Will we die out

[Ola D.]

Hi Bob,
I actually don't wish to suspect the BBC reporting accuracy in this thread.
Whether this is a fact or speculation, I believe it's worth to be considered to constrict the use of pesticides on the long run.

Moreover, this is not the only study supporting the fact that fertility is decreasing. What I wanted to conclude that male/female fertility is decreasing because of our negative influence on the environment, like polution, radiation from nuclear activity.. etc.

[trevorsproston]

There are those who would assert that the fact of existence implies the right to exist. Perhaps it does. However that may be, from the point of view of evolution, we are not a successful species - the most successful mammals are the rodents, for there are many vibrant varieties. There's only one Homo - population notwithstanding, we are a withered branch on the bush of life, much the same as the horse.

Our brains have muddied the waters rather. Instead of tramping our way unconsciously to extinction [which is the fashion], our minds feel unease, if not fear, at the dying of the light, and we ring ourselves about with ingenious defences to stave off our own demise, such as religions. Hope in the salvation of Space Travel is just one more of these defences, which some turn into a belief system, or indeed religion. One of the tenets of this set of beliefs is that somehow, if we can only get out there, we will ensure our posterity. Years ago, someone said the following, which may be a suitable response:

"Said Man to the Universe, 'Sir, I exist'. Replied the Universe, 'I know; but the fact has not created in me any sense of obligation.'"

It may be that speciation through isolation on settled planets will give us the genetic diversity to become as successful as the rats; however, don't hold your breath. Would it not be better simply to go into space because we can? To react to it as a baby does when it finds today that it can move a little farther than yesterday? The difference is that we'll have no doting parent to reward us for our progress - we will be our own assessors. A dreadful responsibility.

Babies need no high-sounding words to start walking - we in our turn should need no high-sounding words to explore space. Let us not worry about species survival. We will survive via the efforts of our ingenious dscendants who will share the same fears as us. Whether anything else will survive our desire for existence remains to be seen.

[Bobunf]

"this is not the only study supporting the fact that fertility is decreasing."

As I pointed out earlier, you don't need a study based on seven individuals to determine that fertility is decreasing worldwide. The Census Bureau reports the enumerated data in great detail.

Why is this happening? You seem to think it is "because of our negative influence on the environment, like polution (sic), radiation from nuclear activity" and, presumably, pesticides.

My own hypothesis is that it is because of the choices being made by the 18% of the population that is female and between the ages of 15 and 40.

I would support this hypothesis by stating that almost wherever and whenever the freedom of women to make reproductive and other choices has expanded, fertility has declined.

I would refute the nuclear activity idea by observing that Indonesia, with practically no nuclear activity, has had a 40% decline in fertility in the last 20 years; Brazil, 64% decline in the last 50 years; Nigeria, 21% in the last 50 years, and there are about 100 other such examples.

The United States, with the most nuclear activity of any country, has had rising fertility over the last twenty years. Could it be that radioactivity increases fertility?

How about this for homework—to substantiate, or refute, the pesticide idea. Compare rates of change in fertility to per capita pesticide use in countries across the world and across time. Is there a correlation, and, if so, in what direction? You might find it illuminating.

Bob

[Essel]

I think human race will try to find ways around the many problems that have been discussed. It may eventually become extinct as the universe in its existing form becomes extinct one day. Matters beyond the physical reality will rule and we being physical cannot cope up with that situation.

Going through the maze of the problems and solutions we could come a long way as a race but for that we have to act in this direction. We shall have to have long terms plans for calamities and disasters. The threat could initially come from within the human race, environment, major subterranean activity, asteroid impact happening within a few decades or centuries and then the mega events like explosion of a supernova nearby, extinction of sun, collision of Milky-way with Andromeda etc. etc and may be ultimately a dead universe or a big collapse.

My suggestions given in another forum include:

First we should create calamity capsules on each continent with provisions to survive hundreds of designated people. All the technology and science that we have developed so far should not go waste and therefore these designated people should have the ability to recreate what has been lost.

The second is to build a large space station on low-earth orbit, much larger than ISS and with simulated gravity and ability to grow plants and foodstuff. Here again people from multiple discipline should be stationed.

The third should be a base in moon….and so on.

Over centuries we shall have most of the major risks covered within the solar system and then we have to look outside.

