Chronic disease risk

The most significant differences between human and a chimp could be, size, hair and brain. But, if we take into account the microscopic world, DID YOU COUNT YOUR MICROBIOME?

It is not just the surface that we are different

What modified our gut flora so dramatically? changing diets and habitats probably both played a role.

They found that a loss of microbial diversity appears to have sped up suddenly in modern humans, “divergence of the microbiome from the microbiome of apes, and a drastic loss of diversity of the microbial community," says Thomas Bosch of the Christian Albrechts University in Kiel, Germany.

In one hand, among the bugs we have lost are a number that help digest plant matter, while in the other hand, we have gained others that help us digest meat. That makes sense in light of our diet.

"Other work has shown if you can't digest complex plant polysaccharides, they sit around in the gut where they can cause inflammation," he says. "So not having certain bacteria could make people more predisposed to chronic inflammation".

For now, all these possible links between the microbiome and our health still need to be firmed up with more studies.

"The new study demonstrates that divergence of humans from great apes was accompanied by the establishment of a completely different, human-specific microbiome," says Bosch. "Whether this change of the micobiome was one of the key drivers of human evolution and the development of human specific features remains to be shown."

Humans Would Beat Neanderthals in Marathon

Who would win if a modern human and a Neanderthal competed in a marathon? A curious question, but which is the answer?

We know that Humans, versus other great apes, are built for running fast and long as opposed to very impressive strength, but what about Neanderthals?

In a research made by the Journal of Human Evolution suggested that In a short sprint, the Neanderthal might have had a chance, but most fit humans would always win longer races.

Nowadays the human (Usain Bolt) has achieve a mark of 9.58s in 100m. But the anthropologist David Raichlen of the University of Arizona and his colleagues said us that our modern human ancestors were better runners. The research was carry out by studying the hominids'fossilized remains.

Neanderthal - not built for long distance running.

Recent research suggests that the energy cost of running at a given speed is strongly related to the length of certain limb bones. The longer these bones are, the more energy it takes for the individual to run.

We know that exist an inherent trade-off between speed and strength throughout the animal kingdom. So that way they deduced that Neanderthals were built more for brawn, with humans evolving lighter, more aerodynamic bodies for running.

PROPOSAL: A hypothetical Summer Olympics (Neanderthals vs. Humans)

It would be a memorable event as the year that Usain Bolt got the WR in Berlin, Germany. In those Olympics, Neanderthals probably had been the stars of events like wrestling, rowing and archery, and humans winning cycling, triathlon and marathon competitions. CAN YOU IMAGINE?

How we tamed ourselves and became modern?

Call a man "tame" or "domesticated" and he's not likely to take it as a compliment. But all of us, male and female, may have to get used to it: At a high-level meeting earlier this month, scientists argued that "self-domestication" was a key process in the evolution of our species. They noted that with our reduced jaws, flat faces, and lower male aggression, humans are to chimps as dogs are to wolves, showing many of the physical traits that emerge during animal domestication. 

Big brow ridges and teeth suggest that ancient Homo heidelbergensis(above) may have had more testosterone than modern Homo sapiens (left).

The accompanying changes in behavior, especially among men, might have helped humans evolve more complex language, live atop each other in cities, and work together to create sophisticated cultures.

No one set out to domesticate humans, of course. But at the first-ever symposium on self-domestication of humans, held at the Salk Institute for Biological Studies, researchers outlined a set of linked behavioral and anatomical changes seen both in animals that humans have tamed and in creatures that have tamed themselves, such as bonobos.

Rapid expansion of human

Model of human brain

A new study could rewrite the story of ape and human brain evolution. While the neocortex of the brain has been called "the crowning achievement of evolution and the biological substrate of human mental prowess," newly reported evolutionary rate comparisons show that the cerebellum expanded up to six times faster than anticipated throughout the evolution of apes, including humans.

The findings suggest that technical intelligence was likely at least as important as social intelligence in human cognitive evolution, the researchers say.

"Our results highlight a previously unappreciated role of the cerebellum in ape and human brain evolution that has the potential to refocus researchers' thinking about how and why the brains in these species have become distinct and to shift attention away from an almost exclusive focus on the neocortex as the seat of our humanity," says Robert Barton of Durham University in the United Kingdom.

"In humans, the cerebellum contains about 70 billion neurons -- four times more than in the neocortex," Barton says. "Nobody really knows what all these neurons are for, but they must be doing something important."

The neocortex had gotten most of the attention in part because it is such a large structure to begin with. As a result, in looking at variation in the size of various brain regions, the neocortex appeared to show the most expansion. But much of that increase in size could be explained away by the size of the animal as a whole. Sperm whales have a neocortex that is proportionally larger than that of humans, for example.

Barton and Venditti say that the cerebellum seems to be particularly involved in the temporal organization of complex behavioral sequences, such as those involved in making and using tools, for instance. Interestingly, evidence is now emerging for a critical role of the cerebellum in language, too.

While plenty of work remains, the new study establishes the cerebellum as "a new frontier for investigations into the neural basis of advanced cognitive abilities," the researchers say.

Humanity Has More Mothers Than Fathers, DNA Reveals

Mothers outnumbered fathers throughout much of human history, a new DNA analysis of people around the world shows. The genetic findings offer evidence for polygyny, when one man has many wives, and other reproductive customs, as people migrated out of Africa.

"Historically more of the women were reproducing than the men," study researcher Mark Stoneking, a professor of biological anthropology at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, said. "This often happens in human societies, because not all men are able to afford wives, or sometimes a few men will have many wives." These practices resulted in females making a larger genetic contribution to the global population than males did, the researchers found.

Stoneking and colleagues used a new method to scrutinize genetic variation within the male Y-chromosome. By looking at one part of the Y chromosome, they found all of the genetic variants, or slight differences in the order of DNA's "letters," within that region.

Credit: razlomov | Shutterstock

He and his colleagues put their new technique to work on DNA samples of 623 males from 51 populations around the world, including Australian, European, and American populations. The new method allowed them to take the DNA samples from each male and compare the paternally inherited Y chromosome (NRY), which gets passed down from father to son, with mitochondrial DNA (mtDNA), which mothers pass down to their children, Stoneking said.

Women likely traveled for marriages, leaving their hometowns and moving in with their husbands, the genetic analysis showed. So, females migrated more than males did, spreading their female mitochondrial DNA far and wide and reducing genetic variability between populations. Men, in contrast, tended to stay put, which resulted in their sons having distinct genes in each population.

On a regional scale, the DNA samples showed a detailed story. For example, people in East Asia and Europe have larger genetic differences for paternal than for maternal DNA, suggesting high levels of female migration. In contrast, populations in Africa, Oceania and the Americas have bigger differences for maternal DNA than for paternal DNA.

Via LiveScience: http://www.livescience.com/47976-more-mothers-in-human-history.html
Full article in Investigative Genetics: http://www.investigativegenetics.com/content/5/1/13