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Scientists Identify 'Ghost Ancestors' in Human DNA, Revealing New Insights into Human Evolution

Scientists Identify 'Ghost Ancestors' in Human DNA, Revealing New Insights into Human Evolution

Researchers from UC Berkeley and Johns Hopkins University have discovered traces of two previously unknown hominin species in modern human DNA. These 'ghost ancestors' were identified through a new method called TRACE, which tracks archaic contributions via ARG estimation. The study, published in the journal Science, reveals that these ancient relatives interbred with Homo sapiens approximately 50,000 years ago, before the most recent migration out of Africa. This discovery suggests that about 0.5 to 1 percent of the modern human genome comes from these unknown ancestors, similar to the genetic contribution from Neanderthals. Additionally, the study found evidence of a 'super-archaic ancestor,' a 1.8-million-year-old lineage that interbred with Denisovans, another ancient human species.

New Study Suggests 'Ghost Lineage' in Human DNA, Expanding Understanding of Ancestral Roots

New Study Suggests 'Ghost Lineage' in Human DNA, Expanding Understanding of Ancestral Roots

A recent study published in Science has revealed the presence of a 'ghost lineage' in the DNA of modern humans, suggesting a previously unknown branch of the human family tree. Researchers, including Yulin Zhang from UC Berkeley and Arjun Biddanda from Johns Hopkins University, used a novel method called TRACE to analyze 503 contemporary genomes. They discovered that 2 percent of the DNA in non-African genomes comes from archaic lineages, with a portion of this DNA not matching any known ancient species. This 'ghost' lineage likely diverged from the human branch over 500,000 years ago, around the same time as Neanderthals and Denisovans.

UC Berkeley Researchers Identify DNA from 'Ghost' Ancestors in Human Genome

UC Berkeley Researchers Identify DNA from 'Ghost' Ancestors in Human Genome

Researchers at UC Berkeley have developed a new technique to identify regions of DNA in modern humans that were inherited from two unknown ancestors, referred to as 'ghost' and 'super-archaic' ancestors. This discovery was made possible by analyzing hundreds of genomes from present-day humans to uncover ancient genealogical relationships. The 'ghost' ancestor interbred with modern humans in Africa over 50,000 years ago, contributing approximately 1% of the DNA found in modern humans. The 'super-archaic' ancestor, a lineage dating back 1.8 million years, interbred with Denisovans in Eurasia, and some of this DNA was passed to modern humans through subsequent interbreeding. The findings suggest that early modern humans lived alongside and interbred with various hominin groups, creating a complex web of genetic connections.

Ancient DNA Study Reveals Ice Age Humans Targeted Female Woolly Mammoths

Ancient DNA Study Reveals Ice Age Humans Targeted Female Woolly Mammoths

An international team of researchers has analyzed ancient DNA from over 500 mammoth bones, revealing that Ice Age humans selectively targeted female woolly mammoths. The study, published in Current Biology, found that large bone accumulations associated with human activity were predominantly female, contrasting with the male-dominated remains found in natural settings. This suggests that human hunting practices were a significant factor in these accumulations, possibly due to the more predictable movement patterns of female-led herds or their smaller size compared to males.

Smallpox DNA is recovered from Spanish conquest-era Chilean mummies

Smallpox DNA is recovered from Spanish conquest-era Chilean mummies

By Will Dunham WASHINGTON, July 30 (Reuters) - When Spanish conquistadors arrived in the New World some five centuries ago, they brought muskets, cannons, armor, horses and attack dogs as they set about colonizing the Americas.

Ancient Smallpox Genomes Confirm European Introduction to the Americas

Ancient Smallpox Genomes Confirm European Introduction to the Americas

Researchers from Trinity College Dublin have recovered and analyzed the first ancient smallpox virus genomes identified in the Americas. The study, published in Science, provides direct genetic evidence that smallpox was introduced to the Americas through European colonization. The viral DNA, recovered from individuals buried in northern Chile, belongs to a now-extinct lineage of variola virus, linking it to strains from medieval Europe. This discovery confirms historical accounts of smallpox's devastating impact on Indigenous populations following European contact.

Ground Squirrels Provide New Insights into Retinal Development

Ground Squirrels Provide New Insights into Retinal Development

Research on thirteen-lined ground squirrels is offering new perspectives on retinal development and photoreceptor differentiation. Unlike most mammals, these squirrels have a higher ratio of cones to rods in their retinas, a trait that deviates from the typical mammalian pattern shaped by evolutionary pressures during the Mesozoic Era. Seth Blackshaw, a neuroscience professor at Johns Hopkins University, is investigating the genetic and developmental mechanisms that lead to this unique retinal structure. His work aims to understand how increased cone production occurs and how retinal cells differentiate, providing insights into the evolution of vision in mammals.

Ancient mummy DNA provides scientific evidence that colonization brought smallpox to the Americas

Ancient mummy DNA provides scientific evidence that colonization brought smallpox to the Americas

New research says ancient mummy DNA provides the firmest evidence yet that European colonization brought smallpox to the Americas

Discovery of Ancient Skull in Spain Challenges Human Evolution Theories

Discovery of Ancient Skull in Spain Challenges Human Evolution Theories

A fragment of a human skull dating back over 200,000 years has been discovered in Ciudad Real, Spain, adding complexity to the understanding of human evolution. This find is significant due to the scarcity of human remains from this period in Europe, a crucial time when early humans with large, complex brains, such as Homo sapiens and Neanderthals, emerged. The skull's features suggest a more primitive human, complicating the evolutionary timeline and challenging existing theories about the development of modern humans and their ancestors.

Study shows prehistoric people targeted female mammoths

Study shows prehistoric people targeted female mammoths

By Will Dunham July 31 (Reuters) - Woolly mammoths were a favorite hunting target for Ice Age people in Eurasia and North America for many reasons. A single animal would provide a large amount of meat and fat. Its hide could be used for clothing.

New Fossil Footprints Reveal Insights into Extinct 'Nutcracker Man'

New Fossil Footprints Reveal Insights into Extinct 'Nutcracker Man'

Scientists have uncovered new fossil footprints in Kenya that provide fresh insights into the extinct hominin species known as 'Nutcracker Man' or Paranthropus boisei. These footprints, dating back approximately 1.4 million years, suggest that P. boisei individuals were taller and heavier than previously thought, with males potentially reaching up to 6 feet in height. The footprints also indicate complex social behavior, as they appear to have been made by a group of adult males traveling together. This discovery offers a new perspective on the physical characteristics and social dynamics of this ancient species.

Nobel Laureate's Team Develops AI-Designed CRISPR Tools with Enhanced Precision

Nobel Laureate's Team Develops AI-Designed CRISPR Tools with Enhanced Precision

A team led by Nobel Laureate Jennifer Doudna has developed AI-designed CRISPR gene editing tools that surpass natural systems in precision and efficiency. The AI-generated enzymes, which have never existed in nature, demonstrate higher editing efficiency and significantly lower off-target effects compared to traditional CRISPR systems. The research, published in Science, highlights the creation of a new CRISPR enzyme that can cut genes more efficiently than its natural counterparts. This development marks a significant advancement in gene editing technology, as the AI-designed tools can modify up to 30% of the protein sequence while maintaining functionality, a feat previously unattainable with natural CRISPR proteins.