Twinning and inbreeding in India: the fraternal component

Area of Science:

• Population Genetics
• Human Demography
• Reproductive Biology

Background:

• Population growth is traditionally linked to factors like sex ratio, fecundability, and offspring survival.
• The role of genetic background, specifically fetal inbreeding status, in population dynamics is less understood.
• Abortions and stillbirths represent significant interferences in population growth that require further investigation.

Purpose of the Study:

• To propose a hypothetical formula integrating genetic factors into population growth models.
• To introduce the concept of a 'Fraternal Component' (FC) derived from this formula.
• To explore the potential of FC as a novel method for estimating dizygotic (DZ) twinning rates.

Main Methods:

• Development of a hypothetical formula incorporating mean birth rate (Mb), population growth percentage (G), inbreeding coefficient (F), stillbirths + abortions (Sa), and sex ratio (Sr).
• Calculation of the Fraternal Component (FC) as a product within the formula.
• Comparison of the calculated FC with existing dizygotic twinning rates in population samples.

Main Results:

• A hypothetical formula was devised to model population growth, including genetic and fetal loss factors.
• The calculated Fraternal Component (FC) showed a close approximation to the dizygotic twinning rate in the studied population sample.
• This suggests a potential correlation between genetic inbreeding, fetal loss, and twinning rates.

Conclusions:

• Population growth is influenced by a complex interplay of demographic and genetic factors.
• The Fraternal Component (FC) presents a novel metric potentially linked to dizygotic twinning rates.
• Further research is warranted to validate the formula and its application in estimating dizygotic twinning rates.