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UK scientists seek permission to genetically modify human embryos with CRISPR-CAS

UK scientists seek permission to genetically modify human embryos with CRISPR-CAS | Amazing Science | Scoop.it

Researchers apply for licence months after Chinese team become first to announce they have altered DNA.  Scientists in Britain have applied for permission to genetically modify human embryos as part of a research project into the earliest stages of human development.


The work marks a controversial first for the UK and comes only months after Chinese researchers became the only team in the world to announce they had altered the DNA of human embryos. Kathy Niakan, a stem cell scientist at the Francis Crick Institute in London, has asked the government’s fertility regulator for a licence to perform so-called genome editing on human embryos. The research could see the first genetically modified embryos in Britain created within months.


Donated by couples with a surplus after IVF treatment, the embryos would be used for basic research only. They cannot legally be studied for more than two weeks or implanted into women to achieve a pregnancy.


Though the modified embryos will never become children, the move will concern some who have called for a global moratorium on the genetic manipulation of embryos, even for research purposes. They fear a public backlash could derail less controversial uses of genome editing, which could lead to radical new treatments for disease.


Niakan wants to use the procedure to find genes at play in the first few days of human fertilization, when an embryo develops a coating of cells that later form the placenta. The basic research could help scientists understand why some women lose their babies before term.


The Human Fertilisation and Embryology Authority (HFEA) has yet to review her application, but is expected to grant a licence under existing laws that permit experiments on embryos provided they are destroyed within 14 days. In Britain, research on embryos can only go ahead under a licence from an HFEA panel that deems the experiments to be justified.

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Amazing Science: Evolution Postings

Amazing Science: Evolution Postings | Amazing Science | Scoop.it

Evolution is the change in the inherited characteristics of biological populations over successive generations. Evolutionary processes give rise to diversity at every level of biological organisation, including species, individual organisms and molecules such as DNA and proteins.All life on Earth is descended from a last universal ancestor that lived approximately 3.8 billion years ago. Repeated speciation and the divergence of life can be inferred from shared sets of biochemical and morphological traits, or by shared DNA sequences.

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Irreversible Evolution? Dust Mites Show Parasites Can Violate Dollo’s Law

Irreversible Evolution? Dust Mites Show Parasites Can Violate Dollo’s Law | Amazing Science | Scoop.it

Our world is quite literally lousy with parasites. We are hosts to hundreds of them, and they are so common that in some ecosystems, the total mass of them can outweigh top predators by 20 fold. Even parasites have parasites. It’s such a good strategy that over 40% of all known species are parasitic. They steal genes from their hosts, take over other animals’ bodies, and generally screw with their hosts’ heads. But there’s one thing that we believed they couldn’t do: stop being parasites. Once the genetic machinery set the lifestyle choice in motion, there’s supposed to be no going back to living freely. Once a parasite, always a parasite - unless you’re a mite.

 

In evolutionary biology, the notion of irreversibility is known as Dollo’s Law after the Belgian paleontologist that first hypothesized it in 1893. He stated that once a lineage had lost or modified organs or structures, that they couldn’t turn back the clock and un-evolve those changes. Or, as he put it, “an organism is unable to return, even partially, to a previous stage already realized in the ranks of its ancestors.”

 

While some animals seem to challenge Dollo’s Law, it has long been a deeply held belief in the field of parasitology. Parasitism is, in general, a process of reduction. Adjusting to survival on or in another animal is a severe evolutionary undertaking, and many parasites lose entire organs or even body systems, becoming entirely dependent on their hosts to perform biological tasks like breaking down food or locomotion. Parasitology textbooks often talk about the irreversibility of becoming a parasite in very finite terms. “Parasites as a whole are worthy examples of the inexorable march of evolution into blind alleys” says Noble & Noble’s 1976 Parasitology: the Biology of Animal Parasites.

 

Robert Poulin is even more direct: “Once they are dependent on the host there is no going back. In other words, early specialisation for a parasitic life commits a lineage forever.” Now, parasites are proving that not only can they evade immune systems, trick other animals, and use their hosts’ bodies in hundreds of nefarious ways, some can go back to living on their own. This is exactly what scientists now believed happened in the Pyroglyphidae — the dust mites.

