The listed phenomena (1.- 6.; intrinsic changes in fertility, mortality, life expectancy) might also occur in non-human organisms but their causes can differ entirely and in general the term and concept of 'demographic change' (or 'demographic transition') in its usual meaning (Greek 'demos' = people; demography as human population dynamics) is hardly applicable to other than human populations.

If you transfer the term 'demographic change' to non-human populations there is always the risk of logical fallacies, i.e. you implicitely consider certain aspects of convential (human) demographic change as relevant for your newly coinded "non-human demographic change", even though they are wrong and absurd in the new context.

It might be better to discuss intrinsic changes in (animal) fertility, mortality, life expectancy etc. as a problem of (animal) population dynamics without the ballast of unwanted meanings if you call it 'demographic change'.

I expect such a transition (whatever you call it) occurred with domestication in many animals. For example, dogs, the first animal to be domesticated, have longer life expectancy than wolves, and also are able to breed more frequently.

On terminology,

the term “demographic change” is already widely use in context of no-human population, but it describes any changes in basic demographic parameters, while the term “demographic transition” describes very specific changes (unidirectional transitions throughout well-defined stages).

Shortly, these stages include: (1) Malthusian phase in which population persists in equilibrium (population size depend on resource availability only), (2) Non-equilibrium growth phase, (3) Non-equilibrium decline phase (in non-equilibrium phases, population size depends more on redistribution of resources inside population than abundance resources per se).

It can be suggested that behind demographic changes in both human and some group-living non-human populations (bacterial colonies, herds, rat families, wolf packs, etc.) may lay the same general mechanism – mutual adaptation of individuals to living in the group (co-selection). If so, then the similar signs of "demographic transition" can be found in both human and non-human populations.

In other words, there is an approach that analytically describes the demographic transitions in populations at the same time it is not based on any purely human features.

Perhaps we should elaborate on these intrinsic changes in population dynamics (...trying to avoid 'demographic change/transition' as a term) in humans and other animals:

'Social development' as a cause explains not much (because it is arguably always the consequence of some deeper lying cause). What remains (apart from extrinsic causes - see the example of human-induced change in domestic animals mentioned by Jennifer Leonard) are innovations/ novelties through (1) mutation (or evolutionary change in general) and (2) new ideas (that lead to technological/economical changes).

I wonder whether there are convincing examples of population changes due to new ideas in animals (other than humans).

"Demographic transition" describes a process of change in basic demographic parameters of a population as an economy develops, health care improves, and overall standard of living increases.  That is, the demography of the process should not (cannot) really be separated from the related socioeconomic changes.  As such, the process only occurs in human populations.  Applying the phrase to non-human populations would be counter to its original meaning and likely create confusion.  Also, in a broader sense, a process whereby overall population growth rate declines (and sometimes reaches zero) would not be favored by natural selection.  Any individual organism that reproduces less than other members of its species would be selected against.  So, the demographic transition is not compatible with the basics of natural selection.

On causes,

There is one most basic cause that crucially effects both survival and fertility of the individual – availability of vital resources. Therefore, in a group, there are two ways of change it; (1) changing inequality of resource distribution within group and (2) changing ability of the group to extract resources.

Both processes do not require any genetic changes (physiology of the individual remains the same) nor “new ideas” (basic behaviour of the individual does not change).

In such “resource driven” demographic process, perhaps, only one thing distinct human from other animals – ability to create super-groups consist of genetically unrelated individuals. However, it seems not crucial for “demographic transition”, although it makes the processes more pronounced.

It would be interesting to find a species that underwent a demographic transition not based on biological factors. In non human biological populations density dependence operates to reduce per capita growth rate. To demonstrate the relevance of the demographic transition model to non human populations you would have to distinguish between biological causes and other social causes.

On confusion,

I agree that the reference to the demographic transition, as a common evolutionary property of any hierarchically-structured communities can create confusion (and I hope to provoke thought, as well), because we are accustomed to consider human demography as special and unique.

However, if the demographic processes in both (human and some non-human) populations, based on the same cause and exhibit similar patterns, then what prevents us to extend the original definition?

On socioeconomic changes

I agree that “the demography of the process should not (cannot) really be separated from the related socioeconomic changes”. But, what is the socioeconomic changes in terms of demographics the individual and society?

In the end, it is the changes in the availability of vital resources necessary for survival and reproduction for each individual, which depend on the change in inequality in the resource distribution and the community's ability to extract resources. Such process occurs in any hierarchically-structured populations, nothing essentially human is present here.

On evolution

In reality, natural selection (especially in closed groups) can lead to a reduction in mean fitness, and even to extinction, there are many well-documented cases and even a special (but a little bit misleading) term – misadaptation. The reason for this is quite clear, within a group with a high level of intraspecific competition; individuals are beginning to spend more resources for survival at the expense of reproduction.

Why more general and biologically grounded view on the demographic transition is important?

It seems that there is a framing effect here, literally, “human demographics – should (must) be explained by purely human features only”.

