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El frío, el hielo y el misterio del ARN: cuáles son los experimentos que buscan conocer el origen de la vida
En el debate sobre el origen de la vida, el ácido ribonucleico (ARN) ocupa un lugar central gracias a sus cualidades excepcionales. Aunque en la biología actual el ADN es el protagonista, muchos investigadores sostienen que el ARN desempeñó un rol decisivo en los primeros pasos evolutivos.
Posee la capacidad de almacenar información genética y de actuar como catalizador en reacciones químicas, lo que dio origen a la hipótesis del “mundo de ARN”: moléculas capaces de codificar su propia composición y de impulsar su reproducción, sentando así las bases de los procesos evolutivos que llevaron a organismos cada vez más complejos, afirma Science.
Durante los años noventa, equipos liderados por Jack Szostak (hoy en la Universidad de Chicago) y David Bartel (hoy en el Instituto Tecnológico de Massachusetts) analizaron trillones de secuencias de ARN, identificando algunas capaces de realizar funciones necesarias para la autorreplicación.
No obstante, estas moléculas presentaban una limitación clave: tenían entre 150 y 200 bases, lo que implica que eran demasiado grandes, y ese tamaño las hacía poco plausibles como productos espontáneos de la química de la Tierra primitiva. Además, probablemente se degradarían antes de poder ser completamente sintetizadas.
En este contexto, los bioquímicos Edoardo Gianni y Philipp Holliger de la Universidad de Cambridge, junto con su equipo, se propusieron superar ese obstáculo y acercar la experimentación a condiciones más similares a las de la Tierra en su origen.
Su trabajo, publicado en la revista Science, logró que ciertas moléculas de ARN generen copias complementarias de sí mismas y, a partir de esas copias, restauren la secuencia original. Este avance acerca la hipótesis del “mundo de ARN” a la realidad experimental y refuerza la idea de que el ARN pudo ser el primer motor de la evolución biológica.
En principio, la clave de este logro fue la reducción significativa del tamaño de las moléculas de ARN utilizadas, que pasaron a ser de 45 bases. Gerald Joyce destacó que “eso es una innovación significativa”, ya que moléculas tan pequeñas tienen una mayor probabilidad de surgir espontáneamente, a partir de los componentes básicos que abundaban en los inicios del planeta. Esto abre nuevas posibilidades para comprender los orígenes químicos de la vida.
Los experimentos se realizaron bajo condiciones de bajas temperaturas. Trabajar con frío ralentizó las reacciones que degradan el ARN y permitió aprovechar un fenómeno físico donde, al congelarse el agua, los nucleótidos y otros componentes quedan excluidos de los cristales de hielo, concentrándose en canales microscópicos llenos de solución. Estos microambientes no solo favorecen la síntesis de nuevas cadenas de ARN, sino que también protegen a las moléculas de su rápida degradación.
El diseño incluyó la utilización de tripletes de nucleótidos, fragmentos formados por tres bases fusionadas, que permitieron que algunas cadenas de ARN permanecieran desplegadas y disponibles como moldes para la copia, mientras que otras conservaron la estructura plegada necesaria para actuar como catalizadores. Tras examinar alrededor de un billón de secuencias aleatorias bajo estas condiciones, el equipo identificó tres ARN capaces de completar este proceso de copia complementaria y restauración.
A pesar de este avance, el experimento presenta limitaciones; ninguna de las moléculas aisladas logró realizar el ciclo completo de autorreplicación por sí sola, y la síntesis de las nuevas cadenas de ARN tomó hasta 72 días en condiciones de frío extremo. Sin embargo, estos resultados son compatibles con la hipótesis de que la vida pudo originarse en ambientes sometidos a ciclos de congelamiento y deshielo, donde los componentes químicos se concentraban y protegían por los propios procesos físicos del entorno.
Jack Szostak considera que el reto siguiente será “lograr que este sistema, o uno similar, sea suficientemente eficiente como para observar ciclos repetidos de replicación”. Si se alcanza ese objetivo, el ARN podría consolidarse como el vínculo más probable entre la química prebiótica y la biología.
El hallazgo del equipo de Cambridge fortalece la hipótesis del “mundo de ARN” y abre nuevas rutas para investigar los orígenes de la vida. Al demostrar que moléculas relativamente pequeñas pueden acercarse notablemente al proceso de replicación, los investigadores ofrecen una base concreta para comprender cómo la evolución pudo comenzar a partir de sistemas moleculares sencillos, incluso en las condiciones más desfavorables del planeta primitivo.
cirugía molecular
El transporte «lo ves y no lo ves»
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Trump DOJ probes Michigan schools over gender curriculum, joins lawsuit against LA race-based program
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The Trump Justice Department on Wednesday launched investigations into three Michigan public school districts over gender-related classroom instruction and sought to intervene in a federal lawsuit challenging a race-based admission and funding program in Los Angeles — intensifying the administration’s push into school policy disputes nationwide.
