Posts tagged biology
Articles and news from the latest research reports.
The Cosmological Foundations of Consciousness explores the cosmological foundations of subjective consciousness in the biological brain, from cosmic-symmetry-breaking, through biogenesis, evolutionary diversification and the emergence of metazoa, to humans, presenting a new evolutionary perspective on the potentialities of quantum interactions in consciousness, and the ultimate relationship of consciousness with cosmology.
Cosmic symmetry-breaking and its interactive fractal and chaotic effects leading to biogenesis.
(a) Life portrayed as the consummation of interactive complexity (Σ) resulting from symmetry-breaking of the fundamental force of nature in the big-bang (α), whatever ultimate fate is in store (Ω). Inset (i) possible fractal inflation , (ii) the distribution of dark energy and matter and the matter of stars and planets. (b) Logarithmic time scale of cosmological events showing life on earth existing for a third of the universe’s current lifetime. (c) Symmetry-breaking of the forces of nature results in the color and weak forces generating 100 atomic nuclei, while gravity and electromagnetism govern long-range structure determining biogenesis, from fractal chemical bonding, to solar systems capable of photosynthetic life in the goldilocks zone of liquid water. (d) Interactive effects of cosmic symmetry-breaking lead to hierarchical interaction of the forces, generating hadrons, atomic nuclei and molecules (i). Non-linear energetics of chemical bonding lead to a cascade of cooperative weak-bonding effects, which generate fractal molecular complexity, from the molecular orbitals of simple molecules (ii), through the 3D structures of complex proteins and nucleic acids (iii) to supra-molecular cell organelles (iv), cells (v), and tissues (vi) and organisms. (e) These fractal effects are complemented by the chaotic effects of gravity as a non-linear force, resulting in extreme variation of the planets, generating a diversity of potential conditions for biogenesis, similar to the dynamic variations surrounding the Mandelbrot set.
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Singing mice (scotinomys teguina) are not your average lab rats. Their fur is tawny brown instead of the common white albino strain; they hail from the tropical cloud forests in the mountains of Costa Rica; and, as their name hints, they use song to communicate.
University of Texas at Austin researcher Steven Phelps is examining these unconventional rodents to gain insights into the genes that contribute to the unique singing behavior—information that could help scientists understand and identify genes that affect language in humans.
The song of the singing mouse is a rapid-fire string of high-pitched chirps called trills mostly used by males in dominance displays and to attract mates. Up to 20 chirps are squeaked out per second, sounding similar to birdsong to untrained ears. But unlike birds, the mice generally stick to a song made up of only a single note.
“They sound kind of soft to human ears, but if you slow them down by about three-fold they are pretty dramatic," said Phelps.
Biologists try to engineer life that can survive on Mars and aid colonisation
With Nasa’s Curiosity Rover safely on Mars and ready to search for signs of life, back on Earth attempts are underway to engineer bacteria that could thrive on the Red Planet.
A team of undergraduates from Stanford and Brown Universities are busy applying synthetic biology to space exploration, outfitting microbes to survive extreme Martian conditions and produce resources needed to sustain a human colony.
Though Mars is potentially a place where life may have survived at some point, it is not an especially friendly environment, and thriving there will not be easy — for humans or microbes. The average surface temperature of Mars is minus 80 degrees Fahrenheit, and the almost-nonexistent atmosphere is 95 percent carbon dioxide. Although water exists in Mars’ ice caps and there’s some evidence that giant oceans once covered the planet, today it’s essentially a deep-frozen desert. Colonising Mars would be challenging and pricey.
'Selfish' DNA in animal mitochondria offers possible tool to study aging
Researchers at Oregon State University have discovered, for the first time in any animal species, a type of “selfish” mitochondrial DNA that is actually hurting the organism and lessening its chance to survive – and bears a strong similarity to some damage done to human cells as they age.
Such selfish mitochondrial DNA has been found before in plants, but not animals. In this case, the discovery was made almost by accident during some genetic research being done on a nematode, Caenorhabditis briggsae – a type of small roundworm.
“We weren’t even looking for this when we found it, at first we thought it must be a laboratory error,” said Dee Denver, an OSU associate professor of zoology. “Selfish DNA is not supposed to be found in animals. But it could turn out to be fairly important as a new genetic model to study the type of mitochondrial decay that is associated with human aging.”
Physics and math shed new light on biology by mapping the landscape of evolution
August 8, 2012
Researchers capture evolutionary dynamics in a new theoretical framework that could help explain some of the mysteries of how and why species change over time.
Although the qualitative description of evolution – its observed behavior and characteristics – is well-established, a comprehensive quantitative theory that captures general evolution dynamics is still lacking. There are also many lingering mysteries surrounding the story of life on Earth, including the question of why sex is such a prevalent reproductive strategy. A team of scientists from the Chinese Academy of Sciences; Jilin University in Jilin, China; and the State University of New York at Stony Brook, led by Prof. Jin Wang, has examined some of these puzzles from a physical science prospective. They propose a new theory of evolution with two ingredients: the underlying emergent “fitness” landscape and an associated evolutionary force called “curl flux,” which causes species to move through the emergent fitness landscape in a spiraling manner.
