Connect with us


Did woolly mammoths overlap with first humans in what is now New England? Researchers trace the age of a Mount Holly mammoth rib fragment from Mount Holly, Vt.



Did woolly mammoths overlap with first humans in what is now New England? Researchers trace the age of a Mount Holly mammoth rib fragment from Mount Holly, Vt.

Woolly mammoths may have walked the landscape at the same time as the earliest humans in what is now New England, according to a Dartmouth study published in Boreas. Through the radiocarbon dating of a rib fragment from the Mount Holly mammoth from Mount Holly, Vt., the researchers learned that this mammoth existed approximately 12,800 years ago. This date may overlap with the arrival of the first humans in the Northeast, who are thought to have arrived around the same time.

“”It has long been thought that megafauna and humans in New England did not overlap in time and space and that it was probably ultimately environmental change that led to the extinction of these animals in the region but our research provides some of the first evidence that they may have actually co-existed,” explains co-author Nathaniel R. Kitchel, the Robert A. 1925 and Catherine L. McKennan Postdoctoral Fellow in anthropology at Dartmouth.

The Mount Holly mammoth, Vermont’s state terrestrial fossil, was discovered in the summer of 1848 in the Green Mountains during the construction of the Burlington and Rutland railroad lines. One molar, two tusks, and an unknown number of bones were excavated from a hilltop bog near Mount Holly. Over time, the specimens became scattered across several repositories, as they transferred from one collection to the next. A rib fragment from the Mount Holly mammoth became part of the Hood Museum of Art’s collection and some of the other skeletal materials are now housed at the Museum of Comparative Zoology at Harvard University and the Mount Holly Historical Museum.

Kitchel stumbled across the Mount Holly mammoth rib fragment last December at the Hood Museum’s offsite storage facility, as curators had invited him to take a look at some of their artifacts from New Hampshire and Vermont. He came across a large bone (approximately 30 cm. in length) that was stained brown in color from age. He had a hunch that this was the remains of a mammoth and when he looked down at the tag, it read, “Rib of fossil elephant. Mt. Holly R.R. cut. Presented by Wm. A. Bacon Esq. Ludlow VT.” This was rather serendipitous for Kitchel, as he had recently delivered a talk at Mount Holly’s Historical Museum for which he had read up on the Mount Holly mammoth.

To appreciate the significance of the Mount Holly mammoth remains, including the rib fragment, it is helpful to understand the paleontology of the Northeast. During the Last Glacial Maximum around 18,000 — 19,000 years ago when glaciers were at their maximum extent, the ice began to retreat, gradually exposing what is now New England. During that period, it is likely that the glaciers probably sufficiently ripped up whatever soil might have been preserving fossils, reducing the likelihood for fossils to remain intact. These changes combined with the Northeast’s naturally acidic soils have created inhospitable conditions for the preservation of fossils. While Kitchel had discussed the complicated paleontology of the Northeast in the past with colleague and co-author Jeremy DeSilva, an associate professor of anthropology at Dartmouth, he never thought that he would have much of an opportunity to work on it.

After seeing this mammoth material in the Hood’s collection, he and DeSilva decided to obtain a radiocarbon date of the fragmentary rib bone. They took a 3D scan of the material prior to taking a small (1 gram) sample from the broken end of the rib bone. The sample was then sent out to the Center for Applied Isotope Studies at the University of Georgia for radiocarbon dating and a stable istotopic analysis.

Radiocarbon dating enables researchers to determine how long an organism has been dead based on its concentration of carbon-14, a radioactive isotope that decays over time. Stable isotopes however, are isotopes that do not decay over time, which provide a snapshot of what was absorbed into the animal’s body when it was alive. Nitrogen isotopes can be used to analyze the protein composition of an animal’s diet. The nitrogen isotopes of the Mount Holly mammoth revealed low values in comparison to that of other recorded mammoths globally while also reflecting the lowest value recorded in the Northeast for a mammoth. The low nitrogen values could have been the result of these mega-herbivores having to consume alder or lichens (nitrogen fixing species) during the last glacial period when the landscape was denser due to climate warming.

