Archive for the ‘evolution’ category: Page 4

Jul 5, 2021

Axions Could Be the Fossil of the Universe Astrophysicists Have Been Waiting For

Posted by in categories: cosmology, education, evolution, particle physics

Finding the hypothetical particle axion could mean finding out for the first time what happened in the Universe a second after the Big Bang, suggests a new study published in Physical Review D.

How far back into the Universe’s past can we look today? In the electromagnetic spectrum, observations of the Cosmic Microwave Background — commonly referred to as the CMB — allow us to see back almost 14 billion years to when the Universe cooled sufficiently for protons and electrons to combine and form neutral hydrogen. The CMB has taught us an inordinate amount about the evolution of the cosmos, but photons in the CMB were released 400000 years after the Big Bang making it extremely challenging to learn about the history of the universe prior to this epoch.

To open a new window, a trio of theoretical researchers, including Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU) Principal Investigator, University of California, Berkeley, MacAdams Professor of Physics and Lawrence Berkeley National Laboratory senior faculty scientist Hitoshi Murayama, Lawrence Berkeley National Laboratory physics researcher and University of California, Berkeley, postdoctoral fellow Jeff Dror (now at University of California, Santa Cruz), and UC Berkeley Miller Research Fellow Nicholas Rodd, looked beyond photons, and into the realm of hypothetical particles known as axions, which may have been emitted in the first second of the Universe’s history.

Continue reading “Axions Could Be the Fossil of the Universe Astrophysicists Have Been Waiting For” »

Jul 1, 2021

Moon-sized “zombie” star challenges what we know about celestial evolution

Posted by in categories: evolution, space

The star is only a little bit larger than Earth’s Moon, but more massive than the Sun and might be a Frankenstein zombie star.

Astronomers discovered the smallest and most massive white dwarf star, about the same size as Earth’s Moon with a mass greater than the Sun.

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Jun 29, 2021

Clearest images emerge of galaxies headed for collision on intergalactic ‘highway’

Posted by in categories: cosmology, evolution, satellites

An international group of astronomers has created images with never-before-seen detail of a galaxy cluster with a black hole at its center, traveling at high speed along an intergalactic “road of matter.” The findings also support existing theories of the origins and evolution of the universe.

The concept that roads of thin gas connect clusters of galaxies across the universe has been difficult to prove until recently, because the matter in these ‘roads’ is so sparse it eluded the gaze of even the most sensitive instruments. Following the 2020 discovery of an intergalactic thread of gas at least 50 million light-years long, scientists have now developed images with an unprecedented level of detail of the Northern Clump—a cluster of galaxies found on this thread.

By combining imagery from various sources including CSIRO’s ASKAP radio telescope, SRG/eROSITA, XMM-Newton and Chandra satellites, and DECam , the scientists could make out a large galaxy at the center of the clump, with a black hole at its center.

Jun 26, 2021

A massive protocluster of merging galaxies in the early universe

Posted by in categories: cosmology, evolution

Submillimeter galaxies (SMGs) are a class of the most luminous, distant, and rapidly star-forming galaxies known and can shine brighter than a trillion Suns (about one hundred times more luminous in total than the Milky Way). They are generally hard to detect in the visible, however, because most of their ultraviloet and optical light is absorbed by dust which in turn is heated and radiates at submillimeter wavelengths—the reason they are called submillimeter galaxies. The power source for these galaxies is thought to be high rates of star formation, as much as one thousand stars per year (in the Milky Way, the rate is more like one star per year). SMGs typically date from the early universe; they are so distant that their light has been traveling for over ten billion years, more than 70% of the lifetime of the universe, from the epoch about three billion years after the big bang. Because it takes time for them to have evolved, astronomers think that even a billion years earlier they probably were actively making stars and influencing their environments, but very little is known about this phase of their evolution.

SMGs have recently been identified in galaxy protoclusters, groups of dozens of galaxies in the universe when it was less than a few billion years old. Observing massive SMGs in these distant protoclusters provides crucial details for understanding both their early evolution and that of the larger structures to which they belong. CfA astronomers Emily Pass and Matt Ashby were members of a team that used infrared and from the Spitzer IRAC and Gemini-South instruments, respectively, to study a previosly identified protocluster, SPT2349-56, in the era only 1.4 billion years after the big bang. The protocluster was spotted by the South Pole Telescope millimeter wavelengths and then observed in more detail with Spitzer, Gemini, and the ALMA submillimeter array.

The protocluster contains a remarkable concentration of fourteen SMGs, nine of which were detected by these optical and infrared observations. The astronomers were then able to estimate the , ages, and gas content in these SMGs, as well as their star formation histories, a remarkable acheievment for such distant objects. Among other properties of the protocluster, the scientists deduce that its total mass is about one trillion solar-masses, and its galaxies are making stars in a manner similar to star formation processes in the current universe. They also conclude that the whole ensemble is probably in the midst of a colossal merger.

Jun 24, 2021

Archaeologists Make Dramatic Discovery: A Prehistoric Human Type Previously Unknown to Science

Posted by in categories: biotech/medical, evolution, science

Two teams of researchers took part in the dramatic discovery, published in the prestigious Science journal: an anthropology team from Tel Aviv University headed by Prof. Israel Hershkovitz, Dr. Hila May and Dr. Rachel Sarig from the Sackler Faculty of Medicine and the Dan David Center for Human Evolution and Biohistory Research and the Shmunis Family Anthropology Institute, situated in the Steinhardt Museum at Tel Aviv University; and an archaeological team headed by Dr. Yossi Zaidner from the Institute of Archaeology at the Hebrew University of Jerusalem.

Timeline: The Nesher Ramla Homo type was an ancestor of both the Neanderthals in Europe and the archaic Homo populations of Asia.

