How did Global Warming become a Christian issue?

[queenofnines]

Mocking others before you present any facts is like advertizing for something you have never seen.

And like you're not guilty of this?  I agree, it is not a nice feeling to made to be felt stupid; however, such a defensive instinct is oftentimes just a reaction to constructive criticism.  People need to be pointed out where their arguments are weak and faulty, though, otherwise how can we ever expect humanity to learn and grow?  One should try not to be TOO over-the-top about it (flat-out calling someone a name is rarely acceptable), but there's nothing wrong with a little spunky jesting.  One may never see the err of their ways without it.

I did not know that scientifically equipping was the criteria for survival? This sounds a bit contradictory at the least.

Incorrect use of the word contradictory here.  You seriously think our survival/reproduction doesn't have limits?

Arbitrarily inserting the idea that large numbers were wiped out without any evidence is a mythical mindset. Not only have you not presented what "large numbers" really mean, but you also have not provided anything that is valid. This seems like a philosophical, faith based message, IMHO.

Sorry because I didn't go into grand detail you think my information was arbitrary or in any way false!

"A dramatic population bottleneck [an evolutionary event in which a significant percentage of a population or species is killed or otherwise prevented from reproducing] is theorized for the period around 70,000 BCE (see Toba catastrophe [VOLCANO] theory). After this time and until the development of agriculture, it is estimated that the world population stabilized at about one million people whose subsistence entailed hunting and foraging, a lifestyle that by its nature ensured a low population density." ~ World Population Wiki

Then we have The Plague of Justinian, which caused Europe's population to drop by 50%; The Black Death, which wiped out 125 million people (and took 200 years to regain that number); 90% of the Native Americans were wiped out by smallpox, measles, and influenza...these are all historical FACTS.

I found it really weird how you questioned my statement that large numbers of people have been wiped out throughout history.  And how you put a label of "philosophical, faith based message" on what was not my humble opinion, but universally-accepted FACTS.  I give you kudos for sticking to the creationist story, though - I prefer believers who actually stand by what their holy book says.     And yes, I do have ulterior motives for saying that. 

[liljp617]

Well shoot!  How could dozens upon dozens of Ph.D-holding mathematicians, anthropologists, and evolutionary biologists have made such a simple mathematical error!?  Back to the lab it is, and let's check the basic math this time ya dumb scientists -.-

Humans are in the genus homo, which is estimated to be roughly 2.3-2.4 million years old.  A species of the genus homo is homo sapiens, which would have resembled modern humans quite a lot (only about 3/4 the brain size however) -- estimated around 500,000 years.  No informed person holds to 200,000 as being the estimated time humans began walking Earth -- that is the estimated time frame for homo sapiens sapiens, which are dubbed a sub-species of homo sapiens (within the genus homo) because they're anatomically modern humans.  Humans, as a species, have been on this planet much longer than 200,000 years.

[queenofnines]

Humans, as a species, have been on this planet much longer than 200,000 years.

Yep, and that's why I said "modern" humans previously (just in case anyone thinks this is a pick on me; I don't think you are).

[rwdeese]

Well shoot!  How could dozens upon dozens of Ph.D-holding mathematicians, anthropologists, and evolutionary biologists have made such a simple mathematical error!?  Back to the lab it is, and let's check the basic math this time ya dumb scientists -.-

Humans are in the genus homo, which is estimated to be roughly 2.3-2.4 million years old.  A species of the genus homo is homo sapiens, which would have resembled modern humans quite a lot (only about 3/4 the brain size however) -- estimated around 500,000 years.  No informed person holds to 200,000 as being the estimated time humans began walking Earth -- that is the estimated time frame for homo sapiens sapiens, which are dubbed a sub-species of homo sapiens (within the genus homo) because they're anatomically modern humans.  Humans, as a species, have been on this planet much longer than 200,000 years.

