottery, found at all sites except Dzindani, comprised fragments of large sandy-ware jars decorated with incisions and barbotine appliqué, with a blue-green glaze on the external surface and an speckled grey or grey-green glaze on the interior surface. Similar jars are known from Siraf on the Gulf Coast of Iran, where they first appear in the eighth century, and on Manda Island, Kenya, where they are found alongside ninth-to-tenth century Chinese ceramics. 

The most common form of imported pottery, found at all of the Dembeni sites, were small fine bowls with a white glaze, typically with a splash of coloured glaze on the interior; the colour of this varies, with the most common being cobalt, turquoise, or gold. Similar bowls are known at Susa in southwest Iran, where examples with cobalt on the interior appear around 720 AD, while turquoise does not appear until about 820 AD, as well as at Shiraf, where cobalt appears around 800 AD and turquoise around 850. This may offer some insight into the chronology of the Dembeni sites, as only white pottery is present at M'Ro Deoua, cobalt at Dembeni, and turquoise at M'Bachile and Sima.

As well as pottery, glass fragments were found at Dembeni, Sima, M'Ro Deoua, and M'Bachile. These were greenish, yellowish, clear, or cobalt blue, and round or cylindrical in shape. All appeared to have been blown, and resembled glassware forms widespread in the Near East. A number of iron items, and slag from iron forging were also found. While it was unclear where these had come from, iron is not a locally available resource in the Comoros. 

All of this appeared to show that the Dembeni people occupied the Comoros between about 800 and 1000 AD, and that from the very earliest, they had strong trading connections with the Near East. This apparently supported the idea that they were migrants from this area, rather than the east coast of Africa. However, two grave sites were also found associated with one of the Dembeni sites, Ngazidia. These both had their heads facing to the south, at odds with Islamic custom, making it highly unlikely that they were Muslims, which would almost certainly have been the case with Near Eastern emigrees of the period.

Founded in 2008, the Sealinks Project seeks to study the movements of ancient peoples and development of trading routes around the Indian Ocean. One of the problems this has sought to resolve is the peopling of Madagascar by settlers from Southeast Asia, and the subsequent adoption of Southeast Asian crops, such as Rice, Coconuts, and Mung Beans into the cultures of the Swahili Corridor. Madagascar was settled in the first millennium BC by hunter-gatherers from Africa, but agriculture appeared to have arrived on the island much later, with settlers from Southeast Asia, and today about 10% of Madagascar's flora is of Southeast Asian origin, either crop plants of weeds introduced along with them.

Between 2010 and 2013, archaeologists from the Sealinks Project carried out excavations at early sites on Madagascar and the Comoros, and settlements of the Swahili Corridor on the coast and offshore islands of East Africa, looking for early examples of both African and Southeast Asian crops, which were then dated using modern radiocarbon methods. Unsurprisingly, Southeast Asian crops were almost absent from the African sites, with only small quantities found at the largest and most active ports. On Madagascar, Southeast Asian crops appear abruptly around 1000 AD, with no evidence of any agricultural activity before this point. Surprisingly, the Comoron sites associated with the Dembeni Culture were also overwhelmingly dominated by Southeast Asian crops (only Sima produced small amounts of African crops such as Millet), and these appeared around 750 AD, significantly earlier than on Madagascar.

(A) Map of eastern Africa, including the Comoros and Madagascar, showing the locations of sites included in the crop study. The relative proportions of African and Asian crops are shown for each site (percentages based on numbers of identified specimens per site). (B) Chronological summary of African vs. Asian crop patterns by site from north to south. Crowther et al. (2016).

This raised some surprising questions. The reliance of the Dembeni people on Southeast Asian, rather than African or Middle Eastern crops, suggests that they did not come from either of these areas, but were instead of Southeast Asian origin, potentially part of the great Austronesian migration of peoples from the Malaysian Peninsula through the Islands of Indonesia and on as far as Hawai'i and New Zealand, but also westward to Madagascar. With the Comoros having apparently been settled before Madagascar, it is possible that the larger island was secondarily settled by the Dembeni people, although it is also possible that older sites on Madagascar have not been located.

