Ashkenazi Jews are known to have an average IQ between 107-115, putting half of the ethnic group into the genius range.

Unfortunately, Ashkenazi Jews are also plague with genetic diseases! One fourth of the population is a carrier of one of several genetic conditions, which include Tay-Sachs Disease, Canavan, Niemann-Pick, Gaucher, Familial Dysautonomia, Bloom Syndrome, Fanconi anemia, Cystic Fibrosis and Mucolipidosis IV.

A “carrier” for a gene means that the person carries only one copy of the gene. The gene is not expressed in that person’s trait or phenotype. However, marrying another carrier or someone with two copies of the gene may produce children with the trait. For example, a carrier for blue eyes may have a different eye color but has children with blue eyes.

When talking about genetic diseases, a carrier for cystic fibrosis does not have the disease but can pass it on to one of the children if the person marries another carrier or homozygote (two copies) for cystic fibrosis.

So why does the Ashkenazi Jewish community have high degree of genetic diseases, and it is related to their IQ?

There’s a new book called “The 10,000 Year Explosion” that seems to explain the relationship between IQ and disease. It has other theories and contents in it besides the Jewish history. I haven’t read the book, but read Amazon reviews. Most give it a grade of 5 stars, but the 2-star said the book is not science.

I’ll look for it in the local library and see if I agree. Have you read it? What did you think about the book?

Image: Newscom

Genes that cause disease have been traced back to the origin of the first cell, scientists from Max Planck found.

A novel method of genomic phylostratigraphy has recontructed the evolutionary origin of disease-causing genes in humans, and the results have surprising implications.

Tomislav Domazet-Lošo and Diethard Tautz from the Max Planck Institute for Evolutionary Biology in Plön (Germany) applied genomic phylostratigraphy to determine that most disease genes originated with the ‘first cell’, and other large groups of genes emerged around the appearance of multi-cellular organisms. BUT no disease-associated genes emerged after the origin of mammals.

What exactly do these results mean? According to the researchers -

• all living things will be affected by similar genetic diseases;
• genetically caused disease will never be beaten completely;
• but it will be easier to identify candidates for further genes (I’m not getting the "how" of this yet).

Science Daily

Quoted from the Times Online on an interview with leading geneticist Professor Steve Jones, of University College London:

“Small populations which are isolated can evolve at random as genes are accidentally lost. World-wide, all populations are becoming connected and the opportunity for random change is dwindling. History is made in bed, but nowadays the beds are getting closer together. We are mixing into a global mass, and the future is brown.”

I wonder how long it will take before the world turns brown? Already, rebuttals are in.

From Gene Expression:

First, we’re nowhere close to panmixia. Second, there is going to be a large variance around the expectation. Even if you remove new mutations, there are a lot of variants out there for selection to pick up from the extant genetic background I would think. The future will not be brown for the same reason that people in an English village do not all have the same hair color despite there being a lot of intermarriage.

From Secondhand Smoke, who believe humans are the exceptional species:

The whole concern about stopping evolution is simply ridiculous. First, there is no way to ever prove or disprove it–at least not in our lifetimes or indeed, those of our great grandchildren. Second, if true, why is it bad? Species like the horseshoe crab that stop evolving do so because they are so successful. Third, what can we do about it even if it is bad?

(Photo credit: http://nationalzoo.si.edu/Animals/PhotoGallery/Primates/7.cfm )

Scientists have long wondered why early primates inhabited forest canopies, given that climbing appears to consume more energy than walking. However Duke University researchers studying primates walking on treadmills found that there was no energy consumption difference in small primates.

This suggests that ancestors of humans, apes and monkeys may have taken to the trees because of their small body size to exploit a new environment giving them an evolutionary advantage compared to fellow mammals.

Early primates, which would have been about the size of large rats, then underwent a number of evolutionary changes as they adapted to their new environment. These changes included nails rather than claws and grasping hands and feet.

Elaine Warburton  www.geneticsandhealth.com

Saturn’s moon Titan - three different views

Courtesy NASA

Titan, one of Saturn’s moons is like a genetic twin to Earth.  It enjoys many of the geological features of the Earth - volcanism, tectonics, erosion, deposition and atmosphere.  The rivers flowing across these plains are formed of a hydrocarbon soup with methane as its main ingredient.

However the one main difference is that it is so cold so most of the water is solid.

The true nature of this once mysterious world is now finally emerging, courtesy largely of the Cassini-Huygens mission, a joint US-European venture, which deposited a landing craft on Titan, and continues to send back data and pictures of Saturn, its rings and its 60-odd moons.