It merey shows that education, in and of itsself, does not equal common sense. The simple math does not fit. I noticed how you didn't directly respond to the argument. Instead, you used another logical fallacy: Misuse of authority - this is an attempt to prove a conclusion by appealing to a real or alleged authorty in such a way that the conclusion does not follow. In other words, so what if many PhD holding people believe in evolution - the facts still must be proved. Anyone reading your response will notice how you do not demonstrate with a single bit of evidence where my math was wrong. Actually, it was wrong in a very specific sense. I kept giving the atheists the benefit of a doubt. The reality is that my numbers should have been much higher. I hope your reponses begin to really engage in the arguments.

[lvstephanie]

What I have a problem with is modern humans have been the same for 200,000 years right? So why are we not evolving? Or is this it, we are going to stay this way forever?

We ARE evolving... Haven't you noticed that populations living nearer to the equator (especially for long periods of time) tend to have darker skin? The added melanin in their skin allows them to bare the sun's rays better, especially where the radiation is the strongest along the equator.

There are other differences between different segments of the human population. Africans tend to have a higher rate of sickle cell anemia than other populations. This is actually an evolutionary trait gained by this population to combat malaria, which is most prevalent in the African jungles. The sickle-shaped blood cells are resistant to infection by malaria; however a person with sickle cell anemia will also die of their disease. However, the gene responsible for SCA is recessive so it requires the offspring to get the gene from both parents meaning only 25% of the population will contract the disease (assuming normal disbursement of the gene among the population). 50% of the population, however, will have one gene for the sickle-shaped cells from one parent, and the other gene for normal shaped cells from the other. These people are also resistant to malaria and can still live normal lives.

The problem with what you attribute to "not evolving" is that natural selection has become less and less of a factor in humans. As our technology increases, things that would have been a selecting influence in older populations are now no longer a factor. As Q-of-9 pointed out, there was a period of time of population stabilization before the advent of agriculture. This was because the selecting criteria of adequate nutrition was eventually reduced by the technology of agriculture. I would further hazard to guess that irrigation, fertilization, seed selection, motorized farming equipment, refrigeration, etc. has decreased this selecting criteria even more to the point where it is negligible to today's population.

In fact with the Industrial Revolution, transportation has greatly eased the stresses of older populations. As such, different subsections of our population are able to get together much more easily and procreate. For most of human's existence, the different continents provided a natural barrier for the co-mingling of other segments of the population. As such you saw the evolution of those different pockets of humans, from the outward appearances like skin color to more inward differences like the trait for sickle cells. Probably the next phase in human evolution will be more of a blending of all of these various traits. As a local radio personality says, we're going to become a race of "Mocha" people where we will eventually begin to look all the same.

[rwdeese]

RW: Mocking others before you present any facts is like advertizing for something you have never seen.

And like you're not guilty of this?  I agree, it is not a nice feeling to made to be felt stupid; however, such a defensive instinct is oftentimes just a reaction to constructive criticism.  People need to be pointed out where their arguments are weak and faulty, though, otherwise how can we ever expect humanity to learn and grow?  One should try not to be TOO over-the-top about it (flat-out calling someone a name is rarely acceptable), but there's nothing wrong with a little spunky jesting.  One may never see the err of their ways without it.

I do not have a problem with spunky jesting (although, when a believer does it on this forum, he is openly attacked by the "non-militant atheists). I am merely pointing out how you have not presented any facts for your case.

RW: I did not know that scientifically equipping was the criteria for survival? This sounds a bit contradictory at the least.

Incorrect use of the word contradictory here.  You seriously think our survival/reproduction doesn't have limits?

The birth rate in most western countries is slowing down dramatically. These are the countries that possess the scientific knowledge to help people live longer. The countries that do not possess this knowledge are growing phenomenally. So, although we may live longer, these other countries will double their populations much faster than we - even with their death rates. So, the point I am making is that longevity may increase for societies that embrace the "scientific" know how, but that does not necessarily equate to population growth.

RW: Arbitrarily inserting the idea that large numbers were wiped out without any evidence is a mythical mindset. Not only have you not presented what "large numbers" really mean, but you also have not provided anything that is valid. This seems like a philosophical, faith based message, IMHO.

