Evolution

A unique adaptation in the foot of birds is the presence of a thumb-like opposable toe, which allows them to grasp and perch.

In their dinosaur ancestors, this toe was small and non- opposable, and did not even touch the ground, resembling the dewclaws of dogs and cats.

The embryonic development of birds provides a parallel of this evolutionary history: The toe starts out like their dinosaur ancestors, but then its base (the metatarsal) becomes twisted, making it opposable. Brazilian researcher Joâo Botelho, working at the lab of Alexander Vargas at the University of Chile, decided to study the underlying mechanisms. Botelho observed that the twisting occurred shortly after the embryonic musculature of this toe was in place.
A new study of some Hesperornithiform bird fossils from the Cretaceous shows how several separate lineages evolved adaptations for diving. They began to go fishing.

Living at the same time as the dinosaurs,  Hesperornithiform has been found in North America, Europe and Asia in 65–95 million years old rocks. Dr. Alyssa Bell and Professor Luis Chiappe of the Dinosaur Institute, Natural History Museum of Los Angeles County, undertook a detailed analysis of their evolution, showing that separate lineages became progressively more adept at diving into water to catch fishes, like modern day loons and grebes.
Does the world really need men?

It has been suggested that, in the age of cloning – and with enough sperm banks around to populate several future generations – the question is legitimate.

However, new research suggests that the reason that we need two sexes is because it improves the overall genetic quality of a species and reduces the risk of population extinction.

A new study and a new microbe provides a new understanding of how, billions of years ago, the complex cell types that comprise plants, fungi, but also animals and humans, evolved from simple microbes, according to a new paper.

Cells are the basic building blocks of all life on our planet. Yet, whereas the cells of bacteria and other microbes are small and simple, all visible life, including us humans, is generally made up of large and complex cell types.

The origin of these complex cell types has long been a mystery to the scientific community, but now researchers writing in Nature detail discovery of a new group of microorganisms that represents a missing link in the evolutionary transition from simple to complex cells.


The vivid pigmentation of zebras, the massive jaws of sharks, the fight or flight instinct and the diverse beaks of Darwin's finches. These and other remarkable features of the world's vertebrates stem from a small group of powerful cells, called neural crest cells, but little is known about their origin.

Scientists have proposes a new model for how neural crest cells, and thus vertebrates, arose more than 500 million years ago. 

The researchers postulate that, unlike other early embryonic cells that have their potential progressively restricted as an embryo develops, neural crest cells retain the molecular underpinnings that control pluripotency -- the ability to give rise to all the cell types that make up the body. 


Common DNA modifications occur through methylation, a chemical process that can dramatically change gene expression, which regulates the eventual production of proteins that carry out the functions of an organism. 

DNA encodes genetic information in its chemical bases: adenine, cytosine, guanine, and thymine. Methylated cytosine is the dominant DNA modification found in eukaryotes, a taxonomical classification that includes mammals, insects, worms, plants, and algae, but new papers have identified an adenine DNA methylation that also epigenetically regulates cellular function in green algae, worms, and flies.


A new paper suggests a need for a fundamental rethink of the evolutionary path of enzymes, the proteins vital to all life on Earth.

Enzymes catalyze a vast array of biologically relevant chemical reactions even in the simplest living cells but biochemist Dr. Wayne Patrick of University of Otago and colleagues assert that while people tend to imagine evolution as a slow and steady march, from barely functional life forms in the primordial soup towards a modern-day pinnacle of near perfection, that may not be true. 


Marsha Lewis, Inside Science TV – There are about 60,000 different vertebrates on this planet.

Mammals, birds, reptiles, amphibians, fish, even you are a vertebrate. And now for the first time, scientists from around the world are coming together to study them on a molecular level.

"The Genome 10k Project is our first look at vertebrate animal life," said David Haussler, a biomolecular engineer at the University of California, Santa Cruz. "We're trying to get at least 10,000 species represented in our genome collection," he said.


Everyone loves vampire squid, right? Their monstrous name belies their gentle nature as graceful underwater flyers who eat poop.

The ability to move in water is key to existence for many species so it may not be a surprise that so many species have converged on swimming. What is intriguing is how diverse creatures have evolved to swim with elongated fins using the same mechanical motion that optimizes their speed.

The Persian carpet flatworm, the cuttlefish and the black ghost knifefish are nothing like each other - their last common ancestor lived 550 million years ago, before the Cambrian period - but all three aquatic creatures converged evolutionaru on the same swimming, according to a new study uses a combination of computer simulations, a robotic fish and video footage of real fish.