- LIFE: the nature of it
- We are made of Star Stuff and Earth Stuff
- The biggest polluter was the ancestor of us all
- The genome is beyond metaphor
- The genome is a mess
- Genes can appear without being inherited
- The genome is not destiny
- Evolution is consistent with the second law of thermodynamics
- Meanings in life are beyond us
- Male-Female, not the ultimate polarity
- You are a community and an ecosystem
- Most of you is not that old really
- SIMILARITIES to other animals
- DIFFERENCES to other animals
- Language divides humans but unites animals
- We shed tears of emotion
- Humans play more
- Humans are introspective because we are social – metacognition and mindfulness
- Humans are more scientific – categorising
- Humans like rules
- Humans are clandestine about sex
- Humans gossip and give gifts
- Humans make fire and cook food
- Only humans have a middle age
- We are long distance runners and throwers, unlike other primates
- Culture more than genes makes humans different from chimps
LIFE the nature of it
“Perhaps the greatest strength of science is to unveil otherwise hidden connections between seemingly disparate phenomena, changing our perspective on our place in the universe.” (Lawrence Krauss ‘Celebrate evolution as only star children can’ p23 New Sci 21 Feb 2009)
“Billions of years ago, a tiny cyanobacterium cracked open a water molecule – and let loose a poison that wrought death and destruction on an epic scale. The microbe had just perfected photosynthesis, a process that freed the oxygen trapped inside water and killed early Earth’s anaerobic inhabitants.”
“This was the biggest change that ever occurred in the biosphere,” says Kevin Redding at ArizonaStateUniversity in Tempe. “The extinction caused by oxygen was probably the largest ever seen, but at the same time animal life wouldn’t be possible without oxygen.”
(Colin Barras ‘Captured: moment life changed forever’ p12 New Sci 8 Dec 2012)
The human genome as a blueprint metaphor and others are flawed and misleading.
“Yet we still don’t have a metaphor that communicates what DNA is all about to those without a background in biology.”
“The Nobel prizewinning biologist David Baltimore has suggested DNA is “a reality beyond metaphor”.”
“Every discovery reveals a new complexity. We now know, for example, that each gene produces not one protein, but an average of 5.7 molecules of various kinds.”
“DNA: the web which spins the spider.” Trevor Spencer Rines
(Stephen Strauss ‘Beyond the double helix’ p22 New Sci 21 Feb 2009)
“Nobody’s perfect. Even healthy people have at least 400 faulty genes, including a few that could lead to life-threatening diseases.”
(In Brief ‘Deep down, we’re all faulty mutants’ p19 New Sci 15 Dec 2012)
“At least 1 in 10 people have some kind of debilitating genetic disease, and most of us will become sick as a result of mutations that cause diseases such as cancer.”
“The reason? Our genome is an unmitigated mess. The replication and repair mechanisms are inadequate, making mutations commonplace. The genome is infested with parasitic DNA that often wreaks havoc. The control mechanisms are prone to error. The huge amount of junk, both between genes and within them, wastes cellular resources.”
(Michael le Page ‘A caring god would not have designed us like this’ p45 New Sci Feb 2010)
“When biologists began sequencing genomes, they discovered that up to a third of genes in each species seemed to have no parents or family of any kind.”
Anne-Ruxandra Carvunis of the University of California, San Deigo, “thinks there is a whole continuum of “proto-genes”. Most will code for proteins that are neutral or harmful, so there will be no selection and the vast majority of proto-genes will revert to non-coding DNA sooner or later. But a few proto-genes that are neutral or maybe even helpful will persist, and start to gather beneficial mutations. Over millions of years of natural selection, they can become a proper gene – and thus is an orphan born.”
(Helen Pilcher ‘All alone’ p40-43 New Sci 19 Jan 2013)
A single gene does not have one single affect. Also genes are activated by ‘switches’ in the genome triggered by environment and the things we decide to do. More than 95 per cent of the genome may lie within 10,000 base pairs of a switch. “It means that nearly all of the genome is in play for something, or if you change it maybe it would an effect on something somewhere,” Birney says.”