The modern people of the Comoros are not obviously Southeast Asian. They appear similar to the peoples of East Africa, and speak a language (Comorian) which belongs to the Sabaki language group, which is otherwise spoken along the Tana River of Kenya, and surrounding parts of the Kenyan coast. Their closest cultural links are with the Swahili culture of coastal Kenya, Tanzania, and Mozambique, itself thought to have derived from the Middle East through trade along the east coast of Africa. Possibly this could indicate that the Dembeni people, although the first settlers of the Comoros, did not survive contact with later settlers from East Africa or the Middle East.

With this in mind, a project led by scientists from the Laboratoire d’Anthropologie Moléculaire et Imagerie de Synthèse at the Université de Toulouse carried out a study in which the genomes of volunteers from the Comoros and coastal Swahili communities in Kenya were compared to an extant database, containing genomes from Africa, Madagascar, the Middle East, Southeast Asia, South Asia, East Asia, and Europe.

Surprisingly, despite long-held assumptions about their having Middle Eastern ancestry, the Kenyan Swahili populations were found to be of entirely sub-Saharan African ancestry. The Kenyan Swahili populations were found to have a homogeneous structure, all more closely related to one another than to any other group, and to be more closely related to Bantu-speaking populations than any other African group. Some of the Kenyan Swahili individuals had recent Somali ancestry, but otherwise the Swahili populations were strongly isolated from Somali and Ethiopian populations. The Comorian and Malagasy populations were more closely related to the Kenyan Swahili populations than to any other African population, although both had admixtures of Southeast Asian ancestry, which made up between 33 and 39% of the ancestry of the Malagasy populations, and 8-9% of the ancestry of the Comorians. Curiously, despite being further south than the Kenyan Swahili populations, the Comorians also had some Middle Eastern ancestry, which made up 6-7% of their genomes.

A statistical model of the ancestry of modern Comorians suggested that their common ancestry formed as a distinct population between 1197 and 792 years before the present, with the admixture of a Swahili and a Southeast Asian group. Different islands within the group have also had subsequent influxes of genetic material from Swahili, Middle Eastern, and Southeast Asian populations. The Madagascan populations showed a more recent origin, with an admixture between a Swahili Group and an Island Southeast Asian group between 876 and 742 years before the present (this population appears to have arrived in the area separately, and not to have migrated from the Comoros). 

Admixture Scenario for Populations along the Swahili Corridor as Estimated by GLOBETROTTER and ADMIXTURE Dark red arrows represent Swahili gene flow; light green arrows represent Island Southeast Asian Banjar or Malay; a yellow arrow represents Middle Eastern gene flow; and the purple arrow represents gene flow from the Horn of Africa. The pink arrow represents gene flow from central and southern Bantu speakers. Dates refer to the last detectable admixture event; dates below pie charts refer to the admixture event between the Swahili and Banjar or Malay; dates in italics represent secondary gene flow. Sex-biased gene flows are represented by male and female symbols in the tip of the arrows; note that they are not presentin Malagasy Antemoro and Comorian Moheli. Brucato et al. (2018).

Thus, the most likely scenario is that the Dembeni people reached the Comoros Islands from Peninsula Malaysia or Island Southeast Asia around 750 AD. They brought with them staple crops from Southeast Asia, as well as Cattle and Goats, and fished in the islands' lagoons and surrounding seas. They exchanged trade goods with the Near East, probably through early East African Swahili intermediaries, with whom they may have intermarried. Despite this cultural exchange, the Dembeni appear to have remained a distinct culture till around 1000 AD, when they were abruptly replaced by the Hanyundru culture, which appears to have been more distinctly Swahili in nature. Modern Comorians derive about 8-9% of their genetic ancestry from this group, and still farm many Southeast Asian crops, but speak a language of apparent Kenyan origin, and are culturally close to the Swahili populations of East Africa.

See also...

The Sarcophagus of Ankhnesneferibra.

Sarcophagus of Ankhnesneferibra, daughter of Psamtik II, 26th Dynasty, circa 530 BC. The British Museum.

