Advertisements

Bare Bones Biology 019-Chickens and Eggs

I love looking out the window at our green and blue and brown world of sunlight and shadow, and being able to learn as much as I can about how it functions. I guess most everyone knows the bottom line is genetics. Of course, life needs all of its various parts and capabilities, but the thing that coordinates them all is the genetic system. The interacting functions of genes direct all of life functions, in response to whatever changes, and something is changing all the time. We couldn’t stay alive if we couldn’t respond to change, and the ecosystem responds to change by the process of genetic evolution.

Evolution is one of the most elegant processes of the living world, and Darwin didn’t know the half of it. Probably we don’t either, but we wouldn’t know any of it if we tried to understand without the scientific method. Science basically teaches us how to use the scientific method of evaluating facts. Religion wouldn’t be religion unless it were based in faith and science wouldn’t be science if it were based in faith. If we want to stop teaching science to our students, then we should be honest about it and stop. There is nothing honorable about teaching fake science instead of real science that is based in the scientific method.

So – we have talked about that enough. If you want to go back over the whole evolution series, you can find the transcripts at FactFictionFancy.wordpress.com, listed under BBB transcripts.

Now we can talk about something else. How about — ummm — which came first the chicken or the egg?

Or to put it another way — where did life come from? Almost everyone has thought about this sort of question, but the fact is that no person has a definitive biological answer. What we do know is that life comes from life. Carrots come from living carrot seeds. Baby chickens come from eggs. It would be impossible to make a baby chicken from scratch — it’s far too complicated. Baby chickens come from chicken eggs. Eggs can make chickens because eggs are also complicated. It takes a very complicated egg to make a very complicated baby that grows up to make a very complicated egg.

Everyone knows that life comes from life. If you put all the atoms and molecules of a living cell into a bag and shake it up, you would not get a living cell (it’s been tried). What you get is a bag of parts sloshing around, because it’s not just the parts that make us alive. It’s also the way the parts are organized. Life is perfectly organized in such a way that all the parts work together to do the processes that are necessary to be alive.

Chickens can make eggs that make more chickens, but people can not make chickens. We can use them, but we can not make them. Cells can make more cells, but people can not make cells.

Probably you knew that, and there is a reason why I brought it up — ecosystems are even more complicated than eggs. Or chickens. Ecosystems can make more ecosystems, but there is no way humans could make an ecosystem. Even though it feels like — with a good farmer, a couple of scientists and pile of technology, surely we could make or fix our ecosystem. But using the basic laws of nature is a very different thing from changing or fixing the basic laws of nature. In reality, the ecosystem was already doing what it is supposed to do before we started tinkering with it. It was keeping itself healthy by responding to changes in its environment. We can’t make it better than balanced.

Technology wants to pretend that we can control nature, but science knows that we can not. The carrot seed can make carrots, and the fertilized egg can make babies, but they can’t do these things on Mars. Chickens and carrots and ecosystems can make life from their lives, but only inside the ecosystem, and our technology can’t do it at all. We can destroy ecosystems, but we can’t make them and we can’t live without them.

Dr. M. Lynn Lamoreux
Bare Bones Biology 019
KEOS 89.1, Bryan, Texas

It is no accident that we all lie nestled together
in the curves of the universe.
We are tugged by the forces of celestial tides.
Time folds in on itself
and outward again in gladness
as we spin around,
each of us an utter miracle
in a sea of tiny white stars.

Jamien E. Morehouse
Rockland, Maine
April 3, 1999

Bare Bones Biology 018 – The Most Important Thing I Know About Evolution

Evolution is a change in a gene pool over time. That’s what I said. But is that really a naïve, reductionist definition? Yes, it is. Certainly the evolution of one species is a change in its gene pool over time, but there really is no such thing as a change in one species over time. Everything in the living ecosystem changes together, and all things in one way or another influence other things.

The word that describes this is Co-evolution. Co-evolution is the way in which two or more species influence each other as conditions of their lives change over time.

For example, think of two gene pools that influence each other. Here is a mouse species. Above is a species of hawk. The hawk eats some of the mice; the remaining mice are able to pass their genes into their mouse gene pool. If the hawk is not able to catch mice, or if it catches so many that there aren’t enough left to eat, it will starve and will not be able to pass its genes on to the next generation of hawk gene pool. Over time the two species co-evolve to reach a balance, so that there normally are enough mice, not too many hawks, the mice are good at getting away, and the hawks are good at catching food.

But, in reality we must consider also that there is another species of hawk in the same space, and it eats mice in competition with the first hawk species. This competition also leads to co-evolution of the two species of hawk, along with the mice. There are other prey species for the two hawks and there are predators upon the hawks. There are also owls and other birds, and coyotes and cats, and deer. All of them are co-evolving. Their gene pools are in a constant process of change over time as a result of selection by all the other organisms. Furthermore, it is not only predator/prey relationships that influence this dance of life. There are parasites, availability of nesting sites, availability of water, climate requirements, and availability of organic food energy. And then the animals pass their feces and then they die and other organisms find their supply of organic food in the remains and provide fertilizer for more plants.

You could imagine the gene pools of all the species in an ecosystem as overlapping shapes, like Venn diagrams, drawn on a piece of paper, and then they move forward through time like a movie, changing the boundaries of the diagrams where their gene pools overlap and influence other species.

But there’s even more, when we consider that the mice and the deer and many of the insect species that are eaten by smaller birds, these all eat plants. In fact, the plants are the only source or organic food energy that keeps this whole enormous blue/green marble of an earth ecosystem alive. Organic energy from photosynthesis is the source of all life on earth, and there are many, many kinds of plants and other organisms on earth that can do photosynthesis. These are food for the life of the ecosystem, and the ability to get food is the biggest kind of selection over the life of any organism of any species.

All the mice and deer and the insects and other organisms that eat plants — all these can pass on their genes if they survive. But if there are too many of them — they will eat up all the food plants and then they will not be able to pass on their genes because they will starve. Then there won’t be enough mice and deer to feed the coyotes and hawks and insect-eating birds, and they will not be able to pass on their genes because of starving.

In other words, the concept of evolution is a simplistic human construct. The real purpose of evolution is to maintain the dance of balance among all the parts of life, so that none of the species destroys any of the other species and all together give life to the whole earth ecosystem that gives life to them. The fittest organism is not the one that disrupts this dance of balance.