Ötzi is the oldest human mummy known and one of the most studied by science. It was discovered in 1991 in the Alps and since then it has not stopped leaking information about what life was like in the Neolithic. Do you dare to find out all its secrets?
WHAT IS A MUMMY?
Mummies are preserved bodies of people and animals that still preserve their skin. The most famous are the Egyptian ones, preserved thanks to the chemical processes applied to the corpses (embalming), although many other cultures practiced mummification. But mummies can also occur naturally if the conditions are suitable to avoid decomposition, such as humid and swampy sites, in the cold of mountains and polar regions or in dry and sandy areas such as deserts. In addition to the skin, other structures that can be preserved over the millennia are nails, hair and bones and teeth.
Unlike fossils, which are millions years old, mummies do not usually exceed thousands of years, although there are fossils of dinosaurs with skin impressions or scales. If you want to know more about the processes of fossilization, we invite you to read Knowing fossils and their age. Ötzi is a sub-fossil because he is younger than 11,000 years old.
WHO WAS ÖTZI?
Ötzi, the Man of Similaun, the Man of Hauslabjoc or simply The Iceman, was discovered in the Ötz Valley (on the Austrian-Italian border of the Alps) by climbers in 1991 at 3,200 meters. Thanks to a storm in the Sahara, the dust reached the Alps and when it warmed with the sun, it melted the ice more than usual and uncovered Ötzi, who had been under the ice for more than 5,000 years. It was not until a later study that his real antiquity was discovered, since in situ seemed to be a dead climber.
Thanks to the technique Carbon 14, it was determined that Ötzi died around 3255 BC (Chalcolithic, Copper Age), which made it the oldest preserved mummy in the world. In addition to the body, more than 70 personal objects (weapons, clothing, tools…) were found, which gave more information about the life of this prehistoric man.
A MODERN HOMO SAPIENS
Throughout various posts we have talked about other species that preceded us , but Ötzi belonged to our species, Homo sapiens. The first Homo sapiens, who appeared in Africa 200,000 years ago, represented the evolutionary transition between H. heidelbergensis to the first modern humans. After more than 7 million years of evolution, H. sapiens are the only hominini survivors.
H. sapiens migrated from Africa to the rest of the continents. If you want to know about how paleoparasitology helps us to follow the migratory routes of our ancestors, do not miss this post . When Ötzi was alive, the Neanderthals had already become extinct a few thousand years ago and their sapiens ancestors had been in Europe since about 45,000 years ago.
The difference between H. sapiens and other species is a very rounded and large skull (1,000-1,400 cm 3 ) compared to the body, a flat and vertical face, small teeth a non-robust jaw, and the presence of chin, feature that does not have any of the preceding species.
If we look at the skeleton, like other recent hominins, Ötzi and we are perfectly adapted to bipedism, with a distinctive light constitution. We have long lower limbs, with the femur tilted to the knee to keep the center of gravity under the body. The pelvis is narrow and short. The spine is curved to maintain balance and distribute weight efficiently while walking, with strong lumbar vertebrae. The arms are relatively short and the hands are agile and they have excellent prehensile precision, with long and thin phalanges compared to neanderthals.
At cognitive level, what made us different from the rest of the hominin species is the symbolic thinking (representation of nature through symbols and abstract thinking), although the debate is still open since the Neanderthals had behaviors that could be considered symbolic (like decorating the body with jewelry or paintings). What is clear is that 40,000 years ago, the clearest evidence of modern behavior appeared in Europe, with the appearance of rock painting and sculpture. Technological innovation, agriculture and livestock are other of our distinctive features.
WHAT VALUABLE INFORMATION HAS REVEALED SCIENCE ABOUT ÖTZI?
Different techniques have been used to reveal information about the mummy and changing the different hypotheses over the years.
CARBON 14 AND DENTITION: AGE
Ötzi was about 46 years old when he died (life expectancy in the Copper Age was about 35 years). This data comes from the study of teeth, which are worn out, perhaps by eating grain throughout his life. The Carbon 14 test was carried out on its body and clothing: he is approximately 5,300 years old. It is estimated that he weighed about 45 kilos and he was 1.60 m tall.
