Primeval: Woolly Mammoths vrs Columbian Mammoths
Model at the Royal BC museum.
Woolly mammoths:
The Woolly mammoth, also a descendent of the Steppes mammoth, was roughly the same size as an African elephant, which makes it smaller than the Columbian. Males reached 3.4m (11.2ft) and weighed up to 6 metric (6.6 short tonnes). Females were smaller and lighter, reaching 2.9m (9.5ft) and up to 4 metric tons (4.4 short tonnes) in weight.
It was adapted to the cold, covered in fur consisting of long guard hairs over a shorter undercoat. The ears and tails are also short to minimise frostbite and heat loss and the trunk had a 'fur-mitten' a third of the way up to warm the bare trunk-tip. They also had a fat layer up to 10cm thick to help keep them warm.
However, its diet, dentition and social behaviour were all similar to the Columbian mammoth, although its lifespan was believed to be slightly shorter at 60-70 years.
But were they so different?
This was going to be a comparison of the two mammoth species, but on my wandering around the internet, I discovered something I think is rather interesting about them, hence this bit:
It had been thought for years that a number of mammoth species ranged across the Americas, however, recent genetic studies have changed this view, although all cautioned that more specimens needed to be sampled.
A 2011 genetic study of the complete mitochondria genome (inherited through the female line) showed that two examined Columbian mammoths, including the morphological typical “Huntingdon mammoth”, were grouped within a subclade of the Woolly mammoths. This suggested the two populations interbred with fertile offspring, possibly with the larger Columbian males successfully competing for the female Woolly mammoths. A similar situation has been documented in the African elephant, the African bush elephant and the African forest elephant. The authors also suggest that the North American type formerly referred to as M. jeffersonii may be one of these hybrids as its morphology is intermediate between Columbian and Woolly mammoths.
A further study in 2015 on mammoth molars suggest that when the ranges of Woolly and Columbian intersected that a meta-population of hybrids existed, that the Columbian and Woolly mammoth both evolved from the Steppes mammoth and that they are so similar in morphology that their classification as separate species may be questionable.
A 2016 genetics study confirmed that the Columbian and Woolly mammoths interbred extensively, with both descended from the Steppes mammoth, and concluded that morphological differences between fossils may therefore not be reliable in determining which species a specimen belonged to. The authors of that study also questioned whether M. columbi and M. primigenius should be considered “good species” as they could interbreed after being separated by a million years.
References:
https://en.wikipedia.org/wiki/Woolly_mammoth
https://a-z-animals.com/animals/woolly-mammoth/
https://www.livescience.com/14372-woolly-mammoth-interbred-columbian-elephants.html
https://www.wired.com/2011/11/inside-the-columbian-mammoth-signs-of-a-woolly-cousin/
https://genomebiology.biomedcentral.com/articles/10.1186/gb-2011-12-5-r51