DID BAD DIET KILL NEANDERTHALS?

Well, I was intrigued to find out why some people like brussels sprouts while others hated them and how this is related to extinction of Neanderthals that had bigger brains than human beings.

Evidently there is a gene in modern humans that makes some people dislike a bitter chemical called phenylthiocarbamide, or PTC, that was also present in sprouts during the time of Neanderthals hundreds of thousands of years ago.

Scientists made their discovery after recovering and sequencing a fragment of the TAS2R38 gene taken from 48,000-year-old Neanderthal bones found at a site in El Sidron, in northern Spain,

The findings were published by the Spanish National Research Council (CSIC) in the Royal Society journal Biology Letters.

The report cited "this indicates that variation in bitter taste perception predates the divergence of the lineages leading to Neanderthals and modern humans.

Substances similar to PTC give a bitter taste to green vegetables such as Brussels sprouts, broccoli and cabbage as well as some fruits.

But they are also present in some poisonous plants. So apparently, having a distaste for it, makes good evolutionary sense as a sense of bitter taste supposedly protects us from ingesting toxic substances," the researchers say.

What intrigued the researchers most is that Neanderthals also possessed a recessive variant of the TAS2R38 gene, which made some of them unable to taste PTC - an inability they share with around one third of modern humans.

These (bitter) compounds can be toxic if ingested in large quantities and, according to the report, it is therefore difficult to understand the evolutionary existence of individuals who cannot detect them.

The report's lead author, Professor Carles Lalueza Fox of the University of Barcelona, speculates that such people may be "able to detect some other compound not yet identified."

This would have given them some genetic advantage and explain the reason for the continuation of the variant gene.

Neanderthals and modern humans shared a common ancestor from which they diverged about 300,000 years ago.

Excavations since 2000 at the site at El Sidron, in the Asturias region, have so far recovered the skeletal remains of at least 10 Neanderthal individuals.

The squat, low-browed Neanderthals lived in parts of Europe, Central Asia and the Middle East for around 170,000 years, but traces of them disappear some 28,000 years ago. Their last known refuge was in Gibraltar.

Why they died out is still unknown, as they once existed alongside modern man.

All we know from DNA is that not one human has a Neanderthal descendants. The Spanish research simply makes the points that some people can taste bitter PTC compounds and some can't, and that was the same with the now extinct Neanderthals species.

The ability to taste PTC is not necessarily an advantage for the survival as a species. It's an advantage if people are likely to eat large amounts of toxic plants. And it's also a disadvantage if you miss out on the benefits of eating brussels sprouts, broccoli and cabbage.

Previous scientific research before the Spanish report indicated that chemical signatures locked into bone suggest the Neanderthals got the bulk of their protein from large game, such as mammoths, bison and reindeer. Evidently the anatomically modern humans that were living alongside them preferred eating smaller mammals, fish and seafood.

The human diet stretched to aquatic birds, which Neanderthals preferred not to eat.

Such dietary differences could have played a role in the extinction of Neanderthals roughly 24,000 years ago but many historians believe that the Neanderthals were out-competed by modern humans who moved in with different, more advanced hunting technology for a wider variety of foods.

Carbon and nitrogen isotopes suggest that Neanderthals living between 37,000 and 120,000 years ago in what are now France, Germany, Belgium and Croatia got the bulk of their protein from large land herbivores,

When big game became, modern humans flourished by eating fish and smaller animals. Neanderthal populations, by contrast, shrank and eventually disappeared in areas from when their usual prey disappeared.

But the study of ancient DNA that offers support that Neanderthals possessed a gene mutation that would have meant they couldn't taste bitter chemicals found in many plants has give greater credibility to speculation that this mutation is beneficial to humans because it makes vitamin-packed vegetables more palatable.