Sorry because I didn't go into grand detail you think my information was arbitrary or in any way false!

Yes, I do... I will respond to these examples. I appreciate you actually responding to my argument instead of more ad homs which I find with some of the other atheists on the forum.

"A dramatic population bottleneck [an evolutionary event in which a significant percentage of a population or species is killed or otherwise prevented from reproducing] is theorized for the period around 70,000 BCE (see Toba catastrophe [VOLCANO] theory). After this time and until the development of agriculture, it is estimated that the world population stabilized at about one million people whose subsistence entailed hunting and foraging, a lifestyle that by its nature ensured a low population density." ~ World Population Wiki

1. I would like you to notice the word "theorized" in the first sentence. I get it. We "dumb" people are expected to believe a myth based upon no evidence whatsoever. Wow!

2. What does the theory hold:
A. They theorize that billions of people died: Well, if man was here over 200,000 years ago, there must have been billions upon billions of people who died by 70,000. Just a side thought - where are all the fossil records that verify this amount of deaths. If my calculations are right, there would have to be one body every 10 feet of this planet. Shouldn't we find hundreds and thousands of these fossils at the very least to verify this craziness.
B. They theorize that billions of people were prevented from reproducing. LOL The theories that one must come up with in order to prove evolution - my goodness. So, I want to know what prevented people from reproducing?
C. They theorize that a volcano created all of this catastrophe.
D. After the catastrophe, only 1,000,000 people were left and this population was stabilized that way for who knows how long.

3. This is a perfect example of how atheists place their faith in those they believe have come to a true understanding of the world around them. Although there are other articles that bring up more research (having read some of them to respond to this quote), all of them are full of un-provable myths and circular reasoning. It takes a lot of faith to believe this stuff. They actually want people to believe what they say without a shred of evidence - not a shred. If this is the atheists definition of facts, I am convinced more than ever about the faith of atheists!

Then we have The Plague of Justinian, which caused Europe's population to drop by 50%; The Black Death, which wiped out 125 million people (and took 200 years to regain that number); 90% of the Native Americans were wiped out by smallpox, measles, and influenza...these are all historical FACTS.

Well, finally something with legitimate evidence is presented. Yes, there was the plague of Justinian. We have some records of how many died in many cities throughout the Eastern Roman Empire. There is no evidence that it was worldwide, however. Yes, we have evidence of the Black Death Plague. Again, we have no evidence that it was worldwide. We do have evidence that approximately 50% of the population died. Concerning the Native Americans, there isn't any evidence that 90% of them were wiped out. There is evidence that 90% of the Native Americans of the Massachusetts Bay were wiped out. We do have evidence that many Native Americans died from diseases between the 1600s and 1800s, but no numbers are recorded.

None the less, if you take time to read my numbers, I have included a 50% death rate every generation, plus a 25% attrition death rate. Even giving those astronomical odds in favor of the evolutionary theory, the population numbers do not fit whatsoever. The present population should be over 50 Billion people. It is interesting to note, however, based upon the death rate and birth rates that we have records for over the last 500 years, that the present population totally fits mathematically to about the time of Noah's family repopulating the earth. Talk about sound mathematical evidence! Real science will always agree with the truth of the Bible!!

I found it really weird how you questioned my statement that large numbers of people have been wiped out throughout history.  And how you put a label of "philosophical, faith based message" on what was not my humble opinion, but universally-accepted FACTS.

The facts that you have presented have not in any way proven your contention. It merely proves that the death rate due to disease is profound at different points in history. However, my numbers accounted for the worst case scenarios taking place every single geneation. Yet, this simple math demonstrates that we should have a much greater population than we do, or at the least, we should have hundreds and thousands of fossilized bodies (or evidence of population) every square mile of the planet.

