My family & other animals: what is it that makes Homo sapiens unique?

It's a curious thing, but I can't recall ever having come across a comprehensive assessment of what differentiates Homo sapiens from all other animals. Hence this post is a brief examination on what I have found out over the years. I originally thought of dividing it into three neat sections, but quickly discovered that this would be, as Richard Dawkins once put it, 'a gratuitously manufactured discontinuity in a continuous reality.' In fact, I found a reasonably smooth gradation between these segments:

1. Long-held differences now found to be false
2. Possibly distinctions - but with caveats
3. Uniquely human traits

Despite the carefully-observed, animal-centered stories of early civilisations - Aesop's fable of The Crow and the Pitcher springs to mind - the conventional wisdom until recently was that animals are primarily automatons and as such readily exploitable by humanity. Other animals were deemed vastly inferior to us by a question of kind, not just degree, with a complete lack of awareness of themselves as individuals.

The mirror test developed in 1970 has disproved that for a range of animals, from the great apes to elephants, dolphins to New Caledonian crows. Therefore, individuals of some species can differentiate themselves from their kin, leading to complex and fluid hierarchies within groups - and in the case of primates, some highly Machiavellian behaviour.

Man the tool-maker has been a stalwart example of humanity's uniqueness, but a wide range of animals in addition to the usual suspects (i.e. great apes, dolphins and Corvidae birds) are now known to make and use tools on a regular basis. Examples include sea otters, fish, elephants, and numerous bird species, the latter creating everything from fish bait to insect probes. Even octopuses are known to construct fences and shelters, such as stacking coconut shells - but then they do have eight ancillary brains in addition to the main one!

We recognise regional variations in human societies as the result of culture, but some animal species also have geographically-differentiated traits or tools that are the obvious equivalent. Chimpanzees are well known for their variety of techniques used in obtaining food or making tools. These skills are handed down through the generations, remaining different to those used in neighbouring groups.

Interestingly, farming has really only been adopted by the most humble of organisms, namely the social insects. Ants and termites farm aphids and fungi in their complex, air-conditioned cities that have more than a touch of Aldous Huxley's Brave New World about them; in a few species, the colonies may even largely consist of clones!

Although many animals construct nests, tunnels, dams, islets or mounds, these appear to serve purely functional purposes: there is no equivalent of the human architectural aesthetic. Octopus constructions aside, birds for example will always build a structure that resembles the same blueprint used by the rest of their kind.

Many species communicate by aural, gestural or pheremonal languages, but only humans can store information outside of the body and across generations living at different times. Bird song might sound pretty, but again, this appears to be a series of basic, hard-wired, communications. Conversely, humpback whale song may contain artistic values but we just don't know enough about it to judge it in this light.

Birds and monkeys are happy to hoard interesting objects, but there is little aesthetic sense in animals other than that required to identify a high-quality mate. In contrast, there is evidence to suggest that other species in the hominin line, such as Neanderthals and Homo erectus, created art in forms recognisable today, including geometric engravings and jewellery.

Some of our ancestor's earliest artworks are realistic representations, whereas when armed with a paint brush, captive chimps and elephants produce abstract work reminiscent of pre-school children. We should remember that only since the start of the Twentieth Century has abstract art become an acceptable form for professional artists.

Jane Goodall's research on the Gombe chimps shows that humans are not the only animal to fight and kill members of the same species for reasons other than predation or rivalry. Sustained group conflict may be on a smaller scale and have less rules than sanctioned warfare, but it still has enough similarity to our own violence to say that humanity is not its sole perpetrator. One interesting point is that although chimps have been known to use sharpened sticks to spear prey, they haven't as yet used their weapons on each other.

Chimpanzees again have been shown to empathise with other members of their group, for example after the death of a close relative. Altruism has also been observed in the wild, but research suggests there is frequently another motive involved as part of a long-term strategy. This is countered with the notion that humans are deemed able to offer support without the expectation of profit or gain in the future; then again, what percentage of such interactions are due to a profitless motivation is open to suggestion.

A tricky area is to speculate on the uniqueness of ritual to Homo sapiens. While we may have usurped the alpha male position in domesticated species such as dogs, their devotion and loyalty seems too far from deity worship to be a useful comparison; certainly the idea of organised religion has to be alien to all other species? Archaeological evidence shows what appears to be Neanderthal rituals centred on cave bears, as well as funereal rites, but the DNA evidence for interbreeding with modern humans doesn't give enough separation to allow religion to be seen as anything other than a human invention. What is probably true though is that we are the only species aware of our own mortality.

