All posts tagged: genome

Why flowering plants survived Earth’s greatest extinction while dinosaurs did not

Why flowering plants survived Earth’s greatest extinction while dinosaurs did not

Published by Jenni Sidey

Flowering plants survived Earth’s worst disasters, including the asteroid strike that ended the dinosaurs, while many others vanished. A sweeping genomic analysis suggests ancient DNA doubling may have helped them endure upheaval, opening a new window on resilience in a warming world. Sixty-six million years ago, a giant asteroid slammed into Earth and changed life forever. The impact wiped out all non-avian dinosaurs and devastated ecosystems across the planet. Fires spread, sunlight dimmed and food chains collapsed. Yet somehow, many flowering plants survived. A new study from Ghent University suggests those survivors may have carried a hidden advantage deep inside their DNA. Researchers found that many flowering plants endured ancient climate catastrophes after accidentally duplicating their entire genomes. The findings come from one of the largest analyses ever conducted on flowering plant genomes. Scientists studied 470 species and traced ancient genome duplication events across more than 100 million years of plant evolution. Their results revealed a striking pattern. Many successful genome duplications appeared during periods of severe environmental turmoil, including mass extinctions, rapid warming events …

Not in Your Genome | M.W. Feldman, Jessica Riskin

Not in Your Genome | M.W. Feldman, Jessica Riskin

Published by José Betancourt

It turns out that if you begin an assertion with “it turns out” and sprinkle it with statistics and acronyms—especially if it’s expressed in the passive voice and followed by a footnote—up to 83 percent of the variation in whether people buy it is explained by their SCI (science credulity index) and 78 percent by their BDS (baloney detection score).1 Here’s how it works. “It turns out,” writes Dalton Conley, the Henry Putnam University Professor in Sociology at Princeton, in his new book The Social Genome, “that almost every trait that has been studied is at least partially influenced” by genetic differences, including “about 40 percent” of the variation in how far people advance in school. “For income,” he continues, “it’s 70 percent. For cognitive ability, 75 percent.” Turning to the footnote, we find no evidence but instead a further assertion that PGIs (“polygenic indices”)—statistical treatments of genetic variants—are “incredibly useful for studying the social world.” This is Conley’s central claim: that genetic analysis offers the key to understanding not just people’s biology but their …

Craig Venter, pioneering human genome decoder, dies at 79 : NPR

Craig Venter, pioneering human genome decoder, dies at 79 : NPR

Published by Sam Flores

Pioneering geneticist J. Craig Venter has died at the age of 79, according to his namesake research institute. K.C. Alfred/The San Diego Union-Tribune/Getty Images hide caption toggle caption K.C. Alfred/The San Diego Union-Tribune/Getty Images J. Craig Venter, a scientist who played a critical role in the sequencing of the human genome, has died at the age of 79, according to his namesake research institute. Venter’s company, Celera Genomics, famously began a scientific race, trying to completely sequence the human genetic code before the government-funded Human Genome Project achieved the same feat. He pioneered new, cheaper, faster approaches such as the “whole genome shotgun method” that critics initially said wouldn’t work. In a 2003 interview with NPR, when Venter was asked about how he felt about being often called a scientific “maverick,” he said that it “depends on how it’s meant by most people, but in the context of stodgy science, I consider it a tremendous badge of honor.” Maverick or no, Venter’s successes and provocations made him a scientific superstar. In 2000, when scientists gathered …

The rich but complicated legacy of genome pioneer Craig Venter

The rich but complicated legacy of genome pioneer Craig Venter

Published by skeptic

Craig Venter in 2010 REUTERS/Jessica Rinaldi Craig Venter, who played a leading role in the sequencing of the human genome and, later, in synthetic biology, has died. According to the J. Craig Venter Institute, the not-for-profit research institute he founded, Venter died “following a brief hospitalization for unexpected side effects that arose from treatment of recently diagnosed cancer”. He was 79. Venter leaves behind a vast and complicated legacy. He made major advances in genomics, fundamental biology and biodiversity. At the same time, he drove the commercialisation of biological research and promoted the idea of science as a competitive race. His path into research was circuitous. He graduated from high school, having been an indifferent student who preferred to sail and surf. But he was then conscripted into the US Navy and sent to Vietnam as a war orderly. Venter later said that this experience inspired him to get his life together. Returning to the US, he attended community college and then university, and by the 1980s, he was working as a biomedical researcher for …

Autism risk genes are shared across human ancestries, large genome study reveals

Autism risk genes are shared across human ancestries, large genome study reveals

Published by José Betancourt

A massive new genetic analysis reveals that the biological traits underlying autism risk are the same across people of different ancestral backgrounds. By examining the DNA of thousands of Latin American individuals, researchers showed that rare genetic changes linked to autism occur in the exact same genes across diverse populations. The results, published in the journal Nature Medicine, point to a universal genetic foundation for autism and highlight the need for more inclusive medical testing. Over the past decade, researchers have identified dozens of genetic variations that increase the likelihood of a person developing autism. These variations tend to appear in highly conserved genes. A highly conserved gene is a segment of DNA that has remained nearly identical across species over vast stretches of evolutionary history. Because these specific genes perform basic cellular functions, they are subject to strict natural selection. Any spontaneous mutations within them are usually weeded out over time because they disrupt essential biological processes. When such rare mutations do occur in humans, they often lead to profound neurodevelopmental changes. Most of …