The data coming back from the mission shows that on Titan it rains methane onto the surface, which then collects into lakes.  There are also equatorial storms in the tropical regions.  So alike do the lakes appear to those on Earth that the cosmological “nomenclature police”, the International Astronomical Union (IAU), have decreed that they can be named after those on our planet.  Titan now features a Lake Abeya, a Lake Mackay and a Lake Ontario, named because their shapes resemble their terrestrial equivalents in Ethiopia, Australia and Canada.

The atmosphere of Titan has also turned out to be reminiscent of Earth’s, possessing layers that mimic the troposphere, stratosphere and ionosphere above our heads.

There may be 1,000 times more liquid hydrocarbons in Titan’s lakes than in all the oil wells on Earth. Its dunes may hold hundreds of times the content of Earth’s coal reserves.

It makes an enticing prospect for the would-be life-hunter in space.

“This combination of liquid water in the interior plus complex organic molecules composes two big ingredients for life - certainly life as we know it - and that makes Titan a very attractive body for future exploration,” says Ralph Lorenz from the project.

Elaine Warburton  www.geneticsandhealth.com 

‘Junk DNA’ could hold the key to the evolution of complex organisms . Vertebrates, animals that possess a backbone, are the most anatomically and genetically complex of all organisms, but explaining how they achieved this complexity has perplexed scientists since the conception of evolutionary theory.

A study, published in Proceedings of the National Academy of Sciences,USA, claims to have solved this scientific riddle by analysing the genomics of primitive living fishes such as sharks and lampreys and their spineless relatives, such as the sea squirts.

Alysha Heimberg of Dartmouth College, UK and her colleagues showed that microRNAs, a class of tiny molecules only recently discovered residing within what has usually been considered ‘junk DNA’, are hugely diverse in even the most lowly of vertebrates, but relatively few are found in the genomes of our invertebrate relatives.

She explained: “There was an explosive increase in the number of new microRNAs added to the genome of vertebrates and this is unparalleled in evolutionary history.”

Co-author, Dr Philip Donoghue of Bristol University’s Department of Earth Sciences continued: “Most of these new genes are required for the growth of organs that are unique to vertebrates, such as the liver, pancreas and brain. Therefore, the origin of vertebrates and the origin of these genes is no coincidence.”

For further information, click on:

http://www.bristol.ac.uk/news/2008/5816.html

Elaine Warburton  www.geneticsandhealth.com

Caenorhabditis elegans (C.elegans)

I’m sure like all of you with young kids, I don’t get enough sleep. I don’t need much naturally but an extra hour or so here and there would be great!  The roundworm C. elegans, a staple of laboratory research, may be key in unlocking one of the central biological mysteries: why do we sleep?

Researchers at the University of Pennsylvania School of Medicine report in this week’s advanced online edition of Nature that the round worm has a sleep-like state, joining most of the animal kingdom in displaying this physiology. This research has implications for explaining the evolution and purpose of sleep and sleep-like states in animals.

In addition, genetic work associated with the study provides new prospects for the use of C. elegans to identify sleep-regulatory genes and drug targets for sleep disorders.

The research showed that there is a period of behavioral quiescence during the worm’s development called lethargus that has sleep-like properties. “Just as humans are less responsive during sleep, so is the worm during lethargus,” explains lead author David M Raizen. “And, just as humans fall asleep faster and sleep deeper following sleep deprivation, so does the worm.”

By demonstrating that worms sleep, Raizen and colleagues have not only demonstrated the need for sleep in nature, but also propose a compelling hypothesis for the purpose for sleep.  The time of lethargus coincides with a time in the round worms’ life cycle when synaptic changes occur in the nervous system.  In other words, in order for the nervous system to grow and change, there must be down time of active behavior. Other researchers at Pennsylvania have shown that, in mammals, synaptic changes occur during sleep and that deprivation of sleep results in a disruption of these synaptic changes - often resulting in changes to mood and normal behavior.

In addition, the research team used C. elegans as a model system to identify a gene that regulates sleep. This gene, which encodes a protein kinase and is regulated by a small molecule called cyclic GMP, has been previously studied but not suspected to play a role in sleep regulation. The findings suggest a potential role for this gene in regulating human sleep and may provide an avenue for developing new drugs for sleep disorders.

Elaine Warburton

Stanford Magazine (May/June 2007) asks, What’s the next step in human evolution?

Luigi “Luca” Cavalli-Sforza, professor emeritus of genetics, is a pioneer in “genetic geography,” a field that uses DNA to help understand human migration throughout history.

…A major genetic change which started already some centuries ago, with the navigation of the oceans, and is becoming faster now, is globalization. This is having major genetic consequences. It will bring back greater unity of the species, by diluting and eventually canceling differences among ethnic groups existing today, that are largely if not exclusively the consequence of adaptation to environments that differ most climatically to which modern humans spread in the last 50,000 years…