[Ola D.]

Originally posted by Bobunf@Dec 10 2004, 09:41 PM
I would refute the nuclear activity idea by observing that Indonesia, with practically no nuclear activity, has had a 40% decline in fertility in the last 20 years; Brazil, 64% decline in the last 50 years; Nigeria, 21% in the last 50 years, and there are about 100 other such examples.

I am not saying here that nuclear radiation is the only cause for the decline of fertility! Please don't misunderstand my point.

The United States, with the most nuclear activity of any country, has had rising fertility over the last twenty years. Could it be that radioactivity increases fertility?

Well, is the population being exposed to the radiation? That's the key!

If the radiation damage occurs in germinal cells, the sex cells, it can cause defective offspring. The defective offspring will in turn produce defective sperm or ova, and the genetic `mistake' will be passed on to succeeding generations, reducing their quality of life until the family line terminates in sterilisation and/or death.[5] A blighted or abnormal embryonic growth can result in what is called a hydatidiform mole instead of a baby.

Here's the rest of the article:
http://www.ratical.org/radiation/NRBE/NRBE5.html

Another one:
http://en.wikipedia.org/wiki/Nuclear_fallo...ects_of_fallout

[Bobunf]

We’re looking at a phenomenon (correct me if I’m wrong) of worldwide declining human fertility.

Hypothesis: Human sponsored nuclear activity is a cause of this observation.

Test the hypothesis; scientific method.

Test result: There’s a negative correlation between human sponsored nuclear activity and the rate of decline in fertility.

I think one has to accept that the test result suggests that human sponsored nuclear activity may not be a cause of the observed decline in human fertility.

“is the population being exposed to the radiation? That's the key!”

Yes, indeed; and what would the above test result suggest?

“If the radiation damage occurs in germinal cells…”

Apparently it doesn’t.

There’s no sense in carrying on and on about how bad radiation is for you. We all know that drinking sulfuric acid in any quantity would cause death. Does that mean that the worldwide de-clining death rate indicates a decline in sulfuric acid production?

But, another test of your hypothesis might work like this: Human sponsored nuclear activity, if it has any affect overall human fertility, would have to affect a very large number of people, and would have to be extensively distributed such that the human sponsored nuclear activity would also affect animal populations including cats, dogs and rabbits.

Has fertility in these, and other, animal populations declined? I think you’ll find that the answer is no.

That’s two failed tests.

[Dave Mitsky]

Bob,

What exactly do you mean by the most nuclear activity?

Dave Mitsky

[astromark]

I don't think the facts suport your conclousions... Yes the fertility of men is and has been dropping. We do not know why.Its easy to speculate, there could be many reasons for our impotancy. Is the human race in danger of slipping into a negative population growth era. No, I dont think so. The global population is growing. is it not?
This will not be what kills of humanity.

[Bobunf]

"What exactly do you mean by the most nuclear activity?"

The US
1. has more nuclear weapons than any other country in the world with the possible exception that Russia may be equal or very close.
2. generates more electricity from nuclear reactors than any other country
3. uses more plutonium in spacecraft than any other country
4. uses radiation for medical imaging and treatment more than any other country
uses more radioactive material in smoke detectors than any other country
5. etc.

Bob

[astromark]

I dont believe this is the problem. I have been told that the amount of radiation emited from a cubic meter of soil is greater than your smoke detectors outputt. The people in our society that recieve large amounts of radiation from medical imaging or other processes are not genaraly still reproducing. Any fallout from re-entrying space craft does not exeed the background radiation here on earth. Power generation has proven to be clean. Having lots of weopons is not using them. I think we are at greater risk from chemical poisoning and pestasides dont you?

[KillRide]

I seiously think it would be nuclear weapons / warfare ( http://www.armageddononline.org/nuke.php ) that take a chunk outta the population.

I don't find the thought of 'mutually assured destruction' all too comforting. In the long run, it would have to be an asteroid impact ( http://www.armageddononline.org/asteroid.php ) or an epidemic similar to the 1918 flu. The more cures we come up with, the more the viruses mutate...

scary stuff.

[Bobunf]

“The more cures we come up with, the more the viruses mutate... “

Viruses have been mutating for a very long time; it’s how they avoid extinction from immune surveillance. But it’s extremely rare for a parasite to exterminate its host population; a poor long run survival strategy.

