Earliest evidence for cultivation of a fruit tree, according to researchers
A joint study by researchers from Tel Aviv University and the Hebrew University unraveled the earliest evidence for domestication of a fruit tree. The researchers analyzed remnants of charcoal from the Chalcolithic site of Tel Zaf in the Jordan Valley and determined that they came from olive trees. Since the olive did not grow naturally in the Jordan Valley, this means that the inhabitants planted the tree intentionally about 7,000 years ago. Some of the earliest stamps were also found at the site, and as a whole, the researchers say the findings indicate wealth, and early steps toward the formation of a complex multilevel society.
The groundbreaking study was led by Dr. Dafna Langgut of the The Jacob M. Alkow Department of Archaeology & Ancient Near Eastern Cultures, The Sonia & Marco Nadler Institute of Archaeology and the Steinhardt Museum of Natural History at Tel Aviv University. The charcoal remnants were found in the archaeological excavation directed by Prof. Yosef Garfinkel of the Institute of Archaeology at the Hebrew University. The findings were published in the journal Scientific Reports from the publishers of Nature.
‘Indisputable Proof of Domestication’
According to Dr. Langgut, Head of the Laboratory of Archaeobotany & Ancient Environments which specializes in microscopic identification of plant remains, “trees, even when burned down to charcoal, can be identified by their anatomic structure. Wood was the 'plastic' of the ancient world. It was used for construction, for making tools and furniture, and as a source of energy. That's why identifying tree remnants found at archaeological sites, such as charcoal from hearths, is a key to understanding what kinds of trees grew in the natural environment at the time, and when humans began to cultivate fruit trees."
In her lab, Dr. Langgut identified the charcoal from Tel Zaf as belonging to olive and fig trees. "Olive trees grow in the wild in the land of Israel, but they do not grow in the Jordan Valley," she says. "This means that someone brought them there intentionally – took the knowledge and the plant itself to a place that is outside its natural habitat. In archaeobotany, this is considered indisputable proof of domestication, which means that we have here the earliest evidence of the olive's domestication anywhere in the world.”
7,000 years-old microscopic remains of charred olive wood (Olea) recovered from Tel Tsaf (Photo: Dr. Dafna Langgut)
“I also identified many remnants of young fig branches. The fig tree did grow naturally in the Jordan Valley, but its branches had little value as either firewood or raw materials for tools or furniture, so people had no reason to gather large quantities and bring them to the village. Apparently, these fig branches resulted from pruning, a method still used today to increase the yield of fruit trees."
Evidence of Luxury
The tree remnants examined by Dr. Langgut were collected by Prof. Yosef Garfinkel of the Hebrew University, who headed the dig at Tel Zaf. Prof. Garfinkel: "Tel Zaf was a large prehistoric village in the middle Jordan Valley south of Beit She'an, inhabited between 7,200 and 6,700 years ago. Large houses with courtyards were discovered at the site, each with several granaries for storing crops. Storage capacities were up to 20 times greater than any single family's calorie consumption, so clearly these were caches for storing great wealth. The wealth of the village was manifested in the production of elaborate pottery, painted with remarkable skill. In addition, we found articles brought from afar: pottery of the Ubaid culture from Mesopotamia, obsidian from Anatolia, a copper awl from the Caucasus, and more."
Dr. Langgut and Prof. Garfinkel were not surprised to discover that the inhabitants of Tel Zaf were the first in the world to intentionally grow olive and fig groves, since growing fruit trees is evidence of luxury, and this site is known to have been exceptionally wealthy.
Dr. Langgut: "The domestication of fruit trees is a process that takes many years, and therefore befits a society of plenty, rather than one that struggles to survive. Trees give fruit only 3-4 years after being planted. Since groves of fruit trees require a substantial initial investment, and then live on for a long time, they have great economic and social significance in terms of owning land and bequeathing it to future generations – procedures suggesting the beginnings of a complex society. Moreover, it's quite possible that the residents of Tel Zaf traded in products derived from the fruit trees, such as olives, olive oil, and dried figs, which have a long shelf life. Such products may have enabled long-distance trade that led to the accumulation of material wealth, and possibly even taxation – initial steps in turning the locals into a society with a socio-economic hierarchy supported by an administrative system."
Dr. Langgut concludes: "At the Tel Zaf archaeological site we found the first evidence in the world for the domestication of fruit trees, alongside some of the earliest stamps – suggesting the beginnings of administrative procedures. As a whole, the findings indicate wealth, and early steps toward the formation of a complex multilevel society, with the class of farmers supplemented by classes of clerks and merchants."