“Part of this complexity comes from the many ways in which our genome interacts with the environment. “I think DNA will become more predictive, but the flip side of this research is understanding how much of complex traits are due to environmental effects, or free will – things that we can change,” says Birney. “DNA is not destiny.””
Ewan Birney of the European Bioinformatics Institute in Cambridge UK.
(Who by ? ‘Unfathomable’ p41-43 New Sci 8 Sep 2012)
If evolution is an random process selecting the best fittest for different environmental niches why does so much complexity appear? Does this not contradict the second law of thermodynamics?
“Perhaps we are only an afterthought, a kind of cosmic accident, just one bauble on the Christmas tree of evolution.” Stephen Jay Gould.
“John Smart, a member of the evolution, complexity, and cognition research group at the Free University of Brussels in Belgium and a leading thinker in this field, argues that evolution and development can be reconciled. That is, it will be possible to define progress in objective terms and explain why it must happen. The case laid out by Smart and other theorists is based on at least FOUR arguments.”
ONE. Eric Chaisson, Harvard University looks at the issue in terms of “energy rate density, a measure of how much energy flow through each gram of a system per second” new definition of complexity. “A star, for all its spectacular output, has a much lower energy rate density (2 ergs per gram per second) than a house plant (3000 to 6000 ergs per gram per second). This sounds counter-intuitive until you remember that stars are just balls of gas.”
“Chaisson argues that energy rate density is a universal measure of the complexity of all ordered systems, from planets and starts to animals and societies.” Plotted on a graph these show an increase in complexity over time.
TWO. Thermodynamics. J. Miguel Rubi of the University of Barcelona in Spain says “strictly speaking, the second law of thermodynamics applies only to systems in equilibrium, a state in which nothing changes. This condition is rarely present in the universe. Earth, for example, is heated by the sun, creating energy gradients on its surface (Scientific American, vol. 299, p62). Where an energy gradient exists, pockets of complexity can arise even as the system as a whole decays into disorder. These pockets provided a foothold for further increases in complexity. Energy gradients thus provide a loophole in the second law that permits life to arise and ascend.”
THREE. Convergent evolution describes when “very different species living in similar environments have independently evolved in similar ways.” Kevin Kelly author of ‘What Technology Wants’, “Gives numerous examples of convergent evolution to support his argument that the outcomes of evolution – of which he considers technology one – are not accidental.” They are inevitable, such as wings.
“While primates and crows are far apart on the evolutionary tree and have very different brain structures, they have independently evolved similar kinds of cognition, including tool use, deception and complex social groupings. The implication, again, is that intelligence always emerges in favourable conditions.”
FOUR Catastrophes, “delay or accelerate the development process they do not significantly change it.” “Development, unlike evolution, has a direction…And while the outcome is not fully determined, it is powerfully constrained. Direction and constraint, however, do not imply design and purpose.” The physical laws set boundaries on the possible for life.
“Far from being “just one bauble”, we would have an explicable, even inevitable, place in the order of things.”
(Michael Chorost ‘The Ascent of Life’ p35-37 New Sci 1 Jan 2012)
“We may do better to stop thinking about the biological world solely in terms of its physical and chemical properties, but see it also as a world made up of biological signs and ‘meanings’.”
“Bio-semiotics is the study of the myriad forms of communications… observable both within and between living systems. It is thus the study of representation, meaning, sense, and the biological significance of sign processes – from intercellular signalling processes to animal display behaviour to humans… artefacts such as language and abstract thought.” says Donald Favareau of the National University of Singapore.
“Each animal in the meadow lived in “its own world filled with perceptions which it alone knows”. A “subjective perceptual universe”, a “myriad perceptual worlds” this is Jakob von Uexkull’s model of a meadow.
Some worlds are very small. For example that of the tick. “By reacting only to the single odorant of sweat, the tick reduces the countless characteristics of the world of host animals to a simple common denominator in its own world.”
