Intersting facts

Human beings differ only in 0.1% of the genetic material, in the other 99.9%, they are identical.

Genetic similarity. Human beings share 7% of genes with E. coli bacterium, 21% with worms, 90% with mice and 98% with chimpanzees.

If one were to recite the ATCG sequence in one's DNA which is 3 billion long and would utter at a rate of 100 ATCG sequences per minute without taking a break for sleeping, eating or drinking, one would speak for 57 long years.

If all 46 chromosomes from one cell were combined and arranged lengthwise, the total length would be 1.8 meters. There are differences in the total number of cells in a human body; according to a general assessment, however, the number should be around 100,000 billion. If the entire DNA from all nuclei in the human body were to be arranged lengthwise, it would measure around 180,000 million km. For a better understanding, compare it to the distance from the Earth to the Sun which is 150 million km - the DNA length would thus be 1,000 times greater.

1000 cell nuclei could be squeezed into a period mark at the end of a sentence.

A genetic study is being done on an African ethnic group Yoruba. They have an unusually high birth rate of twins.

There is genetic proof indicating that the Sans are one of oldest peoples in the world. They may well be the most ancient, and are considered to be a “genetic Adam”.

The banana is a fruit which originated in Asia. During the period of one of the largest human migrations (between 1000 B.C. and 300 A.C.), it was brought to Africa.

In the case of autosomal recessive diseases, the recessive gene, situated on an autosomal chromosome, is passed on in the family. Both gene copies (each one on its own chromosome in a chromosome pair) must be recessive in order for the expression of the gene to take place and the disease to develop. If one only has one copy of this gene, one is a carrier and is usually not even aware of it because the disease has not developed.

Among the sex-linked genetic diseases, haemophilia is an interesting example. The gene for this disease is recessive and linked to the X chromosome. Women have two X chromosomes, while men have only one. In order for haemophilia to develop in women, the woman has to carry both X chromosomes with the diseased gene. If she only carries this gene in one X chromosome, she will not develop the disease but will be a carrier. All men with this recessive gene will fall ill, for they only have one X chromosome and will thus express the disease. This disease was well-understood in the Jewish population although genetics was not as well understood then as it is today. It was already known at that time which women are carriers of the disease and therefore their sons were exempt from circumcision.

In addition to the DNA in the nucleus, human beings also have DNA in their mitochondria. This DNA is inherited only from the mother and is used to study female ancestry. Interestingly, however, in bees the mitochondrial DNA is inherited also from the father. There was one such exceptional case recorded in humans as well.

There are genetic abnormalities that occurred in mitochondrial DNA and they also affect an individual. Mitochondrial DNA is inherited from the mother, for at the time of fertilization of an egg the mitochondria of the sperm do not enter the egg. The egg contains mother's mitochondria and as such the child only possesses mother's mitochondria. Due to such mode of inheritance, the genetic abnormality will be expressed in all children of the abnormality-carrying mother and in no children of the father with the same abnormality.

One out of every 180 children is born with a chromosomal abnormality. The result of the most common abnormality is Down's syndrome.

Merely 2% of the human genome contains information for the formation of proteins. All the rest are the so called non-coding regions because it is still not known what their specific function is.

The Italian regions of Toscana and Umbria are special. They are genetically different from the other Italian regions because of Etruscan genetic heritage in this area.

According to some linguistic theory, the Basques originally hail from Russia, for their haplotype is the same as the haplotype found in inhabitants of some Russian regions.

Genetic studies form a theory of three migrations of the Hans from the North to the South of China.

In a representative group of 50 African monkeys, there are more gene variations than in the entire human race. This means that the entire human race is a descendant of a small group of people from the ancient past. The scientific terms for it is a “bottleneck”. It is probably the result of unfavourable weather conditions which made the majority of the people from the ancient past pass away. The entire human race developed from the small group of survivors. 71,000 years ago, the Toba volcano erupted, causing a six year long volcanic winter. The famine and low temperatures left only around 15,000 survivors. The eruption, however, also caused a change in the Earth's climate; a 1,000 year long Ice age followed.

The modern Maltese people genetically correspond to certain Lebanese which fact supports the theory that most Maltese people are the ancestors of the ancient Phoenicians.

Species	Human being	Chick	Wine fly (Drosophila)	Butterfly	Corn	Rice
Number of chromosomes	46	78	8	Around 380	20	24
Number of genes (approximately)	25.000	23.000	14.000	Unknown	59.000	50.000
Length of the genome (million base pairs)	3.300	1000	165	124.900	2.500	441

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