TAU researchers demonstrate initial success in neutralizing the virus with a single vaccine
- Life Sciences
Researchers from Tel Aviv University demonstrated success of a novel technology that may be developed into a one-time vaccine to treat people with HIV and AIDS. The team used CRISP systems, best known as a gene-editing technique, to engineer type B white blood cells that activate the immune system to produce HIV-neutralizing antibodies.
The study was led by Dr. Adi Barzel and PhD student Alessio Nehmad, both from the School of Neurobiology, Biochemistry and Biophysics at The George S. Wise Faculty of Life Sciences and the Dotan Center for Advanced Therapies at TAU in collaboration with the Sourasky Medical Center (Ichilov). The study was conducted in collaboration with additional researchers from Israel and the US. The study was published in the prestigious journal Nature.
An Inside Operation
There is currently no permanent cure for AIDS. There is also no genetic treatment for AIDS, so the research opportunities are vast. "Based on this study," says Dr. Barzel, "we can expect that over the coming years we will be able to produce a medication for AIDS, additional infectious diseases and certain types of cancer caused by a virus, such as cervical cancer, head and neck cancer and more."
Dr. Barzel explains: "We developed an innovative treatment that may defeat the virus with a one-time injection, with the potential of bringing about tremendous improvement in the patients' condition. When the engineered B cells encounter the virus, the virus stimulates and encourages them to divide, so we are utilizing the very cause of the disease to combat it. Furthermore, if the virus changes, the B cells will also change accordingly in order to combat it, so we have created the first medication ever that can evolve in the body and defeat viruses in the 'arms race'.”
Over the last two decades, the lives of many AIDS patients have improved as a result of game-changing treatments. These treatments control the virus to convert the disease from what was once a universally lethal to a chronic illness. However, the researchers underline that there is still a long way to go before a treatment is found that would provide patients with a permanent cure. The development from Dr. Barzel’s laboratory offers one possible route for the endeavor. HIV destroys certain white blood cells that are critical for immune health, weakening the body’s defenses against serious infections. The technique developed in his lab involves the injection of genetically-engineered type B white blood cells into a patient's body, catalyzing the immune system to secrete antibodies that neutralize the HIV.
B cells are a type of white blood cells responsible for generating antibodies against viruses, bacteria and more formed in bone marrow. When they mature, B cells move into the blood and lymphatic system and from there to the different body parts.
Dr Barzel explains: "Until now, only a few scientists, and we among them, had been able to engineer B cells outside of the body. In this study, we were the first to do this within body and then make those cells generate the desired antibodies. The genetic engineering is conducted with viral carriers derived from viruses that were also engineered. We did this to avoid causing any damage, and solely bring the gene coded for the antibody into the B cells in the body.”
“Additionally, in this case we have been able to accurately introduce the antibodies into a desired site in the B cell genome. All lab models that had been administered the treatment responded, and had high quantities of the desired antibody in their blood. We produced the antibody from the blood and made sure it was actually effective in neutralizing the HIV virus in the lab dish."
Modifying B Cells Inside the Body
The genetic editing was done with a CRISPR, a technology based on a bacterial immune system against viruses. The bacteria use the CRISPR systems as a sort of molecular "search engine" to locate viral sequences and cut them in order to disable them.
PhD student Alessio Nehmad elaborates on the use of CRISPR: “We incorporate the capability of a CRISPR to direct the introduction of genes into desired sites along with the capabilities of viral carriers to bring desired genes to desired cells. Thus, we are able to engineer the B cells inside a patient's body. We use two viral carriers of the AAV family, one carrier codes for the desired antibody and the second carrier codes the CRISPR system. When the CRISPR cuts in the desired site in the genome of the B cells it directs the introduction of the desired gene: the gene coding for the antibody against the HIV virus, which causes AIDS."
One in every five species of reptiles is facing extinction
- Life Sciences
There are over 12,000 species of reptiles crawling our planet, but according to a new international study, involving researchers from Tel Aviv University and Ben-Gurion University of the Negev, 21% of these, or a total of about 2,000 species, are threatened with extinction. How can we save them? Or is it too late?
15.6B Years of Evolution Down the Drain?
The comprehensive study, the first of its kind in history, was conducted by the International Union for Conservation of Nature (IUCN) and included 52 researchers from around the world, including Prof. Shai Meiri of Tel Aviv University’s School of Zoology, The George S. Wise Faculty of Life Sciences and the Steinhardt Museum of Natural History, and Dr. Uri Roll of Ben-Gurion University of the Negev. The study was published in the prestigious journal Nature.
