Toplam 537 içerik listeleniyor
-
The genetic evolution of Zika virus
This is a phylogenetic tree constructed from nucleotide data from 41 viral complete ORF sequences of ZIKV strains An analysis comparing the individual differences between over 40 strains of Zika virus (30 isolated from humans, 10 from mosquitoes, and 1 from monkeys) has identified significant changes in both amino acid and nucleotide sequences during the past half-century. The data, published April 15 in Cell Host & Microbe, support a strong divergence between the Asian and African lineages as...
https://www.biyologlar.com/the-genetic-evolution-of-zika-virus-haber-8121 -
How the ant queen gets her crown: Uncovering the evolution of queen-worker differences
Queen and worker ants develop from the same sets of genes, but end up being structurally, behaviourally, and functionally different. Queen and worker ants develop from the same sets of genes, but perform completely different ecological roles. How the same genes result in two types of individuals is an ongoing mystery. In the past, scientists have only studied a small number of ant species at a time to try to understand the nature of queen-worker differences. However, a team from the Okinawa...
https://www.biyologlar.com/how-the-ant-queen-gets-her-crown-uncovering-the-evolution-of-queen-worker-differences-haber-8124 -
Primate evolution in the fast lane
The pace of evolution is typically measured in millions of years, as random, individual mutations accumulate over generations, but researchers at Cornell and Bar-Ilan Universities have uncovered a new mechanism for mutation in primates that is rapid, coordinated, and aggressive. The discovery raises questions about the accuracy of using the more typical mutation process as an estimate to date when two species diverged, as well as the extent to which this and related enzymes played a role in...
https://www.biyologlar.com/primate-evolution-in-the-fast-lane-haber-8133 -
Research reveals trend in bird-shape evolution on islands
Found throughout the Caribbean, the bananaquit has smaller flight muscles and longer legs on islands with fewer predators. In groundbreaking new work, Natalie Wright, a postdoctoral fellow at the University of Montana, has discovered a predictable trend in the evolution of bird shape.
https://www.biyologlar.com/research-reveals-trend-in-bird-shape-evolution-on-islands-haber-8716 -
Tough times for the tree of life on coral reefs
In terms of evolutionary history, less than a quarter of wrasse species receive minimum protection levels. Marine scientists are calling for a re-think of how marine protected areas (MPAs) are planned and coordinated, following a global assessment of the conservation of tropical corals and fishes.
https://www.biyologlar.com/tough-times-for-the-tree-of-life-on-coral-reefs-haber-8731 -
Kongo Nehri Balıklarının Hızlı Evrimi
Fotoğrafta bir çift akvaryum çiklet balığı türü olan Telegramma brichardi bulunmaktadır. Fotoğraf:Oliver Lucanus
https://www.biyologlar.com/kongo-nehri-baliklarinin-hizli-evrimi -
Kongo Nehri Balıklarının Hızlı Evrimi
Fotoğrafta bir çift akvaryum çiklet balığı türü olan Telegramma brichardi bulunmaktadır. Fotoğraf:Oliver Lucanus
https://www.biyologlar.com/kongo-nehri-baliklarinin-hizli-evrimi -
Kongo Nehri Balıklarının Hızlı Evrimi
Fotoğrafta bir çift akvaryum çiklet balığı türü olan Telegramma brichardi bulunmaktadır. Fotoğraf:Oliver Lucanus
https://www.biyologlar.com/kongo-nehri-baliklarinin-hizli-evrimi -
The Genetic Structure of Anatolia: From the Neolithic to the Oghuz Migrations
Anatolia has witnessed many migrations and has been home to a variety of civilizations. The increasing availability of ancient DNA samples from different periods and cultures makes it now possible to examine the genetic changes that have taken place in Anatolia since the Neolithic. The ancient DNA revolution has already dispelled many myths, but myths and legends die hard. Some of the more persistent ones concern the impact of the last migration wave to hit Anatolia, marked by the arrival of...
