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Neanderthal vs Human skeletons

Neanderthals and Humans are 99.84 percent genetically identical – so where are the differences?

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Research has shown that modern-day humans and their extinct Neanderthal cousins differ by only a fraction of a percent.  So what accounts for the differences that are known to exist between the two? In a ground-breaking new study published online in Science, scientists have discovered the cellular equivalent of on / off switches that determine which genes are activated or not.

Scientists have found that the genomes of Homo sapiens and Neanderthals are 99.84 percent genetically identical, and have fewer than 100 proteins that differ in their amino acid sequence. However, although numerous recent studies have shown that we are a lot more similar to Neanderthals than previously believed, there are still fundamental differences.  For example, Neanderthals had shorter legs and arms, bowlegs, larger hands and fingers, curved arm bones, and more prominent brows. There are also a number of diseases and neurological conditions that have been found in humans but not Neanderthals.  Could all these differences really be contained within a 0.12 percent difference?

Computational biologists Liran Carmel and stem cell biologist Eran Meshorer, at the Hebrew University of Jerusalem, and their team sought to answer this question by examining differences in the epigenomes of humans and Neanderthals, as well as the ancient hominid species known as the Denisovans. The genome is the sequence of 3 billion molecules that constitute all of a person's DNA while the epigenome is which bits of DNA are turned on or off even as the molecular sequence remains unchanged. For example, it is the epigenome that can account for difference traits between identical twins.

Their results revealed around 2,200 regions that were activated in today's humans, but silenced in either or both ancient species, or vice versa. When a gene is silenced, it does not produce the trait it otherwise would. In other words, differences between the species could be accounted for by on / off patterns in the DNA.

One of the major epigenetic differences was related to those that influence the shape and size of limbs. There were also significant differences in the on / off patterns between Neanderthals, Denisovans, and modern humans associated with neurological and psychiatric disorders including autism, schizophrenia and Alzheimer's disease. More of the Neanderthal and Denisovan versions were silenced, while the human versions were active.

However, the scientists acknowledged that the research technique is not without its limitations. Each individual’s epigenome can vary markedly from another’s due to diet, environment, and other factors. It is therefore impossible to know whether the on/off patterns found in Neanderthal genes are typical of the species overall or peculiar to the individual studied. Furthermore, epigenomes can vary between different tissues of the body, so epigenomes gathered from bone, hair, or teeth, will not necessarily say anything about the brain.

Nevertheless, the new method employed in this study is a first step towards further understanding the differences between modern-day humans and our ancient ancestors. As techniques and methods develop, there is promise that we may one day hold all the answers.

Featured image: Comparison of Neanderthal and Modern Human skeletons. Credit: K. Mowbray, Reconstruction: G. Sawyer and B. Maley, Copyright: Ian Tattersall

By April Holloway

Comments

Why don't you have some "faith" in evolution as you do in your religion. It's incalculable the number of bones that have been destroyed by man unintentionally. Also it would be wise to take the world's different climatic conditions into consideration as in Africa and Southern Asia there is generally higher acidity levels in soil and that tends to break down the anatomy faster. Also if you look at areas like Iraq for example there are deserts and caves that would be able to preserve these fossils. Particularly in Europe too with the cold conditions aiding to preserve fossils. I'm telling you Neanderthal Man was real and we as man owe them a debt of thanks for the culture and insight to ponder our origins and (unfortunately) to comfort ourselves into thinking there's more than this life. We're just the lucky apes in my opinion.

I know this might have seemed like a rant, forgive me for that it isn't my intention. I really feel strongly about evolution since I first fully grasped it. I'm only 18 as well and I do respect an opinion of those that are older than me and have had more time to reflect on it. All I ask is that you consider my thoughts before rejecting it, thank you!

aprilholloway's picture

Hi Guillaume, 

The reason why more skeletons have not been found is that bones normally decompose over a number of decades or a couple of centuries at most, unless there are exceptional circumstances, such as cold temperatures or being covered by a particular sediment that preserves the remains.  Neanderthals ceased to exist around 30,000 years ago, so most of their remains have long since disintegrated, apart from those that have been preserved by special conditions.  

There are a number of museums that contain remains of Neanderthals, such as 'Britain: One Million Years of Human History' in the Natural History Museum, London; the Krapina Neanderthal Museum in Croatia; The American Museum of Natural History in New York; the Neanderthal Museum in Mettmann, Germany, and many more. 

You mentioned that skeletons are not enough to prove their existence, but now we also have DNA evidence, as the entire Neanderthal genome has been mapped, allowing scientists to compare the genes to other species. 

April

I will be prepared to take a month and travel to these countries and see for myself the skeletons.
Do you have any details of where they are in these countries, please?

I still say that 500 skeletons is not a whole civilis(z)ation, covering most of Europe, as there must be more that that many dwarfs in the south of England alone.

500 skeletons is simply not enough evidence to propose that there was an entire species.
There has to be more and a different kind of evidence to support the hypothesis.

aprilholloway's picture

Hi Guillaume, to date there are nearly 500 Neanderthal skeletons that have been found, including men, women, and children. They have been found in Germany, Belgium, Gibraltar, Croatia, Israel, Iraq, and France. Certainly not a one-off finding. 

It's good to have your doubts. But keep putting your core-belief towards other perspectives. What we call Neanderthals today might be what the bible refer to as Nephilim for example. A theory presented to me the other day... We have one bone that never stops to grow, and that's our eyebrow-bone. Neanderthals have prominent eyebrow-bone features, which could indicate an extremely long life-span, say close to and around 900 years perhaps.

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