I give you kudos for sticking to the creationist story, though - I prefer believers who actually stand by what their holy book says.      And yes, I do have ulterior motives for saying that.  

lol

[queenofnines]

The birth rate in most western countries is slowing down dramatically. These are the countries that possess the scientific knowledge to help people live longer. The countries that do not possess this knowledge are growing phenomenally. So, although we may live longer, these other countries will double their populations much faster than we - even with their death rates. So, the point I am making is that longevity may increase for societies that embrace the "scientific" know how, but that does not necessarily equate to population growth.

This is fact, but it is talking about our current state (the state of scientific advancement).  I in no way see how this supports your point regarding the math of populations that came before we had scientific advancement.  edit: Upon a re-read of your statement, I see you are trying to assert that population growth is absolutely exponential, which isn't true.  The reason why we had such a large spike recently is a direct result of better food and better medicine.  However, with further advancement also comes the knowledge of all of the costs to raise a child and BIRTH CONTROL, which has an adverse effect on absolute exponential growth.

1. I would like you to notice the word "theorized" in the first sentence. I get it. We "dumb" people are expected to believe a myth based upon no evidence whatsoever. Wow!

Scientific "theory" is not the same as the colloquial use of the word theory.  Any non-ignorant person knows that.  Also, science - unlike religion - does not offer absolutes, nor does it lie to us about knowing things it doesn't.  It simply keeps looking into a matter and presents the best evidence to explain an event along the way.

Again, I can't believe how ungrateful people are sitting at their PERSONAL COMPUTER using THE INTERNET.  Religion didn't give you those -- science did!

there must have been billions upon billions of people who died by 70,000.

Where do you get this "billions upon billions" from when man lived in small tribes, had to rely on its immediate family group for food, and died young (lacking advanced medicine and all)?

This is a perfect example of how atheists place their faith in those they believe have come to a true understanding of the world around them.

I'd rather place my "faith" in a team of people who dedicate their lives to improving, enhancing, and understanding the world as it really is than some collection of writings that were written 2,000+ years ago by anonymous, superstitious idiots.

There is no evidence that it was worldwide, however.

It's significant because the population was much smaller then and it predated Europeans coming to America.

Talk about sound mathematical evidence! Real science will always agree with the truth of the Bible!!

There is also some kind of quack equation that tries to demonstrate how god did use the Big Bang + 6 days to get to the timeframe of the universe that scientists state.  One can start off with a premise and then manipulate data and come up with crackpot theories as he pleases - this, however, is not real science.

Good post, btw lvstephanie!  

[liljp617]

Well shoot!  How could dozens upon dozens of Ph.D-holding mathematicians, anthropologists, and evolutionary biologists have made such a simple mathematical error!?  Back to the lab it is, and let's check the basic math this time ya dumb scientists -.-

Humans are in the genus homo, which is estimated to be roughly 2.3-2.4 million years old.  A species of the genus homo is homo sapiens, which would have resembled modern humans quite a lot (only about 3/4 the brain size however) -- estimated around 500,000 years.  No informed person holds to 200,000 as being the estimated time humans began walking Earth -- that is the estimated time frame for homo sapiens sapiens, which are dubbed a sub-species of homo sapiens (within the genus homo) because they're anatomically modern humans.  Humans, as a species, have been on this planet much longer than 200,000 years.

It merey shows that education, in and of itsself, does not equal common sense. The simple math does not fit. I noticed how you didn't directly respond to the argument. Instead, you used another logical fallacy: Misuse of authority - this is an attempt to prove a conclusion by appealing to a real or alleged authorty in such a way that the conclusion does not follow. In other words, so what if many PhD holding people believe in evolution - the facts still must be proved. Anyone reading your response will notice how you do not demonstrate with a single bit of evidence where my math was wrong. Actually, it was wrong in a very specific sense. I kept giving the atheists the benefit of a doubt. The reality is that my numbers should have been much higher. I hope your reponses begin to really engage in the arguments.

Fair enough.  Let's talk then...

Oh reallly... modern humans have been around for 2000,00 years. Yet, we have only about 6 Billion people on this planet. Talk about a mathe problem! WoW!