https://www.biyologlar.com/the-genetic-structure-of-anatolia-from-the-neolithic-to-the-oghuz-migrations -
Anadolu'da Evrim (Evolution in Anatolia) - Bölüm 1
Konuşmacı: Babür ERDEM Konu: Anadolu'da Evrim. (Anadolu'nun jeolojik evrimine paralel olarak üzerindeki biotanın evrimleşmesi) Yer: Hacettepe Üniversitesi, Evrimsel Biyoloji Öğrenci Kongresi
https://www.biyologlar.com/anadoluda-evrim-evolution-in-anatolia-bolum-1 -
Anadolu'da Evrim (Evolution in Anatolia) - Bölüm 2
Konuşmacı: Babür ERDEM Konu: Anadolu'da Evrim. (Anadolu'nun jeolojik evrimine paralel olarak üzerindeki biotanın evrimleşmesi) Yer: Hacettepe Üniversitesi, Evrimsel Biyoloji Öğrenci Kongresi
https://www.biyologlar.com/anadoluda-evrim-evolution-in-anatolia-bolum-2 -
Y Kromozomu
Bütün insanlarda X veya Y kromozomlarından birisi mutlaka bulunurken, kadınlarda "46, XX"; erkeklerde "46, XY" normal karyotip olarak bulunur.
https://www.biyologlar.com/y-kromozomu-1 -
One of the last strongholds for Western chimpanzees
When Liberia enters the news it is usually in the context of civil war, economic crisis, poverty or a disease outbreak such as the recent emergence of Ebola in West Africa. Liberia's status as a biodiversity hotspot and the fact that it is home to some of the last viable and threatened wildlife populations in West Africa has received little media attention in the past. This is partly because the many years of violent conflict in Liberia, from 1989 to 1997 and from 2002 to 2003, thwarted efforts...
https://www.biyologlar.com/one-of-the-last-strongholds-for-western-chimpanzees -
Kene İle Bulaşan Hastalıklar
ÖZET Parazitlerin neden olduğu hastalıklar önemli sağlık problemidir. Endoparazit ve ektoparaziter hastalıklar mevcuttur. Kenelerle bulaşan hastalıklar en sık görülen vektör kaynaklı hastalıklardır. Keneler bakteri, virüs spiroket, protozoa, nematod ve toksinler gibi patojenleri yayabilir ve böylece ektoparaziter kaynaklı hastalıklara sebep olurlar. Ülkemizde keneler için iklim koşulları, bitki örtüsü ve yüzey şekli bakımından uygun koşullar vardır. Bu...
https://www.biyologlar.com/kene-ile-bulasan-hastaliklar -
Scientists reconstruct ancient impact that dwarfs dinosaur-extinction blast
Picture this: A massive asteroid almost as wide as Rhode Island and about three to five times larger than the rock thought to have wiped out the dinosaurs slams into Earth. The collision punches a crater into the planet's crust that's nearly 500 kilometers (about 300 miles) across: greater than the distance from Washington, D.C. to New York City, and up to two and a half times larger in diameter than the hole formed by the dinosaur-killing asteroid. Seismic waves bigger than any recorded...
https://www.biyologlar.com/scientists-reconstruct-ancient-impact-that-dwarfs-dinosaur-extinction-blast -
Mutasyonlar
Mutasyon, DNA içindeki dört tür nükleotid halkasından bir veya daha fazlasında değişmedir. Bir tek halkada bile değişiklik anımsayacağınız gibi DNA mesajında bir harfin değişmesi demektir.DNA’dan kopya alan mesajcı RNA değişikliği içerecektir ve protein yapmakta olan makine tarafından farklı okunacaktır. Ortaya değişmiş bir protein çıkacak ve amino asit zincirinde bir halka farklı olacak, sonuç olarak da proteinin işlevi değişecektir. Mutasyonların en...
https://www.biyologlar.com/mutasyonlar -
Biyoloji Eğitiminde Evrim ve Yaratılışcılık
Biyolojik bilimlerin temeli olan evrim kurami çagimizin belki de en önemli bilimsel devrimlerinden biridir. Yeryüzündeki canli türlerinin ortak bir atadan evrimleserek ortaya çiktigini, yeryüzündeki yasamin ortak bir geçmisi paylastigini öne süren evrim kurami, insanin kendine ve dogaya bakis açisini degistirmistir. Sayet insan bugünkü konumuna evrim sonucu geldiyse evrimin yasalarini ögrenebilir ve kendinin ve diger canli türlerinin evrimini yönlendirebilir (1). Canli...