COMPUTERIZED AXIAL TOMOGRAPHY (CT SCAN)
A CT Scan in the body of Ötzi brought to light that he was suffering from various oral issues, such as caries (perhaps due to the consumption of bread and oats), periodontitis (pyorrhea) and worn out teeth for using them as a tear tool. He also lost part of a molar and suffered a blow to an incisor.
He also suffered from arthritis, gallstones and he had a lump on one toe, broken nose and ribs that healed before death and had black lungs because of inhaling CO2, maybe from bonfires. More than 60 tattoos (the oldest known) were found throughout his body, consisting of small lines, crosses and points. They were made with small cuts that were then rubbered with charcoal. They do not seem decorative: it is speculated that they were part of some treatment to improve the artirtis, since they indicate the points where he was in pain.
His system also had high levels of arsenic, probably because he worked with minerals and metals.
THE LAST DINNER
An analysis of the stomach revealed that he had eaten two hours before dying. He ate ibex (wild goat), cereals and unidentified plants. They found 30 different types of pollen, so he probably died in the spring. But they also found eggs of a parasite that cause Lyme disease, which mainly affects the vascular, nervous and skeletal system.
X-RAYS: ACCIDENT OR MURDER?
First it was believed that Ötzi died due to crashing into a glacier. But radiographs revealed the presence of an arrowhead on his shoulder, so the researchers analyzed the body more closely and found several injuries in the hands, torso and a blow in the head, the cause of his death.
DNA ANALYSIS: HE SUFFERED DIVERSE DISEASES
Scientists did DNA tests in various blood samples, and they found up to 3 different types of blood. The blood of his flint knife is not from him: everything shows that he was involved in a fight with several people and was killed. His body was not found in a natural position, so two hypotheses are considered: either a partner tried to help him to extract the arrow or the enemies tried to recover it. In any case, they did not take away the advanced technology and Ötzi clothing. Why? The mystery is still open.
In 2008 the complete genome of the Ice Man was published. He was lactose intolerant, his blood was type 0, he had brown eyes, he suffered from the heart and arteries and he is related to the current inhabitants of Corsica and Sardinia. In addition, out of 3,700 DNA samples were donated by Tyrol volunteers. 19 individuals share a genetic mutation with Ötzi.
NON-HUMAN DNA IN ÖTZI
The samples of non-human DNA are usually bacteria that live in our body. A biopsy on the hip brought to light the presence of DNA from a bacterium (Treponema denticola) involved in periodontal disease, which confirmed the results of the CT Scan. They also found remnants of the bacterium Clostridium and Helicobacter pylori so Ötzi had a strong stomachache and diarrhea the day of his death. Besides, the study of Helicobacter from Ötzi has thrown new data on human migrations, the origin of European populations and the impact on our evolution.
DO YOU WANT TO SEE ÖTZI?
This discovery is so important, that they dedicated a museum almost entirely for him: the South Tyrol Museum, in Bolzano. There are exposed the impressive clothes that he wore, made with animal skins such as bears and goats, his shoes, with double layer and stuffed with straw, his tools, weapons… even the first aid kit he was carrying. And he himself, of course, preserved at -6º. Maybe one day we will hear him “talking”: they are trying to reconstruct his tone of voice from the vocal cords.
We still do not know who he was. Maybe a personality? A skilled hunter? A farmer or a stockman? A healer? We will probably never know. What is certain is that he could never imagine the attentions he would continue receiving 5,000 years after his death.
The actual world is in turmoil. News related to terrorism, drug trafficking, coups d’état, refugees crisis or the numerous wars still present flood our screens day after day. And, in a completely understandable bias, the focus is almost exclusively on the people and countries involved. But (and it’s something I ask every time I watch the news) what happens to nature in these regions punished by violence? In this entry we review the most important armed conflicts nowadays and their consequences for the nature surrounding them.
Any human action has repercussions on natural life, and even more wars, intrinsically destructive. A series of damages on the wildlife are associated with them such as deforestation, soil degradation, pollution or hunting, among many others. The first time we really became aware of the great impact of the wars on nature was in the Vietnam War. The US army, in its fight against an invisible enemy, threw more than 75 million liters of herbicides into the jungles, in order to defoliate the trees to find their enemies. However, despite partially achieving its objective (we all know how that war ended) nature was seriously damaged. A study carried out in Vietnam in the mid-1980s found that there were only 24 birds and 5 mammals in an area where there were previously between 145 and 170 birds and between 30 and 55 mammals.