“The Mount Holly mammoth was one of the last known occurring mammoths in the Northeast,” says DeSilva. “While our findings show that there was a temporal overlap between mammoths and humans, this doesn’t necessarily mean that people saw these animals or had anything to do with their death but it raises the possibility now that maybe they did.”

The radiocarbon date for the Mount Holly mammoth of 12,800 years old overlaps with the accepted age of when humans may have initially settled in the region, which is thought to have occurred during the start of the Younger Dryas, a final pulse of glacial cold before temperatures warmed dramatically, marking the end of the Pleistocene (Ice Age).

While other research on mammoths in the Midwest suggests that humans hunted and buried these animals in lakes and bogs to preserve the meat, there’s little evidence that early humans in New England hunted or scavenged these animals.

The researchers are intrigued by the Mount Holly mammoth. The rest of its rib and other bones could be waiting to be discovered. Or, through time, they could have broken apart, dissolved in the acidic soil, or a scavenger could have run off with the bones. There are still a lot of unknowns; yet, the team has already begun further research using modern and more sophisticated archaeological techniques to explore what may be underground at Mount Holly.

Story Source:
Materials provided by Dartmouth College. Original written by Amy Olson. Note: Content may be edited for style and length.

Source link

Continue Reading
Click to comment

Leave a Reply


AI headphones let wearer listen to a single person in a crowd, by looking at them just once




Did woolly mammoths overlap with first humans in what is now New England? Researchers trace the age of a Mount Holly mammoth rib fragment from Mount Holly, Vt.

Noise-canceling headphones have gotten very good at creating an auditory blank slate. But allowing certain sounds from a wearer’s environment through the erasure still challenges researchers. The latest edition of Apple’s AirPods Pro, for instance, automatically adjusts sound levels for wearers — sensing when they’re in conversation, for instance — but the user has little control over whom to listen to or when this happens.

A University of Washington team has developed an artificial intelligence system that lets a user wearing headphones look at a person speaking for three to five seconds to “enroll” them. The system, called “Target Speech Hearing,” then cancels all other sounds in the environment and plays just the enrolled speaker’s voice in real time even as the listener moves around in noisy places and no longer faces the speaker.

The team presented its findings May 14 in Honolulu at the ACM CHI Conference on Human Factors in Computing Systems. The code for the proof-of-concept device is available for others to build on. The system is not commercially available.

“We tend to think of AI now as web-based chatbots that answer questions,” said senior author Shyam Gollakota, a UW professor in the Paul G. Allen School of Computer Science & Engineering. “But in this project, we develop AI to modify the auditory perception of anyone wearing headphones, given their preferences. With our devices you can now hear a single speaker clearly even if you are in a noisy environment with lots of other people talking.”

To use the system, a person wearing off-the-shelf headphones fitted with microphones taps a button while directing their head at someone talking. The sound waves from that speaker’s voice then should reach the microphones on both sides of the headset simultaneously; there’s a 16-degree margin of error. The headphones send that signal to an on-board embedded computer, where the team’s machine learning software learns the desired speaker’s vocal patterns. The system latches onto that speaker’s voice and continues to play it back to the listener, even as the pair moves around. The system’s ability to focus on the enrolled voice improves as the speaker keeps talking, giving the system more training data.

The team tested its system on 21 subjects, who rated the clarity of the enrolled speaker’s voice nearly twice as high as the unfiltered audio on average.

This work builds on the team’s previous “semantic hearing” research, which allowed users to select specific sound classes — such as birds or voices — that they wanted to hear and canceled other sounds in the environment.

Currently the TSH system can enroll only one speaker at a time, and it’s only able to enroll a speaker when there is not another loud voice coming from the same direction as the target speaker’s voice. If a user isn’t happy with the sound quality, they can run another enrollment on the speaker to improve the clarity.

The team is working to expand the system to earbuds and hearing aids in the future.

Additional co-authors on the paper were Bandhav Veluri, Malek Itani and Tuochao Chen, UW doctoral students in the Allen School, and Takuya Yoshioka, director of research at AssemblyAI. This research was funded by a Moore Inventor Fellow award, a Thomas J. Cabel Endowed Professorship and a UW CoMotion Innovation Gap Fund.

Source link

Continue Reading


Birth of universe’s earliest galaxies observed for first time




Did woolly mammoths overlap with first humans in what is now New England? Researchers trace the age of a Mount Holly mammoth rib fragment from Mount Holly, Vt.

