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The Czech Republic and some other European countries’ growth rate is actually negative (on average, women in the Czech Republic give birth to 1.2 children, which is below the number to yield zero population growth, approximately 2.1 children). The Czech Republic's natural growth rate of -0.1 can not be used to determine doubling time because the population is actually shrinking in size.
So in these numbers we have a very strong trait for “k-selection”. But there is another current equally as strong - if not stronger. Many Asian and African countries have high growth rates. Afghanistan has a current growth rate of 4.8%, representing a doubling time of 14.5 years.
Q: I thought “k-selected” species also had rapid population expansion?
MA: The answer is yes; of course “k-selected” species have periods of rapid population expansion. But the kicker is the conditions under which this occurs.
Do you remember the brief phrase I said summarized the k vs. r selection?
Q: Was it quantity vs. quality?
MA: That is correct. But what it also means is that these two strategies are designed to function in different environments. Your K species uses the rapid growth to take advantage of a stable environment with ample resources while the R species responds to a disturbed environment by mass reproduction - obviously hoping that some members will survive the certain crash that always occurs.
So it is not just the growth rate but the environment that frames that growth that really defines which strategy is in play. We have in the “k-selected” species a stable environment that is density dependent. They produce few offspring with extra investment on the part of the parent, they have late maturation (again with much parental care) and they live long lives.
The “r-selected” species thrives in an unstable environment where there is density independence, they produce many offspring with limited parental investment, and they have early maturation, and live short lives.
Q: I don't understand are you saying we are not a “k-selected” species.
MA: No, we are both. Although some organisms are primarily r- or k-strategists, the majority of organisms falls between these two ecological extremes and may display traits of both. Because this concept of a continuous spectrum is such an important concept to understand - I would like to take a moment and discuss it with you.
One way to speak of a continuous spectrum is to frame it in terms of variations within a species. You are quite aware that within any species you have wide differentiation. Size, coloration, abilities etc, it is a never ending list of differences that make God's creation such a wondrous joy. These differentiations are the result of all the possible combinations of genes in an individual member of any species.
So we can say that the intermediate expression of genes results in a wide variety of variations within any species. Pretty much ABC stuff but it is incredibly important in the discussion we are having.
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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?