Few human behaviors seem as simple and natural as laughing. We smile inside the mother's womb, and later share smiles and laughter with friends. They help us break the ice with strangers and, sometimes, we surprise ourselves when we burst into laughter without having planned it. However, behind this apparently simple behavior hides a fascinating evolutionary history. According to a study published in Trends in Neurosciences by neuroscientists Fausto Caruana, from the University of Parma's Institute of Neurosciences, and Sophie K. Scott, from University College London, the brain produces two types of laughter with clearly different meanings.For some time now, psychology and neuroscience have distinguished between spontaneous and voluntary laughter. The former is what erupts in the face of a funny situation. The latter, on the other hand, we use as a social tool to show complicity, kindness, or interest during a conversation. The results of this study indicate that these two types of laughter are governed by two different neural systems.

In 2018, humanity took perhaps the most radical step forward in all of history. It is not an exaggeration: it was the year that the first genetically modified humans were born, thanks to He Jiankui's experiments. What evolution takes millennia to sculpt, the selection of favorable characteristics for survival, we can now achieve in a few months of work in a laboratory. Few discoveries have had such profound implications for our future.

Some people look for their roots to try to understand who they are. Carles Lalueza-Fox (Barcelona, 1965) looks for them to decipher where we come from and better understand our past as a species. For more than two decades, this paleogeneticist from the Institute of Evolutionary Biology (IBE-CSIC-UPF) and current director of the Barcelona Museum of Natural Sciences has been reading the history of humanity in ancient DNA and is one of the world's leading experts. He has contributed to demonstrating that modern humans carry Neanderthal DNA and has reconstructed migrations and interbreeding of prehistoric populations. He has just published Identidad (Crítica), where he delves into a murky terrain: what DNA can explain about who we are and what it cannot.

Xia Quan was a highly valued Chinese doctor. And for this reason, in 1411, when he died during the Ming dynasty, he was buried with some of the instruments he had used. It was a common practice in China, both to honor his skill and so that he could practice his craft in the afterlife.

It is the largest observatory ever built, it will have a field of view a hundred times larger than that of the already mythical Hubble telescope and it has already left Earth. This Sunday morning –at 11:26 a.m., Catalan time and 7:26 a.m. in the United States–, NASA launched the Nancy Grace Roman telescope aboard SpaceX's Falcon Heavy rocket, the company led by Elon Musk. The rocket took off from NASA's John F. Kennedy Space Center in Cape Canaveral, Florida, in an operation that has already been considered a success.

After years of working as a researcher and seeing patients, the "inconsistency" of seeing a lot of research remain "within laboratories" led Andreu Prados to dedicate himself to "communicating" science, to "translate it" for both patients and students and health professionals. Few voices are more didactic than his to talk about one of the most forgotten parts of our body: the vagus nerve. For some time now, videos have been proliferating on social media explaining that it is altered and that there are tricks to retrain it. But what is true in all these publications? Does the vagus nerve really have such a direct impact on our well-being? Prados, who specializes in digestive disorders, explains that knowing it is key to understanding how one of the great ills of the 21st century works from within: stress.

Are you enjoying or preparing for your vacation? The summer period is a time when humans leave our usual routine, travel to find new horizons, or take refuge in more or less familiar surroundings, far from work and, if possible, to cool off from the heat. In general, we mingle with people we don't know, on the sand of the beach, in the water of the pool, or in the middle of a street full of other tourists admiring buildings in old Europe… Be that as it may, you're sure to see people holding hands: a mother or father holding their young child's hand; two little girls holding arms while laughing; a young couple gazing into each other's eyes; and also elderly couples walking side by side. And with this small gesture, they tell each other they still love each other.

It's barely been three months since she arrived in Barcelona and Mónica Bettencourt-Dias (Lisbon, 1972) is already fumbling with Catalan. She has a private tutor and has enrolled her daughters in a summer camp to immerse them in the language. All this shows the intentions of this cellular biologist, who confesses herself to be in love with the city and its culture, and who has just taken over as director of the Centre for Genomic Regulation (CRG) in Barcelona. She is the first woman to head this flagship of biomedical research in Europe, and will lead nearly 500 scientists from 47 different nationalities.

For decades, textbooks have told a relatively simple story about the original human settlement of the Americas. According to this narrative, a group of humans from Asia crossed the Bering region thousands of years ago and, over time, gradually expanded throughout the continent, from north to south. Now, however, one of the most ambitious genomic studies conducted on the descendants of Native Americans suggests that this story is much richer and more complex than previously thought.The research, led by Tábita Hünemeier, a population genetics specialist at Pompeu Fabra University, which involved more than two dozen researchers from around the world, has analyzed complete genomes of indigenous populations from various Latin American countries. According to their publication in the journal Nature, they have discovered more than a million new genetic variants that were absent in large international databases. The result is not only an advance in understanding human history, but also highlights the extent to which a significant part of global human genetic diversity had been practically absent from biomedical research.