Using the James Webb Space Telescope, University of Copenhagen researchers have become the first to see the formation of three of the earliest galaxies in the universe, more than 13 billion years ago. The sensational discovery contributes important knowledge about the universe and is now published in the journal Science.

For the first time in the history of astronomy, researchers at the Niels Bohr Institute have witnessed the birth of three of the universe’s absolute earliest galaxies, somewhere between 13.3 and 13.4 billion years ago.

The discovery was made using the James Webb Space Telescope, which brought these first ‘live observations’ of formative galaxies down to us here on Earth.

Through the telescope, researchers were able to see signals from large amounts of gas that accumulate and accrete onto a mini-galaxy in the process of being built. While this is how galaxies are formed according to theories and computer simulations, it had never actually been witnessed.

“You could say that these are the first ‘direct’ images of galaxy formation that we’ve ever seen. Whereas the James Webb has previously shown us early galaxies at later stages of evolution, here we witness their very birth, and thus, the construction of the first star systems in the universe,” says Assistant Professor Kasper Elm Heintz from the Niels Bohr Institute, who led the new study.

Galaxies born shortly after the Big Bang

The researchers estimate the birth of the three galaxies to have occurred roughly 400-600 million years after the Big Bang, the explosion that began it all. While that sounds like a long time, it corresponds to galaxies forming during the first three to four percent of the universe’s 13.8-billion-year overall lifetime.

Shortly after the Big Bang, the universe was an enormous opaque gas of hydrogen atoms — unlike today, where the night sky is speckled with a blanket of well-defined stars.

“During the few hundred million years after the Big Bang, the first stars formed, before stars and gas began to coalesce into galaxies. This is the process that we see the beginning of in our observations,” explains Associate Professor Darach Watson.

The birth of galaxies took place at a time in the history of the universe known as the Epoch of Reionization, when the energy and light of some of the first galaxies broke through the mists of hydrogen gas.

It is precisely these large amounts of hydrogen gas that the researchers captured using the James Webb Space Telescope’s infrared vision. This is the most distant measurement of the cold, neutral hydrogen gas, which is the building block of the stars and galaxies, discovered by scientific researchers to date.

Adds to the understanding of our origins

The study was conducted by Kasper Elm Heintz, in close collaboration with, among others, research colleagues Darach Watson, Gabriel Brammer and PhD student Simone Vejlgaard from the Cosmic Dawn Center at the University of Copenhagen’s Niels Bohr Institute — a center whose stated goal is to investigate and understand the dawn of the universe. This latest result brings them much closer to doing just that.

The research team has already applied for more observation time with the James Webb Space Telescope, with hopes of expanding upon their new result and learning more about the earliest epoch in the formation of galaxies.

“For now, this is about mapping our new observations of galaxies being formed in even greater detail than before. At the same time, we are constantly trying to push the limit of how far out into the universe we can see. So, perhaps we’ll reach even further,” says Simone Vejlgaard.

According to the researcher, the new knowledge contributes to answering one of humanity’s most basic questions.

“One of the most fundamental questions that we humans have always asked is: ‘Where do we come from?’. Here, we piece together a bit more of the answer by shedding light on the moment that some of the universe’s first structures were created. It is a process that we’ll investigate further, until hopefully, we are able to fit even more pieces of the puzzle together,” concludes Associate Professor Gabriel Brammer.

The study was conducted by researchers Kasper E. Heintz, Darach Watson, Gabriel Brammer, Simone Vejlgaard, Anne Hutter, Victoria B. Strait, Jorryt Matthee, Pascal A. Oesch, Pall Jakobsson, Nial R. Tanvir, Peter Laursen, Rohan P. Naidu, Charlotte A. Mason, Meghana Killi, Intae Jung, Tiger Yu-Yang Hsiao, Abdurro’uf, Dan Coe, Pablo Arrabal Haro, Steven L. Finkelstein, & Sune Toft.

The Danish portion of the research is funded by the Danish National Research Foundation and the Carlsberg Foundation.


Researchers were able to measure the formation of the universe’s first galaxies by using sophisticated models of how light from these galaxies was absorbed by the neutral gas located in and around them. This transition is known as the Lyman-alpha transition.