The Germ Theory of Disease is our most powerful defense against extinction from infection. We know how to protect against the spread of an infection. While pandemics will occur; extinction will not. The worldwide death rate from infection has been declining for two centuries. Reversals of such long term trends are rare.

Species suicide form nuclear weapons is a possibility, but we seem to have overcome an acute phase of that danger, which speaks well, I think, for our future safety from this danger.

Bob

[astromark]

Yes, I agree with Bob. The Nuclear threat does seem to have diminished. Even after the Pentagon and the twin towers were hit the USA did not launch a nuclear responce. Major asteroid strike or commet impact could put us in dier predicament. I wonder if we are safe from our selves still. As we have seen, a small group of fundamentalists or any extremist group could start something we cant stop. Keep an eye on that commet. If its not moving against the background over a few days. Its comming strait in. Oops.

[filrabat]

Yup. We will come to an end one day. If not through our own human-induced foolishness, then either due to
(1) the ever-brightening sun or through all the hydrogen (star fuel) being locked up in stars and star remnants, or
(2) the last main sequence star fading away, or
(3) ENTROPHY (esp proton decay, if protons do indeed decay in the long run).

[ChromeStar]

Maybe Not there has been some speculation of being one day able move to another universe - one like our own or inhabitable

[GOURDHEAD]

While pandemics will occur; extinction will not. The worldwide death rate from infection has been declining for two centuries. Reversals of such long term trends are rare.

Don't forget the prions: they could be the principle cause of the dinosaurs' extinction...aided and abetted by the asteroid.

[eburacum45]

Are we talking about Mad Dinosaur Disease here?

[GOURDHEAD]

Or some equally fatal malady. Prions may not be constrained to the central nervous system.

[Bobunf]

I think of all the things that might cause the extinction of a species prion disease, as manifested in mad cow disease, is one of the least likely.

Firstly, the incidence of the disease is very low, in humans barely at the level of delectability—less than one in ten million.

Secondly, the disease generally manifests itself after the primarily reproduction years, and is thus irrelevant to species survival.

Thirdly, the mode of transmission is pretty bizarre and artificial, involving cannibalism amongst herbivores. One would think relatively easily done away with.

Fourthly, nobody understands the mechanism that produces the mis-folding of the protein. When that understanding is gained, protection from the disease will likely be much simpler and less expensive, as has been the case with almost all diseases.

Whether prions had anything whatever to do with any species extinction, let alone dinosaurs, is just wild speculation. It could also have been some other disease, invading aliens, or horrendous allergy to some new parasite that also went extinct when its dinosaur host disappeared—leaving no trace. Or the whole thing could just be nonsense.

Rest easy; the world won’t end with a prion.

Bob

[lswinford]

Populations don't always follow straight lines or even exponential curves. History has shown a Europe full of people and comparatively devoid of people several times. Archeaology tends to show the waxing and waning of fortunes and populational pressures in distinct and sometimes dramatic fashion.

To quote from a rather persistantly popular old book, a certain wealthy king lamented, "I hated all my labour which I had taken under the sun: because I should leave it unto the man that shall be after me. And who knoweth whether he shall be a wise man or a fool?" He further noted, "that which now is in the days to come shall all be forgotten." The arrogance of comparatively recent years has today's people the most brilliant of luminaries and the ancients to be blithering idiots. Those cycles will undoubtedly continue. We will certainly having our shining moments punctuated by still more dark ages to come. Fertility will rise and fall, England and Sweden are excellent examples, technology will rise and fall, and history has abundantly demonstrated a consistent matrix of reasons. Sometimes fools succeed and sometimes the wise fail and sometimes the forces of the universe about them weigh more heavily than we are able, as a recent earthquake and tsunami so horribly demonstrated.

Economics and business management has brought about some interesting things that may assist in the perpetuation of the human race. Risk management, asset allocation and diversification, and the net multiplier effects from replicating successful enterprise models and timely disbanding of unsuccessful models. When big chain businesses expanded by placing similar or functionally identical successful stores in still further places they not only expanded their profit potential but minimized certain kinds of business risks. While events that caused business to be poor in one area may cause business to be good in another, therefore if you had businesses in both areas then the net effect moderated losses in one place with gains in another. Whether building habitats on the moon, Mars, etc. or Gerard O'Neal-type cities in space, or some combination of both, this is spreading our presence, and spreading our risk, and sustaining our technology--and enhancing our survivability. Similar voices in the future will mimic our cries that 'earth is our crib but man cannot stay in the crib forever' and we will not only want to expand to habitations beyond earth, but beyond our solar system, and eventually even beyond our galaxy.