On the one hand it encourages researchers to search for over-complex, human behavior-based reasons for demographic processes, on the other hand does not allow them to search for the basic biological explanations.

To me the real beauty and utility of the demographic transition (as a model and a process that really does occur in human populations) is that it shows us a way forward.  Imagine a planet in which every country has gone through the demographic transition.  To some extent, I think developed countries should assist developing countries in getting through the transition.  None of this is about biology or ecology. The demographic transition stands as the solution to many of our world problems whether it is a biological property of human populations or not.  There's nothing wrong with thinking about some generally similar process occurring in non-human populations, just don't muddle it up by attaching the phrase "demographic transition" to it.

But what else if not new ideas led to the invention of mineral fertilizers, canalization systems, hygienic measures, vaccines, antibiotics and contraceptives - each with a certain (at least local) impact on human population dynamics?

Arguable 'new ideas' are the critical point behind economical/ technological changes in human demography (mentioned in the opening text) and to leave them out as important factors may lead to an overly simplistic and biologistic view of (human) demography and transisitions in human populations.

The classic demographic transition is characterized by an initial decline in childhood (juvenile) mortality, and then a decline in fertility. The product (and most often the principal motivation) is typically a larger per-offspring investment. Patterns of transfers, shown in the Naitonal Transfer Accounts (NTS) lifetime patterns, illustrate this.  In population biological terms, this is somewhat like shifting from a reproductive strategy that was more toward the "r-selection" side of the spectrum (although no one would consider humans an r-selectionist species) toward the intensely "k-selection" side.  I think this population biological explanation works for some evolutionary shifts -- e.g., the evolution among some taxonomic families of rodents, from high frequencies of litters and rapid development of juveniles (some ground squirrels), to a single litter annually, and their retention and protection in family units (Cynomys, i.e., prairie dogs).  

”in hierarchically structured populations”

Only in those?

On beauty and utility

I think I agree that the term "demographic transition" heavily involved in the political (the criterion separating developed and developing countries) and psychological (we humans are not animals, we do control their own destiny ...) context, but at the same time, this involvement, significantly reduces its scientific value. Of course, we could introduce a new term (demographic changeover, demographic conversion, etc. ) specifically for scientific use, but this duplication may create even more confusion.

For me, the beauty of the model is not so much that the model shows a pleasant picture of the past, but more in that it is able to predict the future.

On new idea and technological innovations

Of course, some technologies may have an effect on the population, I never claimed the opposite.

I insist that this effect is similar to, for example, that the colony of bacteria is switched from low-energy diets on the high-energy one or when a group of animals migrates from pure resources areas to the resource-rich region.

However, we must remember that the assessment of the impact of technology on the demographics is very tricky. Let's see. What is common in the following innovations: the invention of the wheel, fire, agriculture, literacy, gunpowder, cannons, ships; introduction of religion, state, sciences, medicine, education; discovery of America, Australia, etc.?

All these and other innovations (introduced before 19th century), had no significant effect on the demographics. Population persisted in the Malthusian stagnation phase.

You may have guessed what a particular innovation of the 19th century changed the rules of “the game of demography”.

OK, but do You have in mind/plan to test the hypothesis?

Demographic transition (as a model and a real process) has scientific value whether it is applicable to non-human populations or not.  Also, its scientific value isn't necessarily increased by finding it (or a similar process) in a non-human population. If we were to find it occurring in a non-human population then does that somehow mean that it is an inevitable outcome of human existence? .... "no".  There is no guarantee that a given human population will complete the transition.  Indeed, many sub-Saharan countries seem to be stuck in late Phase 2 (death rates have decreased but birth rates have not) for various historical, social, economic, and political reasons. Some aspects of the DT may be deeply rooted in innate human biology but it is mostly a socioeconomic and political phenomenon.  Our understanding of DT in human populations is not advanced by transferring the concept to non-human populations.  Nonetheless, it is worthwhile and interesting to think about how intrinsic and extrinsic factors could lead to a decrease in growth rate of a non-human population in such a way that there is long-term benefit to the population.

Here's an argument for the thesis that the genus Homo is unique in being constituted by a niche and set of life-history adaptations where the only game in town for achieving reproductive success is to be part of a social network that supports the individual's family-formation efforts, in turn providing the environment for that individual to continue to obtain resources to transfer to mates and offspring, sustained over long periods of time. More simply, it's not just the intensity of intergenerational transfers, but also the intensity of social network management, group mobilization, exchange, sustained cooperation, and conflict management that generates the material and energy needed to raise offspring. The ongoing, regionally mosaic demographic transition process isn't just about contraception and the innovative shift from natural to planned fertility. It's also about how human capital--as Galor emphasizes--becomes ever more valuable as the demand for education and status symbols (honest signals of having or having received transferable resources) becomes highly positively elastic in relation to supply.

