# Congenital anomalies from a physics perspective. The key role of "manufacturing" volatility

## TL;DR

This paper proposes that random manufacturing discrepancies, independent of genetic or environmental factors, significantly contribute to congenital anomalies, as demonstrated through controlled experiments across species, linking manufacturing variability to infant mortality.

## Contribution

Introduces the concept of manufacturing discrepancies as a third cause of congenital anomalies, supported by experimental evidence across multiple species, expanding traditional genetic and environmental explanations.

## Key findings

- Manufacturing variability accounts for 10-20% of congenital anomalies.
- Cloned organisms under controlled conditions show residual variability.
- Infant mortality trends reflect underlying manufacturing-related anomalies.

## Abstract

Genetic and environmental factors are traditionally seen as the sole causes of congenital anomalies. In this paper we introduce a third possible cause, namely random "manufacturing" discrepancies with respect to ``design'' values. A clear way to demonstrate the existence of this component is to ``shut'' the two others and to see whether or not there is remaining variability. Perfect clones raised under well controlled laboratory conditions fulfill the conditions for such a test. Carried out for four different species, the test reveals a variability remainder of the order of 10%-20% in terms of coefficient of variation. As an example, the CV of the volume of E.coli bacteria immediately after binary fission is of the order of 10%. In short, ``manufacturing'' discrepancies occur randomly, even when no harmful mutation or environmental factors are involved. Not surprisingly, there is a strong connection between congenital defects and infant mortality. In the wake of birth there is a gradual elimination of defective units and this screening accounts for the post-natal fall of infant mortality. Apart from this trend, post-natal death rates also have humps and peaks associated with various inabilities and defects.\qL In short, infant mortality rates convert the case-by-case and mostly qualitative problem of congenital malformations into a global quantitative effect which, so to say, summarizes and registers what goes wrong in the embryonic phase. Based on the natural assumption that for simple organisms (e.g. rotifers) the manufacturing processes are shorter than for more complex organisms (e.g. mammals), fewer congenital anomalies are expected. Somehow, this feature should be visible on the infant mortality rate. How this conjecture can be tested is outlined in our conclusion.