Frederik Stjernfelt of AarhusUniversity in Denmark. “The danger is that biology is trapped in a dualism where all organic communication, from cells to apes, are claimed to be describable as simple physiochemical causes only – while on the other hand, full intentional meaning is a specifically human privilege. How could such a thing have developed phylogenetically, if not from simpler semiotic processes in biology?”
(Liz Else ‘A meadowful of meaning’ p28-31 New Sci 21 Aug 2010)
The natural world is more challenging, alien, complex, beautiful, mysterious and difficult to grasp than culture. Like the tick we are bound by our particular sensory outlook and our metaphors are not up to reality.
“Many invertebrates are hermaphrodites – where they have the advantages of sex and both parties can reproduce. Some reptiles can reproduce asexually and some fish can switch sex when it suits them. The division into males and females is only complete for birds and mammals.”
(Letter from Brain Horton, West Launceston, Tasmania. p37 New Sci 19 Nov 2011)
However, Virgin birth (parthenogenesis) does occur in mammals though it is extremely rare in mammals, and do not occur naturally. But beyond mammals it is much more common. There are also a few all female species. “Altogether, around 90 female only species of fish, amphibians and reptiles have been discovered, but like the molly most still need males of other species to be present.” They survive genome stagnation longer by cheating and stealing DNA. They mate with other species but occasionally incorporate a fragment of DNA. (Helen Pilcher ‘Look, no dad!’ p34-35 New Sci 2 Mar 2013)
“You started life as a single cell. Now you are made of many trillions. There are more cells in your body than there are stars in the galaxy. Every day billions of these cells are replaced. And if you hurt yourself, billions more cells spring up to repair broken blood vessels and make new skin, muscle or even bone.” (Bob Holmes ‘Healing touch: the key to regenerating bodies’ p13 New Sci 16 Feb 2010)
“One aspect of your uniqueness isn’t, strictly speaking, part of you at all. It comes from the 100 trillion bacteria that live both on and in you. They outnumbered the body’s cells 10 to 1 and in genetic terms they are even more dominant: microbes account for 3.3 million genes, compared with your measly 23,000. “You’re 0.7 per cent human,” says Jeremy Nicholson a biochemist at Imperial College London.”
(Caroline Williams “One and only you” p32-36 New Sci 28 July 2012)
Our microbe community is not constant. Our skin microbes get exchanged with work colleagues and other players in contact sports. Changes of light, temperature, air flow and materials changes the community on you too.
(Amy Maxmen “The Great Indoors” p30-31 New Sci 13 July 2013)
The ‘holobiont’ (Eugene Rosenberg, University of Tel Aviv, Israel) is the more than symbiontic community that is you. “Bugs R Us” as Richard Jefferson puts it.
New microbes “can allow the holobiont to adapt quickly to changing circumstances and even acquire new abilities during its lifetime” and thus stimulant more rapid adaptation than changes in the host animals genome.
(Carrie Arnold “The Other You” p31-34 New Sci 12 Jan 2013)
The microbes in the gut also affect our behaviour by producing “chemicals that act on the brain.” This may explain why chronic gut conditions are often linked with mood disorders.
(Jessica Hamzelou ‘Born dirty, with a gutful of bacteria’ p7 New Sci 14 Apr 2012)
A wide range of studies from very different groups of scientist mostly working separately have developed the idea of “the ecological theory of disease”. It has it’s origins in the noticed difference between town and country children. “We can all hold up long lists of species that require other species, their partners and neighbours to survive….The point is public health researchers, medical researchers and doctors don’t think like ecologists.” We are not just part of the eco system our bodies are eco systems, of single celled organisms, only some of which we regarded as our own cells.
Lots of research has been dome into the bad species we need to avoid, but not on the good ones we need to attract and nurture. “The precise melange of beneficial species we need could involve hundreds of thousands of species or more. Those species do not always have names. Recently, I catalogued the species on my body and my house, finding more than 2000 species, most of which experts could not identify. Which ones were good for me? Who knows? What is worse, no one could tell me which good species I might be missing.”
