Eating Meat helped Humans have a shorter Breast Feeding period

New research appears to explain that eating meat was why humans breast feed less than great apes.
Below excerpt from the  Daily Mail

The research compared 67 species of mammals, including humans, apes, mice and killer whales, and found a clear correlation between eating meat and earlier weaning.

The research compared 67 species of mammals, including humans, apes, mice and killer whales, and found a clear correlation between eating meat and earlier weaning.

They found young of all species stop suckling when their brains have developed to a particular stage, but that carnivores reached this point more quickly than herbivores or omnivores. 

Eating meat enabled the breast-feeding periods and thereby the time between births to be shortened,' said Elia Psouni, lead author of the study. 'This must have had a crucial impact on human evolution.'

Among natural fertility societies, the average duration of breast-feeding is 2 years and 4 months. This is not much in relation to the maximum lifespan of our species, around 120 years.
It is even less if compared to our closest relatives: female chimpanzees suckle their young for 4 to 5 years, whereas the maximum lifespan for chimpanzees is only 60 years.

Below excerpts from the  Psouni, Elia et al abstract at PLoS

Our large brain, long life span and high fertility are key elements of human evolutionary success and are often thought to have evolved in interplay with tool use, carnivory and hunting. 

Crucially, carnivory predicted the time point of early weaning in humans with remarkable precision, yielding a prediction error of less than 5% with a sample of forty-six human natural fertility societies as reference. Hence, carnivory appears to provide both a necessary and sufficient explanation as to why humans wean so much earlier than the great apes.

While early weaning is regarded as essentially differentiating the genus Homo from the great apes, its timing seems to be determined by the same limited set of factors in humans as in mammals in general, despite some 90 million years of evolution.

Our analysis emphasizes the high degree of similarity of relative time scales in mammalian development and life history across 67 genera from 12 mammalian orders and shows that the impact of carnivory on time to weaning in humans is quantifiable, and critical.

Since early weaning yields shorter interbirth intervals and higher rates of reproduction, with profound effects on population dynamics, our findings highlight the emergence of carnivory as a process fundamentally determining human evolution.