Heh, seriously?  People thousands of years ago were not scientifically equipped for all manner of diseases, plagues, droughts, and other ills...therefore, populations were very much at risk for having large numbers wiped out.  The explosion of population we see now is the direct result of the Agricultural and Industrial Revolutions, which didn't happen until the 17th-19th centuries!  Also the amount of progress we are expected to have in the 21st century alone is equivalent to 20,000 years worth of progress that came before it.

For someone who claims to have Ph.D's, I'm surprised you would say something so silly!

Mocking others before you present any facts is like advertizing for something you have never seen. You may end up looking foolish!

1. I did not know that scientifically equipping was the criteria for survival? This sounds a bit contradictory at the least.
2. Arbitrarily inserting the idea that large numbers were wiped out without any evidence is a mythical mindset. Not only have you not presented what "large numbers" really mean, but you also have not provided anything that is valid. This seems like a philosophical, faith based message, IMHO.
3. Here, let me help you: Let us take your theory concerning the timeframe for humans as 200,000 years (this number is quite arbitrary, but many evolutionists [not all] believe it).

So, the question can be asked, "how long does it take for the population to double? If one were to invest $100 in the bank at 7% interest per year, it would take 10 years for this to double - $200.00. It would take another 10 years for that to double - $400.00. So, for the sake of argument, let us take two people and double their number. We won't count twins, etc... In normal circumstances, this would take a little less than 2 years. How long would it take these 4 people to double their number if all things are normal? Another 20 or 30 years? [excursus: the reality is that the first couple could have children every year, which would double the population in 4 years, and in by 8 more years the population would double again. However, we are giving the evolutionists the benefit of the doubt] To help the evolutionists again, we will propose that it takes 150 years for the population to double. This means that after 150 years after one couple procreated, 8 people existed. Now, let us ask a silly question: "How long would it take for the initial population of the two to become 6.7 billion people? It would only take 4,800 years! This is simple math, and is only meant to show how evolution does not "add up!"

Now, let us pretend that "??" evolved to be a human 200,000 years. Of course, to give the benefit of the doubt to the evolutionists again, we will pretend that two have evolved at the same time. So, we will start with one couple. Now, let us really help the evolutionist's cause. Let us say that the each couple only lived 150 years (btw, using 150 years gives the evolutionist a great mathematical advantage), but only had 4 children during those 150 years. So, this would mean that every time the population doubled, 25% would die. So, you start off with 2 people. They have 4 people. These 4 people have 16. However, 25% leave because of attrition. This leaves 12. Let us really help the evolutionist and say that another 50% die because of famine, disease, war etc... every generation from the beginning of man's existence. Now, you have 6 people living at the end of the first 300 years. These 6 have 4 children each. This is 24, but again, attrition takes 25%, leaving them 18. 50% die, leaving them 12. So, in 450 years, there are only 12 people. So, instead of double each generation, they are only adding. It takes them 900 years to double. Now, take 200,000 and divide it by 900 years for each doubling. You will come up with 222 doublings by the year this year. This means that all one needs to do is double the population on the calculator 222 times. Just doubling it 30 times will bring the population to 6.4 Billion. Ok, let us help the evolutionist out some more. Let us say that there was a major catastrophe that took place after 30 doublings. Only 10% live! That would be 6.4 million. We go back to doubling the population every 900 years. After 30 doublings, we now have 675539943986144 in population. Ok, let us help the evolutionist again. Another big catastrophe! This time only one couple lives. So, we start over, and it takes 900 years to double in population again. Now remember, for 200,000 years to pass by, we need to double 222 times. We have only done it 30 doublings. We have over 200 left. Ok, let us help them out some more, we have two or three more catastrophes, and we are left with one couple again. This time it is about 27,000 years ago. All the criteria is the same. We are only allowed to double every 900 years. Oh no - our calculations tell us that we have over 6.4 billion people on the earth again. Who came up with this 200,000 mythical number anyway?

