The origin of modern humans: A cytogenetic model

Ibraimov, A. I.

doi:10.1007/bf02436607

Cited by 25 publications

(48 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this case, the merging of two pairs of ancestral acrocentrics allowed: а) to birth the individuals with different, including the low, number of Q-HRs; b) the populations gradually to eliminate two pairs of acrocentrics with a particularly high frequency of Q-HRs. Just the latter circumstance prevented the birth in the population of individuals with different, and especially with a low number of chromosomal Q-HRs, which, as we believe, is better adapted to harsher ecological conditions of the environment (Ibraimov, 1993(Ibraimov, , 2010(Ibraimov, , 2011(Ibraimov, , 2017.…”

Section: Interpretationsmentioning

confidence: 83%

“…We also state that the modern man without individuals in the population with different, and in particular, the low number of chromosomal Q-HRs would not be able to populate all climatic and geographical zones of Africa and Eurasia (Ibraimov, 1993(Ibraimov, , 2010(Ibraimov, , 2011. In this case, the main problem in appearance of the modern human included in deliverance from chromosomes in the gene pool of the ancestors, bearing Q-HRs with a very high frequency, preventing to give birth in the population to individuals with different numbers of Q-heterochromatin.…”

Section: Journal Of Molecular Biology Researchmentioning

confidence: 89%

“…Perhaps, just at this stage in the life history of our ancestors, the evolutionary changes appeared in the genome, which, ultimately, resulted to the emergence of the modern human. In particular, the individuals with a number of chromosomal Q-HRs in the genome closest to the modern Africans became adapted better in the new climate conditions (see Ibraimov, 1993Ibraimov, , 2010Ibraimov, , 2011Ibraimov, , 2015Ibraimov, , 2017.…”

Section: Interpretationsmentioning

confidence: 99%

“…If the population have uniform distribution of chromosomal Q-HRs, then it will be difficult, if not possible, to birth the individuals with different numbers of Q-heterochromatin in the genome. As the presence of individuals in human population with different numbers of Q-HRs in the karyotype (from 0 to 10) is due to the fact that Q-HRs are unevenly distributed on seven potentially Q-polymorphic autosomes (Ibraimov, 1993(Ibraimov, , 2011Ibraimov & Mirrakhimov, 1985).…”

Section: Interpretationsmentioning

confidence: 99%

“…Therefore, it is highly likely that this chromosome rearrangement in the karyotype of the common ancestor ultimately, contributed, to the appearance of the modern man. As it allowed the appearance in the population of individuals with different number of chromosomal Q-HRs in the genome, thereby opened a completely new way of adaptation to the climatic and geographical conditions, different from the East Africa (for more details see Ibraimov, 1993Ibraimov, , 2010Ibraimov, , 2015Ibraimov, , 2017.…”

Section: Journal Of Molecular Biology Researchmentioning

confidence: 99%

See 4 more Smart Citations

From 48 to 46 Chromosomes: Origin of Modern Man

Ibraimov¹

2017

JMBR

Self Cite

View full text Add to dashboard Cite

It is old-established that the chromosome number in the chimpanzee, gorilla and orangutan was 48 and not 46 as in man. However, cause and effect of such chromosome rearrangement is unknown. A hypothesis has been proposed that natural selection caused merger of two pairs of autosomes into one chromosome. In the changed climate of the East Africa individuals with less amount of chromosomal Q-heterochromatin regions (Q-HRs) in genome were the most adapted. Two pairs of acrocentrics in the genome the common ancestor, which merged into a single chromosome, apparently, carried on their short arms of Q-HRs with a very high frequency, preventing the birth of individuals with a low number Q-heterochromatin. With the merger of these two pairs of acrocentrics into one, the number of autosomes bearing the Q-HRs reduced from nine to seven pairs, as in the modern human. Such chromosome rearrangement resulted in two important consequences: а) chromosomal Q-HRs distributed into seven Q-polymorphic autosomes, so that it was possible to give birth to the individuals with different, including the low, number of Q-heterochromatin; b) in the population individuals with low number of Q-HRs appeared, able to adapt to new, harsher climatic conditions. With the lapse of time, these individuals formed a new population in the new territory, where individuals with a number of chromosomal Q-HRs like the modern natives of Africa, and with the number of 46 chromosomes in the genome began to dominate. Thus, the cause of the origin of the 46 chromosome karyotype from an ancestral 48 chromosome line was natural selection, and an effect was adaptation, i.e. individuals with different, including the low, number of Q-HRs, got the advantage to open up and to colonize new ecological zones of the East Africa.

show abstract

Section: Interpretationsmentioning

confidence: 83%

Section: Journal Of Molecular Biology Researchmentioning

confidence: 89%

Section: Interpretationsmentioning

confidence: 99%

Section: Interpretationsmentioning

confidence: 99%

Section: Journal Of Molecular Biology Researchmentioning

confidence: 99%

See 3 more Smart Citations

From 48 to 46 Chromosomes: Origin of Modern Man

Ibraimov¹

2017

JMBR

Self Cite

View full text Add to dashboard Cite

show abstract

A unique genomic sequence in the Wolf-Hirschhorn syndrome [WHS] region of humans is conserved in the great apes

et al. 1996

View full text Add to dashboard Cite

The Wolf-Hirschhorn syndrome (WHS) is caused by a partial deletion in the short arm of chromosome 4 band 16.3 (4p 16.3). A unique-sequence human DNA probe (39 kb) localized within this region has been used to search for sequence homology in the apes' equivalent chromosome 3 by FISH-technique. The WHS loci are conserved in higher primates at the expected position. Nevertheless, a control probe, which detects alphoid sequences of the pericentromeric region of humans, is diverged in chimpanzee, gorilla, and orangutan. The conservation of WHS loci and divergence of DNA alphoid sequences have further added to the controversy concerning human descent.

show abstract

Paradise lost: Mitochondrial eve refuted

Pickford

1991

Hum. Evol.

View full text Add to dashboard Cite

The origin of modern humans: A cytogenetic model

Cited by 25 publications

References 18 publications

From 48 to 46 Chromosomes: Origin of Modern Man

From 48 to 46 Chromosomes: Origin of Modern Man

A unique genomic sequence in the Wolf-Hirschhorn syndrome [WHS] region of humans is conserved in the great apes

Paradise lost: Mitochondrial eve refuted

Contact Info

Product

Resources

About