Other wars, such as the Civil War in Rwanda, apart from causing more than 500,000 deadsand displacing more than 2 million of people, left the nature of the country in a state of absolute crisis. In the Akagera National Park, one of the most emblematic environments in the country, deforestation wreaked havoc: 200,000 of the 300,000 hectares of forest were lost in just 3 years, as well as 90% of large mammals.
But what is happening today? How are the wars of today affecting the survival of nature? Here we review the most important current conflicts and their difficult coexistence with the wildlife of the region.
Israeli-Palestinian Conflict (1948-present)
Although the last war between Israel and Palestine began in 2005, violence between the two countries has been present since the creation of the state of Israel. Thousands of people have been dead for decades, and millions have been displaced against their will. And, of course, nature has not come out unscathed.
One of the most famous cases occurred in 2006. The Israeli army bombarded two oil tanksnear a power station in Jieh, Lebanon (where a terrorist group called Hezbollah was emplaced) causing a spill of 10,0000 and 15,000 cubic meters of oil in the Mediterranean sea. This black tide spread along 90 km of the coast of Lebanon, carrying the death with it. In addition, this phenomenon severely affected the habitat of the green turtle (Chelonia mydas) in one of the last well-preserved places that this species still had in the Mediterranean basis.
However, in early 2016, images that would call even more international attention came to light: dozens of animals from the Gaza zoo appeared completely mummified after suffering a terrible agony and starving.It happened twice since the zoo opened in 2007, but the strongest famine took place in 2014, following a conflict between Israel and Hamas’s Palestinian forces.It is estimated that about 80 animals died because of famine, including crocodiles, tigers, baboons or porcupines.When rescue services were able to reach the zoo, only 15 animals remained alive, many of them with severe symptoms of malnutrition.
Second Congo War (1998-2003)
This war, also known as the Great War of Africa or the African World War, has caused the death of more than 5 million people since then, which has given it the dubious honor of being the deadliest armed conflict since The Second World War. Although the war officially ended in 2003 and there is an elected government since 2006, the Democratic Republic of the Congo lives in a state of instability typical of a country at war.
The guerrillas use the country’s many natural resources to obtain money so they can continue the war. And ivory is the most precious commodity, the one that produces the most benefits. That is why African elephant populations (Loxodonta africana) have been reduced by 90% since the beginning of the conflicts. Something worse has occurred to the northern white rhinoceros (Ceratotherium simum cottoni) a subspecies of the white rhinoceros. Its last specimens, 2 males and 2 females living in the Garamba National Park, are believed to have died between 2006 and 2008 at the hands of the guerrillas, causing the extinction of this subspecies.
Bushmeat, or the food coming from wild animals, is another major problem stemming from the numerous military conflicts in the country. In the wake of extreme poverty, many villagers have been forced to hunt to survive.And the primates has been one of the most harmed groups.The populations of the great primates, once counted by millions, have been drastically reduced.It is believed that there are only 200,000 lowland gorillas, 100,000 chimpanzees and 10,000 bonobos in freedom.
Syrian Civil War (2011-present)
Undoubtedly, the most famous war at the moment. This conflict has killed more than 500,000 people and has caused one of the most important humanitarian crises of our time: it is estimated that there are more than 10 million of refugees because of the war. Those who have remained in Syria, have been displaced from the interior to the coastal zone, becoming a great threat to the forests of the region. According to Aroub Almasri, a Syrian government environmentalist, most people need food, electricity and fuel to cook and warm up, which has lead to clear the area’s forests, mostly in protected areas. Apart from the severe impact of deforestation, there are also a large number of fires that have been spreading throughout the region in recent times. A particularly affected area is the Fronlok forest on the border with Turkey. In these mountains the degree of endemism is high, and many species are at a serious risk of disappearing from the area, especially a type of oak, Quercus cerris, native to the region and which would begin to be threatened.
Due to the fragmentation of the habitat, it is believed that an iconic species of the Mediterranean zone and classified as critically endangered by IUCNhas become extinct in Syria. It is the bald ibis (Geronticus eremita), a bird of which only 500 individuals remain and is present only in three countries: Morocco, Turkey and Syria. In spite of Syria‘s enormous effort to maintain a stable population in its territory, the war wiped out the last individuals of this species in the region. Only one individual of the species remains, a female named Zenobia, who was seen for the last time in Palmyra before ISIS troops entered the city.