The Civil Rights Division said it is examining whether the Detroit Public Schools Community District, Godfrey-Lee Public Schools and the Lansing School District included «sexual orientation and gender ideology (SOGI) content in any class for grades pre-K-12.»
If such instruction is provided, investigators will assess whether parents were notified of their right to opt their children out and whether the districts «limit access to single-sex intimate spaces, such as bathrooms and locker rooms, based on biological sex.»
Assistant Attorney General Harmeet Dhillon said the department is focused on enforcing parental rights and Title IX.
TRUMP ADMINISTRATION THREATENS TO PULL FEDERAL FUNDS FROM VIRGINIA SCHOOL DISTRICTS IN GENDER POLICY DISPUTE
Assistant Attorney General for Civil Rights Harmeet Dhillon arrives for a news conference at the Justice Department on September 29, 2025 in Washington, DC. (Andrew Harnik/Getty Images)
«This Department of Justice is fiercely committed to ending the growing trend of local school authorities embedding sexuality and gender ideology in every aspect of public education,» Dhillon said.
She added that «Supreme Court precedent is clear: parents have the right to direct the religious upbringing of their children,» including exempting them from instruction that conflicts with their beliefs.
Dhillon also said Title IX requires protecting «the safety, dignity, and innocence of our youngest citizens… by ensuring that they have unfettered access to bathrooms and locker rooms of their biological sex.»
GOP SENATOR PROBES 18 BLUE STATES, DC OVER TRUMP’S TRANSGENDER ATHLETE ORDER
The Department of Justice announced actions involving three Michigan school districts and Los Angeles Unified School District on Wednesday. (BRENDAN SMIALOWSKI/AFP via Getty Images)
The department noted the Michigan districts receive «hundreds of thousands of dollars of taxpayer funding» and said investigators will evaluate compliance with Title IX of the Education Amendments of 1972 and the Supreme Court’s 2025 decision in Mahmoud v. Taylor. Officials emphasized the Civil Rights Division «has not reached any conclusions about the subject matter of the investigations.»
In a separate action, the Justice Department said it is seeking to intervene in a lawsuit filed by the nonprofit 1776 Project Foundation challenging the Los Angeles Unified School District’s Predominately Hispanic, Black, Asian, and Other (PHBAO) Program.
According to the department’s proposed complaint, the program categorizes students by race and neighborhood demographics for funding and magnet school admissions, separating students into «Anglo,» meaning White, and other racial categories. Neighborhoods with fewer than 30% White residents are designated as disadvantaged, and certain schools receive additional funding, a reduced student-teacher ratio by 5.5 students, and magnet admissions preferences.
JUSTICE DEPARTMENT SUES PUBLIC SCHOOL DISTRICT OVER ALLEGEDLY DISCRIMINATORY POLICIES
AG Pam Bondi said «treating Americans equally is not a suggestion» in a DOJ statement on the matter. (Joe Raedle/Getty Images)
The complaint states LAUSD treats attending school with non-White students «as a disadvantage equal to attending an overcrowded school.»
Attorney General Pam Bondi said the federal government is intervening to enforce equal protection guarantees.
«Treating Americans equally is not a suggestion — it is a core constitutional guarantee that educational institutions must follow,» Bondi said.
Dhillon said students «should never be classified or treated differently because of their race,» adding that «Racial discrimination is unlawful and un-American.»
First Assistant U.S. Attorney Bill Essayli said LAUSD’s desegregation program has «outlived its usefulness to the point of being unconstitutional.»
The Michigan investigations remain ongoing, and the LAUSD case is pending in federal court.
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Representatives for the Michigan districts did not immediately respond to Fox News Digital’s requests for comment.
«Because this matter involves pending litigation, we are unable to comment on the specifics,» LAUSD said in a statement. «However, Los Angeles Unified remains firmly committed to ensuring all students have meaningful access to services and enriching educational opportunities.»
justice department,education,pam bondi
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EXCLUSIVE: This was the kind of prison break officials say could have changed the region, and perhaps even the world, overnight.
Nearly 6,000 ISIS detainees, described by a senior U.S. intelligence official as «the worst of the worst,» were being held in northern Syria as clashes and instability threatened the Kurdish-led Syrian Democratic Forces, the guards responsible for keeping the militants locked away and preventing a feared ISIS resurgence. U.S. officials believed that if the prisons collapsed in the chaos, the consequences would be immediate.
«If these 6,000 or so got out and returned to the battlefield, that would basically be the instant reconstitution of ISIS,» the senior intelligence official told Fox News Digital.
In an exclusive interview, the official walked Fox News Digital step by step through the behind-the-scenes operation that moved thousands of ISIS detainees out of Syria and into Iraqi custody, describing a multi-agency scramble that unfolded over weeks, with intelligence warnings, rapid diplomacy and a swift military lift.
US MILITARY LAUNCHES AIRSTRIKES AGAINST ISIS TARGETS IN SYRIA, OFFICIALS SAY
ISIS wives and children remain in «fragile» Syrian detention camps under Damascus control while male fighters transfer to Iraq, leaving detention crisis unresolved. ( Santiago Montag/Anadolu via Getty Image)
The risk, the official explained, had been building for months. In late October, Director of National Intelligence Tulsi Gabbard began to assess that Syria’s transition could tip into disorder and create the conditions for a catastrophic jailbreak.
