WHY ARE LIGERS SO MUCH BIGGER THAN TIGONS?
The large size of the liger and small size of the tigon is due to “genomic imprinting” – the unequal expression of genes depending on parent of origin i.e. whether certain growth genes are inherited from the male or the female. This is linked to the species’ lifestyle and breeding strategy – whether the female mates with only one male while in heat (non-competitive) or whether she mates with many males (competitive). This results in “growth dysplasia”. The following explanation is greatly simplified as a number of other genes are contributed unequally by the male and female parents and also affect the general health and longevity of the offspring. Lions live in prides led by several adult males. The lionesses mate with each of those males. Each male wants his offspring to be the ones to survive, but the female’s genes want multiple offspring to survive. The father’s genes promote size of the offspring to ensure that his offspring out-compete any other offspring in the womb at the same