The findings of the study show that 30% of forest-dwelling reptiles and about 14% of those living in arid areas are threatened, and that 58% of all turtle species and 50% of all crocodile species are in danger of becoming extinct. The researchers sadly point out that if all of the 1,829 species of turtles, crocodiles, lizards, and snakes that have been found to be threatened do indeed become extinct in the coming years, the world will lose a cumulative wealth of 15.6 billion years of evolution.
Fortunately, no species of reptile has become extinct in Israel in the last decade, but there are many species that are endangered, such as the Hermon Gecko, the Be’er Sheva fringe-fingered lizard and several more.
50% of all crocodile species are in danger of becoming extinct
Mapping Out the Threats
The IUCN is an international body whose role is, among other things, to assess the threat of extinction posed to various species. Each species of animal or plant receives a score on a five-point scale. The purpose of this ranking is to define those species that are the most endangered, thereby enabling decision makers and various bodies, such the Israel Nature and Parks Authority, to outline policies accordingly.
In 2004, the IUCN released a comprehensive report on amphibians, and a few years later it issued reports on birds and mammals. The IUCN has been working on the reptile report for the past 18 years, having invited experts on this taxonomic group from all over the world to participate.
“In general, the state of reptiles in the world is bad,” says Prof. Meiri. “It’s worse than that of birds and mammals, though not as bad as that of the amphibians. And of course there are a lot of nuances. We see that turtles are in a worse position than lizards and snakes, but that may be because we know more about turtles. Perhaps if we knew more about snakes, we would see that they, too, are in big trouble.”
“The biggest threat to reptiles is the destruction of their habitats due to agriculture, deforestation, and urban development, and less because of direct hunting, which mainly affects turtles and crocodiles. We created detailed maps of these threats. For example, if a particular species is highly threatened in the Israel’s Arava desert, but not in the rest of its habitat range that may span the entire Arabian Peninsula, then globally it is not considered a threatened species. The new assessments, for more than 10,000 species of reptiles, will allow us to understand their conservation needs, and hopefully enable us to find far more intelligent solutions for them than we have been able to so far.”
Prof. Shai Meiri
Dr. Uri Roll adds, “This is important work that forms the initial basis for risk assessment among various reptiles around the world, but is certainly not the end of the story. We still lack a lot of information about the various risks facing reptiles. For example, climate change is expected to have significant effects on reptiles. The current assessment that has just been published does not yet include these future threats in its reptile risk assessments. We still have a lot of work ahead of us.”
When asked whether it is still possible to stop the wheels from turning, Prof. Meiri says that “There’s room for optimism, but not overly so. It is finally possible, thanks in part to this study, to plan dedicated nature conservations for reptiles as well - there is more awareness and there are ways in which we can help them. In Israel, great efforts are made to protect various kinds of turtles. Less attention is paid to most species of lizards and snakes, however, which make up the vast majority.”
Researchers find that bats navigate well, also during the day, thanks to their unique sensory integration
- Life Sciences
It is time to bust a myth about bats – bats actually see well during the day and they know how to navigate the space during daylight hours. A new Tel Aviv University study has found that fruit bats use their biological sonar during the day, even though their vision is excellent and would ostensibly eliminate the need for the bats to emit calls to the environment and use their echoes to locate objects (echolocation). The researchers believe that due to the high accuracy of the bats’ bio-sonar system in estimating how far objects are, echolocation offers an additional tool – on top of vision – to help ensure that the bats are navigating as effectively as possible. This is similar to a person crossing the street using their sense of hearing as well as sight to make sure the road is clear.
Enjoying the Tel Aviv Sun
The study was conducted under the supervision of Prof. Yossi Yovel, head of Tel Aviv University’s Sagol School of Neuroscience and a researcher at the School of Zoology in The George S. Wise Faculty of Life Sciences and the Steinhardt Museum of Natural History. The study was led by Ph.D. student Ofri Eitan in cooperation with Dr. Maya Weinberg, Dr. Sasha Danilovich, and Reut Assa, all from Tel Aviv University, and Yuval Barkai, an urban nature photographer. The study will be published in the journal Current Biology.
The researchers explain that in general, bats are active mainly at night, and echolocation is the tool they use to navigate their way in the dark. They also say, however, that in recent years a growing phenomenon has been witnessed in Israel, particularly in Tel Aviv but also in other cities, in which Egyptian fruit bats roam around even during the day. In the current study, the researchers sought to examine what happens when the bats are active during the day, and whether they are aided by their unique bio-sonar even in conditions of good visibility.