“We have neglected the book of life for so long that at our current rate of research, that without investment in projects larger than any yet imagined, much less implemented, we won’t catch up for hundred of years. Meanwhile, some of the species we are losing from forests and wild lands (or just from our modern lives) could easily be the ones that help to make us whole. If only we knew which ones.”
(Rob Dunn ‘Dig deep for health’ p28-29 New Sci 4 Aug 2012)
Hair on your head = up to 6-7yrs old.
Surface of the skin = up to 2 weeks.
Gut lining = up to 2 or 3 days.
Fat cells = 10yrs old on average.
Heart = less than half of the cells replaced in a lifetime.
And “we spent the first 30 hours of our lives as a single cell.”
(Jessica Hamzelou ‘Many versions of you’ p35-39 New Sci 16 Mar 2013)
SIMILARITIES to other animals
In 1994 Cambridge Declaration on Consciousness was “publicly proclaimed by three eminent neuroscientists, David Edelmen of the Neurosciences Institute in La Jolla, California, Philip Low of Stanford University and Christof Koch of the California Institute of Technology.” It stated that “the weight of evidence indicates that humans are not unique in possessing the neurological substrates that generate consciousness. Non-human animals, including all mammals and birds and many other creatures, including octopuses, also possess these neurological substrates.”
In Francis Crick’s book ‘The Astonishing Hypotheses: the scientific search for the soul’ (1994) he wrote “it is sentimental to idealise animals” and “that for many animals life in captivity is better, longer and less brutal than life in the wild.” [We also generally do better in captivity than we do in the wild.]
(Marc Bekoff ‘Welcome to our world’ p24-25 New Sci 22 Sep 2012)
“An Orang-utan called Kikan acted out an event that had taken place a week before, when my research assistant helped dig a stone sliver from her foot. All Kikan wanted was for the assistant to “listen” to the memory – watch her act it out – because when the assistant had watched her she simply left. She was still an infant, so that’s some mind.” (Glendon College, York University, Toronto, Canada.)
(Liz Else “One minute with… Anne Russon” p25 New Sci 21 Aug 2010)
Friendship in wild chimps has been observed for the first time recently. “The animals had already ruled out the area as a good source of fruit, suggesting they went back just to find him. He had moved on, but rejoined to group six weeks later (Primates, DOI:10.1007/s10329-012-0298-2).”
(Jessica Hamzelou ‘Bonobos go out of their way to rescue friends’ p12 New Sci 10 Mar 2012)
”In all of the great apes except for the chimpanzee, all documented cases of cannibalism are outliers.” David Dellatore, Oxford Brookes University UK.
(Ewen Callaway ‘Cannibal bonobos needed the food’ p14 New Sci 6 Feb 2010)
“They [Bekoff and Pierce] see moral actions as dictated by the behavioural code of social species, the communal operating instructions that bond a group safely together, the “social glue” of survival. They believe such codes are necessarily species-specific and warn against for instance, judging wolf morals by the standards of monkeys, dolphins or humans.”
“In one lab study Diana monkeys, for instance, the animals had to put tokens into a slot to receive their food. When an elderly female couldn’t manage hers, a neighbouring male inserted the tokens for her. In a different kind of experiment, rats refused to push a lever for food when they realised their action meant another animal got an electric shock.”
(Deborah Blum ‘Justice for all’ 44 New Sci 9 May 2009. Review of “Wild Justice: The moral lives of animals” by Mark Bekoff and Jessica Pierce.)
Culture, modelling the thoughts of others, emotions, tool use, morality and personality are all present in the animal kingdom. Also see www.newscientist.com/uniquelyhuman.