Second Libyan Civil War (2014-present)
After the first Libyan civil war, which ended with the fall of Colonel Gaddafi, the country entered into a spiral of violence sponsored by the numerous armed groups that control the country. The importation of meat from abroad has stopped, and the owners of sheep, goats and camels keep their animals as if they were gold because of shortages. Because of this, armed groups are heading to the south of the country, where anarchy prevails and there are a lot of wild animals to take advantage of.
One of the most harmed species has been the rhim gazelle (Gazella leptoceros), classified as threatened by IUCN and with its populations in decline. Ten years ago the population did not exceed several hundred individuals, and it is believed that today the situation is much worse.
But the gazelles are not the only ones harmed by the banditry and impunity reigning in Libya. Large numbers of migratory birds, which have to cross the African country on their way to Europe, are slaughtered by hunters. In addition, the oases that they use to rest are being opened by the hunters, which causes that hundreds of cranes, ducks, herons and flamingos are annihilated without anyone can do anything.
In addition, the effect of the Libyan war on nature does not remain within its borders.In 2015, weapons from Libya were found near elephant corpses in Mali, a heavily threatened elephant subspecies.It is believed that the ivory of the Mali elephants is serving to finance the Libyan militias.
The Colombian government against the FARC and other guerrillas (1964-2016)
Despite the peace agreement reached few months ago between the Colombian government and the FARC, both social and environmental wounds will take a long time to be closed. For a long time the militias have been financed largely from the money generated by illegal cocaine crops. Placed deep in the Colombian jungle, thousands of hectares of pristine foresthave been cleared for the construction of laboratories and coca plantations. In addition, in an attempt to stop this type of illegal crops, the government fumigated extensive forest areas withglyphosate, a herbicide that, despite being considered harmless, caused the death of birds, small mammals and insects, what in turn left without sustenance the people who live on hunt. Another added problem is that illicit crops have spread to protected areas. Thus, according to a report by the National Parks of Colombia, FARC were present in 37 protected areas of the country, and 3791 hectares of coca plantations were also detected in there.
However, the illicit activity that most threatens Colombia’s nature is illegal mining, one of the most lucrative activities for armed groups. Not for less, since while 1 kg of coca is sold at about 4.3 million pesos, 1kg of gold is sold at 85 million pesos, about 20 times more. For this reason, large areas of jungle have been destroyed by backhoes to open gold (60%), coltan (25%), charcoal (10%) and tungsten (5%) mines. Deforestation resulting from illegal mining reaches unimaginable numbers: between 1990 and 2010, an average of 310,349 hectares of forest per year were deforested, that is, 6206.000 hectares in all that time, or what is the same, 5.4% of the Colombian surface.
Finally, FARC actions against oil extraction have caused serious oil spills in areas of high environmental value. This is the case, for example, of the 492-liter oil spill in Puerto Asis, Putumayo, in June 2015. The FARC intercepted a convoy containing tanks with oil and spilled them, affecting 9 wetlandsand spreading oil along the Putumayo River.
War in Afghanistan (2001-2014)
Either the last war and the previous one had a strong impact on the region’s wildlife. It is estimated that between 1990 and 2007, more than one-third of Afghanistan’s forests were cleared, either by refugees to use wood for cooking, fuel or construction, or by logging industries, which cut down the forests of the region with impunity.
Nevertheless, the news are more optimistic than would be expected of a country plunged into war for decades. Between 2006 and 2009, the first censuses since the 1970s were carried out in the province of Nuritán, with the help of trap cameras, the study of faeces and the realization of transects. The results were encouraging: 18 black bears, 280 porcupines and many red foxes, gray wolves, golden jackals, wildcats, palm civets and rhesus macaques were observed, and even the elusive snow leopard (Panthera uncia), concretely 3 distinct individuals.