https://www.biyologlar.com/biyoloji-egitiminde-evrim-ve-yaratiliscilik -
Detecting HIV diagnostic antibodies with DNA nanomachines
New research may revolutionize the slow, cumbersome and expensive process of detecting the antibodies that can help with the diagnosis of infectious and auto-immune diseases such as rheumatoid arthritis and HIV. An international team of researchers have designed and synthetized a nanometer-scale DNA "machine" whose customized modifications enable it to recognize a specific target antibody. Their new approach, which they described this month in Angewandte Chemie, promises to support the...
https://www.biyologlar.com/detecting-hiv-diagnostic-antibodies-with-dna-nanomachines -
Symphony of Science - The Greatest Show on Earth! A music video about Evolution
Symphony of Science - The Greatest Show on Earth! A music video about Evolution
https://www.biyologlar.com/symphony-of-science-the-greatest-show-on-earth-a-music-video-about-evolution -
Functional human liver cells grown in the lab
In new research appearing in the prestigious journal Nature Biotechnology, an international research team led by The Hebrew University of Jerusalem describes a new technique for growing human hepatocytes in the laboratory. This groundbreaking development could help advance a variety of liver-related research and applications, from studying drug toxicity to creating bio-artificial liver support for patients awaiting transplantations. The liver is the largest internal organ in the human body,...
https://www.biyologlar.com/functional-human-liver-cells-grown-in-the-lab -
Scientists create functional liver cells from stem cells
The liver plays a critical role in human metabolism. As the gatekeeper of the digestive track, this massive organ is responsible for drug breakdown and is therefore the first to be injured due to overdose or misuse. Evaluating this drug-induced liver injury is a critical part of pharmaceutical drug discovery and must be carried out on human liver cells. Regretfully, human liver cells, called hepatocytes, are in scarce supply as they can only be isolated from donated organs. Now, in research...
https://www.biyologlar.com/scientists-create-functional-liver-cells-from-stem-cells -
Jeofiziksel değil, çevresel bir bariyer: Anadolu Diyagonali
Şekil 1. Anadolu ve yakın çevresinde biyolojik çeşitlilik sıcak noktaları.
https://www.biyologlar.com/jeofiziksel-degil-cevresel-bir-bariyer-anadolu-diyagonali -
Broad, MIT scientists overcome key CRISPR-Cas9 genome editing hurdle
Researchers at the Broad Institute of MIT and Harvard and the McGovern Institute for Brain Research at MIT have engineered changes to the revolutionary CRISPR-Cas9 genome editing system that significantly cut down on "off-target" editing errors. The refined technique addresses one of the major technical issues in the use of genome editing. The CRISPR-Cas9 system works by making a precisely targeted modification in a cell's DNA. The protein Cas9 alters the DNA at a location that is specified by...
https://www.biyologlar.com/broad-mit-scientists-overcome-key-crispr-cas9-genome-editing-hurdle -
Evrim İçin Özel Bir Kaynak
Darwin'in 'Türlerin Kökeni' adlı eseri 2009 yılında 150. yaşına giriyor. Dünya çapında saygın doğal tarih müzeleri, evrim kuramının getirdikleri üzerine türlü etkinlikler düzenliyor. Evrim konulu bir dersin en temel konularından biri, gezegenimizin oluşumundan bu yana süregelmiş yerbilimsel ve evrimsel olayların kapsamlı bir özetini yapabilmek. Bu oldukça iddialı bir iş. Öncelikle ortada bir ölçek sorunu var. Elde tıpkı bir akordeon gibi genişleyip daralacak...
https://www.biyologlar.com/evrim-icin-ozel-bir-kaynak -
Yasamin evrimsel gecmisi uzerine turkce bir kaynak.