But then, as that certain old book also notes, we may encounter limitations overwhich we might not be able to surpass, "Hitherto shalt thou come, but no further." Then too, the first Superman movie also depicted the risk of staying in one place and becoming oblivious to dangerous changes.

[folkhemmet]

Will we die out? Well, it's going to be pretty hard to wipe out all 6-7 billion of us. Even if a man-made or natural pandemic takes out 99.9 percent of us that still leaves, if my math is correct, about 6 million people. That's how many people were around at the end of the last ice age. And here we are writing on computers.

This is not to say that we shouldn't be worried about dying out. It is pretty hard to refute the argument that we should be preventing the extinction of our own species the best we can. All of art, science, literature, politics, and argumentation itself depends on the existence of human beings.

We must distinguish between our extinction or the end of the world and the end of the world as we know it. I remember having a discussion about this very subject with friends in the ninth grade. My one friend pointed out that most disasters, man-made or otherwise, would not mean the end of the world but rather would mean the end of our modern technological civilization.

As for complete extinction, I heard a former astronaut on NASA TV recite some figure that there is a 1 in 455 chance that humanity will be wiped out by either a comet, asteriod, or super-volcanoes within the next 100 years. He was saying, and I believe quite correctly, that we better start moving off earth and colonizing the final frontier before it is too late!

[Bobunf]

"Fertility will rise and fall"

I don't think there has ever been a time when fertility for some definable group of humans displayed any kind of cyclical behaviour. Do you have some example?

I think there is a fairly strong inverse correlation between GDP per capita and fertility, to some extent overwhelmed by the strong secular downward trend of fertility in the 20th century. But I don't think there's any broad cyclical behaviour in GDP per capita, except, perhaps, for the business cycle, which is pretty short term; and, I think, completely unrelated to human survival.

Bob

[lswinford]

Fertility rates fell in Rome because of lead poisoning from the plumbing, although specific numbers would be hard to derive. The fertility rates in the English colonies in North America were a scandal to England in the 17th and 18th centuries. The populations of places like England and Sweden were referenced because of some common statistics over time. Sweden has a population between 8-9 million today. A study in Historical Methods (Anders Brandstrom, 3/22/1998) for infant mortality suggests that the Swedish population essentially doubled between 1850 and 1900. Two years later, John Rogers illustrated periods of birth rates historically rising and falling in Sweden. Use the statistical site ssd.scb.se for some numbers: short-term stagnation with sudden jumps like 1891-1892-1893 and before WWII compared to after and in the 1860s there was a measurable decline following an uneven increase. Jean-Claude Chesnais (Population and Development Review, 12/1/1996) observed a paradoxical population shift in Europe in his introductory statement:

"Fertility rates in Western Europe are well below replacement level while population growth rates are close to zero. Although Mediterranean nations used to exhibit high fertility levels while Scandinavia used to report low ones, the situation has been reversed. In examining fertility differential, the status of women in Italy and Sweden are analyzed and the attitudes and policies toward the family in Italy and Germany are contrasted with those in Sweden and the UK."

Fertility rates float for a variety of reasons and those reasons change over time. For instance, Chesnais' prescription for fixing the population problem in Europe is, "Evidence shows that higher status of women may be needed in raising fertility to replacement level in advanced industrial nations." It is almost a truism that populations where women have low status and families face great hardships or there is low range of educational or entertainment sophistication have high birth rates, greater fertility rates. These things are not static. The scandalous rates of America have changed, wherein the English descendants, generally comparatively prosperous, have few children while immigrants, often from comparatively impoverished lands, have many. American Blacks had been the predominant minority here, but the Hispanic population, with a noble showing by various Asian immigrant groups are displacing Blacks and Native Americans, and also minimizing their relative socio-political influence.