One might discover social insects with a hierarchical division of labor and reproduction where you get a structurally analogous shift, where rich but patchy or complex environments favor larger body size, greater transfers, lower fertility, and greater longevity. But the difference in scale between ants or wasps and humans is so huge that one might reasonably expect ecological speciation to take over in the former, whereas the shift in humans is a biocultural one within a single biological species.

On r-k reproductive strategies

The "r - k selection” approach gives a plausible description of the situations in stages 1 and 2-3 of the demographic transition, but it does not explain why (and how) this “strategic shift” occurs.

O. Galore in his "unified theory" suggests that the reason lies in the growth of the cost and the accumulation of "human capital". I'm not ready to discuss all the details of a very complex concept of human capital, but I note that a simpler explanation for the "economical demographic paradox" (counterintuitive, reverse dependence of the average number of resources on the average birth rate) is exist. Literally, change in the distribution of resources leads to the fact that a growing proportion of the population has more than enough resources to survive, but at the same time smaller surplus necessary for reproduction.

On hierarchically-structured populations

Yes, the demographic transition can occur only in hierarchically-structured populations. In other communities also occur demographic changes, but a completely different type, for example, persistent long-term decline in average fitness in such populations is not evolutionary feasible.

Briefly causal diagram is as follows:

Natural selection (co-section) --> change in the hierarchical structure --> change the total amount of extracted resources and/or the distribution of resources --> change the resource-depended birth/mortality rates.

On plan, the first part of the plan, it's just to try to convince colleagues that a simple, logical, biologically-based explanation for the demographic transition is possible and exist.

On scientific value and impact

Of course, the modern concept of the demographic transition has a certain scientific value. On the other hand, there is little doubt that a more general theory (including both human and non-human cases) will be of great scientific value, as well as quantum mechanics is of great scientific value than Newtonian mechanics, simply because it includes the latter as a special case.

Potentially, the theory with greater scientific value will have a greater impact. Unfortunately, when it comes to concepts heavily involved in the political context, the scientific value of the new theory should be higher than the sum of political and scientific value together. This creates a very high barrier to entry, and often leads to scientific stagnation.

I agree that the modern concept of DT is very weak (based on several observations only), it does not have a unified theory rather there are several possible untested guesses.

I'm not convinced that a "simple, logical, biologically-based explanation" for DT is possible.  The social/political/economic behavior of humans is too complicated to be completely explained by biology.  The key feature in the DT is initial decline in death rate and then decline in birth rate.  Decline in DR occurs with better health care, hygiene and sanitation systems, improved nutrition and reliable food supply. Decline in BR occurs with greater willingness of females (and males) to use contraceptives. Use of contraceptives and family planning becomes more prevalent as women become better educated and take control of their own reproductive futures.  At a fundamental level, DT is the composite outcome of choices that humans make. Certainly, there may be some innate biology in action when a person makes a social and economic choice.  But this innate biology certainly does not explain DT.  It is tempting to want a biologically-based explanation for DT because if it is based in biology it might be seen as more scientific and valid.  However, it already is scientific and valid.  I agree that "the theory with greater scientific value will have a greater impact" .... but with regard to DT, "impact" on what?  We need DT to have an impact on politicians and policy-makers (particularly in the USA) in the form of awareness and realization that it is a good thing for a country and humanity in general. A speculative and unnecessary biological explanation will not help.

On differences between proximate (that shape the process) and ultimate causes (those that trigger the process)

Of course, it is hardly possible to explain all the features of human behaviour by biology. Fortunately, we do not need to do this, because in this case we are only interested in the ultimate causes that trigger the process of demographic transition. This does not mean that other (proximate) factors do not affect a population (they actually significantly affect the rate of processes), but they are not the ultimate cause of the process (ie even without these factors, the process would be continued in any way).

Now, let us again recall that until the 19th century, the entire sum of technologies, innovations and complex human history did not trigger the demographic transition. Why? Maybe the “composite outcome of choices that humans make” is not ultimate cause? (or people before 19th century did not able to make a choice? ) What happened in the 19th century that initiated the process of demographic transition?

I could give an answer now, but will be more convincing if you find it by yourself.

“Simple, logical, biologically-based explanation” is it possible or not possible?

Actually, it is a little bit obsolete question, because such explanation already exists (see for example article attached to the post for details). Moreover, it is curious that in general this explanation/prediction appeared in 1795 (Marquis de Condorcet, Sketch for a historical picture of the progress of the human spirit), i.e. even before the demographic transition has started.

Thesis Rethinking the basis of the population growth

Alexander, has your paper (biological explanation for the DT) been published in a peer-reviewed journal? -Joe

It has not been published. 

The best predictor of the demographic transition in humans is the economic cost of raising children that are competitive on the mating market (see Shenk et al 2013 PNAS). This is unlikely to ever be a factor in animals

Where goes our humanity? God (Nature) will give result. Don't worry about it, relax and take a deep breath, the stress we do not need. The main thing is that people are not strained, thay must shall wisely and moderately live. People should not injure yourself and the world around them. And death and birth, sickness, and old men will always be.