(Christine Kenneally ‘So you think you’re unique’ p34-38 New Sci 24 May 2008 )
“It began with cooperation. When life first arose, teams of small molecules got together to perform tasks none could manage alone – or that’s the theory. For the first time networks like this have been built in the lab.” Niles Lehman of Portland State University in Oregon and colleagues “pitted the cooperative network against a selfish, self-repairing molecule, the co-operators won out (Nature, DOI: 10.1038/nature11549).” [And so from groups of molecules, to groups of cells, then groups of animals, to groups of species.]
(Bob Holmes “Teamwork was key to success” p10 New Sci 20 Oct 2012)
Our interactions with wild animals, such as wolves raiding bins, mice in the home and birds at a feeder, lead to them becoming domesticated, but they ‘self-domesticated’, we did not choose to shape their behaviours. There is always selection in the natural environment, but there is not always competition between individuals and species. “Nature is also replete with examples of species evolving to be friendlier, more tolerant and social. In those cases, the ones which are able to survive by being friendly can outcompete those which are less friendly.” We have also unconsciously self-domesticated ourselves. “Selection of friendliness over aggression was what made dogs happen. And in our ape family, it seems that bonobos have been selected to be more friendly. That then makes us look at our own species; does that mean that we have been under selection to be less aggressive and more tolerant? That is how we went from having a dispersed distribution to being able to live in very high density populations since the agricultural revolution.”
(Tiffany O’Callaghan ‘Survival of the friendliest’ p30-31 New Sci 2 Mar 2013. Interview with Brian Hare, at Duke University’s Canine Cognition Centre.)
HUMAN DIFFERENCES to other animals
There are 7000 languages spoken by humans. This is “more languages in one species of mammal than there are mammalian species.”
“To put linguistic diversity in perspective, you could take a gorilla or chimpanzee from its troop and plop it down anywhere these species are found, and it would know how to communicate. You could repeat this with donkeys, crickets or goldfish and get the same outcome. This highlights an intriguing paradox at the heart of human communication. If language evolved to allow us to exchange information, how come most people cannot understand what most other people are saying?”
“We should expect new languages to arise as people spread out and occupy new lands because as soon as groups become isolated from one another their languages begin to drift apart and adapt to local needs. (New Scientist, 10 Dec 2011, p34). But the real puzzle is that the greatest diversity of human societies and languages arises not where people are most spread out, but where they are most closely packed together.”
“People living in close quarters seem to have chosen to separate into many societies, leading lives so separate that they have become incapable of talking to one another. Why?”
“Splitting into distinct cultural and linguistic groups actually brings disadvantages, such as slowing the movement of ideas, technologies and people. It also makes societies more vulnerable to ricks and plain bad luck.”
“An answer to this question is emerging with the realisation that human history has been characterised by continual battles. Ever since our ancestors walked out of Africa, beginning around 60,000 years ago, people have been in conflict over territory and resources. In my book Wired for Culture (Norton/Penguin, 2012) I describe how, as a consequence, we have acquired a suite of traits that help our own particular group to outcompete the others. Two traits that stand out are “groupishness” – affiliating with people with whom you share a distinct identity – and xenophobia, demonising those outside your group and holding parochial views towards them. In this context, languages act as powerful social anchors of our tribal identity. How we speak is a continual auditory reminder of who we are and, equally as important, who we are not.” “Where different groups live in close proximity, distinct languages are an effective way to prevent eavesdropping or the loss of important information to a competitor.”
“In support of this idea, I have found anthropological accounts of tribes deciding to change their language, with immediate effect, for no other reason than to distinguish themselves from their neighbouring groups. For example, a group of Selepet speakers in Papua New Guinea changed its word for “no” from bia to bune to be distinct from other Selepet speakers in a nearby village. Another group reversed all its masculine and feminine nouns – the word for he became she, man became woman, mother became father, and so on.”
“For most of our history, people would have encountered only their own cultural group and immediate neighbours. Globalisation and electronic communication mean we have become far more connected and culturally homogenised, making the benefits of being understood more apparent. The result is a mass extinction of languages to rival the great biological extinctions in Earth’s past.”
