Chapter !8 - Genomics and Human Biology Code : KSI0017

<Index of Chapter 8>

 

Genomics in personal identification

1. The genomes of all individuals except identical siblings are unique. Like fingerprints, genomes provide a unique personal identification. A blood strain at a crime scene, like a set of fingerprints, can be traced to a specific individual.

2. The genome of every person ccombines chromosomes from his or her parents . Unlike fingerprints, therefore, genomes can indicate familial relationships. notably, identification of paternity. 

3. Each person's genome contains genes that influence, even if they do not inevitably determine, recognizable features. 

4. Thus, unlike fingerprints, genomes contain much more information about a person than simple identification. The treatment of this information by governmental authorities raises ethcial and legal questions. 

 

Such a  short repeitive segment of DNA is called a cariable number tandem repeat (VNTR) . 

Restriction fragment length polymorphism (RELP)

VNTRs are charcteristics of genome sequences; RELPs are artificial mixtures of short stretches of DNA created in the laboratory in order to identify VNTRs.

 

DNA fingerprinting has shown itself to e a very reliable and useful method of personal identification. 

 

-Mitochondrial DNA

> Human mitochondrial DNA is 16569 bp long. It contains a  hypervariable 100 bp region, which varies by 1-2 % between unrelated individuals. The mitochondrial DNA of unrelated people typically differs at eight positions. 

 

-Gender identification

It is possible to decide whether a nuclear DNA sample came from a male or female. Obviosuly, detection of any sequence unique to the Y chromosome will prove male origin. Another technique in common use apppies the appearance of different versions of the gene for angiogenein on the X and Y chromosomes. 

 

-Physical characteristics

In addition to matching a DNA sample with an individual, it's possible to analyse crime-scene samples to infer several characteristics, including eye and hair colour, complexion and ethnicity. Use of these inferences in criminal investigation remains controversial, and there is substantial variation in what different jurisdictions permit. 

 

The domestication of crops

Characteristics that improve the product  

: enlargement of fruit and or seed.

: improved flavour and or nutrition.

 

Characteritics that facilitate harvesting 

: synchronization of ripening time.

: Larger central stalks relative to side shoots technically, increased apical dominance. 

: Seeds do not fall off the plant. However, to facilitate harvesting the link of the seed to the plant should be relatively weak. The loss of seed dispersal can render the plant no longer viable in the wild. 

 

Tillering - shoots fill empty spaces between plants. This makes it unnecessarty to plant seeds at specific intervals.

Increased self- pollination. 

 

Studies of the henomes of crop plants have applications to agriculture including the search for varieties that produce yields improved in quality and quantity, require less fertilizer and pesticides, and are resistant to disease. If genomes of wild progenitor species are also, available, it is possible to study the genomics of domestication. 

 

-Maiza

-Rice

Ex > Golden rice

-Chocolate

-The T.cacao genome

 

Genomics in anthropology

-The neanderthal genome

It has been possible to sequene DNA from bones of Neanderthals., a species of hominid that has been extinct for about 30, 000 years. Humans and Neanderthals both inhabited Europe for about 6000 years. 

One question addressed using the Neanderthal sequence is whether there was human - Neanderthal interbreeding. It has been estimated that 1-4$ of the human genome is Neanderthal derived. However, this conclusion is controversial. 

 

-Ancient populations and migrations

> Agriculture reached britain about 5000 years ago.

Genomics and language