By measuring the light, the researchers were able to distinguish gas from the newly formed galaxies from other gas. These measurements were only possible thanks to the James Webb Space Telescope’s incredibly sensitive infrared spectrograph capabilities.


The universe began its “life” about 13.8 billion years ago in an enormous explosion — the Big Bang. The event gave rise to an abundance of subatomic particles such as quarks and electrons. These particles aggregated to form protons and neutrons, which later coalesced into atomic nuclei. Roughly 380,000 years after the Big Bang, electrons began to orbit atomic nuclei, and the simplest atoms of the universe gradually formed.

The first stars were formed after a few hundred million years. And within the hearts of these stars, the larger and more complex atoms that we have around us were formed.

Later, stars coalesced into galaxies. The oldest galaxies known to us were formed about 3-400 million years after the Big Bang. Our own solar system came into being about 4.6 billion years ago — more than 9 billion years after the Big Bang.

Source link

Continue Reading


Scientists map networks regulating gene function in the human brain




Did woolly mammoths overlap with first humans in what is now New England? Researchers trace the age of a Mount Holly mammoth rib fragment from Mount Holly, Vt.

A consortium of researchers has produced the largest and most advanced multidimensional maps of gene regulation networks in the brains of people with and without mental disorders. These maps detail the many regulatory elements that coordinate the brain’s biological pathways and cellular functions. The research, supported the National Institutes of Health (NIH), used postmortem brain tissue from over 2,500 donors to map gene regulation networks across different stages of brain development and multiple brain-related disorders.

“These groundbreaking findings advance our understanding of where, how, and when genetic risk contributes to mental disorders such as schizophrenia, post-traumatic stress disorder, and depression,” said Joshua A. Gordon, M.D., Ph.D., director of NIH’s National Institute of Mental Health (NIMH). “Moreover, the critical resources, shared freely,willhelp researchers pinpoint genetic variants that are likely to play a causal role in mental illnesses and identify potential molecular targets for new therapeutics.”

The research is published across 15 papers in Science, Science Advances, and Scientific Reports. The papers report findings along several key themes:

  • Population-level analyses that link genetic variants, regulatory elements, and different molecular forms of expressed genes to regulatory networks at the cellular level, in both the developing brain and adult brain
  • Single-cell-level maps of the prefrontal cortex from individuals diagnosed with mental disorders and neurodevelopmental disorders
  • Experimental analyses validating the function of regulatory elements and genetic variants associated with quantitative trait loci (segments of DNA that are linked with observable traits)

The analyses expand on previous findings, exploring multiple cortical and subcortical regions of the human brain. These brain areas play key roles in a range of essential processes, including decision-making, memory, learning, emotion, reward processing, and motor control.

Approximately 2% of the human genome is composed of genes that code for proteins. The remaining 98% includes DNA segments that help regulate the activity of those genes. To better understand how brain structure and function contribute to mental disorders, researchers in the NIMH-funded PsychENCODE Consortium are using standardized methods and data analysis approaches to build a comprehensive picture of these regulatory elements in the human brain.

In addition to these discoveries, the papers also highlight new methods and tools to help researchers analyze and explore the wealth of data produced by this effort. These resources include a web-based platform offering interactive visualization data from diverse brain cell types in individuals with and without mental disorders, known as PsychSCREEN. Together, these methods and tools provide a comprehensive, integrated data resource for the broader research community.

The papers focus on the second phase of findings from the PsychENCODE Consortium. This effort aims to advance our understanding of how gene regulation impacts brain function and dysfunction.

“These PsychENCODE Consortium findings shed new light on how gene risk maps onto brain function across developmental stages, brain regions, and disorders,” said Jonathan Pevsner, Ph.D., chief of the NIMH Genomics Research Branch. “The work lays a strong foundation for ongoing efforts to characterize regulatory pathways across disorders, elucidate the role of epigenetic mechanisms, and increase the ancestral diversity represented in studies.”

The PsychENCODE papers published in Science and Science Advances are presented as a collection on the Science website.

Source link

Continue Reading


Copyright © 2017 Zox News Theme. Theme by MVP Themes, powered by WordPress.