Once life is established, is the evolution of intelligence inevitable?
Guy Cox
Sydney, Australia
Advertisement
It seems pretty possible that life could arise in an environment where it would remain at the level of bacteria. They can survive almost anywhere, as they do in extreme environments on Earth, and quite possibly did on Mars. It is only when complex life forms evolve and compete for resources that intelligence becomes either possible or advantageous.
Pat French
Longdon upon Tern, Shropshire, UK
This is a difficult question to answer, as we are only aware of a single example of life emerging, found under a single set of conditions and that is defined by the subject of the enquiry, i.e. us.
Unicellular organisms existed for billions of years without much change. It would appear that the merging of two single-celled organisms to create the first multicellular organism only happened four times as far as we are aware. However, after that momentous accident, evolution accelerated and then diversified exponentially in the event known as the Cambrian explosion.
If we assume that some form of brain is required for intelligence to exist, then the answer to the question must be: no, intelligence isn鈥檛 inevitable, because single-celled life won鈥檛 necessarily evolve the required brain. The multi-cell accident may never happen.
Whether or not it is inevitable that multicellular life develops intelligence is unknowable so long as only one example, under one set of conditions, is known to us.
Hillary Shaw
Newport, Shropshire, UK
Firstly, what is 鈥渋ntelligence鈥�? A car could be programmed to use its sensors to avoid all obstacles, thereby protecting its owner, who maintains it. This might look 鈥渋ntelligent鈥�, but surely isn鈥檛.
Secondly, just because an attribute is useful doesn鈥檛 mean it will be created by the random mutations we call evolution: it might be useful for spiders to fly, but they don鈥檛. Organisms are also largely ignorant of their wider environment (this seems to include many humans) and will breed up to the limits of their habitat, at which point something like intelligence may provide a competitive edge in avoiding starvation. Or another mutation may open up a new, abundant food source. Intelligence may then be an unnecessary luxury and be lost, so have to be repeatedly re-evolved.
Alex McDowell
London, UK
Intelligence helps animals both hunt and evade predators. Hence its evolution is inevitable once animal life is established.
The inevitability of its evolution is demonstrated by the fact that it is found in humans, dolphins and octopuses, despite these animals being so distantly related. It has evolved twice in humans: Neanderthals and Homo sapiens both evolved to be more intelligent than their common ancestor Homo heidelbergensis.
Don Lim
Bangkok, Thailand
I think human intelligence is just an efficient set of biological algorithms that happens mostly through interactions of neurons. In the case of artificial intelligence, biological algorithms are re-enacted with electronic parts, such as transistor logic gates. This ensures maximum energy efficiency.
Anything that saves energy will be selected and proliferate, whether it is a physical structure of molecules or a logical process. It is the same in terms of predicting the most probable outcome and consequences in accordance with the information stored in memory. Intelligence is just a group of logical and conceptual processes, rather than a physical feature, like a wing, that evolves and gets selected for.
Once you have several intelligent individuals in a species, there might be a new pressure to outsmart them among others. This may accelerate the evolution of intelligence. We see this with companies developing artificial intelligence, which constantly have to come up with smarter models in order to survive.
In short, intelligence, just like any physical feature, saves energy and maximises the probability of survival. Therefore it is inevitable that more and more efficient information storage and processing mechanisms will take over. When these mechanisms become complex enough, they get to be called intelligence.
Will Higgs
Gilsland, Northumbria, UK
The question of the probability (and advisability!) of the development of intelligence has been succinctly addressed by the band Everything Everything. Their track Distant Past, warning of a post-apocalyptic return to the Stone Age, contains the immortal line: 鈥淭wo thumbs, I cross the Rubicon鈥�. In other words, an opposable thumb condemns us to destroy our environment.
To answer this question 鈥� or ask a new one 鈥� email lastword@newscientist.com.
Questions should be scientific enquiries about everyday phenomena, and both questions and answers should be concise. We reserve the right to edit items for clarity and style. Please include a postal address, daytime telephone number and email address.
New Scientist Ltd retains total editorial control over the published content and reserves all rights to reuse question and answer material that has been submitted by readers in any medium or in any format.
听