The ODNI sent the official to Syria and Iraq at that time to begin early discussions with both the SDF and the Iraqi government about how to remove what the official repeatedly described as the most dangerous detainees before events overtook them.
Those fears sharpened in early January as fighting erupted in Aleppo and began spreading eastward. Time was running out to prevent catastrophe. «We saw this severe crisis situation,» the official said.
U.S. ANNOUNCES MORE MILITARY ACTIONS AGAINST ISIS: ‘WE WILL NOT RELENT’
A fighter of the Islamic State of Iraq and the Levant (ISIL) holds an ISIL flag and a weapon on a street in the city of Mosul, June 23, 2014. (Reuters Photo)
According to the source, the ODNI oversaw daily coordination calls across agencies as the situation escalated. The official said Secretary of State Marco Rubio was «managing the day to day» on policy considerations, while the ODNI drove a working group that kept CENTCOM, diplomats and intelligence officials aligned on the urgent question: how to keep nearly 6,000 ISIS fighters from slipping into the fog of war.
The Iraqi government, the official said, understood the stakes. Baghdad had its own reasons to move quickly, fearing that if thousands of detainees escaped, they would spill across the border and revive a threat Iraq still remembers in visceral terms.
The official described Iraq’s motivation bluntly: leaders recognized that a massive breakout could force Iraq back into a «2014 ISIS is on our border situation once more.»
The U.S. Embassy in Baghdad, the official said, played a pivotal role in smoothing the diplomatic runway for what would become a major logistical undertaking.
Then came the physical lift. The official credited CENTCOM’s surge of resources to make the plan real on the ground, saying that «moving in helicopters» and other assets enabled detainees to be removed in a compressed timeframe.
«Thanks to the efforts… moving in helicopters, moving in more resources, and then just logistically making this happen, we were able to get these nearly 6000 out in the course of just a few weeks,» the official said.
ISIS FIGHTERS STILL AT LARGE AFTER SYRIAN PRISON BREAK, CONTRIBUTING TO VOLATILE SECURITY SITUATION
A view of Hol Camp, where families linked to the Islamic State group are being held, in Hasakah province, Syria, Wednesday, Jan. 21, 2026. (Izz Aldien Alqasem/Anadolu via Getty Images)
The SDF, he said, had been securing the prisons, but its attention was strained by fighting elsewhere, fueling U.S. fears that a single breach could spiral into a mass escape. Ultimately, detainees were transported into Iraq, where they are now held at a facility near Baghdad International Airport under Iraqi authority.
The next phase, the official said, is focused on identification and accountability. FBI teams are in Iraq enrolling detainees biometrically, the official said, while U.S. and Iraqi officials examine what intelligence can be declassified and used in prosecutions.
«What they were asking us for, basically, is giving them as much intelligence and information that we have on these individuals,» the official said. «So right now, the priority is on biometrically identifying these individuals.»
The official said the State Department is also pushing countries of origin to take responsibility for their citizens held among the detainees.
«State Department is doing outreach right now and encouraging all these different countries to come and pick up their fighters,» he said.
While the transfer focused strictly on ISIS fighters, the senior intelligence official said families held in camps such as al-Hol were not part of the operation, leaving a major unresolved security and humanitarian challenge.
ISIS EXPLOITING SYRIA’S CHAOS AS US STRIKES EXPOSE GROWING THREAT
Syrian Democratic Forces (SDF) fighters pose for a photo with the American flag on stage after a SDF victory ceremony announcing the defeat of ISIL in Baghouz was held at Omer Oil Field on March 23, 2019 in Baghouz, Syria. (Chris McGrath/Getty Images)
The camps themselves were under separate arrangements, the official said, and responsibility shifted as control on the ground evolved.
According to the official, the Syrian Democratic Forces and the Syrian government reached an understanding that Damascus would take over the al-Hol camp, which holds thousands of ISIS-affiliated women and children.
«As you can see from social media, the al-Hol camp is pretty much being emptied out,» the official said, adding that it «appears the Syrian government has decided to let them go free,» a scenario the official described as deeply troubling for regional security. «That is very concerning.»
The fate of the families has long been viewed by counterterrorism officials as one of the most complicated, unresolved elements of the ISIS detention system. Many of the children have grown up in camps after ISIS lost territorial control, and some are now approaching fighting age, raising fears about future radicalization and recruitment.
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Iraqi security forces pose with ISIS flag which they pulled from University of Anbar on July 26, 2015. Forces clashed with ISIS militants inside the compound. (Reuters)
For now, the official said, intelligence agencies are closely tracking developments after a rapid operation that, in their view, prevented thousands of experienced ISIS militants from reentering the battlefield at once and potentially reigniting the group’s fighting force.
«This is a rare good news story coming out of Syria,» the official concluded.
syria,iraq,isis,national security,fbi,terrorism
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