“Already a mere 15 of the Earth’s 7000 languages account for about 40 per cent of the world’s speakers, and most languages have very few speakers.”
The rate of lose would be quicker but fore “the powerful psychological role language plays in marking out our cultural territories and identities. One consequence of this is that languages resist ‘contamination’ from other languages, with speakers often treating the arrival of foreign words with a degree of suspicion…”
“This resistance to change leaves plenty of time to for linguistic diversity to pop up. Various street and hip-hop dialects, for example, are central to the identity of specific groups, while mass communication allows them easily to reach their natural constituencies.”
“In today’s world it is the countries with the least linguistic diversity that have achieved the most prosperity.”
(Mark Pagel ‘War of Words’ p39-41 New Sci 8 Dec 2012)
“Not long after birth, tears begin to accompany crying, and the system that signals our, at times, cathartic tears. That is, once we realised that crying provided a sort of solace, we devised ways to prompt this experience on demand.”
“Among the areas of the brain whose activation may prompt tears of tragic joy are the medial and lateral prefrontal cortex – key to the experience of empathy. But Trimble concludes that it is also decreased activation in the more primitive amygdale, associated with fear and strong emotion, that leads tragedy to elicit feelings of empathy and intimacy.”
(Randolph Cornelius ‘The art of crying’ p45 New Sci 1 Dec 2012 review of “Why Human Like to Cry” by Michael Trimble, Oxford University Press 2012)
“Humans are not nature’s only funsters. All mammals play, as do some birds and a few other animals. But no other species pursues such a wide variety of entertainment or spends so much time enjoying themselves.”
“Crucially for the entertainment industry, we will also happily congregate with unrelated individuals, a situation that would leave both chimps and bonobos tearing strips off each other.” [Thus indicating we are more tolerant.]
Marc Bekoff at the University of Colorado, Boulder “identifies four primary purposes – physical development, cognitive development (“eye/paw coordination” as he calls it), social development and training for the unexpected.”
“Playing is an evolutionary adaption for learning, agrees Francis Steen, University of California, Los Angeles…..he sees playing as a sort of simulator that allows us to imagine and try out different scenarios with little risk. “In play we are most fully human,” he says. ”
“Bekoff believes social development is the most important purpose of play for humans, not least because it underpins morality.”
Watching others play improves your own skills, and produces feel good endorphins.
(Kate Douglas and Bob Holmes “The nature of the beast” p39-40 New Sci 21 Apr 2012)
“As a human, we can be aware that we are aware of our basic sensory inputs, and that allows us to reflect on the accuracy and validity of our feelings and judgements.” This reflection could be improved with training. [We can be mindful and aware and accept or deliberately ignore or do the opposite.]
Schizophrenia creates problems with this metacognition, this awareness of awareness. Work by Janet Metcalfe at Columbia University has shown that those with this condition are unaware when a cursor they are meant to have full control of on a computer, is partly being moved remotely by someone else, whereas the control subjects thought something odd was happening.
(Emma Young ‘Higher levels’ p35-36 New Sci 18 May 2013)
“In the 1970s, the idea emerged that it was the need to understand other people’s minds that made us aware of our own.” Then we benefit from sharing our experiences and knowledge not just out smarting our rivals.
Research by Chris Frith at the University of College London [and others] has shown that “people make better decisions in laboratory tasks if they are allowed to mull over the pros and cons of the evidence with a partner (Science, vol 329, p5995).”
For our ancestors “The better they are at reflecting on their feelings and judgements, the better their collective decision-making about whether to hunt or flee.”
(Clare Wilson ‘Why be conscious?’ p38-39 New Sci 18 May 2013)
“From earliest infancy, humans are constantly sorting the world into categories, predicting how things work, and testing those predictions. Such thinking, which is the essence of science, is evident in a range of human universals from time, calendars and cosmology to family names and measuring.”
“And it is not confined to humans – all animals need scientific thinking to survive.”
“Clearly, no other animal does science to the extent that we do, though. So, what sets us apart? One likely candidate is our drive to ask why?”
