Guts

I've had a long convo with -a person who wants to remain anonymous-, a former Young Earth Creationist (YEC) about evolution (and religion, and abiogenesis, and morality...). This convo is ongoing with the exact same result; -S- returning to her default position of denial (of evolution) and affirmation (of creation). The latest development is that -S- is now a believer of Intelligent Design (ID); her beliefs have evolved (changed over time). She's not a Christian any more.

I'm not sure if she's gone from YEC to Old Earth Creationism.

It seems nearly impossible to convince -S- that evolution is possible, probable and, in fact, a scientific fact.

Still, one can only try :-) and try, and try, and try again.

The thing is that -S- needs to look at evolution from a different angle because she has been bombarded with creationist' propaganda that she chooses to believe over the biologists' evidence.

How can you convince someone who believes the earth is 10.000 years old, or less?

• Radiometric dating?
• Carbon dating?
• Plate tectonics?
• Erosion?
• Milankovitch Cycles?
• Magnetic reversals?
• Sediment layers?
• Dendrochronology?
• Calcareous rocks?
• K-Pg boundary?
• Stromatolites

All these points have been explained... to no avail. Whatever scientists measure, check and double check, it fails to make an impact. All these independent fields of science give ages older than 10.000 years.

Dendrochronology has more than one uninterrupted chronologies over 10.000 years old. It also has a method of cross dating which yields results up to 50.000 years old, the maximum limit of carbon dating.

Maybe she doesn't know about weathering of stones (similar to erosion) or about Igneous rocks.

The point being that multiple scientific disciplines, each boasting countless observations and experiments, all point to an old earth. Sediments, for instance, accumulate slowly as is observed and tested. Granite weathers slowly... as is observed and tested. Plates move slowly... as is observed and tested. Etcetera.

Take the Siberian traps, formed by flow basalt and massive. Creationists claim there were huge volcanoes during the flood... those would have resulted in other basalts because under water the lava cools rapidly. As is confirmed by 'observational' science.

But, lets return to the subject of evolution. Biology defines evolution as “change in allele frequency in populations”. As implied in my post about meiosis, this is really a truism. So much so, that creationists have started to adopt the phrase 'micro-evolution'... as if there exists a method for stopping 'macro-evolution' from happening.

Some people represent evolution as a causal process (even convinced 'evolutionists' do that); “this happened therefore life adapted”. This is a common misrepresentation. The real story is slightly different; “random genetic mutations happen all the time and some are better adapted to the changing environment”.

Lets examine an example. There is a population of prey and a population of predators. Some animals are faster because of their genetics and some are slower. The predators are capable of capturing the slower animals... The next generation of prey have more of the genes of the faster animals and, over time (over many generations), the whole population will become faster.

The same applies to the predators. They have faster and slower members and the slower members will be left without food and die. Therefore the slower animals will have less offspring and the whole population of predators will become faster.

Natural selection is an arms race between predator and prey... The real world is a tat more complicated as there are multiple prey species and multiple predators in an area.

Guts

One of the many strawman logical fallacies of -S-, is that “working guts need to be in place” for the evolution of the eye, wings, hands, etcetera to take place. In other words, guts need to have evolved before eyes, wings, hands, etcetera. The funny thing is that she's right. Biologists who have read -S-'s objections to evolution got seriously worried that the bar-room theory of evolution would collapse. That, or they had already taken that into account. You never know what scientists think of...

Here is a very short story about how the guts might have evolved. I'm not a biologist, so the following should not be taken too seriously.

1. A single celled world. All you can see, some 600 million years ago, are micro-organisms. Bacteria, virus... whatever else there is (amoebas). Evolution had been going on for 3 billion years already, so competition for food is fierce. One single random genetic mutation results in the collagen molecule causing bacteria to lump together.
   
   
   - A double celled organism in a sea of single cells? That's a competitive advantage, as it's harder for a double celled organism to be eaten, or it's easier for a double celled organism to trap food...
   
   
   Once collagen binds two cells together, this 'information' gets passed on to the next generation and this allows another generation to form groups or clusters.
   Suddenly, all single celled organisms die out overnight! As the brilliant “Why are there still apes?” question implies. 
   
   
   Or maybe not. The single celled organisms in New York are hardly affected by the death of a single celled organism in Sidney. Some cry a little when they read about it in the newspapers ("The Unicellular Times", "Cambrian News").
   
   
   Most lifeforms to this date are single celled organisms. No harm done.
   
   
   
   
2. The clusters of bound cells without structure, by single random genetic mutations over countless generations, become bigger and bigger as long as there is a selection pressure to increase size (predators and preys become bigger). At some point, a single random mutation makes the cells cluster in an unusual form which happens to get more nutrients to all cells.
   
   
   - A structured group of cells in an unstructured world? That's a competitive advantage, as the structured group of cells can grow bigger and get more food more easily.
   
   
   Once structure starts evolving, all single celled and unstructured clusters die out magically! That, or they are unaffected and evolve in their own peculiar way, generation after generation.
   
   
   Sponges are groups of cells without much structure. Push a sponge through a sieve and it will form another sponge. Sponges continue to evolve. No harm done.

3. The structured group of cells, an animal feeding off floating particles, other animals or plants, sticks to the seabed thanks to one single random genetic mutation.
   
   
   - An animal sticking to the seabed in a world of drifting food? That's a competitive advantage, as the food floats by. Animals sticking to the seabed keep evolving, just like the other organisms around it keep evolving; one generation at a time.
   
   
   
   
4. The animals evolve (a branching process) into wildly different shapes over millions of years. One single mutation makes a funnel shape. This might (I dunno) increase the water flow and get more food to the animal. A funnel evolves into a tube, one generation at a time. One single mutation at a time.
   A tube with water entering at one side and exiting at the other side is a rudimentary gut. This is the result of millions of generations of minute genetic accumulation. But evolution never stops.

5. Maybe the first muscles already evolved before the tube was closed, or maybe they evolved afterwards. At any rate, getting a contraction (with tube or without tube), is a competitive advantage, as water flow increases (and with water, nutrients). Pulsing tubes have more offspring and their pulses become better over thousands of generations. Each tube having multiple offspring and the fittest offspring having more...

And then a mouth evolved and an anus and gills and spines and fins and eyes and teeth and on and on and on and on evolution goes, accumulating tiny changes over generations.

The thing is that according to the theory of evolution, there once lived a common ancestor of all lifeforms with guts, from insects, to vertebrates. So, yes -S-, the gut was in place when eyes started evolving.

What's interesting is that evolution is a branching process where some organisms can maintain a successful shape for a long time. Single celled organisms are still hugely successful. Sponges are still around. Sea squirts are still there... and barnacles also...

Mutation (Genotype) → Characteristics (Phenotype) → Fitness → Meiosis → Repeat

-S-, I hope there's finally a click in your brain.

Ps. Karl Meyer (@karlmeyer), who has beer-reviewed this post, proposes a similar approach to sexual reproduction.
Pps. Edited at the request of -S-