For those who want to think deeper about this:

http://ldolphin.org/popul.html

a) populations do not grow in a similar exponential manner as you suggest. You're completely ignoring those who die - quite a thing to ignore. In fact any animal population grows according to the basic difference equation:
N(y+1) = N(y)*F(1-N(y))
where N(y+1) is the population next year, N(y) is the population this year, F is the fecundity (ie a measure of how randy and how fertile the population is). N(y) = 1 is the maximum population. N(y)=0 is extinction.

The important thing to note is the 1-N(y) - this represents natural limits on the population. These include resources and other environmental factors (availability of food, shelter etc). As the population rises (ie as N(y) gets bigger) then the growth factor slows down (1-N(y) gets closer to 0). This is obvious - increased competition for finite resources.

b) What is this nonsense about each couple 'only' lasting 150 years? Do you know any 150 year old couples? Neither does this 'give the evolutionist an advantage' - it is just fantasy. By saying that people live to 150 you are in fact allowing the population to increase more rapidly, not less rapidly. In fact the early hominids probably had a lifespan of 20 years or so. Even in the 17th century the average lifespan of a human was not much more than 30.

c) You completely ignore 'minimum survival' limits. Below a certain size all the energy of the group must go into foraging for food - this means that any children born are a drag on the survival of the group which in turn means pressure to limit population. You might think the thing to do would be to breed like mad to get more people to gather more food - but in the 6-10 years it takes to raise the children the group will have died out. This is one reason that we see populations go up and down like crazy. This is well known and can be observed in the lab with such specimens as the fruit fly (a favourite for this type of research because they are very short lived, thus you can breed a lot of generations in a short time).

d) We don't actually need to guess - we have pretty good data for human population numbers over the last couple of thousand years - the Romans were great census takers. It is estimated that just over 55 million people lived in the combined eastern and western Roman Empire (CE 300–400).
The Plague of Justinian caused Europe's population to drop by around 50% between 541 and the 700s. By 1340 Europe had a population of about 70 million and the world population is estimated at somewhere between 420 and 460 million. By 1400 the black plague reduced this by 100 million or so back to around 350 million.

It is only with the advent of the city that populations really started to climb (say around 7000 years ago). Before that the population scraped along pretty static - just as we see with modern primates. Even in virgin forest you do not get an explosion of chimp numbers, because the environment will only support so many and because of the high natural loss.

In short you're spouting nonsense based on a lack of understanding of population dynamics and simple maths.  The "simple math" doesn't work, because you're understanding of the simple math is incorrect.  Once you posit that a factor (be it population or whatever) grows in an exponential manner then, by definition, it will grow massively after a short period. Consider the story of the peasant who does a service for the emperor. The emperor asks the peasant what he would like as a reward. The peasant points to a chess board and says -

'Highness, put one grain of rice on the first square. Now put 2 on the second, 4 on the third, 8 on the fourth and continue until you have filled all the squares. I will take that as my reward.'

The emperor instructs the vizier to do this small thing. The vizier returns after a few hours and speaks to his majesty thus:
'Your highness, you are bankrupt and still our debt is unpaid.'
2^64 grain of rice is more rice than the entire world has ever grown or ever will grow.


One of two things is going on here: you don't know what you're talking about or you do know and you're being purposely dishonest.  Either way, I don't particularly care.  Your positions have yet to seem genuine to me in any thread and I know trolling/flamebaiting when I see it.

[queenofnines]

If my calculations are right, there would have to be one body every 10 feet of this planet. Shouldn't we find hundreds and thousands of these fossils at the very least to verify this craziness.

This pointing of fingers shows you are coming from an uninformed position.  Fossils are extremely RARE.  If a deer dies in a forest, it's not going to leave a fossil unless its body was preserved by something (volcanic ash, for example).  The deer is simply going to decompose and then recycle its matter back into the universe.