For the first time, the researchers studied the activity and sensory behavior of the fruit bat during the day. The research was conducted with the help of photography and audio recordings of the bats’ activities throughout the day, in three different situations: in the morning, as they went out to explore in Tel Aviv; later in the day, when they visited Tel Aviv’s sycamore trees; and while they were drinking water from an artificial pool. In each of these situations, the bats used echolocation.
Daytime Integration of Senses
Ofri Eitan explains: “We compared the bats’ landings and flights between the trees, and found that prior to landing, the bats increased the sounds they emitted in order to use the echoes to help estimate the distance to the ground. In addition, we found that even in the pools of water, bats increased the rate of their calls before coming into contact with the water and reduced it (and sometimes even ceased the calls completely) after ascending from the water to fly to an open area. On the other hand, there were cases in which the bats emerged from the pool and had a wall placed in front of them, and once again returned to the use of echolocation. So, all our results show that the fruit bats make functional use of echolocation.”
Prof. Yossi Yuval concludes: “Our results are unequivocal and show that fruit bats make frequent use of echolocation even during the day when visibility is good. We hypothesize that this is due to the fact that echolocation helps the bats to measure the distances of objects in the environment more accurately, and that their brains combine the visual information along with the auditory information. This study shows how important integration between different senses is, just as we humans integrate visual and auditory information when we cross a street, for example.”
Experimental drug has potential to treat rare syndromes that impair brain functions
- Social Sciences
Researchers at Tel Aviv University, led by Prof. Illana Gozes from the Department of Human Molecular Genetics and Biochemistry at the Sackler Faculty of Medicine and the Sagol School of Neuroscience, have unraveled a mechanism shared by mutations in certain genes which cause autism, schizophrenia, and other conditions. The researchers also found that an experimental drug previously developed in Prof. Gozes' lab is effective in lab models for these mutations, and believe the encouraging results may lead to effective treatments for a range of rare syndromes that impair brain functions and cause autism, schizophrenia, and neurodegenerative diseases like Alzheimer's.
"Some cases of autism are caused by mutations in various genes,” explains Gozes. “Today, we know of more than 100 genetic syndromes associated with autism, 10 of which are considered relatively common (though still extremely rare). In our lab, we focus mainly on one of these, the ADNP syndrome. The ADNP syndrome is caused by mutations in the ADNP gene, which disrupt the function of the ADNP protein, leading to structural defects in the skeleton of neurons in the brain. In the current study, we identified a specific mechanism that causes this damage in mutations in two different genes: ADNP and SHANK3 - a gene associated with autism and schizophrenia. According to estimates, these two mutations are responsible for thousands of cases of autism around the world."
To start with, the researchers obtained cells from patients with ADNP syndrome. They discovered that when the ADNP protein is defective, neurons with faulty skeletons (microtubules) are formed, impairing brain functions. They also found, however, that ADNP mutations take different forms, some of which cause less damage.
Gozes explains that in some mutations, a section added to the protein protects it and reduces the damage by connecting to a control site of the neuron's skeletal system and that this same control site is found on SHANK3 – a much studied protein, with mutations that are associated with autism and schizophrenia. “We concluded that the ability to bond with SHANK3 and other similar proteins provides some protection against the mutation's damaging effects," she says.
At the next stage of the study, the researchers found additional sites on the ADNP protein that can bond with SHANK3 and similar proteins. One of these sites is located on NAP, a section of ADNP which was developed into an experimental drug, called Davunetide, by Prof. Gozes' lab.
Moreover, the researchers demonstrated that extended treatment with Davunetide significantly improved the behavior of lab animals with autism caused by SHANK3.
"In previous studies we showed that Davunetide is effective for treating ADNP syndrome models. The new study has led us to believe that it may also be effective in the case of Phelan McDermid syndrome, caused by a mutation in SHANK3, as well as other syndromes that cause autism through the same mechanism," explains Gozes.
Participants in the study: Dr. Yanina Ivashko-Pachima, Maram Ganaiem, Inbar Ben-Horin-Hazak, Alexandra Lobyntseva, Naomi Bellaiche, Inbar Fischer, Gilad Levy, Dr. Shlomo Sragovich, Dr. Gidon Karmon, and Dr. Eliezer Giladi from the Sackler Faculty of Medicine and Sagol School of Neuroscience at TAU, Dr. Boaz Barak from The School of Psychological Sciences, Gershon H. Gordon Faculty of Social Sciences and the Sagol School of Neuroscience at TAU, and Dr. Shula Shazman from the Department of Mathematics and Computer Science at the Open University. The paper was published in the scientific journal Molecular Psychiatry.