However, there are still threats for Afghan wildlife. The large number of bombsthrown during the years made a dent in the abundance of migratory birds. Many birds died directly from the impact of the bombs or poisoned when they came into contact with contaminated water. Others, however, varied their rute due to the bombing and no longer cross the country. This is the case of the Siberian crane (Grus leucogeranus), a species critically endangered by IUCN that has not been seen in Afghanistan since 1999. In addition, due to the war and the incipient Afghan economy, hundreds of hunters Are forced to catch live birds for subsequent smuggling into rich Arab countries.This has led to the fact that, in some regions of Afghanistan, migratory bird watching has declined by 85% since the start of the war.
Korean Conflict (1950-present)
The KoreanDemilitarized Zone is the proof that even something as tragic as a war can bring positive consequences. In 1953, following the peace agreement by both countries, the Korean Demilitarized Zone, a strip of land 4 km wide and 250 km long that separates both countries, was created. The area, which has a strong military presence of about 2 million soldiers, has remained virtually unchanged and sparsely populated since then.
The area is characterized by a great topographic richness and high variety of ecosystems, which allows it to contain a great diversity. Some scientific expeditions have documented more than 1,100 species of plants, 80 species of fish, 50 of mammals and hundreds of birds.In addition, it is a frequent stop for many species of migratory birds that head towards Mongolia, the Philippines or Australia.
Recently, thanks to improved relations between the two countries, the area can be visited for only about 43 euros. In addition, due to its exceptional conservation status and high diversity, somecampaigns are under way to turn the area into a protected area. One of these campaigns, the DMZ Forum, proposes to declare the area as World Heritage Site and World Park for Peace, in order to be able to protect it from a possible urban development on the day that peace between the two countries is reached.
In All You Need Is Biology we often make reference to fossils to explain the past of living beings. But what is exactly a fossil and how is it formed? Which is the utility of fossils? Have you ever wondered how science knows the age of a fossil? Read on to find out!
WHAT IS A FOSSIL?
If you think of a fossil, surely the first thing that comes to your mind is a dinosaur bone or a petrified shell that you found in the forest, but a fossil is much more. Fossils are remnants (complete or partial) of living beings that have lived in the past (thousands, millions of years) or traces of their activity that are preserved generally in sedimentary rocks. So, there are different types of fossils:
Petrified and permineralized fossils: are those corresponding to the classical definition of fossil in which organic or hollow parts are replaced with minerals (see next section). Its formation can leave internal or external molds in which the original material may disappear.
Ichnofossils (trace fossils): traces of the activity of a living being that are recorded in the rock and give information about the behavior of the species. They may be changes in the environment (nests and other structures), traces (footprints), stools (coprolites-excrements-, eggs …) and other traces such as scratches, bites…
Amber: fossilized resin of more than 20 million years old. The intermediate state of amber is called copal(less than 20 million years) old. The resin, before becoming amber can trap insects, arachnids, pollen… in this case is considered a double fossil.
Chemical fossils: are fossil fuels like oil and coal, which are formed by the accumulation of organic matter at high pressures and temperatures along with the action of anaerobic bacteria (bacteria that don’t use oxygen for metabolism).
Subfossil: when the fossilization process is not completed the remains are known as subfossils. They don’t have more than 11,000 years old. This is the case of our recent ancestors (Chalcolithic).
Living fossils: name given to today’s living organisms very similar to species extinct. The most famous case is the coelacanth, it was believed extinct for 65 million years until it was rediscovered in 1938, but there are other examples such as nautilus.
Pseudofossils: are rock formations that seem remains of living beings, but in reality they are formed by geological processes. The best known case is pyrolusite dendrites that seem plants.
Obviously fossils became more common after the appearance of hard parts (shells, teeth, bones …), 543 million years ago (Cambrian Explosion). The fossil record prior to this period is very scarce. The oldes tknown fossils are stromatolites, rocks that still they exist today formed by the precipitation of calcium carbonate because of the activity of photosynthetic bacteria.
The science of fossils is Paleontology.
HOW A FOSSIL IS FORMED?
The fossilization can occur in five ways:
Petrifaction: is the replacement of organic material by minerals from the remains of a living being buried. An exact copy of the body is obtained in stone. The first step of petrificationis permineralization: the pores of the body are filled with mineral but organic tissue is unchanged. It is the most common method of fossilized bones).
Gelling: the body becomes embedded in the ice and don’t suffer transformations .
Compression : the dead body is on a soft layer of soil, such as clay, and is covered by layers of sediment .
