Genetic error led humans to evolve bigger, but more vulnerable, brains
S E E D E D C O N T E N T
Newly-discovered genes that helped supersize human brains along with DNA retrieved from extinct humans, which can still be found in people living today, are expanding scientists' understanding of how our species evolved.
One of the major features that distinguish humans from other primates is the size of our brains, which underwent rapid evolution from about two to three million years ago in a group of our ancestors in Africa called the Australopithecines. During this period, the human brain grew almost three-fold to reach its current size. Scientists know this from skull remains, but have puzzled over how it happened.
This year, the mystery was partially solved by Professor Pierre Vanderhaeghen at the Flanders Institute for Biotechnology in Belgium. Prof. Vanderhaeghen, who was conducting his work as part of the GENDEVOCORTEX project, went on a hunt for the genes that drove the growth of human brains.
Scientists had suspected that brain expansion began in our human ancestors when they evolved genes that are switched on in the foetus, when a lot of key brain development occurs. Prof. Vanderhaeghen therefore looked for genes present in human foetal tissue, but missing from our closest living relatives, apes.
His lab discovered 35 hominid—present only in apes and humans—genes that were active in foetal brain tissue. They then became intrigued by three specific genes—all similar to NOTCH genes, an ancient gene family involved in sending messages between cells and that are present in all animals. They found that the three new genes, collectively named NOTCH 2NL, were created by a copy and paste error of an original NOTCH gene.
This error created entirely new proteins which likely helped our ancestors' cerebral cortex to balloon. This is the part of our brain responsible for our language, imagination and problem-solving abilities. Scientists at the University of California, Santa Cruz, have also identified the NOTCH 2NL genes in DNA from Homo sapiens' extinct cousins—the Neanderthals and Denisovans.
'(The NOTCH 2NL) genes are only present in humans today. They were also present in Neanderthal DNA, but not in chimpanzees," Prof. Vanderhaeghen said.
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Duplication + mutation = new information.
E.A Mutation is rejected by over 90% of Science as a cause/effect in Evolution!
Could that be because over 90% of mutations are negative and hence one has an ever dwindling pool to draw from, is that the line to extinction!
OMFG...
Mutations are the only way to get genetic diversity, the only way to end up with changes in DNA. Without them, all life on Earth would be nothing but exact clones of the very first cell.
There is ZERO controversy when it comes to mutations and evolution. It's some pretty obvious shit.
Hell, genetic mutations can be observed in just one person's lifetime. By the time a person becomes middle-aged they will have experienced several mutations in their own DNA. Most of them are in somatic body cells and are not heritable, but mutations that occur in reproductive cells can be passed on to offspring (germ line mutations). That's one reason why it becomes riskier to have children as we age, for men at least. Sperm is constantly being produced throughout a man's lifetime, which means that the DNA he was born with is constantly making copies of itself in the production of new sperm. Errors happen along the way, so the older a man is, the more errors his sperm cells are likely to have accumulated. Women don't have that particular problem, though. They only produce eggs once, all at the same time, before they are even born.
And yes, many mutations are harmful, but they tend to die out because of that, long before they can become fixed in a population. Only the helpful or neutral mutations stick around, and even then there's a chance of them dying out early on simply through random drift.
At any rate, it is the height of absurdity to assert that 90% of science rejects mutation events as a prime mover of evolution. That's right up there with Flat Earth shit and YEC. Without mutations, DNA can't change. It's about as straightforward as it gets.
E.A ok so then you will be willing to have a Discussion on this?
Are you are unable to comprehend what I just explained to you?
Without mutations there can be no genetic diversity, no descent with modification. Every life form would be an exact copy of the first cell. There is nothing to discuss on that front.
E.A Just for those reading this what is the Immune System and how does it work?
What is an " error Count " in DNA and how does it work?
Apoptosis is what and why it is present in ALL organism?
E.A I asked you a Question YOU have Failed!
END!
Your are trying to offer facts to those who live in the realm of alternative facts.
Total BS! Mutations are well established as a factor in biological evolution.
DNA is a treasure trove of information. What an exciting time to be alive with such an opportunity to learn about our origins.
And, indeed, life is a symphony of mutation in the context of an ever-changing environment.
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Absolutely, through it we can trace our lineage, see our place in comparison to other species and possibly through it's manipulation eliminate disease or even direct our future evolution. Exciting times we live in.
It is exciting. I can hardly believe how fast it's happening. It seems like every day there's a new discovery to read about.
People with young kids or grandkids would probably do well to point them in the direction of genetics for possible careers. It looks like it's going to be huge, especially in medicine, with custom treatments specifically tailored to every patient's DNA and the like, not to mention the CRISPR stuff that could very well be used to disable cancer genes before a person even gets sick. And agriculture, too. All kinds of possibilities for agriculture. Crops with new disease resistance, crops that don't require chemical pesticides, crops that contain more nutrients than they do at present.
And all of that is on top of the history of life encoded in DNA, for evolutionary biologists and anthropologists. Many different fields seem to be benefiting from advances in genetics. Talk about a new frontier of science. It's amazing.
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