Ankhnesneferibra was daughter of Psamtik II, the third Pharaoh of the 26th Dynasty of Egypt, known as the 'Sais Kings' or 'Saites', after the city of Sais in the Nile Delta, from where they ruled. In 595 she was sent to Thebes, to become the adoptive daughter of Nicotris I, God's Wife of Amun (the leader of the Egyptian Gods)and ruler of the city, adopting the title of Divine Adoratrice of Amun (High Priestess of the Cult of Amun). Nictrotis was a daughter of  Psamtik I, first Pharaoh of the 26th Dynasty and Psamtik II's grandfather, and as God's Wife of Amun ruled Thebes from 655 BC until her death in 585 BC, when Ankhnesneferibra succeeded her, becoming both Divine Adoratrice and God's Wife of Amun, until 560 BC, when Nicotris II, the daughter of Amasis II (fifth pharaoh of the 26th Dynasty and grandson of Psamtik II), became Divine Adoratrice of Amun, and adoptive daughter of Ankhnesneferibra.

Ankhnesneferibra ruled in Thebes from 585 until 525 BC, when Egypt was Invaded by the Achaemenid Persians under the Emperor Cambyses II, bringing the 26th Dynasty to an end. Cambysis re-organised the administration of Egypt significantly, incorporating it into his empire as a province, and abolished the roles of Divine Adoratrice of Amun and God's Wife of Amun (unfortunate for Nicrotis II, who by this time had been waiting for the role for 35 years). 

Statue  of Ankhenesneferibre, God's Wife of Amun, in the collection of the Nubian Museum of Aswan. John Campana/Flikr/Wikimedia Commons.

The title of God's Wife is a curious one. It originally applied to the wives and mothers of Pharaoh's (who were seen as living embodiments of the gods), with no specific god being associated with the post. This appears to have been modified to God's Wife of Amun in the New Kingdom, with little initial alteration of the role. The role as understood in the time of Ankhnesneferibra appears to have been created by Ramasses VI, the fifth Pharaoh of the 20th Dynasty, who gave the titles of God's Wife of Amun and Divine Adoratrice of Amun to his daughter Iset, with the intention that she would remain an unmarried virgin and adopt the daughter of the next Pharoah as her daughter and heiress. 

The God's Wife of Amun became the effective ruler of Thebes (ancient capital of Egypt) under Shepenupet I, the daughter of the 23rd Dynasty Pharoah Osorkon III, who adopted Amenirdis I, daughter of the Kushite invader Kashta as her daughter and Divine Adoratrice, thus securing her own political power and Kashta's claim to be a legitimate Pharaoh, ruler of Egypt, and founder of the 25th Dynasty at the same time. Kashta faced a rival claim to the throne from Tefnakht I, founder of the 24th Dynasty, which was also based in Sais, after the Kushites had conquered most of Egypt, including the traditional capital, Thebes.

For the Pharaohs of the 26th Dynasty the role of God's Wife of Amun was clearly an important one, and signficant to their claim to be legitimate rulers. The first Pharaoh of the 26th Dynasty, Psamtik I, was installed as a client Pharaoh at Sais by the Assyrian King Ashurbanipal, following the Assyrian invasion of Egypt, but secured independence when the Assyrians were forced to withdraw to concentrate on defending the heartlands of their empire against the Babylonians. A capable military leader, Psamtik I was able to drive out the Kushite Pharaoh's of the 25th Dynasty, smashing many of the monuments associated with their reign to assert his status as legitimate Pharaoh of Egypt. 

At this time, Shepenupet II, daughter of the Kushite Pharaoh Piye (son of Kashta) was the God's Wife of Amun, and her niece Amenirdis II was Divine Adoratrice. Psamtik I deposed Amenirdis II, installing his daughter Nicotris I as adoptive daughter of Shepenupet II, Divine Adoratrice and heir to the title of God's Wife, but left Shepenupet II in place as God's Wife and ruler of Thebes, like Kashta before him using this act to legitimise his own reign. 

Pavel Alekseyevich Cherenkov (1904-1990): Discoverer of Cherenkov Radiation.

Pavel Alekseyevich Cherenkov. Voronezh State University.

Pavel Alekseyevich Cherenkov was born in 1904 in the village of Novaya Chiglain in what was then the Voronezh Governorate of South Russia (now the Voronezh Oblast of Central District, Russia) to peasant farmers Alexey Cherenkov and Mariya Cherenkova. His mother died two years aftern his birth, with his father quickly remarrying, and Pavel and his sister being raised by their stepmother from this time.

Cherenkov's education was interrupted by the Russian Revolution, and he did not complete his secondary education until 1924. He subsequently enrolled at the Voronezh State University to study physics and mathematics, supporting himself while he studied through tutoring and unloading rail cars, and returning home to work on the farm in the summer.

