"It ain't like it used to be!" unusually means new technology is replacing the old. Life just keeps getting better. Flush toilets, electric lights, the automobile, the jet plane, and now electronics to do information transfer, and underpin almost every activity.

Life is better than ever before in hundreds of measurable ways. However it is not better in all ways. The trends of the past are not the trends of the future.

We are not keeping track of what supports these trends. That if these trends change what it means to the lives of future generations.

If there are 10 cells present, when they divide, then the new population will be 20. When they divide again there will be 40. And when they divide again there will be 80 cells etc.

Cells can keep dividing until there is no more space or food for them to divide.

The population size of all biological species follow this curve. Some more gracefully than others. For example if you plow an island and plant just a few seeds of grass, the first years will have just a few plants that grow to seed. These seeds will fall or blown and most likely will find soil and grow new plant to seed the following year. Soon the grass will cover most of the soil and most seeds will never get to grow because they can nhot find soil where they can put donw a root. They will rot and become part of the soil. The seeds do not seem to scream in agony that they can not plant themselves and grow to grass.

Next lets put a pair of rabbits on the island. They two will have new babies each year and the babies will have babies. And as long as they have enough space to roam and grass to eat, their population grows and the curve rises from flat to vertical.

At some point the suckling rabbit babies are weaned and they find that grass is a little harder to find. In fact may of the new babies and the some of the older infirm rabbits can not find enough to eat and die when they previously had no trouble surviving.

The population continues to grow ever more slowly until some animal has to die for each new one survive.

Rabbits do not seem to mind this condition and parents of baby rabbits do not try to kill other rabbits to have food for their young.

They can get along in this state indefinitely as long as they don't eat all the grass down to the roots, the plants die, the soil is washed off the island, and the entire ecosystem is destroyed. This seldom happens. If it did in the past these both species are gone from the island.

Now lets introduce two mice on to the island. They eat grass and grass seeds. Maybe the one that would have rotted anyway. They follow the same population growth curve as the rabbit. They share the same food supply and thus the grass can not support both groups to the level they would be at if the other was not present. There is competion for food.

The mice do not try and kill the rabbits and the rabbits do not try and kill the mice. However, if either could eat all the food the other would stave.

Is humankind a biological species. Will its population follow the same curve as the goats?

The answer is a resounding yes. With two caveats.

The first is that humans can find ways to make the same sunlight produce more food. So unlike the goats, humankind's can fertilize and water the grass so the same land area produces more food and thus raises the level of the cap.

Technology raising the cap has been going on since humans kept records. So it might appear that population has been growing exponentially and the caps have little effect on the total population. We must be pretty much in the bottom half of the S curve.

We are still rising faster each year than the year before. As if we are not influenced by any of our environmental limits.

That is not exactly true, we are emptying the fisheries and forests. Raising the CO2 levels in our atmosphere, and killing off other species by taking their space.

We might be also killing off other humans, for example the Europeans killed off the native Americans to take their land. That is we could be experiencing a large expanding population of one group while a decreasing population of another.

That should be an indication that the time is not two far off when the limits of the environment will start reducing the slope of our growth. If all goes to biological plan we will have an increase mortality, and a decrease in fertility and the net result will be a constant population living at subsistence.

Did I say subsistence? Who is living at subsistence. Not you and not me. While a goat eats grass. After he is full he does not eat anymore. His maximum consumption is fixed by his stomach.

But you and I can store the grain turn it into other things. Convert some things into usable energy, feed it to other animals, Eat the animals. Get energy out of the grown. Convert energy into fertilizer. In other words the consumption per person can be anything we want. The waste requirements like CO2 or land fills can be anything we want.

On the other hand technology can squeeze more for us out the same space.

But all this does not change two things. The first is that we can not have any more stuff than the world will provide.

And second one of us flying around in his own personal Lear jet can make it impossible for

a lot of dirt poor farmers with a little irrigation pumps from irrigating and then not eating.

So it still a Sigmoidal curve. Expect instead of counting noses to get the relationship between total consumption and limits, to get a handle on how the population growth you are counting the size of foot prints. And w

Now lets and wolves to the island. The wolfe can eat rabbits or mice.

The wolf population can grow like any other biological species. However, its population is not limited by just the rabbits. The wolfe population can eat all the rabbits. And then start eating the mice. When the mice poulation drops the wolf population will stave and the two species hit their limits.

the mixe population cannot grow any more for they become easy to catch. The wolf population can not grow any more because they are close to starving.

If the wolves ate every mouse like they did rabbits, they could kill themselves by killing their food supply. The island would have only grass.

Now let's add two humans to the island.