Chimps don’t try to figure out why like human children do, they just keep trying again. “Another possibly unique feature of humans is our ability to grasp abstract concepts.” Chimps struggle with this. “Crucially, this understanding allows us to use what we have learned in one domain to make causal predictions in another.”
“Our nimbleness at abstract causal reasoning is tied up with our facility with language and probably underlies many of our other social skills, such as rituals and rules of behaviour, too.” This is possibly what sets us apart from the apes.
(Kate Douglas and Bob Holmes ‘The nature of the beast’ p39-40 New Sci 21 Apr 2012)
“The question of whether every human society has formal laws is far from settled, but they do all have rules…..we humans, with our language skills and greater brainpower, have developed much more elaborate systems of rules, taboos and etiquette to codify behaviour. Though every society has different rules, they always involve regulating activity in three key areas – a sure sign that these are fundamental to human nature.”
KINSHIP and specifically the inheritance of goods. Also duties to family members. “And all have incest taboos, usually prohibiting sexual intercourse between immediate family (though royalty are sometimes exempt).”
SAFETY. When it is permissible to kill people. “I don’t know of any society that doesn’t condemn murder” says Sally Engle Merry at New York University. “However, what constitutes a legitimate killing is complicated.” “In some societies, any stranger is fair game. Others allow killing to avenge the murder of kin, and many allow the group to kill someone who violates its norms. But every group draws the line somewhere.”
STUFF. “Every society also has rules governing the use of objects. The notion of private property is by no means universal but people everywhere have rules that stipulate who is entitled to use certain things at particular times.”
“Kinship, safety, stuff. Across the whole range of human cultures this is what our rules say we care about. But perhaps there is a deeper part of human nature that underlies all these concerns; a desire for rules themselves. Rules help us navigate the hazardous waters of interpersonal relationships and provide a framework for knowing how to act, says Justin Richland at the University of Chicago, Illinois. That makes them an essential part of us. “It’s the most basic feature of human nature,” agrees Fox. “We’re the rule-making animal.”
(Kate Douglas and Bob Holmes ‘The nature of the beast’ p39-40 New Sci 21 Apr 2012)
We are strange biologically speaking. “Women are continually receptive and have concealed ovulation – that is, there is no external sign that they are in a position to conceive. We are the only monogamous primate to live in large mixed-sex groups.” And finally there is “our predilection for clandestine copulation.”
“Women won some control from men by evolving concealed ovulation and continual sexual receptivity to confuse paternity (Ethology and Sociobiology, 14, p381). Then our ancestors did something completely different from other great apes – males and females started sharing parental care. Monogamy was born.”
Robin Dunbar of the University of Oxford has suggested that to strengthen the pair bond “privacy may also have emerged as a way to increase intimacy.”
“Dunbar sees clandestine copulation as a trade-off, because as well as strengthening relationships it makes infidelity easier.”
David Buss of the University of Texas at Austin says, “Humans are socially monogamous, not sexually monogamous”.
“Infidelity is widespread in all traditional cultures and private sex allows it to occur without loss of reputation.”
When copulation is hidden it also avoids covetousness, disapproval of parents/family members, and children being threatened by the creation of rival siblings.
(Kate Douglas and Bob Holmes ‘The nature of the beast’ p39-40 New Sci 21 Apr 2012)
“Some anthropologists believe we gossip to manipulate the behaviour of others, which may explain why gossip often takes place within earshot of the person being gossiped about.”
When Robin Dunbar of the University of Oxford “eavesdropped on people gossiping, he found that barbed comments were relatively rare compared with innocuous ones. He believes that gossip is the equivalent of primate grooming – our social relationships are too numerous to cement each one with time-consuming grooming, so we chat, instead.”
Polly Wiessner of the University of Utah “observes that a juicy titbit of gossip is a gift – and, incidentally, gift-giving is another human universal.”