He graduated in 1928, going on to teach at a High School for two years, before moving to Leningrad (St Petersburg), where he married Maria Putintseva, daughter of Alexei Mikhailovich Putintsev, Professor of Russian Literature, and enrolled at the Institute of Physics and Mathematics of the Academy of Sciences of the USSR, as a graduate student. 

Cherenkov's original project was to study 'The luminescence of uranyl salt solutions under the action of gamma-rays', under the supervision of Sergey Ivanovich Vavilov. This was achieved by shining a beam of gamma rays through solutions of uranyl salts. Upon doing this, Cherenkov discovered a faint blue glow was produced, which eventually became the main focus of his studies. 

However, the glow was initially interpreted by Vavilov as being a result of the luminescence of impurities in Cherenkov's solutions, leading him to suspect that Cherenkov was lazy in his preparation technique. Furthermore, Cherenkov's experimentation technique, which involved sitting in a darkened room with a black cloth over his face before running experiments in order to ensure that he would be able to perceive the faint glows produced, led some of his fellow students to accuse him of spiritualism - a dangerous allegation in Stalin's Russia.

Both Cherenkov's father Alexey Cherenkov, and his father-in-law, Alexei Putintsev, were arrested for political crimes in the 1930s, with Alexey Cherenkov first disappearing, and eventually being executed, while Alexei Putintsev was sentenced to hard labour at a logging camp. This meant that Maria Chernekov, as the daughter of a dissident, could not find work, leaving the family (by this time they had a son, Alexey junior, and would later have a daughter, Yelena) reliant upon Pavel Cherenkov's income as a researcher.

In 1934 the Institute of Physics and Mathematics of the Academy of Sciences of the USSR was relocated to Moscow, becoming the Lebedev Physical Institute. Here Cherenkov was able to produce a clearly visible blue light from a bottle of water he could be confident lacked any impurities, leading others to begin to take his findings more seriously. 

Cherenkov was able to demonstrate that focussing gamma rays on a bottle of water produced a cone of blue light, which points in approximately the same direction, but typically is not centred on the original beam. Two colleagues of Cherenkov's, Igor Tamm and Ilya Frank were able to calculate that the light was the result of electrons travelling at speeds faster than the speed of light in water being fired into the water, creating a shockwave within the local electromagnetic field. 

Cherenkov, Tamm, and Frank, convinced that their discovery was of great significance, submitted their findings to the journal Nature in 1937, although their paper was rejected. They then submitted the same paper to the Physical ReviewPhysical Review later that year, where it was published.

This 'Cherenkov Effect' became the best available method for distinguishing between subatomic particles produced in particle accelerators, where the angle by which a particle is deflected and the light it emits can be used to calculate its mass and velocity. The method is also used to study cosmic rays.

In 1940 Pavel Cherenkov was awarded the title of Doctor of Physico-Mathematical Sciences, and promoted to Section Leader at the Lebedev Physical Institute. In 1946 Cherenkov, Ivanovich, Frank, and Tamm, were awarded the State Stalin Prize for their work. 

Also in 1946, Pavel Cherenkov began working on electron accelerators with Vladimir Iosifovich Veksler, work for which he received a second Stalin Prize in 1952, and was awarded a professorship in 1953, going on the lead the Photo-meson Processes Laboratory at the Lebedev Physical Institute and construct the Soviet Union's first synchrotron facility.

In 1958 Pavel Cherenkov, Igor Tamm, and Ilya Frank were awarded the Nobel Prize for Physics, 'For the discovery and recognition of Cherenkov Radiation'. In 1970 Cherenkov was made an Acadamician of the Soviet Academy of Sciences. In 1977 he was awarded the USSR State Prize, and in 1984 declared to be a 'Hero of Socialist Labour'.

Pavel Alekseyevich Cherenkov died on 6 January 1990, and is buried in Novodevichy Cemetery in Moscow.

Ardipithecus kadabba: The oldest member of the Human Family.

Fossil Hominid remains from the Late Miocene Middle Awash deposits. (a) ALAVP-2/10, mandible and all associated teeth; ALA-VP-2/120, ulna and humerus shaft; ALA-VP-2/11, hand phalanx . (b) AME-VP-1/71, lateral, plantar and dorsal views of foot phalanx. (c) STD-VP-2, teeth and partial clavicle. (d) DID-VP-1/80, hand phalanx. (e) ASKVP-3/160, occlusal, mesial and buccal views; ASK-VP-3/78, posterior view. All images are at the same scale. Haile-Selassie (2001).

