Page #52
Q: Why is that?
MA: Because not all answers are yes and no. And not all problems are black and white. We were discussing how it is impossible to describe the human species as either a “r-selected” or a “k-selected” species because we present traits of both evolutionary strategies. Our species presents a range of these traits across a wide spectrum of expression. It is not one way or the other. Even among the scientific community there is great confusion about this dynamic. We have scientists who have attempted to attribute these variations in strategies to race.
It was a foolish error from the beginning. The variations within any given race are as great as or greater than between any two races. When you read about this type of speculation always remember that this type of racial stereotyping has been postulated for generations and it is as bogus as it comes. The variations are real, but they are exclusively related to behavior and nothing else.
That behavior is motivated by countless different factors but it is not attributable to race.
Q: OK, I think I understand that we are largely a K species but that within our species there are many different behaviors, some of which are K and some of which are R. Is that close?
MA: Yes, this bit of explanation has to do with the famous r = n – m, the equation that lets us see if we are expanding, stabilizing or shrinking as a species. Now we know that r (the rate of increase has been modulating downward for the past 40 years) but it is still in the positive range. Because we as need to determine if the species is indeed modulating it's r to the point of 0 and achieving balance with it's environment and not just posting a small dip in a 600 year upward trend - we must examine the data closely.
And, as we have been discussing, that data is very mixed. Some cultures are into negative population growth (think the Czech Republic and some other European countries) while some cultures are expanding rapidly. (Think Latin America, the Middle East and Sub-Saharan Africa). China is at 1.7 and India is at 2.8 in total fertility rates. So even among the most populous countries there is a difference. And these differences can lead to huge outcomes. With India above the 2.1 replacement rate in fertility and China below the norm it would only take to the year 2040 for India to be the most populous country on earth.
But again, predicting future growth rates of any population is very risky business - that is why we are taking such pains to be as accurate as possible in our evaluation of that old pesky r = n - m.
Q: OK, so if I read this right you are saying that there still might be a case for the “r-selected” behavior to overwhelm the “k-selected” behavior and instead of leveling off either continue expanding or to crash? Is there any way to know for sure?
MA: Yes there is.
Q: In all honesty, I don't see how, over the short term, k type behavior can overcome the population explosions evident in some parts of the world.
MA: Remember, there are trends and countertrends in many countries or cultures - even modernized societies. Let us take England for a moment. That is as about as proper an established modern country as can be found. Do you know what the most common name given boys at birth in England was last year? Here is a hint Jack has been the most popular for 14 years in a row.
Q: William or Harry?
MA: No, the correct answer would be Mohammed.
Q: For real?
Page #53
MA: Yes of course, it is once again the collision between two different evolutionary currents. Immigration from other countries is sparking a baby boom in some areas while the resident population is declining as a whole. It is an uneven picture. One wave is reproducing and spreading while the other current is falling further and further behind even meeting the fertility rate necessary to maintain their population.
That is what we mean when we speak of differentiation between members of a species. Differentiation in reproductive strategies to the same environment is a pretty telling marker of evolutionary conflict.
Q: I believe that I have a good handle on this subject now; can I summarize what I have heard?
MA: Of course, go ahead.
Q: This discussion originated when we speculated on the future of our species in a changing environment. You have since tried to teach me some of the dynamics involved in making such a prediction.
What I now understand is that from the beginning our species has been subject to at least two different evolutionary strategies involving reproduction, fertility rate and species expansion. Good so far?
MA: Excellent, and especially the part where you say “at least two”, because there are many factors involved - but these two paradigms are easiest to understand. Please go on.
Q: Our current large population numbers are the results of countless surges, crashes and plateaus of population growth. During this long evolutionary development, some varieties of humans have risen to prominence then completely disappeared due to competition from a better adapted group.
MA: There is nothing wrong with the word variety but you might be better served to use the term groups.
Q: Point taken. These surges in population growth by one or more groups are described, by you, as waves.
Q: There have been large waves like the one out of Africa, the one across the Bering Strait and the expansion of the Old World into the new. But there have been lots of smaller waves within those events - like Clovis Man and others. The current wave started after the Black Death and the migration to the New World. That wave (which you and I have been calling the First Wave) rolled across the planet and finally peaked in the early 60’s.
From that time on the rate of increase in the total number of humans has been slowing. However, there are cross currents within that decrease in rate - as there are with many other species. I also understand that there are very distinguishable traits associated with what is called an “r-selected” species, such as early maturity, a large number of offspring, limited or no parental long term investment in these offspring, and that this behavior normally leads to a rapid expansion of that species and a sudden collapse in their numbers.
There are also distinguishable traits associated with what is called a “k-selected” species, such as late maturation, few offspring and a large investiture in those offspring, and that this behavior typically leads this group to fully occupy the habitat, at that point their numbers level off and arrive at some type of balance with their environment.
MA: That is pretty close.
There is one caveat that I should add. In old school Biology we would normally think of any single species as either K or R selected. The understanding that there are multiple expressions of both these traits within any given species, while not controversial, is new. Not a large point but one that could be questioned.
Q: I understand that, although it is difficult to see how you could not see the different strategies in our species.