来源：《新科学家》
原文刊登日期：2021年7月7日
Consciousness has deep origins and appears to have evolved several times. This alone suggests that it must provide important benefits when it comes to survival. But what might these be?
意识有很深的起源，而且似乎已经进化了好几次。仅这一点就表明，当涉及到生存时，它必须提供重要的好处。但好处可能是什么呢？
Biologists hadn’t grappled with this question until quite recently. Many of those who are now considering it, think one probable answer is flexibility of behaviour. “We are better able to react to the contents of the conscious mind, as opposed to the unconscious content that will usually trigger automatic reflex-like responses,” says Andreas Nieder at the University of Tübingen, Germany. Being conscious also offers a way to evaluate the world – through feelings that make an individual aware of whether something is good or bad. And consciousness entails selective attention, which allows the brain to focus its processing activity on what is most important.
直到最近，生物学家才开始解决这个问题。许多正在考虑这个问题的人认为，一个可能的答案是行为的灵活性。德国Tübingen大学的安德烈亚斯·尼德说：“相对于通常会引发自动反射式反应的无意识内容，我们更能对有意识的内容做出反应。”有意识也提供了一种评估世界的方式——通过让个体意识到某事是好是坏的感觉。意识需要有选择性的注意，这使得大脑将处理活动集中在最重要的事情上。
As a result of all this, instead of reacting in set ways to given stimuli, conscious animals can make complex decisions. “That would be a survival benefit that helps an individual, and then the entire species, to survive better in the changing world,” says Nieder.
因此，有意识的动物可以做出复杂的决定，而不是对给定的刺激做出固定的反应。尼德说:“这对个体和整个物种来说都是一种生存益处，可以帮助它们在不断变化的世界中更好地生存下去。”
Greater behavioural flexibility also fits with the idea that consciousness is associated with a particular type of thinking called unlimited associative learning – the ability to combine multiple cues into a single perception. This allows animals to respond flexibly to the challenges they face, rather than relying on hardwired behaviours. It means, for instance, that they can better discriminate between a healthy and a poisonous source of food based on small perceptual differences. “Associative learning is one of the greatest adaptations on the planet,” says Eva Jablonka at Tel Aviv University in Israel.
更大的行为灵活性也符合这样一种观点，即意识与一种被称为无限联想学习的特殊思维方式有关——这种能力将多个线索结合成一个单一的感知。这使得动物能够灵活地应对它们面临的挑战，而不是依赖于固有的行为。例如，这意味着他们可以根据细微的感知差异，更好地区分健康和有毒的食物来源。“联想学习是这个星球上最伟大的适应之一，”以色列特拉维夫大学的伊娃·雅布隆卡说。
According to Jablonka and Simona Ginsburg at the Open University of Israel, consciousness first emerged around 530 million years ago and the resulting behavioural complexity it brought had huge knock-on effects. It created greater competition among species, driving the rapid diversification of animal species known as the Cambrian explosion. Predators, for example, would have been better at detecting their prey, which, in turn, would have needed to find new ways to avoid detection – pushing the predators to become even more sophisticated in their strategies. “There is a kind of ongoing co-evolutionary arms race,” says Jablonka.
根据以色列开放大学的Jablonka和Ginsburg的研究，意识首次出现在大约5亿3000万年前，由此产生的行为复杂性产生了巨大的连锁反应。它造成了物种间更大的竞争，推动了被称为寒武纪大爆发的动物物种迅速多样化。例如，捕食者更善于发现他们的猎物，反过来，猎物也需要找到新的方法来避免被发现——这使得捕食者的策略更加复杂。“这是一种正在进行的共同进化军备竞赛，”雅布隆卡说。
But the emergence of consciousness didn’t just allow animals to adopt more complex behaviours. Jablonka suggests that it is responsible for much of the beauty that we see in nature too. It pushed plants to evolve colourful flowers that would stick out from the competition to attract pollinating insects. “It changed the world completely,” she says. “The world would have been a very different place, and a very much more boring place, without consciousness.”
但意识的出现并不只是让动物采取更复杂的行为。雅布隆卡认为，我们在自然界中看到的许多美丽也是由它造成的。它促使植物进化出五颜六色的花朵，从而在吸引授粉昆虫的竞争中脱颖而出。“意识彻底改变了世界，”她说。“如果没有意识，世界将会是一个非常不同的地方，一个非常无聊的地方。”