In the late 1990s Ethiopian palaeoanthropologist Yohannes Haile-Selassie led a series of excavations at Alaya in the Middle Awash area of the Afar Region of Ethiopia. These uncovered an ancient woodland habitat, dated to between 5.2 and 5.8 million years ago, and yielded, among other things, a collection of loose teeth and bone fragments, which Haile-Selassie assigned to the Primate Ardipithecus, at that time believed to be an ancestor of the living Chimpanzees. At that time these Late Miocene fossils were the oldest known member of the Chimpanzee lineage, only slightly younger than the presumed split between the ancestors of Chimpanzees and Humans, between 6.5 and 5.5 million years ago. These specimens were older than and not identical to those previously assigned to the Pliocene Ardipithecus ramidus, causing Haile-Selassie to erect a new subspecies, Ardipithecus ramidus kadabba ('kadabba' implies the first ancestor in the Afar language).

Ethiopian palaeoanthropologist Yohannes Haile-Selassie in March 2017. Wikimedia Commons.

Further work on both the site and the fossils it yielded refined the age of the specimens to between 5.77 and 5.54 million years old. More notably, work on both Ardipithecus kadabba and Ardipithecus ramidus by Haile Salassie, along with American palaeoanthropologist Tim White, and Japanese palaeoanthropologist Gen Suwa, led to a revision of the genus Ardipithecus. Thus, Ardipithecus kadabba was promoted to a full species, probably ancestral to Ardipithecus ramidus (making it a 'chronospecies'). Furthermore, it is no longer considered to oldest ancestor of the Chimpanzee lineage, but instead is placed on the Hominin side of the family tree (anything more closely related to Humans than to Chimpanzees is a Hominin), making it the oldest member of the Human family.

Java Man.

The original Trinil 1 (tooth), Trinil 2 (skullcap), and Trinil 3 (femur) specimens discovered by Eugene Dubois on the banks of the Bengawan Solo River in 1891-2, collectively refered to as 'Java Man'. Now in the collection of the Naturalis Biodiversity Center in Leidan, the Netherlands.. Peter Maas/Wikimedia Commons.

 In 1879, Charles Darwin's book 'The Descent of Man, and Selection in Relation to Sex' had proposed (amongst other things) that modern Humans were descended from African Apes. This was a matter of considerable controversy at the time, with many people, and in particular several religious groups, declaring the proposition highly offensive. Among the scientific community, and in particular those members of it who studied Human and animal anatomy, this was less of a surprise, and broadly in line with what many other people had been thinking. 

One aspect of the theory, which was widely contested, however, was the idea that Humanity had originated in Africa. In the nineteenth century, it was generally assumed that civilization had originated in Asia, and spread into Africa via Egypt, which contained the oldest known archaeological sites on the continent at that time. Since Asia is also home to Apes (including the Orangutan, which was then little understood, and many people believed could talk), it seemed quite possible that this continent could have been home to not just the origin of civilization, but the origin of Humanity itself.

Marie Eugène François Thomas Dubois, a trained physician with an interest in zoology working at the University of Amsterdam was inspired by this idea, and sought funding for an expedition to the Dutch East Indies (now Indonesia) to search for evidence of this origin. When this was (unsurprisingly) rejected, he enlisted as a surgeon with the Royal Netherlands East Indies Army, receiving a posting in Sumatra in 1887, where he began is search for a hypothetical Human ancestor.

Dubois's excavations in caves in Sumatra (inspired by the discovery of Neanderthal remains in caves at several locations in Europe), failed to produce any evidence of ancient Humans, but did uncover a range of large Mammal skeletons, bringing him to the attention of the colonial government. Palaeontology was still a new science in the late nineteenth century, and the discovery of large vertebrate fossils was a matter of national prestige. In Europe, an countries such as Britian, France, Germany, and even Belgium had all made impressive discoveries on their home territories, as had the young United States, and British and German colonies in Africa. Neither the Netherlands, nor any of its colonies, had produced any significant fossil discoveries at this time, making Dubois' discoveries significant for the colonial administration.

Marie Eugène François Thomas Dubois (Eugène Dubois). Wikimedia Commons.

