Why is the Human Genome Project called a mega project?

Explanation

(i) The international human genome project was launched in the year 1990. It was a mega project and took 13 years to complete.
(ii) The human genome is about 25 times larger than the genome of any organism sequenced to date and is the first vertebrate genome to be completed. Human genome is said to have approximately `3xx10^(9) bp)`.
(iii) HGP was closely associated with the rapid development of a new area in biology called bioinformatics.
(iv) The methodologies of the Human Genome Project involved two major approaches. One approach was focused on identifying all the genes that are expressed as RNA (ETSS - Expressed Sequence Tags). The other approach was sequence annotation. Here, sequencing the whole set of genome was taken, that contains all the coding and non-coding sequences and later assigning different regions in the sequences with functions. These sequences were subsequently annotated and are asigned to each chromosome.
(v) The genetic and physical maps on the genome are assigned using information on polymorphism of restriction endonuclease recognition sites and some repetitive DNA sequences, called microsatellites.
(vi) The latest method of sequencing even longer fragments is by a method called Shotgun sequencing using super computers, which has replaced the traditional sequencing methods.
(vii) Scientists have identified about 1.4 million locations where single base DNA differences (SNPs - Single nucleotide polymorphism - pronounced as .snips.) occur in humans. Identification of .SNIPS. is helpful in finding chromosomal locations for disease associated sequences and tracing human history.