Scientists have theorized that ancient humans evolved by adapting to environmental change. Now they describe a role reversal with alarming implications.
Evolutionists have long suggested that modern humans are, at least in part, a product of millions of years of evolutionary adaptation to changing environments across the globe. Now a broad body of scholars and scientists are saying that the roles have been reversed — that humans have become, rather than the acted upon, the instigators of environmental change, with likely dire implications if steps are not taken to address the shifts. No issue reflects this more, they maintain, than humankind’s critical relationship with water.
Paleoanthropologists, archaeologists, and a variety of other scientists have engaged themselves for decades in researching the internal and external mechanisms of human evolution, a key element of which has been the impact of the environment — climatological, geological, and biological — on humans over 3 - 4 million years. Central to this research has been the archaeological and paleontological evidence that has emerged to support the success with which certain species of humans, Homo sapiens or modern humans being the lone survivor, have adapted to shifts in climate and the availabilty and allocation of water. Read more.
Computer simulations provide new mathematical support for the “grandmother hypothesis” – a famous theory that humans evolved longer adult lifespans than apes because grandmothers helped feed their grandchildren.
"Grandmothering was the initial step toward making us who we are," says Kristen Hawkes, a distinguished professor of anthropology at the University of Utah and senior author of the new study published Oct. 24 by the British journal Proceedings of the Royal Society B.
The simulations indicate that with only a little bit of grandmothering – and without any assumptions about human brain size – animals with chimpanzee lifespans evolve in less than 60,000 years so they have a human lifespan. Female chimps rarely live past child-bearing years, usually into their 30s and sometimes their 40s. Human females often live decades past their child-bearing years. Read more.
Researchers have discovered a gene duplication related to the human brain that may have been responsible for adaptive evolutionary changes leading from ancient primate ancestors to modern humans. According to the scientists who participated in the study, two gene duplications occurred that were related to brain development, an aspect of change that was key to the emergence of ancestral and, ultimately, modern humans.
"There are approximately 30 genes that were selectively duplicated in humans," said Franck Polleux, a study participant and expert in brain development at The Scripps Research Institute. "These are some of our most recent genomic innovations."
Polleux and Evan Eichler, who is a genome scientist at the University of Washington, focused on a key gene known as SRGAP2. This gene was apparently duplicated at least twice over the past four million years, once about 3.5 million years ago and again about 2.5 million years ago. Read more.
Pioneer individuals who were in the vanguard of colonization in a region of Quebec had a selective advantage in bestowing their genes as the predominant genetic makeup of the expanding populations that followed, concludes a recent study. By implication, the study suggests that similar range expansions that have occurred in human history may have played a key role in recent human evolution.
The study team, led by Damian Labuda at the University of Montreal, Hélène Vézina from the University of Quebec at Chicoutimi (UQAC) and Laurent Excoffier from the University of Bern, along with the SIB Swiss Institute of Bioinformatics, examined the impact of rapid territorial and demographic expansions on recent human evolution and diversity by using and analyzing genealogical data, including more than one million individuals, of Charlevoix Saguenay-Lac-Saint-Jean, a recently colonized region of Quebec. Because of the availability of complete genealogies reconstructed from local parish registers, researchers were able to study human population range expansion in real time. Read more.
A foundational project is currently underway at Lake Mungo and those lakes that abound it to document the history of human settlement, past environmental change and landscape evolution that has occurred in this area. This immense undertaking comes after a long hiatus of research being conducted here and hopes to provide the first systematic archive of its archaeological traces.
Documenting the history of human settlement seems like an epic task in any part of the world; in the stark beauty of the Willandra Lakes World Heritage Area, it involves tracing back no less than 45,000 years.
Upon arriving to the now dry lake bed which lies at the heart of Mungo National Park, it is not hard to appreciate the ancient nature of this part of the world - it is one of the oldest places outside of Africa to have been occupied by modern humans. Read more.
Professor Chris Stringer tells how conflicting theories and new discoveries have shaped our understanding of humanity’s past – and of how narrow the line is between survival and failure
Our species’ origins have been a source of fascination for millennia and account for the huge range of creation myths that are recorded in different cultures. Linnaeus, that great classifier of living things, gave us our biological name Homo sapiens (meaning “wise man”) and our high rounded skulls certainly make us distinctive, as do our small brow ridges and chins. However, we are also remarkable for our language, art and complex technology.
The question is: where did these features evolve? Where can humanity place its homeland? In terms of our earliest ancestors, the answer is generally agreed to be Africa. It was here that our first ape-like ancestors began to make their homes on the savannah. However, a fierce debate has continued about whether it was also the ultimate birthplace of our own species. Read more.
It is a tale of two caves. Each has a story to tell about ancient human occupants who scratched a living out of Ice Age Europe. They may have lived in one of these caves as long ago as 900,000 years B.P. (before the present era). Scientists in southeastern Spain have been methodically piecing together the stories in these caves through careful excavation and analysis of finds that may significantly expand our knowledge of early humans and how they lived in what is today southern Europe. What is more, their finds may help fill in an important chapter in human evolution. Read more.
New fossil finds in South Africa continue to stir the pot in world-wide scientific efforts to fill the gaps between the earlier more ape-like hominids known as australopithecines and the later Homo genus of the human evolutionary family tree. The finds may represent, according to researchers, a new species of early humans that could be directly ancestral to our own genus, Homo. The latest reported research now provides additional grist for the discussion mill, opening new questions about the anatomical evolutionary path that humans took to become what we are today. Read more.