In 1889 Dubois was relieved of his military duties, and provided with two assistants from the East Indies Army's corps of engineers, and fifty convict labourers. After another season in Sumatra, during which no Human remains were found, Dubois switched his attention to Java in 1890. This proved to be successful, with his team uncovering the molar and skullcap now known as Java Man in 1891, and the femur in 1892.

Dubois described the molar and skullcap under the name Anthropopithecus, a now obsolete term used to describe both some Hominin fossils (including a tooth from the Sivalik Hills of India, which resembled the one from Java), as well as the living Chimpanzee. He envisaged the living individual as being a Human-like Gibbon (his preferred choice for a Human ancestor) and living Humans. Following the discovery of the femur, which was longer and straighter than that of any Ape, emphasising the Human-like qualities of the remains, Dubois amended this to Anthropopithecus erectus, emphasising that the creature had an upright, Human-like stance. 

Dubois was originally cautious about his find, referring to it as a Human-like Ape, but refraining from designating it as a Human ancestor. However, examination of the skull-cap suggested that it had a cranial capacity of about 900 cm², far larger than any Ape, further emphasising the fossil's Human affinities, which led Dubois to redescribe the specimen as Pithecanthropus erectus, using a genus name the German naturalist had used for a (then hypothetical) missing link between Apes and Humans.

In the 1930s German palaeontologist Gustav Heinrich Ralph von Koenigswald carried out a series of further excavations, on Java, uncovering a number of additional Hominin specimens, which he believed to be closely related to those Dubois had discovered, and assigned them to the same species. Surprisingly, Dubois objected strongly to this, claiming that his fossils were those of Ape-men (and therefore a missing link between the two groups) while von Koenigswald's were close to modern Humans.

'Solo Man', one of the Hominin specimens discovered on Java by Gustav Heinrich Ralph von Koenigswald, now in the collection of the Smithsonian Natural History Museum. Ryan Somma/Wikimedia Commons.

Following the Second World War various scientists reviewed Dubois'  and von Koenigswald's material, as well as other Hominin fossils from other sites in Asia and Africa, coming to the conclusion that these all belonged to a single species, which German biologist Ernst Mayr named Homo erectus, placing it in the same genus as modern Humans, but using Dubois' specific name, which had priority as the first specimen described, thus making Java Man the holotype of the species. 

Today it is more-or-less universally accepted that Humanity has its roots in Africa, and Homo erectus is considered to have been the first Human species to have spread out of Africa, moving across Arabia and into South Asia, then China and Southeast Asia, eventually down into the Sundaland Region, which included Sumatra and Java, but which was still attached to mainland Asia during the Pleistocene, when sealevels were generally lower. 

Sundaland at the Last Glacial Maximum, showing the modern distribution of land in dark grey and the additional land exposed during the glacial maximum in light grey. The northern boundary of Sundaland defined by 9°N latitude shown as a dashed line. Possible lakes are marked by the letter L, the mouths of the major Molengraaff Rivers are indicated by letters as follows: 1, South Sunda River; 2, North Sunda River; 3, Siam River; 4, Malacca River. Bird et al. (2005).

The exact age range of Homo eructus is unclear; fossils dating from between about 1.4 million years ago and about 400 000 years ago have been assigned to the species, although there is considerable variation between these, leading some palaeoanthropologists to split the species into several different species or subspecies. As the holotype of Homo erectus, Java Man always remains within that species, sometimes being assigned to the subspecies Homo erectus erectus, while other specimens are re-assigned based upon their perceived similarity to it. This situation is not helped by the exact age of Java Man being unknown, not simply because dating methods were less advanced in the nineteenth century, but also because Dubois, having been provided with a free workforce by the authorities on Java, was not present when the fossils were excavated by his labourers, and was therefore uncertain about the horizon they were excavated from. 

However Homo erectus should be defined, the species is considered to have made remarkable advances over its predecessors, spreading out of Africa and across Asia into a range of entirely new environments, as well as developing the distinctive Acheulean tool set, distinguished by carefully shaped axes and points, unlike anything which had come before it. Homo erectus is also generally credited with having been the first Hominin to use fire, as well as having built the oldest wooden structures in Africa, half a million years ago.

Acheulean hand-axe from a hill-top plateau, 425 m above sealevel, 15 km to the northwest of the city of Naqada, Egypt. In the collection of the Petrie Museum in London. Osama Shukir Muhammed Amin/Wikimedia Commons.