The forecast of an exceptional influx of visitors to observe this Wednesday's total solar eclipse and the high temperatures, which will skyrocket the risk of forest fires, have forced the authorities to reinforce prevention measures in various areas of the territory. In Segrià, Granja d'Escarp, Seròs, Almatret, and the Montmaneu plains, access to wooded areas will be restricted; a measure that was agreed upon in Lleida this Monday in a meeting with representatives of the Rural Agents, Civil Protection, and the territorial services of the Interior, but which had already been taken previously in the Ports Natural Park – in Montsià, Terra Alta, and Baix Ebre – and in the Serra del Montsant Natural Park, in effect between 9 p.m. on Tuesday and 8 a.m. on Thursday.

In the summer, when coastal waters warm up, the presence of a bacterium that can cause serious infections in humans increases. It is Vibrio vulnificus, a microorganism that naturally lives in marine and brackish waters in different parts of the world. The U.S. state of Louisiana has reported nine cases of infection this 2026, five of which have resulted in the death of those affected. All cases have required hospitalization, and authorities have linked them to the exposure of wounds to seawater. During the previous ten years, the state had reported an average of about seven cases and one death annually.

Just a year ago, the case of a baby, K.J. Muldon, who suffered from a rare genetic metabolic disease –which can cause irreversible and fatal neurodegeneration– and was cured thanks to personalized gene therapy. A pioneering example of so-called n=1 therapy, that is, a therapy specifically created to treat a specific mutation present in only one patient. This success story was considered one of the great scientific achievements of 2025, and filled many parents with hope for their children affected by very serious rare diseases without treatment.

The total solar eclipse on the 12th is a historic event and that is why we dedicate this Sunday's dossier to it, where we highlight the scientific significance of recording a unique phenomenon.

Make the most difficult easy: getting science, and especially everything related to the universe, to awaken the curiosity of those who listen. And not only that. He is capable of spreading his passion for the cosmos and, in turn, for life. With only a few days left until the total solar eclipse that can be seen from Catalonia, Joan Anton Català, astrophysicist, quantum chemist, and science communicator, is the most sought-after man, but he makes a space in his busy schedule to explain to us how extraordinary this phenomenon will be that we will be able to see on August 12. The eclipse of the century (Cossetània) is the guide it has published for those who do not want to miss any detail.

A piece of a SpaceX rocket that had been floating in space since last year crashed into the Moon this Wednesday morning. The high-speed impact occurred at 2:35 AM in the United States – 8:30 AM in Catalonia – although it took several hours for scientists to confirm it.

Tintin, Professor Calculus and Captain Haddock are on the pyre, waiting for the Incas to light it with a large magnifying glass to concentrate the sun's light. But Tintin addresses the king of the stars and asks him to cover himself with a veil if he does not wish for his death. The sun darkens completely, causing panic among the Incas. Tintin asks the sun to shine again. The star lights up and the three are freed.

Scientists from the University of Berkeley and Johns Hopkins University have revealed a new secret in the history of the human species: they have found traces from two unknown ancestral lineages in human DNA. These are lineages we did not inherit from Neanderthals or Denisovans, but rather from older species. However, their appearance, where they lived, or which species they belonged to are questions still without an answer.

The scene repeats every summer in thousands of Catalan homes: the light off, the silence of the night, and suddenly, the sharp, insistent buzzing that grazes our ear. The reaction is almost a Pavlovian reflex: we turn on the light, look for the little invader on the wall, and with a sharp slap of a slipper, we put an end to the annoyance. Until recently, this domestic victory returned us the tranquility of a bite-free sleep. Today, however, this gesture hides a much more disturbing reality: the mosquito is no longer just an annoying neighbor, it has become the vector for diseases that just four days ago we considered exotic.Catalonia has entered a new epidemiological era. The dengue outbreak in Vila-seca in the summer of 2024, with eight autochthonous cases, was the definitive alarm signal: the virus no longer only arrives by plane, but circulates among us through the tiger mosquito ("Aedes albopictus). This invasive species, recognized by its white stripes and its diurnal activity, has joined the common mosquito (Culex pipiens), the one of a lifetime, which is nocturnal and acts as the main transmitter of the Nile virus. As researcher Rachel Lowe, director of the Global Health Resilience group at the Barcelona Supercomputing Center (BSC-CNS), explains, "Barcelona is a global hub with a high risk of emergency or re-emergence of various pathogens." According to Lowe, rising temperatures and altered rainfall patterns create a "perfect cocktail" for the expansion of these vectors.

Catalonia –and Europe– is experiencing an unprecedented summer, with extreme temperatures that have exceeded 45 degrees in some parts of the country and a historic record of heat-related deaths has been reached. According to data from the Daily Mortality Monitoring System (MoMo), only in the month of June, 218 deaths attributable to extreme heat were recorded, a 300% increase in cases compared to the same period last year. And although these official data do not publish a breakdown by gender, previous epidemiological studies indicate that women die more than men from this cause.

Even in the middle of the morning, the activity at the Blanes fishermen's guild is frantic: a coming and going of boxes full of anchovies and sardines, and mullets and other fish, arriving at this Girona fish market for auction. Unaware of this hustle and bustle and sheltered under the jetties, about forty individuals rest, impassive, in enormous water tanks. Some have only been here a short while and are recovering, waiting for their moment to come. Others are already prepared and will return to the sea soon.