The honeybee study caused eyebrows not only because it revealed that an animal with less than one million neurons (compared to the human brain's 86 billion), could consider zero as a quantity but also because bees evolved 600 million years ago from mammals. Avargus Weber stated that their last common ancestor could not even perceive numbers. Nieder, who wasn't involved in the insect work, said that this meant that the ability to grasp numbers and the empty set evolved independently within the two lineages.HaDi MaBouDi from the University of Sheffield, England, stated that a completely different neural substrate was responsible for such high cognitive ability. Researchers have not been able to study honeybees' neural activity as they complete numerical tasks. This makes it difficult for researchers to compare their representations to zero with monkeys. Scientists realized that they needed to study the brain of another animal to find out how and why the ability not to quantify anything evolved.Parallel HistoryNieder and his team then turned to crows. They have had no ancestors with primates in more than 300 million year and have evolved very different brains. Nieder explained that birds do not possess a prefrontal cortex. Instead, they have their own intelligence brain centres with a unique structure, wiring, and developmental trajectory.However, the researchers discovered a familiar numerical understanding about zero. The crows were more likely to mix up blank screens with images of one dot than images of three, four, or five dots. The brain activity of the crows during these tasks was recorded and revealed that neurons in their pallium, a part of their brain, represented zero along with other numerosities. This is similar to what is found in primate prefrontal cortex. Nieder stated that this is a natural result from a physiological standpoint. The crow brain and the monkey brain show exactly the same responses.The same neural framework can be explained in different brains because it is an efficient solution for a common computational problem. It's exciting because it suggests that this is the best way to solve a common computational problem, Avargus Weber stated. There may be physical or other limitations on the brain's ability to process zero and other numerosities. Vallortigara stated that there may be very few ways to encode numbers.However, just because monkeys and crows encode an abstract concept such as zero in the same manner does not necessarily mean it is the only way. Vallortigara suggested that it could be possible that other solutions were discovered during natural history and biological evolution to perform similar computations. To find out, researchers will need to study animals. For instance, Vallortigara's colleagues discovered a brain area in Zebra Fish that correlates with numerosity in a paper published in Cerebral Cortex. However, they have not yet tested whether the animal can assess zero.As the foundation of their numerosity is better understood, bees may also have some surprises. MaBouDi and colleagues published a study last year that showed that the bumblebees count by a fundamentally different strategy when they are presented with four objects. Their findings suggest that honeybees might have different mechanisms than what has been previously observed.Perhaps the most fundamental question about numerical abstraction in brains of different animals is not how it works, but why it exists. Why is it necessary for animals to be able to recognize certain quantities? Evolution has repeatedly ensured that animals understand that four is less that five and that four squares are conceptually equal to four circles.Vallortigara believes that one reason could be because arithmetic is so important. Arithmetic is a constant task for animals. He said that even simple animals can do arithmetic. It is possible to abstract numerosity information so that the brain can perform more efficient computations.This is where zero might fit in. The area will remain dangerous if there are two predators in the environment, and one leaves. Rugani suggests that animals must be able subtract in such situations. However, they also need to be able interpret zero as the result a previously performed numerical subtraction. This can then be associated with specific environmental conditions. Rugani stated that the environment is safe when you get to zero. Zero can indicate a need for foraging in another location when searching for food.Nieder isn't convinced. Nieder isn't convinced. He says there's no pressing need for animals not to understand zero. However, he believes that it should be enough to see it as an absence. He said that he doesn't believe animals use numerosity zero in their daily lives.Another possibility is that a greater understanding of numerosity and zero could have resulted from the brain's ability to recognize visual objects within the environment. Nieder and his associates trained an artificial network to recognize objects within images in 2019, and the ability to distinguish numbers of items was born spontaneously. This could have been a result of that more general task.A glimpse at Maths Building BlocksNieder believes that the existence of abilities for numerical abstraction in animals may indicate that something is already in place that could be used as an evolutionary basis for understanding zero.He stressed that while the animal's achievements are impressive, there are important differences between how animals and humans conceptualize numerosity. We don't just understand quantities, we also link them to arbitrary numerical symbols. Nieder stated that a set of five objects does not equal the number 5. The empty set does not equal 0.Dyer stated that even though animals can associate three items with 3 with the symbol 2, it doesn't mean that they can put these symbols together to get 5 + 2. This is a trivial mathematical problem that an elementary school student can solve, but experiments to test this kind of symbolic reasoning in animals have not been done.Humans have taken this step beyond numerosity, creating a symbolic system for enumeration. They can now develop a more precise concept of number, manipulate numbers according to specific rules and create an entire science around mathematics.Nieder hopes his research on zero will help to show how an abstract sense might emerge from a more practical and approximate one. His current research focuses on the relationship between symbolic and non-symbolic numbers.Butterworth, Vallortigara and other colleagues are currently working with Caroline Brennan, Queen Mary University of London's molecular geneticist, to discover the genetic mechanisms that underlie numerical ability. They have identified genes associated with dyscalculia (a math learning disability) in humans and are now manipulating similar genes in zebrafish. Vallortigara stated that genetics is the most important part of the story. It would be truly a breakthrough to identify genes that are number-related.