(Kate Douglas and Bob Holmes “The nature of the beast” p39-40 New Sci 21 Apr 2012)
We have been using fire since Homo Erectus 1.9 million years ago. Other animals fear fire. Also uniquely we cook.
(Christine Kenneally ‘So you think you’re unique’ p34-38 New Sci 24 May 2008 )
“Humans are the only animals to enjoy a lengthly post-reproductive, pre-decrepitude chapter in our lives.”
“The assumption that middle age is a pretty nondescript phase of life seems to have extended to scientists too: paediatricians and gerontologists abound, but there are few “middle-age-ologists”.”
(Editorial ‘No more midlife crises?’ p3 New Sci 10 Mar 2012)
“Compared to other animals, humans have a very unusual pattern to our lives. We take a very long time to grow up, we are long-lived, and most of us stop reproducing halfway through our lifespan. A few other species have some elements of this life-plan, but only humans have distorted the course of their lives in such a dramatic way. Most of that distortion is caused by the evolution of middle age, which adds two healthy decades after the babies stop appearing – two decades which other animals simply do not get.”
“As people get older they no longer need spectacular visual acuity or mate-attracting unblemished skin. Yet they did need their brains, and that is why we still invest heavily in them during middle age.”
“As the years pass, less fat is stored in depots ready to meet the demands of reproduction – the breasts, hips and thighs – or under the skin where it gives a smooth, youthful appearance. Once our baby-making days are over fat is stored in larger quantities and also stored more centrally, where it is easiest to carry about.”
This is a transition as significant as puberty. “It is an evolutionary novelty unique to humans – a resilient, healthy, energy-efficient and productive phase of life which has laid the foundations for our species’ success.”
“In prehistory, and still today, human survival is entirely dependent on skilled gathering of rare, valuable resources. Humans cooperate, plan and innovate so they can extract what they need from their environment – be that roots to eat, hides to wear or rare metals to coat smartphone touchscreens. We lead an energy-intensive, communication-driven, information-rich way of life, and it was the evolution of middle age which supported this.”
“There is evidence the many hunter-gatherers take decades to learn their craft and resource-acquiring abilities may not peak until they are over 40.”
”Research suggests that a human child requires resources to be provided by multiple adults – almost certainly more than two young parents. For example, a recent study of South American hunter-gatherers suggested that each couple requires the help of an additional 1.3 non-reproducing adults to provide for their children. Thus middle-aged people may be seen as an essential human innovation, an elite caste of skilled, experienced “super-providers” on which the rest of us depend.”
“Functional brain imaging studies suggest that they sometimes use different brain regions than young people when performing the same tasks, raising the possibility that the nature of thought itself changes as we get older.”
“A central and related feature of middle age is the many healthy years we enjoy after we have stopped reproducing. Female humans are especially unusual animals because they become infertile halfway through their lives, but male humans often also effectively “self-sterilise” by remaining with their post-menopausal partners. Almost no other species does this.”
(David Bainbridge ‘Marvellous middle age’ p48-51 New Sci 10 Mar 2012. Based on his book. “Middle Age: A Natural History”)
From 10 kilometres and above humans are amongst the fastest long distance animals. This endurance running may have enabled humans to run prey to exhaustion. “Other primates can fling objects with force, but underarm and with a poor aim. Only humans can launch a projectile such as a spear or a rock from over the shoulder with power and precision.” The unique human wrist and shoulder makes this throwing possible.
(Graham Lawson ‘Superhumans’ p33 New Sci 16 Mar 2013)
We share 98.5% of the DNA of chimpanzees and yet we seem so different. However, the picture is more complicated than it seems, as genes behave differently if they are duplicates, in a different part of the genome or expressing differently. Much of what makes us, us is cultural, but this does not exist independently of biology.
“To crack the mystery of human uniqueness we need to know how genomes build bodies and brains, how brains create culture, and how culture eventually feeds back to alter the genome. It remains a distant goal.”
(Dan Jones ‘Riddles Of Our Past: Why are we so different from chimps?’ p35 New Sci 24 Mar 2012)