Evolution

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. 


Researchers have determined that the eardrum evolved independently in mammals and diapsids - the taxonomic group that includes reptiles and birds. Published in Nature Communications, the work shows that the mammalian eardrum depends on lower jaw formation, while that of diapsids develops from the upper jaw. Significantly, the researchers used techniques borrowed from developmental biology to answer a question that has intrigued paleontologists for years.


The famous Vitruvian Man, drawn by Leonardo da Vinci, pictures the canon of human's proportions - though we did not become bilaterally symmetric all at once.

There are two main points of view on the last common bilaterian ancestor, its appearance and the course of evolution. It is likely that the ancestor of Bilateria appeared at the end of the Vendian period which is the last geological period of the Neoproterozoic Era preceding the Cambrian Period. It lasted from approximately 635 to 541±1 million years ago. The organisms, which lived in the Vendian sea, were mostly radially symmetrical creatures. Some of them were floating in the water, while others were crawling along the bottom or leading sessile benthic life.

Invasive plants animals and plants spreading is not new but predicting the dynamics of these invasions is difficult - and of great ecological and socioeconomical interest. Scientists at Eawag and University of Zurich are now using computer simulations and small artificial laboratory worlds, to study how rapid evolution makes invaders spread even faster.