The human genome begins organizing itself far earlier than expected

The human genome begins organizing itself far earlier than expected

Published by Jenni Sidey

Life begins with a quiet but precise choreography inside the nucleus. For decades, scientists believed that a newly fertilized egg started in disorder, its DNA loosely arranged and waiting for instructions. That view is now shifting. New research reveals that the genome begins organizing itself far earlier than expected, building a structured framework before it even turns on its own genes. This discovery comes from a team led by Professor Juanma Vaquerizas from the Medical Research Council, who developed a powerful new method called Pico-C. With this tool, scientists can now see the three-dimensional structure of DNA in extraordinary detail, even in the earliest stages of life. Their findings suggest that the genome is not a blank slate. Instead, it is already carefully arranged, preparing cells for the moment they begin to function independently. “We used to think of the time before the genome awakens as a period of chaos,” explains Noura Maziak, lead author of the study. “But by zooming in closer than ever before, we can see that it’s actually a highly disciplined …

Microbe with the smallest genome yet pushes the boundaries of life

Microbe with the smallest genome yet pushes the boundaries of life

Published by skeptic

Symbiotic bacteria live inside specialised organs called bacteriomes within insects. This image shows a cross-section of the planthopper Callodictya krueperi, with fluorescent probes labelling three microbes: Vidania (red), Sodalis (yellow) and Sulcia (green) Courtesy Anna Michalik et al Symbiotic bacteria living inside insect cells have the smallest genomes known for any organism. The findings further muddy the distinction between cellular organelles like mitochondria and the most barebones microbes in nature. “Exactly where this highly integrated symbiont ends and an organelle starts, I think it’s very difficult to say,” says Piotr Łukasik at Jagiellonian University in Kraków, Poland. “This is a very blurred boundary.” Planthoppers are insects that subsist entirely on plant sap, and supplement their nutrition thanks to an ancient relationship with symbiotic bacteria. Over many millions of years, these microbes evolved to live inside specialised cells in the planthoppers’ abdomens, producing nutrients that the planthoppers can’t get from their sugary diet. Many of these bacteria are totally dependent on their hosts and have let their genetic toolkits deteriorate to a fraction of their ancestral size. Łukasik and his colleagues were …

The hidden power of epigenetics: Best ideas of the century

The hidden power of epigenetics: Best ideas of the century

Published by skeptic

At the dawn of the millennium, the number of genes in our genome was still up for discussion. When we finally got our first official estimate, the number was so far below expectations that it helped turbocharge a movement to rethink the evolutionary process. In 2001, the Human Genome Project announced we have no more than 40,000 protein-coding genes – a figure that has since been revised down to about 20,000. We needed other mechanisms to explain the complexity of our biology and evolution. It was epigenetics’ time to shine. Epigenetics is a catch-all term to describe how a wide variety of molecules interact with DNA or RNA to influence the activity of genes without changing the underlying genetic code. Two cells with identical genomes but different epigenetic markers can look and behave very differently. Epigenetics offers a way to squeeze more complexity out of the genome, through things like environmental factors. And some biologists are convinced it can do much more, potentially even influencing the evolutionary process. We know how this might happen. In a 2019 study in which yeast was exposed to a toxic chemical, the toxin killed the yeast by interacting with a protein produced by one of its genes. But …

Scientists recover genome from woolly rhino eaten by Ice Age wolf

Scientists recover genome from woolly rhino eaten by Ice Age wolf

Published by Sam Flores

Jan 14 : About 14,400 years ago, a weeks-old wolf puppy ate its last meal – meat from a woolly rhinoceros – shortly before dying on the harsh Ice Age landscape of northeastern Siberia. In a first, researchers have extracted DNA and recovered the rhino’s genome from a chunk of undigested meat from the stomach contents found in the puppy’s remains, discovered in permafrost near the village of Tumat. These genome findings provided insight into the fate of this impressive cold-adapted horned herbivore species once common in northern Europe and Asia. The researchers compared this rhino’s genome to those of two other individuals from the same species that lived thousands of years earlier – about 18,000 and 49,000 years ago – to examine genetic changes over time. In doing so, they learned that the woolly rhinoceros as a species remained genetically healthy until the end of the Ice Age before apparently suffering a rapid population collapse, probably because the warming climate erased their preferred steppe-tundra environment. For instance, the newly recovered genome showed no evidence …

Woolly rhino genome recovered from meat in frozen wolf pup’s stomach

Woolly rhino genome recovered from meat in frozen wolf pup’s stomach

Published by skeptic

The woolly rhino was one of the icons of the last glacial period The History Collection / Alamy A genome reconstructed from a tiny piece of flesh found in the stomach of a wolf pup that died 14,400 years ago suggests that woolly rhinos were still genetically healthy even as they faced imminent extinction. No one will ever know how a young female wolf pup died at a site near what is now the town of Tumat in northern Siberia, Russia. But it is most likely that she and her sister, together known as the Tumat Puppies, had just been fed the meat of a woolly rhinoceros (Coelodonta antiquitatis) by their mother when their den collapsed, entombing the siblings in permafrost for 14,400 years. The first of the puppies was found at the site in 2011 and the second in 2015. A dissection of the stomach contents of one of the puppies yielded a piece of woolly rhinoceros flesh. Edana Lord at Stockholm University in Sweden, a member of the team that studied the fragment, …