Okullarımızda Evrim Kuramının öğretilmemesi büyük bir kayıp. Madalyonun bir de öbür yüzüne bakarsak, eğitimi verecek olan öğretmenlerin elinde konuyu anlatabilmek için gerekli kaynak ve materyalin olmadığını görürüz. Evrim konulu bir dersin en temel konularından biri, gezegenimizin oluşumundan bu yana süregelmiş olan olayların kapsamlı bir özetini yapabilmektir. Evrimsel olayları, üzerinde yaşadığımız dünyanın yerbilimsel tarihi ile birlikte sunabilmek...
https://www.biyologlar.com/yasamin-evrimsel-gecmisi-uzerine-turkce-bir-kaynak- -
Anadolu biyocoğrafyasını anlamak, biyolojik değişkenliği anlamaktan geçer!
"Her şeyin biricikliği" açısından özel bir coğrafya: Anadolu
https://www.biyologlar.com/anadolu-biyocografyasini-anlamak-biyolojik-degiskenligi-anlamaktan-gecer -
Shiny fish skin inspires nanoscale light reflectors
A nature-inspired method to model the reflection of light from the skin of silvery fish and other organisms may be possible, according to Penn State researchers. Such a technique may be applicable to developing better broadband reflectors and custom multi-spectral filters for a wide variety of applications, including advanced optical coatings for glass, laser protection, infrared imaging systems, optical communication systems and photovoltaics, according to Douglas Werner, John L. and...
https://www.biyologlar.com/shiny-fish-skin-inspires-nanoscale-light-reflectors -
Odd histone helps suppress jumping genes in stem cells, study says
A family of proteins known as histones provides support and structure to DNA, but for years, scientists have been puzzling over occasional outliers among these histones, which appear to exist for specific, but often mysterious reasons. Now, researchers have uncovered a new purpose for one such histone variant: preventing genetic mutations by keeping certain so-called "jumping genes" in place. This research, which began at Rockefeller University and was published May 4 in Nature, reveals a...
https://www.biyologlar.com/odd-histone-helps-suppress-jumping-genes-in-stem-cells-study-says -
Tough times for the tree of life on coral reefs
Marine scientists are calling for a re-think of how marine protected areas (MPAs) are planned and coordinated, following a global assessment of the conservation of tropical corals and fishes. Researchers from the Australian Research Council Centre of Excellence for Coral Reef Studies (Coral CoE), at James Cook University in Townsville, analysed the extent to which the evolutionary histories of corals and fishes are protected, rather than looking at individual species. "Our interest was in...
https://www.biyologlar.com/tough-times-for-the-tree-of-life-on-coral-reefs -
Griffith uses 3-D tissue engineering to revolutionize dental disease
The discomfort and stigma of loose or missing teeth could be a thing of the past as Griffith University researchers pioneer the use of 3D bioprinting to replace missing teeth and bone. The three-year study, which has been granted a National Health and Medical Research Council Grant of $650,000, is being undertaken by periodontist Professor Saso Ivanovski from Griffith's Menzies Health Institute Queensland. As part of an Australian first, Professor Ivanovski and his team are using the latest...
https://www.biyologlar.com/griffith-uses-3-d-tissue-engineering-to-revolutionize-dental-disease -
Algae use their 'tails' to gallop and trot like quadrupeds
Long before there were fish swimming in the oceans, tiny microorganisms were using long slender appendages called cilia and flagella to navigate their watery habitats.
https://www.biyologlar.com/algae-use-their-tails-to-gallop-and-trot-like-quadrupeds -
Spider and centipede venom evolved from insulin-like hormone
Funnel-web spider venom contains powerful neurotoxins that instantly paralyze prey (usually insects). Millions of years ago, however, this potent poison was just a hormone that helped ancestors of these spiders regulate sugar metabolism, similar to the role of insulin in humans. Surprisingly, this hormone's weaponization--described on June 11 in the journal Structure--occurred in arachnids as well as centipedes, but in different ways. Researchers at the University of Queensland in Australia...
