Human-Chimp ancestor was similar to modern african apes

After comparing fossilized shoulder blades, scientists think that the last common ancestor between chimps and humans could have been a modern African ape. And recently published findings say our ancestors stayed up in the trees much longer than we thought.

We split from other apes a very long time ago, so fossils from that time are very rare. In order to test evolutionary hypotheses, a team of scientists compared 3D shape measurements of scapulas of humans, chimpanzees, gorillas, orangutans and gibbons and saw that we have features that clearly link us with African apes.

The image above shows us the scapula of different species. African ape like (top left), modern human (bottom right), predicted ancestral forms (in gray), Australopithecus afarensis (top right), Australopithecus sediba (middle left), Homo ergaster (middle right) and Homo neanderthalensis (bottom middle).

The explanation to this is that we share a common ancestor with these apes, and although we have evolved a lot, modern African apes haven’t. The reason for this to have happened is that humans evolved towards living on the ground while apes continued living in the trees.

https://www.ucsf.edu/news/2015/09/131526/shouldering-burden-evolution

Ancient neanderthal skulls reveal insights into human evolution

Not long ago, 17 skulls have been found in a Middle Pleistocene cave in Spain. Some show some Neanderthal features and other more primitive ones, and this suggests that Neanderthals didn’t evolve these defining characteristics all at once but in stages. In fact, despite having some Neanderthal features, some of the findings had small brain cases, while Neanderthals could even have brain cases bigger than humans.

These fossils have some features in common with Neanderthals but are too primitive to be Neanderthals but too young to be some primitive human ancestors so specialists conclude that these fossils are the oldest reliably dated proto-Neanderthals.

The Neanderthal features they had were related to chewing. Modifications were made due to the intensive use of the frontal teeth, often used as a “third hand”, used to grip objects like meat, so they could have free hands to steady the object and cut it with a tool.

The findings suggest a mosaic pattern of evolution, with different traits evolving separately at different rates, making Neanderthalization more like a build-up rather than a linear evolution.

For more further information, check:

http://www.eurekalert.org/pub_releases/2014-06/aaft-swm061314.php 

http://news.nationalgeographic.com/news/2014/06/140619-neanderthal-spain-skulls-bones-pit-science-heidelbergensis/#

Orrorin tugenensis and the unclear origin of bidepalism

Nowadays, we all know that our ancestors began to diverge from the other arboreal neighbors, by developing bipedality which become a great advantage. But analysis carried out in 2013 suggests that bipedality could appear before Australophitecus afarensis. The discovery of a 6 million year old femur carried out by Sergio Almécija and his group of researchers from Stony Brook University in 2000, suggest that bidepality could appear before Lucy, which means 2 million years before.

The bones of these individual belong to the species Orrorin tugenensis, that lived approximately 6 million years ago at the end of the Miocene in eastern Africa (Tugen Hills, central Kenia). To analyze the bone, it was subjected to cutting-edge technology that analyses the 3D morphology. The obtained information was compared with a variety of apes and other hominids, and they concluded that the femur has an intermediate morphology between fully bipedal primates and those that were arboreal or quatrupedal. One comparison was with Australopithecus afarensis (Lucy) and determined that Orrorin´s femur and humerus are about 1,5 times larger.

Although some scientist and researchers do not agree Orrorin tugenensis was a truly hominin, it was likely one of the very first, and this new information brings new hypotheses about how bipedality could have been originated.

For the moment, there is no enough evidence to determine if this individual was the first to develop bidepality, and further study of other ape from the Miocene will be needed, in order to better understand where and when bipedality originated.

For more further information: http://www.newswise.com/articles/early-tree-dwelling-bipedal-human-ancestor-was-similar-to-ancient-apes-and-lucy-but-not-living-apes

Just a short video to show you the evolution

This following video created by dutch graphic designer Jurian Möller, illustrates 550 million years of evolution, completed with dates and species. Transitioning from modern man to amphibian to the earliest of the Animalia and back again in seconds, this is a charming depiction of human evolution:

To know more about his work and his book: http://evoboek.nl/en/

Cadaver study suggests fist fighting could have played a role in hand evolution

A newly published research suggests that our hands didn’t evolve only to improve our hand´s technical abillity, but also to figth between males that wanted to mate with females. That suggests that the human fist is not just an added evolutionary change due to natural selection, it also  gives advantge to figth between hominids.

The research was done by David Carrier and his researcher group from the university if Utah, and prove that the evolutional changes given in the hand made possible (by the anatomy of the hand and specially of the thumb) the clousure of the fist.

Along history, the male-male competition has been very important in great ape mating systems, A closed fist protects the hand bones from injury by reducing the tension in bones when strinking. The special anatomy and proportions of the thumb redirects the energy in a punch through the hand and the damage caused in the bones is lower. To prove that hypothesis, they used cadavers and to measure the bone deformation during striking by attaching tension indicators in the hand bones. 

As they reported in the Journal of Experimental Biology, they found that tension and pressure were much higher in strikes where the hand was in a  relaxed position where it was in a closed position, with the fist closed.

Those findings demonstrate that our hand proportions evolve apart from improving technical ability also to allow the use of hands as a weapon during fighting.

SOURCE:  http://www.eurekalert.org/pub_releases/2015-10/uou-dmp101615.php

HAND BONE MORPHOLOGY IN HUMAN´S EVOLUTION

Humans are not the only animals that are able to use tools, but it is the one who use them more efficiently than any other species in the world. This ability is not only due to the highly developed brains, it is also because of the special morphology of our hands. 

One discovery of a hand bone of 1,42 million years old proves it. These results came from the autor Carol Ward from the University of Missouri and were published in Proceedings of the National Academy of Sciences.

This discovery was carried up in Kenia where a 1.42 million year old metacarpal bone was discovered. By making different probes, researchers determined that it was of a Homo Erectus hominids, and presented a very important feature; a styloid process.

 This process is a small bony bump at the proximal end of the bone, which can be found in different bones of the body. In the hand, it connects the hand to the wrist and allows much more pressure force when hand is gripping an object. This feature, allows making and using objects more efficiently.

This discovery is very important because there was no evidence of this process in a more ancient hominid. Concretely, it was seen in Neanderthals, but it was not clear when was it formed.  In the place where metacarpal bone was discovered, there were many stone tools that reach as far back as 1.6 million years ago.

ARTICLE: http://www.pnas.org/content/111/1/121.abstract

Physical anthropology is a scientific discipline that focuses on the humans, their relation with non-human primates and their extincthominin ancestors. It is part of anthropology that studies the human beings.

This discipline is subdivided in different branches depending on the the type of studies. Although there are different branches, all of them are related with the evolutionary theory and with the human beings and are to understant human morphology and behavior among evolution. The most notable subunit is paleoanthropology that is the study of fossils to understand human evolution. It studies the extinct hominid and other primate species to determine the environment in which humans evolved and how they dispersed among earth.