What are turtles, and where did they come from?
Precise answers to these questions have long eluded scientists. But new research led by Daniel Field of Yale University and the Smithsonian Institution recasts the turtle’s disputed evolutionary history, providing fresh evidence that the familiar reptiles are more closely related to birds and crocodiles than to lizards and snakes. (more…)
New Bedford Harbor pollution prompts PCB-resistance in Atlantic killifish
For four decades, waste from nearby manufacturing plants flowed into the waters of New Bedford Harbor—an 18,000-acre estuary and busy seaport. The harbor, which is contaminated with polychlorinated biphenyls (PCBs) and heavy metals, is one of the EPA’s largest Superfund cleanup sites.
It’s also the site of an evolutionary puzzle that researchers at Woods Hole Oceanographic Institution (WHOI) and their colleagues have been working to solve. (more…)
Genetic differences are significantly associated with the likelihood that people take on managerial responsibilities, according to new research from UCL (University College London).
The study, published online in Leadership Quarterly, is the first to identify a specific DNA sequence associated with the tendency for individuals to occupy a leadership position. Using a large twin sample, the international research team, which included academics from Harvard, NYU, and the University of California, estimate that a quarter of the observed variation in leadership behaviour between individuals can be explained by genes passed down from their parents. (more…)
A study dating the age of more than 1 million single-letter variations in the human DNA code reveals that most of these mutations are of recent origin, evolutionarily speaking. These kinds of mutations change one nucleotide – an A, C, T or G – in the DNA sequence. Over 86 percent of the harmful protein-coding mutations of this type arose in humans just during the past 5,000 to 10,000 years.
Some of the remaining mutations of this nature may have no effect on people, and a few might be beneficial, according to the project researchers. While each specific mutation is rare, the findings suggest that the human population acquired an abundance of these single-nucleotide genetic variants in a relatively short time. (more…)
A recent finding by medical geneticists sheds new light on how facioscapulohumeral muscular dystrophy develops and how it might be treated. More commonly known as FSHD, the devastating disease affects both men and women.
FSHD is usually an inherited genetic disorder, yet sometimes appears spontaneously via new mutations in individuals with no family history of the condition.
“People with the condition experience progressive muscle weakness and about 1 in 5 require wheelchair assistance by age 40,” said Dr. Daniel G. Miller, University of Washington associate professor of pediatrics in the Division of Genetic Medicine. Miller and his worldwide collaborators study the molecular events leading to symptoms of FSHD in the hopes of designing therapies to prevent the emergence of symptoms or reduce their severity. (more…)
Study part of growing body of knowledge surrounding gene-environment interplay
TORONTO, ON – It is time to put the nature versus nurture debate to rest and embrace growing evidence that it is the interaction between biology and environment in early life that influences human development, according to a series of studies recently published in a special edition of the Proceedings of the National Academy of Sciences (PNAS).
“Biologists used to think that our differences are pre-programmed in our genes, while psychologists argued that babies are born with a blank slate and their experience writes on it to shape them into the adults they become. Instead, the important question to be asking is, ‘How is our experience in early life getting embedded in our biology?’” says University of Toronto behavioural geneticist Marla Sokolowski. She is co-editor of the PNAS special edition titled “Biological Embedding of Early Social Adversity: From Fruit Flies to Kindergarteners” along with professors Tom Boyce (University of British Columbia) and Gene Robinson (University of Illinois). (more…)
Complex brains evolved much earlier than previously thought, as evidenced by a 520-million-year-old fossilized arthropod with remarkably well-preserved brain structures.
The remarkably well-preserved fossil of an extinct arthropod shows that anatomically complex brains evolved earlier than previously thought and have changed little over the course of evolution. According to University of Arizona neurobiologist Nicholas Strausfeld, who co-authored the study describing the specimen, the fossil is the earliest known to show a brain.
The discovery will be published in the Oct. 11 issue of the journal Nature. (more…)
Discovery could help lead to prevention of radical surgery for rare childhood disease
Hemimegalencephaly is a rare but dramatic condition of infancy in which half the brain is malformed and much larger than the other half. Its cause is unknown, but the current treatment is radical: the surgical disconnection and removal of the diseased half of the brain.
In a paper published in the June 24 online issue of the journal Nature Genetics, a team of doctors and scientists says mutations in a trio of genes that help regulate cell size and proliferation are likely culprits in causing the disorder, though perhaps not the only ones.
These mutations, known as de novo somatic mutations, are genetic changes in the cells of the brain. Because they are in non-sex organs, the mutations are not transmitted to the child by either parent. (more…)