[Bobunf]

“Fertility rates fell in Rome…”

What is your source for this assertion? And what period(s) of time is this supposed to involve? One is talking about around 1100 years for the Western Empire. And what areas? Just the city of Rome? Italy? The entire Roman Empire? What about Byzantium? Any assertion as to the cause of any possible fall in fertility related to lead plumbing would be the wildest speculation—supported by nothing.

There is a very big, and crucial difference between fertility, birth rate and population change.

The total fertility rate is the expected lifetime number of live births per female, To put it specifically, for a given year, t, the sum for all x of the number of births in year t to women aged between exact ages x and x +1 divided by the number of women attaining exact age x in year t where x is any whole number between 15 and 50.

For the number of years in the future that one knows the total fertility rates, one can accurately predict population. Death rates and migration are compartively stable, and have generally less significant effects than fertility rates.

The birth rate is equal to the number of births in a year divided by the total population. This is not a very useful number for most purposes since the denominator includes men, children and women over 50. Also, and obviously, as different sized cohorts of women move through the life cycle, the birth rate will rise whenever a relatively large cohort enters periods of high age specific fertility.

To give a simple example, if all women gave birth at age 20, and it happened that there was a co-hort of women twice the size of the other groups, and all cohorts had the same age specific fertil-ity rate, the birth rate would suddenly double when this cohort reached age 20, then fall back to the background. And this process would cyclically repeat every 20 years, even though the total fertility rate had not changed at all. The significance for predicting future population size would be about zero.

Changes in total population are affected by death rates and migration as well as fertility. It’s not possible to impute fertility rates only from changes in total population.

“The fertility rates in the English colonies in North America were a scandal to England in the 17th and 18th centuries.”

How does this subjective statement say anything about quantitative measures of the total fertility rates? Maybe these people were prudes; maybe they read or heard exaggerated or inaccurate ac-counts involving sexual promiscuity or other phenomena; maybe there was a political or eco-nomic agenda.

“Fertility rates float for a variety of reasons and those reasons change over time.” I don’t think any evidence supports this assertion. Total fertility rates in the modern world—the only period for which we have reliable quantitative information—show a very consistent strong secular down trend. No floating.

Why fertility rates change is not known. People speculate and develop hypothesis, but the lack of understanding is, I think, rather dramatically demonstrated by the 2002 UN release of population estimates for 2050. Their estimate of world population was reduced from 11 billion to 8.9 billion—almost a 20% reduction involving looking ahead little more than a generation.

Since we don’t know the reasons, I would think it would be hard to maintain that those reasons have changed.

Bob

[rainbow]

The earth is already dying as people is wasting the earth's resources. another 20- 100 years more and the earth will really really die.mankind will be wiped out... .. some people thought if going to mars to live after earth died.... but how can we get water? so thers no way to solve that problem... Anyway, who knows about space explorations???? post some answers about the solar system please.... i need to do some work on those...

[suntrack2]

the five aspects are very important in this regard:
1. sky,2.air,3.water,4.fire.5.earth these are the basic factors while their proportion taking into account anything if grows then the calamities occur, if calamities occurs then these are falling impact on human being, later the man heated with these factors. the question of the life of earth? it is difficult to say, but earth will remain but the proportion of the factors may be largely increase or may be largely decrease,

have anyone imagine if a great sea turn into the desert? if a dezert turn into the big mountain? the mountain turn into the deep valley? these are all questions of irregular results of the nature afterall, if the time has come for the mass deaths of the humankind on earth then it is upto the nature, nature shape up the weight on earth, earth itself manage its load in shaped manner. so this question of "will we die out" no immediate statement can be made in this regard. may be the situation comes later than only a couple will be there on earth? then it will again reproduce the paradise of humankind on earth.

[Ola D.]

Originally posted by lswinford@Jan 3 2005, 03:06 PM
Populations don't always follow straight lines or even exponential curves.

No they don't.
Populations form a sigmoid curve (S-shaped curve) which is divided into 3 parts representing three stages: lag, log and stationary.

The lag curve shows slow increase in numbers of the population as the reproduction rate is fairly low because at this stage the population is tryiing to accomodate and adapt the surroundings. The log shows an exponential growth rate. While in the stationary the death rate would equal to birth rate.

Scientifically, we, humans, are in the log phase. A constructed plot of the world human population would appear as steeply rising J-shaped curve.