https://www.biyologlar.com/spider-and-centipede-venom-evolved-from-insulin-like-hormone -
These gigantic whales have nerves like bungee cords
Nerves aren't known for being stretchy. In fact, "nerve stretch injury" is a common form of trauma in humans. But researchers reporting in
https://www.biyologlar.com/these-gigantic-whales-have-nerves-like-bungee-cords -
Clues contained in ancient brain point to the origin of heads in early animals
A new study from the University of Cambridge has identified one of the oldest fossil brains ever discovered - more than 500 million years old - and used it to help determine how heads first evolved in early animals. The results, published today (7 May) in the journal Current Biology, identify a key point in the evolutionary transition from soft to hard bodies in early ancestors of arthropods, the group that contains modern insects, crustaceans and spiders. The study looked at two types of...
https://www.biyologlar.com/clues-contained-in-ancient-brain-point-to-the-origin-of-heads-in-early-animals -
Scientists discover oldest plant root stem cells
Scientists at Oxford University have discovered the oldest known population of plant root stem cells in a 320 million-year-old fossil.
https://www.biyologlar.com/scientists-discover-oldest-plant-root-stem-cells -
Male hormones help lemur females rule
Lemur girls behave more like the guys, thanks to a little testosterone, according to a new study. Males rule in most of the animal world. But when it comes to conventional gender roles, lemurs -- distant primate cousins of ours -- buck the trend. It's not uncommon for lady lemurs to bite their mates, snatch a piece of fruit from their hands, whack them in the head or shove them out of prime sleeping spots. Females mark their territories with distinctive scents just as often as the males do....
https://www.biyologlar.com/male-hormones-help-lemur-females-rule -
New procedure allows long-term culturing of adult stem cells
A new procedure developed at Massachusetts General Hospital (MGH) may revolutionize the culturing of adult stem cells. In their report that has been published online prior to its appearance in the August 6 issue of Cell Stem Cell, the team describes generating and expanding airway stem cells from the sorts of tissue samples collected during routine treatment of lung disorders. The overall approach appears applicable to several other tissue types, including skin and the linings of the...
https://www.biyologlar.com/new-procedure-allows-long-term-culturing-of-adult-stem-cells -
Gene fuels age-related obesity and diabetes
Practically everyone gets fatter as they get older, but some people can blame their genes for the extra padding. Researchers have shown that two different mutations in a gene called ankyrin-B cause cells to suck up glucose faster than normal, fattening them up and eventually triggering the type of diabetes linked to obesity. The more severe of the two mutations, called R1788W, is carried by nearly one million Americans. The milder mutation, known as L1622I, is shared by seven percent of the...
https://www.biyologlar.com/gene-fuels-age-related-obesity-and-diabetes -
Gene Drive Technology: Where is the future?
Gene drive technologies may one day help alleviate the burden caused by diseases transmitted by mosquitoes and other animal vectors.
https://www.biyologlar.com/gene-drive-technology-where-is-the-future -
Gene Drive Technology: Where is the future?
Gene drive technologies may one day help alleviate the burden caused by diseases transmitted by mosquitoes and other animal vectors.
https://www.biyologlar.com/gene-drive-technology-where-is-the-future -
Tiny genetic tweak unlocked corn kernels during domestication
If not for a single genetic mutation, each kernel on a juicy corn cob would be trapped inside a inedible casing as tough as a walnut shell. The mutation switches one amino acid for another at a specific position in a protein regulating formation of these shells in modern corn's wild ancestor, according to a study published in the July 2015 issue of GENETICS, a publication of the Genetics Society of America. "Humans completely reshaped the ancestor of corn, effectively turning the cob inside...
https://www.biyologlar.com/tiny-genetic-tweak-unlocked-corn-kernels-during-domestication -
Lowly 'new girl' chimps form stronger female bonds
Low-ranking "new girl" chimpanzees seek out other gal pals with similar status, finds a new study of social relationships in the wild apes. The study is available online and is scheduled to appear in the July 2015 issue of the journal Animal Behaviour. Unlike most primates, female chimps are loners compared to males. "They spend about half their time alone or with dependent kids," said Duke University research scientist Steffen Foerster, who co-authored the study. "Chimpanzee females' more...
