This dialog is focused on how rapid social evolution is driving biological evolution and how the result is increasing longevity in advanced countries. I sent Marios* an e-mail with the paragraphs marked VG which appear in this blue font. And Marios responded with the paragraphs in black font marked MK.
VG. I propose an explanatory framework that can lend clarity to discussions relating evolution to longevity. That framework views social evolution as a separate and important matter in addition to biological evolution. Social evolution takes place in cultural niches, that is, societies. By social evolution I would mean the evolution of all key aspects of the environment and behavior of people in a society: how people live, work and communicate, their social, government, economic production and family systems, their institutions of all kinds, the technologies they have and how they have adapted to use of those technologies, what they eat and drink, their belief systems, their expectations and how they think. For my purpose here I focus on common elements of advanced industrial and post-industrial societies, including those in most European countries, the US and Canada, Japan, Australian and large sections of Chinese and Indian societies.Some key points are:
VG. 1. While biological evolution of humans appears to be very slow, social evolution is happening very rapidly, the use of cell phones and Internet and the resulting changes in communication capabilities and availability of knowledge being recent examples.
MK. This is a very good point. Rapidly-evolving social developments will augment and complement biological evolution, particularly post-Darwinian evolution.
VG. 2. The principles of human social evolution cannot be derived from the principles of human biology, just as the laws of biology cannot be derived from those of chemistry and chemistry cannot be derived from physics. However, chemistry must be compatible with physics, biology must be compatible with chemistry and the rules of social evolution must be compatible with the laws of biology.
MK. The two concepts are interdependent. I believe that one drives the other and vice-versa
VG. 3. Most dramatic increases in longevity have come about through social evolution such as the adoption of sanitation systems, recognizing the existence of diseases, inoculations, cleaner are and cleaner water, laws, dentistry, medicines, seat belt laws, stopping smoking, improved nutrition, safer cars and products of all kinds. The list goes on and on and there is still very far to go.
MK. Yes, however we are likely to witness a much more far-reaching social and cultural influence on human longevity. Technological developments will inextricably modify our society, I hope for the best. The internet is changing everything. New technology makes it easy for people to exercise at home, aids their diet, and promotes psychological well-being via remote interactions with friends. I believe that increased external inputs (emanated from the interaction between technology and society) are essential in stimulating human brain evolution, which in turn, must result in increased lifespans, for reasons I explain elsewhere.
VG. 4. It is far too narrow to see biological evolution of humans only in terms of genetics. It is mainly happening through changes in the epigenome. And evolution due to changes in the epigenome can happen very rapidly compared to evolution due to changes in genes. This can be seen in certain animals which rapidly adapt to changed environments in a few generations, including dramatic changes in their body characteristics, without any changes in their genetics. And, with better nutrition and a healthier environment, children now are growing up to be taller adults than their parents were in several developing countries.
MK. There is increasing evidence supporting the role of epigenetic changes in shaping our evolution. Here, I am not referring to the slow, cumbersome process of evolution by natural selection, but to the new type of human evolution based on self-organising complexity and intellectual development. The way we stimulate our brain, our thoughts, actions and lifestyle all have an epigenetic effect on our genes, which helps in initiating events that result in progressively longer lifespans.
VG. 5. Social evolution is driving biological evolution. The changes in the epigenome of humans result from social evolution. And by evolutionary standards the change is very fast as can be seen in terms of human longevity.
MK. I agree, as mentioned above. Social evolution is a much more efficient and quick way to evolve, compared to the Darwinian model. By social evolution I also mean cultural and technological changes that influence the entire process.
VG. 6. Complex societies demand greater longevity because they demand preservation and extension of knowledge. That is why in advanced and advancing societies, for years now average lifespan has been increasing about 4 hours every day. Life expectancy at birth approximately doubled between 1850 and 2004 and in primitive times it was perhaps 22 years for those who survived childhood with 30 years being very old. Our genes have not changed during this time. The evolution has been social and in our epigenomes.
MK. We will witness a gradual increase of our lifespans, with a few individuals breaking through the existing maximum lifespan (around 120 years), and an increasing number of super-centenarians (those aged 110 years plus), over and above what is currently predicted. Subsequently, it may become the norm for people to live to 130 plus. However, this seems a relatively slow process for achieving truly indefinite lifespans of centuries or even millennia. Perhaps there will be a quicker mechanism, which will suddenly augment (inflate) the process. I don’t know.
VG. 7. As longevity has been increasing, so have the main events of life been spread out: getting married, having the first children, finishing education and starting work, and end of the time when productive work is possible. Back in the bronze age, most women started having babies when they were biologically able to do so – at 13 to 15; now the average age of marriage is over 30.
MK. This also will have a profound effect on societal evolution and thus biological evolution. Issues of fertility, decline in male sperm and hormonal changes are influenced by society and are relevant to longevity. For example, technological developments have caused pollution, which has now (according to some) caused a decline of function of human sperm, and thus lower fertility. Lower fertility is (according to some views) positively correlated with longer lifespans. This is an intricate example of how society changes affect biological evolution.
VG. 8. I therefore agree with Marios that longer and longer lives will result from our social and epigenetic evolution – assuming no cataclysmic events that are serious enough to destroy or seriously set back our societies. I also believe we can accelerate the trend to greater longevity and believe it would be a very good thing to do so from a social and economic viewpoint.
MK. Personally I am only interested in the biology of the process, but will consider any influences derived from social, cultural and technological domains. I will leave the economical, ethical and psychological implications of super-longevity for others to debate.
VG. 9. Finally, I have to acknowledge that this discussion itself is a manifestation and instrument of social evolution. “If you find yourself riding on a horse, the best thing is to ride the horse in the direction in which it is going.”
MK. It is indeed. But my advice is also “try not to fall off”!
VG. 10. So let’s get on with discovering how we can support people living healthy lives longer. I see one possible approach which conceivably could crack the human aging barrier of 123 years and keep people alive and healthy for several hundred years. It is described in the blog entry Closing the loop in the stem cell supply chain – presented graphically.
MK. I read all your blogs relating to stem cells, and I believe that this is a way forward. I am suggesting some ways for possible help, such as making use of transposons that may eventually be used in order to influence stem cell DNA along the lines you suggest. Also, newer developments in Synthetic Biology may provide the tools for accelerating any interventions upon stem cell production and function. These are just two areas of possible interest but there are many others. We need to encourage scientific dialogue in this respect and get interested scientists to take part. There is a lot of research currently going on but I find the approach rather fragmented. Many, if not all, researchers are unaware of the relevance their results have upon achieving indefinite lifespans. Their vision is restricted by funding constraints. We need to break through this barrier, but fortunately there are some platforms where we can expect dialogue (see www.imminst.org for example).