 

Mites, as a whole, are a frighteningly successful but often overlooked group of organisms. More than 48,000 species have been described. These minuscule relatives of spiders can be found worldwide in just about every habitat you can imagine. Many are free-living, but there are also a number of parasitic species, including all-too-familiar pests like Sarcoptes scabiei, the mite which causes scabies. Exactly how the different groups of mites are related to each other, however, has been a hot topic of debate amongst mite biologists. Though the closest relatives of dust mites are the Psoroptidia, a large and diverse parasitic group of mites, many have argued that dust mites came from free-living ancestors — ‘living fossils’ of a sort, the only surviving line of ancestral free-living mites that later gave rise to parasites. In fact, Pavel Klimov and Barry O’Connor from the University of Michigan were able to find 62 different hypothesis as to how the free-living the dust mites fit into the mite family tree. Sixty-two, the team decided, was simply too many. So, they turned to the mites’ genes.

 

To test which of the hypotheses had the most merit, Klimov and O’Conner conscripted a team of 64 biologists in 19 countries to obtain over 700 mite specimens, which they then used to construct a mite family tree. They sequenced five nuclear genes from each species, then applied statistical analyses to construct a tree of relationships called a phylogeny. And that’s when they saw it: deeply nested inside a large group of parasites were our everyday, non-parasitic, allergy-causing dust mites.

 

“This result was so surprising that we decided to contact our colleagues to obtain their feedback prior to sending these data for publication,” said lead author Pavel Klimov. “Parasites can quickly evolve highly sophisticated mechanisms for host exploitation and can lose their ability to function away from the host body,” he explained. “Many researchers in the field perceive such specialization as evolutionarily irreversible.” But, their data were clear. “All our analyses conclusively demonstrated that house dust mites have abandoned a parasitic lifestyle, secondarily becoming free-living.”

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New Species Of Flowering Plant Evolved During Last 150 Years In Scotland

New Species Of Flowering Plant Evolved During Last 150 Years In Scotland | Amazing Science | Scoop.it

Biologist Dr Mario Vallejo-Marín from the University of Stirling has found a new species of monkey flower, created by the union of two foreign plant species, on the bank of a stream in Scotland. during the last 150 years. Thousands of wild species and some crops are thought to have originated in this way, yet only a handful of examples exist where this type of species formation has occurred in recent history.

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EMBO 2012 - International workshop on Evolution in the Time of Genomics

EMBO 2012 - International workshop on Evolution in the Time of Genomics | Amazing Science | Scoop.it

Molecular evolution was born fifty years before the planned Conference, with a seminal paper by Zuckerkandl and Pauling (1962) which demonstrated that aminoacid changes in the globins followed a molecular clock and could provide information on the phylogeny of vertebrates and on the timing of their appearance on earth.

Principal themes and objectives of the event From changes in aminoacids to changes in nucleotides, the molecular level has provided an essential input into evolutionary investigations for the past decades. More recently, the molecular level has moved from the genes to the genome, so far mainly in the case of vertebrates (in which the coding sequences only represent about 2% of the total). The availability of full genome sequences has provided new possibilities for investigators in the field and major problems can now be tackled in a very precise way using bioinformatic tools. Indeed, an example of this approach has been the recent solution (Bernardi, 2007)of a twenty-year-old debate, that between neutralists and selectionists.


One of the major current debates concerns adaptive vs. non-adaptive evolution. Random events in evolution were originally raised as a fundamental problem by Jacques Monod in his famous book "Chance and necessity". The problem has now been shifted to the genome level. A preliminary discussion took place in October 2010 in a Meeting "Chance and Necessity in Evolution" (Ravello, Italy; papers are in press in a special issue of Genome Biology and Evolution). The proposed meeting should go deeper into such a basic issue. While this will be one of the main subject of the meeting in which different views will confront each other (with Bernardi, Jarosz, Koonin, Ohta, Ptashne), other basic topics in Genome Evolution will be addressed. Werner Arber, Hamilton Smith (two Nobel Laureates) and George Church will discuss in depth the results obtained so far "directing" evolution in microbial systems, their interpretation and even the ethical issues raised. Davidson, Gehring and Gojobori will deal with the evolution of developmental processes; Martin, Saccone and Wallace with the evolution of mitochondrial genomes; Okada and Shapiro with the impact of mobile elements on genome evolution; Jeffreys and Saitou with recombination and biased gene conversion; Bustamante, Felsenfeld, Hartl and Haussler with regulation of gene expression and copy number variation in the human genome. Last but not least, Emile Zuckerkandl will recollect the beginning of Molecular Evolution.