The researchers captured evolutionary relationships in a system of equations. They then created quantitative pictures that visualized evolutionary pathways as journeys through a mountainous terrain of peaks and valleys of biological fitness. The key breakthrough beyond the conventional quantitative theory of evolution is the emergent curl flux, which is generated by interactions between individuals within or across species. The underlying emergent landscape gradient and the curl flux act together as a “Yin and Yang” duality pair to determine the dynamics of general evolution, says Wang. An example of similar behavior is the particle and wave duality that determines the dynamics of the quantum world, he notes. The researchers also note that this combined effect is analogous to the way electric and magnetic forces both act on electrons.
The new theory provides a physical foundation for general evolution dynamics. The researchers found that interactions between individuals of different species can give rise to the curl flux. This can sustain an endless evolution that does not lead to areas of higher relative fitness, even if the physical environment is unchanged.
This finding offers a theoretical framework to explain the Red Queen Hypothesis, which states that species continually evolve in order to fend off parasites that are themselves continually evolving. The hypothesis, first proposed by evolutionary biologist Leigh Van Valen in 1973, gets its name from the character of the Red Queen in Lewis Carroll’s book Through the Looking-Glass, who observed that in her world it was necessary to keep running just to stay in one place. The idea of endless co-evolution through the maintenance of the genetic variation due to the curl flux could help explain the benefits of sexual reproduction, since the mixing and matching of genes preserves a greater diversity of traits. When a species’ arms race with a co-evolving parasite takes an unexpected twist, a previously unnecessary trait could suddenly turn into the key to surviving. In the co-evolving world, there is no guarantee for “survival of the fittest” and it is often necessary to keep running for survival.
Source: PHYS.ORG
UC San Diego Team Aims to Broaden Researcher Access to Protein Simulation
Using just an upgraded desktop computer equipped with a relatively inexpensive graphics processing card, a team of computer scientists and biochemists at the University of California, San Diego, has developed advanced GPU accelerated software and demonstrated for the first time that this approach can sample biological events that occur on the millisecond timescale.
These results have the potential to bring millisecond scale sampling, now available only on a multi-million dollar supercomputer, to all researchers, and could significantly impact the study of protein dynamics with key implications for improved drug and biocatalyst development.
Scientists peek at the early evolution of sex chromosomes
Two new studies offer insight into sex chromosome evolution by focusing on papaya, a multimillion dollar crop plant with a sexual problem (as far as growers are concerned) and a complicated past.
The research reveals that the papaya sex chromosomes have undergone dramatic changes in their short evolutionary histories (they are about 7 million years old; by comparison, human sex chromosomes began their evolution more than 167 million years ago). One of the two studies compares the papaya X chromosome with that of a closely related non-sex chromosome (called an autosome) in a sister species. The other looks at differences between the X and Y chromosomes.
It’s a longstanding question in biology: How do cells know when to progress through the cell cycle? In simple organisms such as yeast, cells divide once they reach a specific size. However, determining if this holds true for mammalian cells has been difficult, in part because there has been no good way to measure mammalian cell growth over time.
A team of MIT and Harvard Medical School (HMS) researchers has precisely measured the growth rates of single cells, allowing them to answer that fundamental question. In the Aug. 5 online edition of Nature Methods, the researchers report that mammalian cells divide not when they reach a critical size, but when their growth rate hits a specific threshold.
Protein Involved in DNA Replication, Centrosome Regulation Linked to Dwarfism, Small Brain Size
ScienceDaily (July 31, 2012) — Research just published by scientists at Cold Spring Harbor Laboratory (CSHL) links gene mutations found in some patients with Meier-Gorlin syndrome (MGS) with specific cellular dysfunctions that are thought to give rise to a particularly extreme version of dwarfism, small brain size, and other manifestations of abnormal growth which generally characterize that rare condition.
Although only 53 cases of Meier-Gorlin syndrome have been reported in the medical literature since the first patient was described in 1959, it is a malady whose mechanisms are bringing to light new functions for some of the cellular processes common to all life. Pathology related to MGS is traced in the new research to one of these, the fundamental process called mitosis in which cells replicate their genetic material and prepare to divide into two identical “daughter” cells.
CSHL President and Professor Bruce Stillman, Ph.D., a cancer biologist who has made seminal discoveries over three decades that have helped reveal the exquisite choreography of how chromosomes are duplicated in cells, led the new research, which suggests how, during mitosis, mutant versions of a protein called Orc1 contribute in two distinct ways to severe MGS pathology. The research is published online ahead of print in Genes & Development.