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!

Buzzing away: are insects on the verge of global extinction?

It's odd how some of these posts get initiated. For this particular one, there were two driving factors. One was passing a new house on my way to work where apart from the concrete driveway, the front garden consisted solely of a large square of artificial grass; the owners are clearly not nature lovers! The second inspiration was listening to a BBC Radio comedy quiz show, in which the panel discussed the recent report on global insect decline without being able to explain why this is important, apart from a vague mention of pollination.

Insect biologists have long sung the praises of these unrewarded miniature heroes, from JBS Haldane's supposed adage about God being "inordinately fond of stars and beetles" to EO Wilson's 1987 speech that described them as "the little things that run the world." In terms of numbers of species and individuals, invertebrates, especially insects, are the great success story of macroscopic life on our planet. So if they are in serious decline, does that spell trouble for Homo sapiens?

The new research claims that one-third of all insect species are currently endangered, extrapolating to wholesale extinction for the class Insecta over the next century. Although the popular press has started using evocative phrases such as "insect genocide" and even "insectageddon", just how accurate are these dramatic claims?

The United Nation's Red List currently describes three hundred insect species as critically endangered and a further seven hundred as vulnerable, but this is a tiny proportion of the total of...well, at lot more, at any rate. One oft-quoted figure is around one million insect species, although entomologists have estimated anywhere from 750,000 up to 30 million, with many species still lacking formal scientific identification. The hyperbole could therefore easily sound like unnecessary scaremongering, until you consider the details.

The new report states that butterflies and caddis flies are suffering the greatest decline, while cockroaches - as anyone who has faced a household infestation of them will know, they are likely to remain around until the end of world - and flies are the least affected orders. So, to paraphrase Monty Python, what have the insects ever done for us?

Pollination is of course of key importance, to both horticulture and un-managed 'wild' environments. Insects are near the base of many food webs; if numbers were much reduced, never mind removed, the impact on the rest of the ecosystem would be catastrophic. With the human population set to top ten billion in thirty years' time, we require ever larger regions of productive land for agriculture. They may be small at an individual level, but arthropods in general total about seventeen times the mass of all us H. sapiens. Insects replenish the soil, as alongside bacteria they break down dead matter and fecal material. So important is this latter function that New Zealand has been trialling non-native dung beetles to aid cattle farmers.

One key way to save fresh water and lessen the generation of the potent greenhouse gas methane is to reduce meat consumption in favour of insect protein. If insects are no longer around, then that will be an additional challenge in reducing environmental degradation. This of course also ignores the fact that insects are already a component in the diet of many developing nations. Last year I wrote about how scientists have been creating advanced materials derived from animals. Again, we are shooting ourselves in the foot if we allow this ready-made molecular library to be destroyed.

What is responsible for this global decline? Perhaps unsurprisingly, it turns out to be the usual suspects. Agricultural chemicals including pesticides have been associated with honey-bee colony collapse disorder (not incidentally, some tests have found honey samples with neonicotinoids - the mostly widely-used insecticides - exceeding the recommended human dosage) so clearly the same culprit is affecting other insects. Fresh waterways, home to many aquatic insect species, are frequently as polluted as the soil, either due to agricultural run-off or industrial contaminants. Wild landscapes are being converted with great haste into farm land and urban sprawl, with an obviously much-reduced biota.

Climate change is playing its part, with soil acidity increasing just as it is in the oceans. Even areas as remote as central Australia have seen marked decreases in insects as higher temperatures and lower rainfall outpaces the ability to adapt to the new conditions. I've often mentioned the role of invasive species in the decimation of indigenous vertebrates, but insects are equally prone to suffer from the arrival of newcomers. Although New Zealand has very strict biosecurity protocols, the likes of Queensland fruit flies and brown marmorated stink bugs are still occasionally found in or around ports of entry.

Many nations have no such procedures in place, resulting in local species being out-competed or killed by introduced species or pathogens to which they have no resistance. Until fairly recently, even New Zealand had a lax attitude to the issue, resulting in the decline of native species such as carabid beetles. When I conducted a brief survey of my garden in 2017 I found that one-third of the insect species were non-native, most of these being accidental imports since the arrival of European settlers.

If insects are so vital to our survival, why has there been so little interest in their well-being? There are some fairly obvious suggestions here. Firstly, at least in Western cultures, insects have been deemed dirty, ugly things that can be killed without a second thought. Wasps, ants and cockroaches in particular are seen in this light of being unwelcome pests, with typical insect-related phrases including "creepy crawlies" and "don't let the bed bugs bite".

It's fairly well-known that malaria-carrying mosquitoes are the most dangerous animals for us humans in terms of fatalities. The widespread outbreaks of the Zika virus haven't done them any favours either. As Brian Cox's television series Wonders of Life showed, their small size has given them veritable super powers compared to us lumbering mammals, from climbing up sheer surfaces (as a praying mantis was doing a few nights' ago on my window) to having amazing strength-to-weight ratios. All in all, insects are a bit too alien for their own good!

Clearly, scale prejudice is also a key factor. On a recent trip to Auckland Central Library I only found one book on insects versus dozens on birds. Photographic technology has been a double-edged sword when it comes to giving us a clearer picture of insects: close-ups are often greeted with revulsion, yet until Sir David Attenborough's 2005 BBC series Life in the Undergrowth, there was little attempt to film their behaviour with the same level of detail as say, the lions and antelopes of the Serengeti. It should also be mentioned that when Rachel Carson's ground-breaking book about the dangers of pesticides, Silent Spring, was published in 1962, the resulting environmentalism was largely in support of birds rather than insects.

Among all this doom and gloom, are there any ways to prevent it? One thing is for certain, and that is that it won't be easy. The agricultural sector would have to make drastic changes for a start, becoming much smarter in the use of chemicals and be held responsible for the local environment, including waterways. Vertical farming and other novel techniques could reduce the need for new agricultural land and water usage, but developing nations would be hard-pressed to fund these themselves.

Before any major undertaking, there's going to have to be either a fundamental crisis, such as food shortages, in a rich nation or a massive public relations exercise to convince people to consider insects in the same light as giant pandas or dolphins. This is not going to be easy, but as David Attenborough put it: "These small creatures are within a few inches of our feet, wherever we go on land - but often, they're disregarded. We would do very well to remember them."