 

http://events.embo.org/12-evolution/

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Mini mammoth once roamed Crete

Mini mammoth once roamed Crete | Amazing Science | Scoop.it
Evolution crafted pint-sized pachyderm on Mediterranean island.

 

VIDEO: http://www.youtube.com/watch?v=JCRbJZaOTUc&feature=colike


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Modular gene networks as agents of evolutionary novelty

Modular gene networks as agents of evolutionary novelty | Amazing Science | Scoop.it

How to create multicellular organisms

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Frozen Mummy’s Genetic Blueprints Unveiled

Frozen Mummy’s Genetic Blueprints Unveiled | Amazing Science | Scoop.it

By peering deeply into the DNA of the mummy known as Ötzi, geneticists have expanded the rap sheet on the 5,300-year-old Iceman: He had brown eyes, brown hair and blood type O, was lactose intolerant and his modern-day relatives live on Corsica and Sardinia.


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Evolution of new species requires only a few genetic changes

Evolution of new species requires only a few genetic changes | Amazing Science | Scoop.it

Only a few genetic changes are needed to spur the evolution of new species—even if the original populations are still in contact and exchanging genes. Once started, however, evolutionary divergence evolves rapidly, ultimately leading to fully genetically isolated species, report scientists from the University of Chicago in the Oct 31 Cell Reports.

 

"Speciation is one of the most fundamental evolutionary processes, but there are still aspects that we do not fully understand, such as how the genome changes as one species splits into two," said Marcus Kronforst, Ph.D., Neubauer Family assistant professor of ecology and evolution, and lead author of the study.

 

To reveal genetic differences critical for speciation, Kronforst and his team analyzed the genomes of two closely related butterfly species, Heliconius cydno and H. pachinus, which only recently diverged. Occupying similar ecological habitats and able to interbreed, these butterfly species still undergo a small amount of genetic exchange.

 

The researchers found that this regular gene flow mutes genetic variants unimportant to speciation—allowing them to identify key genetic areas affected by natural selection. The butterfly species, they discovered, differed in only 12 small regions of their genomes, while remaining mostly identical throughout the rest. Eight of these coded for wing color patterning, a trait important for mating and avoiding predation, and under intense selection pressure, while the other four remain undescribed.

 

"These 12 spots appear to only function well in the environment their species occupies, and so are prevented from moving between gene pools, even though other parts of the genomes are swapped back and forth," Kronforst said.

 

The team also compared the genomes of these two groups to a third species, still closely related but further removed on an evolutionary time scale. Here, they found hundreds of genomic changes, indicating that the rate of genetic divergence accelerated rapidly after the initial changes took hold.

 

"Our work suggests that a few advantageous mutations are enough to cause a 'tug-of-war' between natural selection and gene flow, which can lead to rapidly diverging genomes," Kronforst said.

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For Early Primates, a Night Was Filled With Color

For Early Primates, a Night Was Filled With Color | Amazing Science | Scoop.it
A genetic examination of tarsiers indicates that the saucer-eyed primates developed three-color vision when they were still nocturnal.

 

A new study suggests that primates’ ability to see in three colors may not have evolved as a result of daytime living, as has long been thought. The findings, published in the journalProceedings of the Royal Society B, are based on a genetic examination oftarsiers, the nocturnal, saucer-eyed primates that long ago branched off from monkeys, apes and humans.

 

By analyzing the genes that encodephotopigments in the eyes of modern tarsiers, the researchers concluded that the last ancestor that all tarsiers had in common had highly acute three-color vision, much like that of modern-day primates.

 

Such vision would normally indicate a daytime lifestyle. But fossils show that the tarsier ancestor was also nocturnal, strongly suggesting that the ability to see in three colors somehow predated the shift to daytime living.

