Resurrecting Darwin’s Niata - anatomical, biomechanical, genetic, and morphometric studies of morphological novelty in cattle

Abstract

The Niata was a cattle variety from South America that figured prominently in writings on evolution by Charles Darwin. Its shortened head and other aspects of its unusual morphology have been subject of unsettled discussions since Darwin’s time. Here, we examine the anatomy, cranial shape, skull biomechanics, and population genetics of the Niata. Our results show that the Niata was a viable variety of cattle and exhibited anatomical differences to known chondrodysplastic forms. In cranial shape and genetic analysis, the Niata occupies an isolated position clearly separated from other cattle. Computational biomechanical model comparison reveals that the shorter face of the Niata resulted in a restricted distribution and lower magnitude of stress during biting. Morphological and genetic data illustrate the acquisition of novelty in the domestication process and confirm the distinct nature of the Niata cattle, validating Darwin’s view that it was a true breed.

Why the long face? Comparative shape analysis of miniature, pony, and other horse skulls reveals changes in ontogenetic growth

“…A strong shortening of the rostrum, as can be found in some dog and pig breeds (Geiger & Haussman, 2016; Evin et al, 2017), is most likely possible due to their energy rich diet (carnivore/omnivore) that can be exploited with fewer, smaller, or differently placed teeth. In cows, which also feed on nutrient poor grass, one case of rostral shortening is known: the Niata breed (Veitschegger et al, 2018); this was likely possible due to the more efficient uptake of nutrients through rumination. There is evidence of rostral shortening in a extinct herbivorous, non-ruminant browsing mammal clade, the short-faced kangaroo subfamily Sthenurinae (Prideaux, 2004).…”

Intensive human contact correlates with smaller brains: differential brain size reduction in cattle types

“…Aurochsen data were taken with mechanical calipers (mm) by the first author. Domestic cattle data were taken from Veitschegger et al [42] and converted to linear measurements. Equivalency of measurements between the two datasets was confirmed by first authors of both studies.…”

Morphological variation under domestication: how variable are chickens?

“…We explored skull shape of wild and domesticated fowl. Quantitative analyses show that the variability of domesticated forms is much larger than that of wild forms, in dogs [ 7 ], pigeons [ 4 ], cattle [ 8 ] and horses [ 9 ]. The association of traits into modules (=modularity) and low magnitudes of trait intercorrelation (=integration) have together been hypothesized to generate morphological variation [ 10 ].…”