Continue reading “Archaeologists Make Dramatic Discovery: A Prehistoric Human Type Previously Unknown to Science” »

Jun 20, 2021

Urban foxes self-evolve, exhibiting Darwins domestication syndrome

Posted by in categories: evolution, food

A new study finds surprising evidence of the self-evolution of urban foxes.

Jun 19, 2021

A Ginormous Arc of Galaxies Was Just Detected in The Distant Universe

Posted by in categories: evolution, space

The Universe is a large place, and there are a lot of large things in it. Not just galaxies, but groupings of galaxies, and the cosmic web that connects them all together.

Scientists have just discovered what appears to be one of these groupings, and it could have serious implications for our understanding of the evolution of the Universe. It’s an almost-symmetrical arc of galaxies at a distance of 9.2 billion light-years away, and, at 3.3 billion light-years across, it’s one of the biggest structures ever identified.

Astronomers are calling it the Giant Arc, and, if confirmed, it joins a growing number of these giant structures. This number represents a dilly of a cosmological pickle.

Continue reading “A Ginormous Arc of Galaxies Was Just Detected in The Distant Universe” »

Jun 17, 2021

Protein Sequences from Mastodon and Tyrannosaurus Rex Revealed by Mass Spectrometry

Posted by in categories: biotech/medical, evolution

Fossilized bones from extinct taxa harbor the potential for obtaining protein or DNA sequences that could reveal evolutionary links to extant species. We used mass spectrometry to obtain protein sequences from bones of a 160000-to 600000-year-old extinct mastodon (Mammut americanum) and a 68-million-year-old dinosaur (Tyrannosaurus rex). The presence of T. rex sequences indicates that their peptide bonds were remarkably stable. Mass spectrometry can thus be used to determine unique sequences from ancient organisms from peptide fragmentation patterns, a valuable tool to study the evolution and adaptation of ancient taxa from which genomic sequences are unlikely to be obtained.

Jun 17, 2021

Mitochondrial genomes of praying mantises (Dictyoptera, Mantodea): rearrangement, duplication, and reassignment of tRNA genes

Posted by in categories: biotech/medical, evolution, genetics

The metazoan mitochondrial genome (mitogenome) is an ideal model system for comparative and evolutionary genomic research. The typical mitogenome of metazoans encodes a conserved set of 37 genes for 13 protein-coding genes (PCGs), two ribosomal RNA (rRNA) genes, and 22 transfer RNA (tRNA) genes1, with genome-level characters, such as genome size, gene content, and gene order, display high diversity in some lineages2,3. Gene rearrangements are observed frequently in some groups, while gene duplication and loss are distributed sporadically in limited lineages such as Bivalvia, Cephalopod, and Afrobatrachia4,5,6. These remaining duplicate genes and pseudogenes represent important data for exploring the evolutionary history and mechanisms of gene rearrangement and recruitment. For the arrangement of mitochondrial genes, the variation in relative positions of PCGs and rRNA genes are more limited compared with that of tRNA genes across organisms within a phylum7. The tRNA genes with characteristics of diverse changes in relative position, gene content, and secondary structure, are considered as an important tool in studying the evolution of mitogenome, in particular to the rearrangement mechanism8,9,10. Additionally, its variation is usually linked to evolutionary relationships in a wide range of lineages at different taxonomic levels suggesting these features of tRNA could be utilized as useful phylogenetic markers11.

The extensive gene rearrangements (including PCGs and RNA) of insect mitogenomes have been detected in several lineages within the Diptera (Trichoceridae, Cecidomyiidae), Hemiptera (Enicocephalidae), Hymenoptera, Thysanoptera, Psocoptera and Phthiraptera12,13,14,15,16,17,18, while most of investigated mitogenomes share the same gene order with the hypothesized ancestral pancrustacean mitogenome arrangement19 or possess rare tRNA rearrangement. Previously reported dictyopteran mitogenomes consistently display the typical ancestral gene order and content, however only two species are praying mantises and the rest are cockroaches and termites. Members of the Mantodea, a separate lineage within the Dictyoptera, have evolved many unique morphological and behavioural features as the ambush and pursuit predators20,21,22. A better understanding of the diversity of mitogenome evolution in this enigmatic order underlines the need for exploring more taxa with the diverse praying mantis.

Herein, we report eight new mitogenomes from Mantodea and describe their general characteristics. Two new gene rearrangements and reassignment of tRNA genes are described, and evolutionary mechanisms for the gene rearrangements and duplication are discussed. Further, we examine the relationship between tRNA gene duplication and codon usage, and investigate whether these tRNA features vary with phylogeny.

Jun 15, 2021

Heart on a chip: Micro-nanofabrication and microfluidics steering the future of cardiac tissue engineering

Posted by in categories: bioengineering, biotech/medical, evolution, nanotechnology

Circa 2019

The evolution of micro and nanofabrication approaches significantly spurred the advancements of cardiac tissue engineering over the last decades. Engineering in the micro and nanoscale allows for the rebuilding of heart tissues using cardiomyocytes. The breakthrough of human induced pluripotent stem cells expanded this field rendering the development of human tissues from adult cells possible, thus avoiding the ethical issues of the usage of embryonic stem cells but also creating patient-specific human engineered tissues. In the case of the heart, the combination of cardiomyocytes derived from human induced pluripotent stem cells and micro/nano engineering devices gave rise to new therapeutic approaches of cardiac diseases. In this review, we survey the micro and nanofabrication methods used for cardiac tissue engineering, ranging from clean room-based patterning (such as photolithography and plasma etching) to electrospinning and additive manufacturing. Subsequently, we report on the main approaches of microfluidics for cardiac culture systems, the so-called “Heart on a Chip”, and we assess their efficacy for future development of cardiac disease modeling and drug screening platforms.

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