The coexistence of the two normally incompatible traits suggests that primates were able to function during twilight or bright moonlight for a time before making the transition to a fully diurnal existence.

 

“Today there is no mammal we know of that has trichromatic vision that lives during night,” said an author of the study, Nathaniel J. Dominy, associate professor of anthropology at Dartmouth. “And if there’s a pattern that exists today, the safest thing to do is assume the same pattern existed in the past.

 

“We think that tarsiers may have been active under relatively bright light conditions at dark times of the day,” he added. “Very bright moonlight is bright enough for your cones to operate.”

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QMP's curator insight, April 19, 2013 5:50 PM

This is a great article about how the night time helped early primates to evolve the colored vision that we experience today.

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Evolution is actually pretty predictable

Evolution is actually pretty predictable | Amazing Science | Scoop.it

A study of insects, including the large milkweed bug (above), suggests evolution may be driven by a simple and repeated genetic solution to an environmental pressure that a broad range of species happen to share.

 

New research by Andolfatto and colleagues published in the journal Science suggests that knowledge of a species’ genes—and how certain external conditions affect the proteins encoded by those genes—could be used to determine a predictable evolutionary pattern driven by outside factors.


Scientists could then pinpoint how the diversity of adaptations seen in the natural world developed even in distantly related animals. The researchers carried out a survey of DNA sequences from 29 distantly related insect species, the largest sample of organisms yet examined for a single evolutionary trait. Fourteen of these species have evolved a nearly identical characteristic due to one external influence—they feed on plants that produce cardenolides, a class of steroid-like cardiotoxins that are a natural defense for plants such as milkweed and dogbane.

 

Many different insects independently evolved the same molecular tricks to defend themselves against the same toxin suggests that studying a small number of well-chosen model organisms can teach us a lot about other species. Yes, evolution is predictable to a certain degree.

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Tracing the genetic pathway from the first Eukaryotes to Homo sapiens

Tracing the genetic pathway from the first Eukaryotes to Homo sapiens | Amazing Science | Scoop.it

www.dhushara.com/book/unraveltree/unravel.htm

 

The Tree of Life, in biological terms, has come to be identified with the evolutionary tree of biological diversity. It is this tree which represents the climax fruitfulness of the biosphere and the genetic foundation of our existence, embracing not just higher Eukaryotes, plants, animals and fungi, but Protista, Eubacteria, and Archaea, the realm, including the extreme heat and salt-loving organisms, which appears to lie almost at the root of life itself.

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Geologic and Biological Timeline of the Earth

Geologic and Biological Timeline of the Earth | Amazing Science | Scoop.it
Biological and Geologic Timeline of the Earth. The origin of the Earth and the Moon. The evolution of life on Earth.
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14 extinct animals that could be resurrected

14 extinct animals that could be resurrected | Amazing Science | Scoop.it
Can lost species ever become un-extinct? In the 1993 science fiction film "Jurassic Park," dinosaurs are cloned back to life after their DNA is discovered still intact within the bellies of ancient mosquitoes that were preserved in amber. While the science of cloning is still in its infancy, many scientists now believe it's only a matter of time before many extinct animals again walk the Earth.

 


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Giant Stick Insect Believed Extinct Finds Secret Hideaway, Hides for 80 Years

Giant Stick Insect Believed Extinct Finds Secret Hideaway, Hides for 80 Years | Amazing Science | Scoop.it

The insect is so large — as big as a human hand — it's been dubbed a "tree lobster." It was thought to be extinct, but some enterprising entomologists scoured a barren hunk of rock in the middle of the ocean and found surviving Lord Howe Island, Australia.

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Analysis of 2,135 of the world’s known languages traces evolution of human communication

Analysis of 2,135 of the world’s known languages traces evolution of human communication | Amazing Science | Scoop.it

Merritt Ruhlen, a lecturer in Anthropology at Stanford, and his longtime collaborator Murray Gell-Mann, a founder and Distinguished Professor of the Santa Fe Institute, have mapped the evolution of word order in a paper titled "The Origin and Evolution of Word Order," published in the Proceedings of the National Academy of Sciences (PNAS). http://tinyurl.com/8xotm7x


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