[lvstephanie]

a) populations do not grow in a similar exponential manner as you suggest. You're completely ignoring those who die - quite a thing to ignore. In fact any animal population grows according to the basic difference equation:
N(y+1) = N(y)*F(1-N(y))
where N(y+1) is the population next year, N(y) is the population this year, F is the fecundity (ie a measure of how randy and how fertile the population is). N(y) = 1 is the maximum population. N(y)=0 is extinction.

The important thing to note is the 1-N(y) - this represents natural limits on the population. These include resources and other environmental factors (availability of food, shelter etc). As the population rises (ie as N(y) gets bigger) then the growth factor slows down (1-N(y) gets closer to 0). This is obvious - increased competition for finite resources.

....

c) You completely ignore 'minimum survival' limits. Below a certain size all the energy of the group must go into foraging for food - this means that any children born are a drag on the survival of the group which in turn means pressure to limit population. You might think the thing to do would be to breed like mad to get more people to gather more food - but in the 6-10 years it takes to raise the children the group will have died out. This is one reason that we see populations go up and down like crazy. This is well known and can be observed in the lab with such specimens as the fruit fly (a favourite for this type of research because they are very short lived, thus you can breed a lot of generations in a short time).

That's interesting to point out the fruit fly, and the equation for population growth... Here's my little population math:

Surface area of landmass on Earth is about 1.5e8 square kilometers (km²) (The e8 means x10⁸ or 100 million; a 1 followed by 8 0's)
Assume each fruit fly occupies 1 square millimeter (mm²) (I'll use this for the sake of discussion, although this is an exaggeration since a fruit fly is about 2 mm in length)
1.5e8 km² = 1.5e20 mm²
Assume life expectancy of a fruit fly is 1 week (Another exaggeration since the development time (egg to adult) is a little over one week, not to mention the days they live after adulthood)
Thus assume 1 year has 52 generations.
Average female lays 400 eggs in her lifetime.
Assume only 1% survive (That is a HUGE exaggeration! That's a MUCH higher attrition rate than the 50% + 25% given for the human growth model posited by RW)
1% of 400 = 4 new flies survive each generation.
Parents die that 2nd week, so the fly population that 2nd week is only of the offspring = 4 flies.
From 2 parents come 4 new flies; thus the population doubles each week.

In 68 weeks, the population = 2⁶⁸ = 2.95e20 flies = 2.95e20 mm² space occupied by flies > 1.5e20 mm²
This is almost double the surface area of Earth's landmass in less than one and a half years (1.5 years = 78 weeks)

But how can this be?! Fruit flies have been on Earth MUCH longer than only a year and a half (heck, it's entire genome was sequenced in the year 2000)... Yet we don't see fruit flies occupying all of the area on Earth (even if I were to use the volume of the Earth and assumed 1 mm³ of space per fly, the population would be larger than the Earth's volume in less than 2 years). The reason is because of all sorts of pressures on the fly population, including food, living area, etc. This is what liljp meant by by the increased competition for finite resources. Even though at the beginning there may be a large population spike, eventually the population will either crash (the resources are too small to sustain the population, so the population declines due to malnutrition, etc.) or will stabilize (esp. if the population is able to learn what best population level will provide enough resources for each member to live).

When human's lived in tribes, the populations stabilized at a very low level because of this competition. Families would not have had 4 children, rather they'd probably have only one or two children. This is probably why the early Bible had a lot of laws regarding sexual morals (which were the laws of the Jewish tribes)... Laws proscribing promiscuity were probably due to maintaining healthy population levels (among other reasons). This is why the human population was so small for most of its existence; until only about 7000 BC, humans were hunters / gatherers. After 7000 BC, agriculture was beginning to be developed, which allowed humans to gather into larger societies. Even then, the populations wouldn't have drastically increased at that point either. Limitations in productivity, the poorness of early crops compared with today, lack of refrigeration, etc. all would have limited the amount of food available to the early civilizations. It's only been in the last 500 years (basically after the Industrial Revolution) that humans have been able to overcome a lot of these limitations on food.