One area in which humans used to be deemed sole practitioners is abstract thought, but even here there is evidence that the great apes have some capability, albeit no greater than that of a pre-schooler. Common chimps and bonobos raised in captivity have learnt - in some cases by observation, rather than being directly taught - how to use sign language or lexigrams to represent objects and basic grammar. It's one thing to see a button with a banana on it and to learn that pressing it produces a banana, but to receive the same reward for pressing an abstract symbol shows a deeper understanding of relationship and causality.

A consideration of a potential future is also shared with birds of the Corvidae family, who are able to plan several steps ahead. Where humans are clearly far ahead is due to a gain in degree rather than just kind. Namely, we have the ability to consider numerous future paths and act accordingly; this level of sophistication and branch analysis appears to be uniquely human, allowing us to cogitate about possibilities in the future that might occur - or may never be possible. Both prose and poetic literature are likely to be uniquely human; at least until we can decipher humpback whale song.

Finally, there is science, possibly the greatest of human inventions. The multifarious aspects of the scientific endeavour, from tentative hypothesis to experimentation, advanced mathematics to working theory, are unlikely to be understood let alone attempted by any other species. The combination of creative and critical thinking, rigour and repetition, and objectivity and analysis require the most sophisticated object in the known universe, the human brain. That's not to say there aren't far more intelligent beings out there somewhere, but for now there is one clear activity that defines us as unique. And thank goodness it isn't war!

New neurons: astrocytes, gene therapy and the public fear of brain modification

Ever since the first cyberpunk novels of the early 1980s - and the massive increase of public awareness in the genre thanks to Hollywood - the idea of artificially-enhanced humans has been a topic of intense discussion. Either via direct augmentation of the brain or the development of a brain-computer interface (BCI), the notion of Homo superior has been associated with a dystopian near-future that owes much to Aldous Huxley's Brave New World. After reading about current research into repairing damaged areas of the brain and spinal cord, I thought it would be good to examine this darkly-tinged area.

Back in 2009 I posted about how science fiction has to some extent been confused with science fact, which coupled with the fairly appalling quality of much mainstream media coverage of science stories, has led to public fear where none is necessary and a lack of concern where there should be heaps. When it comes to anything suggestive of enhancing the mind, many people immediately fall back on pessimistic fictional examples, from Frankenstein to Star Trek's the Borg. This use of anti-scientific material in the consideration of real-world STEM is not an optimal response, to say the least.

Rather than working to augment normal humans, real research projects on the brain are usually funded on the basis that they will generate improved medical techniques for individuals with brain or spinal cord injuries. However, a combination of the fictional tropes mentioned above and the plethora of internet-disseminated conspiracy theories, usually concerning alleged secret military projects, have caused the public to concentrate on entirely the wrong aspects.

The most recent material I have read concerning cutting-edge work on the brain covers three teams' use of astrocytes to repair damaged areas. This is an alternative to converting induced pluripotent stem cells (iPSCs) to nerve cells, which has shown promise for many other types of cell. Astrocytes are amazing things, able to connect with several million synapses. Apparently Einstein's brain had far more of them than usual in the region connected with mathematical thinking. The big question would be whether this accumulation was due to nature or nurture, the latter being the high level of exercise Einstein demanded of this region of his brain.

Astrocyte research for brain and spinal cord repair has been ongoing since the 1990s, in order to discover if they can be reprogrammed as functional replacements for lost neurons without any side effects. To this end, mice have been deliberately brain-damaged and then attempts made to repair that damage via converted astrocytes. The intention is to study if stroke victims could be cured via this method, although there are hopes that eventually it may also be a solution for Parkinson's disease, Alzheimer's and even ALS (motor neurone disease). The conversion from astrocyte to neuron is courtesy of a virus that introduces the relevant DNA, although none of the research has as yet proven that the converted cells are fully functional neurons.

Therefore, it would seem we are some decades away from claiming that genetic manipulation can cure brain-impairing diseases. But geneticists must share some of the blame for giving the public the wrong impression. The hyperbole surrounding the Human Genome Project gave both public and medical workers a false sense of optimism regarding the outcome of the genome mapping. In the late 1990s, a pioneer gene therapist predicted that by 2020 virtually every disease would include gene therapy as part of the treatment. We are only just over a year short of this date, but most research is still in first phase trial - and only concern diseases that don't have a conventional cure. It turned out that the mapping was just the simplest stage of a multi-part programme to understand the complexities of which genes code for which disorders.

Meanwhile, gene expression in the form of epigenetics has inspired a large and extremely lucrative wave of pseudo-scientific quackery that belongs in the same genre as homeopathy, crystal healing and all the other New Age flim-flam that uses real scientific terminology to part the gullible from their cash. The poor standard of science education outside of schools (and in many regions, probably within them too) has led to the belief that changing your lifestyle can fix genetic defects or affect cures of serious brain-based illnesses.