Ruins of Kilwa Kisiwani and Ruins of Songo Mnara, UNESCO World Heritage Site, Tanzania.

The ruins of Kilwa Kisiwani, Tanzania. Ron Van Oers/UNESCO. 

Located on two islands close to each other just off the Tanzanian coast, about 300 km south of Dar es Salaam and 9° south of the Equator, are the remains of two port cites, Kilwa Kisiwani and Songo Mnara. The larger, Kilwa Kisiwani, was occupied from the 9th to the 19th century and reached its peak of prosperity in the 13th and 14th centuries. In 1331-1332, the great traveller, Ibn Battouta made a stop here and described Kilwa as one of the most beautiful cities of the world.

Kilwa Kisiwani and Songo Mnara were Swahili trading cities, and their prosperity was based on control of Indian Ocean trade with Arabia, India and China, particularly between the 13th and 16th centuries, when gold and ivory from the hinterland was traded for silver, carnelians, perfumes, Persian faience and Chinese porcelain. Kilwa Kisiwani minted its own currency in the 11th to 14th centuries. In the 16th century, the Portuguese established a fort on Kilwa Kisiwani and the decline of the two islands began.

Ruins of Kilwa Kisiwani, Tanzania. Wikimedia Commons.

The remains of Kilwa Kisiwani cover much of the island with many parts of the city still unexcavated. The substantial standing ruins, built of coral and lime mortar, include the Great Mosque constructed in the 11th century and considerably enlarged in the 13th century, and roofed entirely with domes and vaults, some decorated with embedded Chinese porcelain; the palace Husuni Kubwa built between about 1310 and 1333 with its large octagonal bathing pool; Husuni Ndogo, numerous mosques, the Gereza (prison) constructed on the ruins of the Portuguese fort and an entire urban complex with houses, public squares, burial grounds, etc.

The ruins of Songo Mnara, at the northern end of the island, consist of the remains of five mosques, a palace complex, and some thirty-three domestic dwellings constructed of coral stones and wood within enclosing walls.

Ruins of Songo Mnara, Tanzania. Ron Van Oers/UNESCO. 

The islands of Kilwa Kisiwani and Songo Mnara bear exceptional testimony to the expansion of Swahili coastal culture, the lslamization of East Africa and the extraordinarily extensive and prosperous Indian Ocean trade from the medieval period up to the modern era.

Born on 24 March 1733, Joseph Priestly, discoverer of oxygen.

Portrait of Joseph Priestly in 1795 by Ellen Sharples. National Portrait Gallery/Britanica.

 

Born on 24 March 1733 in Birstall, Yorkshire, Joseph Priestly, chemist, physicist, teacher, minister, and theologian. Most famous today for the discovery of oxygen, he also discovered nine other gasses, nitric oxide, nitrogen dioxide, nitrous oxide, hydrogen chloride (gaseous hydrochloric acid), ammonia, sulphur dioxide, silicon tetrafluoride, nitrogen, and carbon monoxide. Priestly also discovered carbonated water, and was awarded the Royal Society's Copley Medal in 1773.

A dissenting minister, and founder of Unitarianism, Priestly believed in the power of science to improve the world for mankind, although he was notoriously bad at capitalizing on his inventions, and frequently upsetting both the authorities of the day and the public with his religious views, campaigning for the rights of dissenters, and support for the French Revolution. In 1791, while he was living in Sparkbrook, Birmingham, his house was looted and burned by rioters after it became public knowledge that he was hosting a dinner party to celebrate the second anniversary of the storming of the Bastille.

Rioters Burning Dr. Priestley's House at Birmingham, 14 July 1791, by Johann Eckstein. Norton Anthology of English Literature/Wikimedia Commons.

Following the burning of his house, Priestly relocated to Hackney, then a parish in Middlesex, and where he established a new home and laboratory with the help of wealthier supporters. However, he continued to be unpopular with both the public and the government, being burned in effigy, and regularly targeted by political cartoonists, as well as politicians who saw him as an enemy of the British Government. In 1792 he was granted French citizenship by a decree of the French National Assembly, but with Britain and France on the brink of war, relocating to France was not feasible, and in 1794 Priestly emigrated with his family to Pennsylvania, where he lived until his death in 1804.