https://www.biyologlar.com/lowly-new-girl-chimps-form-stronger-female-bonds -
Biodiversity: 11 new species come to light in Madagascar
Madagascar is home to extraordinary biodiversity, but in the past few decades, the island's forests and associated biodiversity have been under greater attack than ever. Rapid deforestation is affecting the biotopes of hundreds of species, including the panther chameleon, a species with spectacular intra-specific colour variation. A new study by Michel Milinkovitch, professor of genetics, evolution, and biophysics at the University of Geneva (UNIGE), led in close collaboration with colleagues...
https://www.biyologlar.com/biodiversity-11-new-species-come-to-light-in-madagascar -
Nesli Tükenen Hayvanlar İçin Neler Yapılabilir
Yabani Hayvanların biz insanlarla kontrollü ortak yasam alanlarını paylaşım geleneği çok eskilere dayanmaktadır. Yaklaşık 3 bin yıllık tarihi bir geçmişi olan bu ilişkiyi gerek yabani hayvan barınakları ve gerekse hayvanat bahçelerinin (ZOO) yaptıkları birçok araştırmadan biliyoruz. Bunlar arasında Cin`deki "intelligentia park i" en tarihi olanı unvanına sahiptir ve bunun dışında eski mısırdaki hayvan barınakları ve Romalılar döneminde "Campagna"lardaki fil...
https://www.biyologlar.com/nesli-tukenen-hayvanlar-icin-neler-yapilabilir -
Many endangered species are back -- but face new struggles
A study of marine mammals and other protected species finds that several once endangered species, including the iconic humpback whale, the northern elephant seal and green sea turtles, have recovered and are repopulating their former ranges. The research, published in the June edition of Trends in Ecology and Evolution, suggests that some species, including humpback whales, have reached population levels that may warrant removal from endangered species lists. But returning species, which defy...
https://www.biyologlar.com/many-endangered-species-are-back-but-face-new-struggles -
Eukaryotes: A new timetable of evolution
Contaminated samples have evidently created some confusion in the timetable of life. On the basis of ultra-clean analyses, an international team, including scientists from the Max Planck Institute for Biogeochemistry, has disproved supposed evidence that eukaryotes originated 2.5 to 2.8 billion years ago. In contrast to prokaryotes such as bacteria, eukaryotes have a nucleus. Some researchers thought they had discovered molecular remnants of living organisms in rock samples up to 2.8 billion...
https://www.biyologlar.com/eukaryotes-a-new-timetable-of-evolution -
TOHUM KILIFLARINDAKİ ÖZEL MADDELER
Tohumların genel tasarımlarındaki farklılıkların yanısıra, kılıfları da tam ihtiyaç duyacakları özelliklere sahip olarak yaratılmıştır.Tohumun içindeki embriyo son derece değerlidir. Bu nedenle yeni bitki tam olarak gelişene kadar bu embriyonun özenle korunması gerekir. Bu koruma her bitki türüne göre değişiklik gösteren tohum kılıfları ile sağlanmıştır. Tohum kılıfını oluşturan maddenin dayanıklılığı oranında tohum dış ortamın olumsuz...
https://www.biyologlar.com/tohum-kiliflarindaki-ozel-maddeler -
Archaeopteryx: Tour the Exhibit with Pete Larson
Most scientists believe that birds evolved from small therapod dinosaurs. The key step was the development of feathers, turning animals that could walk or climb into animals that could fly. The first fossil discovered with feathers was found in 1861; just two years after Charles Darwin published his theory of evolution in 1859. Archaeopteryx, which lived over 150 million years ago, is a classic example of an evolutionary link between two groups of animals. As of today, there are only ten...
https://www.biyologlar.com/archaeopteryx-tour-the-exhibit-with-pete-larson -
Deciphering the olfactory receptor code
In animals, numerous behaviors are governed by the olfactory perception of their surrounding world. Whether originating in the nose of a mammal or the antennas of an insect, perception results from the combined activation of multiple receptors located in these organs. Identifying the full repertoire of receptors stimulated by a given odorant would represent a key step in deciphering the code that mediates these behaviors. To this end, a tool that provides a complete olfactory receptor signature...
https://www.biyologlar.com/deciphering-the-olfactory-receptor-code