Alas, although gene expression can be affected by environmental influences, we are ultimately at the mercy of what we inherited from our parents. Until the astrocyte research has been verified, or a stem cell solution found, the terrible truth is that the victims of strokes and other brain-based maladies must rely upon established medical treatments.

This isn't to say that we may in some cases be able to reduce or postpone the risk with a better lifestyle; diet and exercise (of both the body and brain) are clearly important, but they won't work miracles. We need to wait for the outcome of the current research into astrocytes and iPSCs to find out if the human brain can be repaired after devastating attacks from within or without. Somehow I doubt that Homo superior is waiting round the corner, ready to take over the world from us unenhanced humans…

Animal farm: agricultural revolutions happening in your own garden

Various forms of symbiosis - the mutual interactions between species - have long been recognised, not least the hundreds of microorganisms that co-exist within and upon us Homo sapiens. But going beyond mere symbiosis, there appear to be examples of interactions between species that are nothing less than astonishing. Following a recent spate of television documentaries on the Neolithic period, the time when humans started to farm first animals and then crops, it seemed a good excuse to look at examples of other animals that also farm. Although mostly restricted to arable farmers (technically speaking, fungi culturists) there is also one fascinating case of pastoralism.

The best-known examples are probably insects, with many species of leaf-cutter ant and termites known to farm strains of fungi as a food source. It has been assumed (although I’m not sure on what basis, since farming activity would presumably be invisible to the fossil record) that these insects developed their sophisticated social structures, including caste systems, prior to the adoption of farming. This is the direct reverse of the earliest human farmers, wherein the earliest cities of the Near East, for example, arose after livestock domestication. It’s difficult to see how insects started the process and raises the interesting question of whether it offers the farming species any superiority over non-farmers of similar genera. After all, in human cultures it appears that early farmers had to work far harder for their daily bread than the gatherer-hunters who preceded them, the latter being a way of life that continues in isolated pockets even to this day. So it may not be an improvement on non-farming lifestyles - just different. Another nail in the coffin for any followers of the Victorian notion of progress…

Staying with insects, a diverse group of over three thousand beetles cultivate the ambrosia fungus for food, in a relationship thought to stretch back tens of millions of years. Unlike ants and termites, these beetle species do not all live in large, strictly-organised colonies. Heading for wetter environments, marsh snails have also been found to cultivate fungus that is ‘sown’ from spores embedded in their own excrement! Then in the water itself, some species of damselfish farm algae on the remnants of coral they have themselves killed, a process that bares a striking resemblance to Amazonian deforestation for cattle ranching. Unfortunately, the fishing by humans of damselfish predators has had the effect of aiding the population of fishy farmers and thus only increased the rate of coral loss.

Finally, the pastoralist in the pack, our everyday common or garden ant. In a bizarre simulcrum of dairy farming, some ant species control, supervise and ‘milk’ aphids. Had the species involved been more cuddly (i.e. one of us mammals) then it might have seemed all the more astonishing – a real-life antidote to Beatrix Potter-esque anthropomorphism. As it is these genuine animal farmers, with individual brains weighing a few thousandths of a gram, will drug aphids, protect them from predators and bad weather, and even use biochemicals to affect their growth patterns. And all in return for the honeydew they extract from the aphids.

You may have noticed the use of very human activities in these descriptions: domestication; caste systems; protection, etc. We are only just beginning to understand the behavioural diversity to found amongst other species, only to find we are continuously removing yet more barriers that differentiate ourselves from the rest of the biosphere. It is tempting to suggest this last example of animal farmers includes a form of slavery, with drug-controlled drones and just a whif of Brave New World. If these examples of non-human farmers were found on another planet, would we possibly consider it to be a sign, incredibly alien to be sure, of intelligence? Clearly, the brain size of the individuals involved doesn’t count for much, but a colony of 40,000 ants has the collective number of brain cells of one human. If the ants were able to store information in chemical signatures, something akin to a library, then wouldn’t this be a form of hive mind? Speculative nonsense of course, but does anyone remember the 1970’s film Phase IV?

It’s difficult to be anything other than dumbfounded as we learn more about animal behaviour, especially at what seems to be a programmed/non-conscious level. If the permutations are like this on Earth, the possibilities on other worlds are seemingly limitless. Again, this questions whether we could even recognise whether another species is intelligent or not. Perhaps Douglas Adams put it best: "Man has always assumed that he was more intelligent than dolphins because he had achieved so much...the wheel, New York, wars and so on...while all the dolphins had ever done was muck about in the water having a good time. But conversely, the dolphins had always believed that they were far more intelligent than man...for precisely the same reason."

Enough said!