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.
Charles Darwin, for all his brilliance, was perhaps paralyzed by insecurity. There are not many other explanations for why he delayed publishing his seminal work, "On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life", until 1859.
Evolution has endowed females of certain species of amphibians, reptiles and fish with the ability to clone themselves and perpetuate offspring without males.
It has even happened more recently but these virgin births don't mean males are unneeded. Fertilization is still ensuring the survival of the maximum number of healthy offspring.
A species can increase its numbers faster in harsh environments when its females do not have to find worthy males and scientists have speculated that this ability arose independently in certain species, either due to conflict between the sexes or to ensure survival when mates were scarce. Many of these species now consist entirely of females.
Genetic modification of maize over the last century has led to desirable shoot characteristics and increased yield - and that likely contributed to the evolution of root systems that are more efficient in acquiring nutrients, such as nitrogen, from the soil, according to a new study.
About half of the yield gains in commercial corn in the last 100 years has come from improved plant genetics, explained Larry York, a postdoctoral research fellow at the University of Nottingham. The other half came largely from agronomic practices, such as fertilizer use and higher planting densities.
For being a fellow of above average height (<6'2" now - age will do that) traveling to Holland can be a strange experience. It seems like everyone is around my height. The men are tall, the women are tall.
Netherlands has the tallest people in the world. Yet they used to be the shortest
. While everyone got taller during that time, Dutch average height went up 8 inches in two centuries.
Life has adapted to all sorts of extreme environments on Earth, among them, animals like the deer mouse, shimmying and shivering about, and having to squeeze enough energy from the cold, thin air to fuel their bodies and survive.
In a new paper, Scott, Cheviron et al., have examined the underlying muscle physiology from a group of highland and lowland deer mice. Peromyscus maniculatus - deer mice - were chosen because they exhibit the most extreme altitude range of any North American mammal, occurring below sea levels in Death Valley to more than 4,300 meters high in the mountains.
An evolutionary puzzle has baffled palaeontologists for more than 180 years - the origins of Toxodon platensis and Macrauchenia patachonica, South American ungulates (hooved animals) described by Charles Darwin as the ‘strangest animals ever discovered’.
Previous attempts by scientists to pinpoint the origin of the animals using morphology-based and DNA analysis of fossils had failed but a new study presents evidence that the animals were related to mammals like horses, rather than elephants and other African species as some taxonomists have maintained.
Science 2.0, a new methodology for collaboration, communication, publication and participation, has tackled the evolution of an important protein and discovered its connection in human history, as well as clues about its role in complex neurological diseases.
Most animals have a dorso-ventral (back-to-belly) body axis which determines the position of the central nervous system - dorsal in humans, ventral in insects.
Though there are obviously morphological differences, the same signaling molecules of bone morphogenetic protein (BMP) molecules establishes the dorso-ventral axis including the central nervous system in both insects and vertebrates, which led to the conclusion that this molecular mechanism was already present in the common ancestor.
Tracing the origin of the dorso-ventral axis has not been easy but sea anemones have provided some answers.