Inclusion : organisms trapped in amber, or petroleum .
Impression: organisms leave impressions in the mud and the trace is preserved until the clay hardens.
UTILITY OF FOSSILS
Fossils give us information on how living things were in the past, resulting in evidence of the biological evolution and help to establish the lineages of living things today.
Those who are of a certain age can be use to date the rocks in where they are found (guide fossils).
They give information of geological processes such as the movement of the continents, the presence of ancient oceans, formation of mountains…
The chemical fossils are our main source of energy .
They give climate information from the past, for example, studying the growth of rings in fossilized trunks or deposition of organic matter in the glacial varves.
To determine the age of fossils there are indirect methods (relative dating) and direct (absolute dating). As there is no perfect method and accuracy decreases with age, the sites are often dated with more than one technique.
The fossils are dated according to the context in which they are found, if they are associated with other fossils (guide fossils) or objects of known age and it depends on the stratum they are found.
In geology, stratums are different levels of rocks that are ordered by their depth: according to stratigraphy, the oldest ones are found at greater depths, while the modern ones are more superficial, as the sediments have not had much time to deposit on the substrate. Obviously if there are geological disturbances dating would be wrong if there were only this method.
This methods are more accurate and are based on the physical characteristics of matter.
They are based on the rate of decay of radioactive isotopes in rocks and fossils. Isotopes are atoms of the same element but with different number of neutrons in their nuclei. Radioactive isotopes are unstable, so they are transformed into a more stable ones at a rate known to scientists emitting radiation. Comparing the amount of unstable isotopes to stable in a sample, scientits can estimate the time that has elapsed since the fossil or rock formed.
Radiocarbon (Carbon-14): in living organisms, the relationship between C12 and C14 is constant, but when they die, this relationship changes: the uptake of C14 stops and decay with a descomposing rate of 5730 years. Knowing the difference between C12 and C14 of the sample, we can date when the organism died. The maximum limit of this method are 60,000 years, therefore only applies to recent fossils.
Aluminum 26-Beryllium 10: it has the same application as the C14, but has a much greater decaying period, allowing datings up to 10 datings millions of years, and even up to 15 million years.
Potassium-Argon (40K/40Ar): is used to date rocks and volcanic ash older than than 10,000 years old. This was the method used to date the Laetoli footprints, the first traces of bipedalism of our lineage left by Australopithecus afarensis.
Uranium Series (Uranium-Thorium): various techniques with uranium isotopes. They are sed in mineral deposits in caves (speleothems) and in calcium carbonate materials (such as corals).
Calcium 41: allows to date bones in a time interval from 50,000 to 1,000,000 years .
The magnetic north pole has changed throughout the history of Earth and its geographical coordinates are known in different geological eras.
Some minerals have magnetic properties and are directed towards the north magnetic pole when in aqueous suspension, for example clays. But when laid on the ground, they are fixed to the position that the north magnetic pole was at the time. If we look at what coordinates are oriented such minerals at the site, we can associate it with a particular time.
This dating is used on clay remains and as the magnetic north pole has been several times in the same geographical coordinates, you get more than one date. Depending on the context of the site, you may discard some dates to reach a final dating.
THERMOLUMINESCENCE DATING AND OPTICALLY STIMULATED LUMINESCENCE (OSL)
Certain minerals (quartz, feldspar, calcite …) accumulate in its crystal structure changes due to radioactive decay of the environment. These changes are cumulative, continuous and time dependent to radiation exposure. When subjected to external stimuli, mineral emits light due to these changes. This luminescence is weak and distinct as apply heat (TL), visible light (OSL) or infrared (IRSL).
Can be dated samples that were protected from sunlight and heat to more than 500 ° C, otherwise the “clock” is reset as the energy naturally releases.
ELECTRON PARAMAGNETIC RESONANCE (ESR)
The ESR (electro spin resonance) involves irradiating the sample and measuring the energy absorbed by the sample depending on the amount of natural radiation which it has been subjected during its history. It is a complex method which you can get more information here.
Carbonell, E. (coord) (2011). Homínidos. Las primeras ocupaciones de los continentes (pg 26-37). Ariel Historia.
Coenraads, R. (2005). Rocas y fósiles. Libros cúpula.