Table 5.

Moral valuation of animal lives

Animal	Proxy animal	Cortical neurons	Neurons	Brain mass	Moral value
Humana	–	16 billion	86 billion	1508 g	1
Cattleb	–		3 billion		0.035
Pigc	–	432 million			0.027
Chickend	Red junglefowl	61 million			0.0038
Salmone	Shark			1.8 g	0.0012
Shrimpf	Lobster		100,000		1.2 × 10−6
Cricketg	Fruit fly and ant		250,000		2.9 × 10−6
Mealwormg,h	Fruit fly, ant and zebrafish		25,000		2.9 × 10−7

^a(Azevedo et al. 2009, Herculano-Houzel 2009)

^b(Herculano-Houzel 2016)

^cThe number only refers to neocortical neurons (Jelsing et al. 2006); hence, it underestimates the cortical neurons

^d(Olkowicz et al. 2016)

^eThe body mass of a salmon was assumed to equal 4.5 kg (FRS Marine Laboratory 2006), while the brain:body mass ratio was assumed to equal that of a shark—1:2496 (Serendip 2016)

^f(Lobster Institute 2016)

^g(Burne et al. 2011; Shulman and Bostrom 2012)

^hThe factor difference between an adult insect and the larva (a mealworm is the larva of the mealworm beetle) was assumed to equal that of a zebrafish, which is a factor of 10: a larval zebrafish has 100,000 neurons (Naumann et al. 2010), while an adult zebrafish has 1 million neurons (Alivisatos et al. 2012)