The growing frequency and popularity of Caesarean births are seemingly affecting our evolution as a species, say scientists.
More mothers now need surgery to deliver a baby due to their narrow pelvis size, according to some researchers.
Scientists have drawn the conclusion that the instances when the baby can’t fit through the birth canal has gone up from 30 in 1,000 in the 1960s, to 36 in every 1,000 births today.
Historically, these genes can not continue to pass on as it is fatal to both the mother and the baby.
A group of scientists in Austria stated that the trend is likely to continue, but not to the extent that non-surgical births would just end abruptly.
Dr Sam Waltham, of the lab for evolutional biology at the University of Vienna, said there was a long standing question in the understanding of human evolution.
“Why is the rate of birth problems, in particular what we call fetopelvic disproportion – basically that the baby doesn’t fit through the maternal birth canal – why is this rate so high?” he said.
“Without modern medical intervention such problems often were lethal and this is, from an evolutionary perspective.
“Women with very narrow pelvis would not have successfully lived through child labor a century ago. But they survive now and by doing so pass the genes for smaller pelvises on to their daughters.”
It has been a long standing evolutionary question why the human pelvis has not evolved over the last few centuries?
The researchers along with the World Health Organization (WHO), and other medical institution conducted a long running experiment to investigate the case.
In the result they found opposing evolutionary forces.
One is a trend towards larger newborns, which arguably is better in terms of the child’s health.
But, if the fetuses become too large, then it will be a very dangerous childbirth procedure, which historically would have proved disastrous for mother and baby.
And their natural child bearing birth genes would not passed on to the next generation.