Better understanding evolution by changing the popular focus

Mainpage / E-Mail / Facebook / Twitter

Better understanding evolution by changing the popular focus

(this text is a first draft, any comments are welcome.)

Introduction

Charles Darwin. The father of the evolution theory. Natural selection, survival of the fittest, adaptation, random mutation, sexual selection. A well known name and well known concepts. We all know that individuals in a population vary slightly due to genetic drift, random mutation, random recombination and a few other mechanisms. Some of these individuals are better adapted to survive in an environment than others. This includes sexual ability, the ability to secure a mate and reproduce, in effect the reproductive rate. These individuals are the ones that pass on their genes the most. Species change gradually over time, getting better and better adapted to their environment. Sometimes this results in evolutionary races where one species tries to out do another.

When an environment changes, it can suddenly wipe out whole species, leaving only alive those individuals and those species which possess the traits necessary to survive in the new circumstances.
These are the notions that live in todays popular scientific discourse across multiple disciplines and in the popular media (the notions in the field itself might differ).

Our current popular paradigm states:

Natural selection via survival of the fittest.

Focus:

Competition between individuals and species.

Mechanism:

Sexual selection of succesful adaptations gained through random genetic alteration. Variations exist in any population. Some individuals have a higher rate of reproduction. Their genes offer the best combination of adaptation to the environment, fertility and sexual attractiveness. These individuals can pass on their unique traits more succesfully and gradually replace others, thus altering the species.

Theory:

Evolution is change in the heritable characteristics of biological populations over successive generations by means of natural selection which in turn operates via the mechanism of survival of the fittest random genetic alteration.

Fittest here is meant as the most succesful in reproduction, not necessarily the strongest.

Sources of the popular notions for evolution:

https://en.wikipedia.org/wiki/Evolution

http://www.darwins-theory-of-evolution.com/

https://en.wikipedia.org/wiki/Survival_of_the_fittest
http://www.livescience.com/topics/evolution
http://evolution.berkeley.edu/evolibrary/article/evo_0
https://answers.yahoo.com/question/index?qid=20080622111809AAZsx7G

Challenge

I claim that the popular focus for evolution theory is wrong. I propose that the most important pressure source behind evolution is change in the biophysical environment across space and time. Organisms for which a change in circumstances is significant will change on a functional level whereas organisms for which a change is not significant will merely expand existing capabilities and features. Only via changing circumstances can all life be explained. It is the mechanism behind creating new species. Adaption, survival of the fittests, random mutation and recombination, these are just some of the supporting mechanisms that allow species to change. If the media focus shifted from these supporting mechanisms toward the main cause behind evolution, the broad popular multi discipline discourse on evolution could change for the better.

Of course, this is a bold statement and might rub people the wrong way. And i am not exactly schooled in evolution theory, so i might be talking out of my backside. Perhaps what i state is already very well known. Then again, this is the Internet and this is just a blog.

I came to this theory because i had trouble understanding how the mechanism of evolution that are popularized in media could ever have had enough time (alteration cycles) to produce some of the functional aspects organism have that seem so useful that they could be interpreted as man made. There had to be something missing. Of course this was just a feeling or a mere guess. Yet it made me try to reconstruct how evolution might happen.

Biophysical circumstances as the main evolutionary pressure

Natural selection via changing circumstances

Did you ever wonder why some animals seem to have such useful appendices? Take the crab. It has an armored shell to protect itself. It has large claws to pick stuff up and defend itself. It's eyes are on stilts. This creature seems almost like something that is designed by a human. Our engineers designed many mechanical devices for us that are similar to the claws of a crab. Like diggers, cranes, etc. We also made armored vehicles to protect ourselves from gunfire. Now the key question is: how would you (randomly or otherwise) mutate a bacteria into a tank with claw? Into something that seems so purposefully designed? How many cycles of reproduction and alteration would you need to achieve this? Given that the biophysical circumstances an organism lives in do not change?

Let's put it another way. You have a shark population in the ocean. Species X. You can easily imagine, that those individuals that are slightly faster, more agile and bigger might dominate. In other words, the species gets bigger and faster. Fins change form over time for more speed. Mouths, eyes, etc. do the same. So the original humble species X might evolve into a huge creature like a great white which has a big mouth, or a mako which is very fast. But why on Gods earth would it ever crawl out of the ocean? Or develop lungs? Why would changes that have no use be rewarded and build into species altering appendices that have a function the original species never needed to survive? Oceanic circumstances have remained fairly constant for millions of years at a stretch, with some variation in temperature and salinity. No need to reward individuals with oddly shaped fins that allow you to crawl in the deep ocean. Yet there is the epaulette shark.

Changing circumstances across space

Here we see that the popular focus for evolution theory is wrong. It's not only about survival of the fittest and genetic alteration. These are mere mechanics. The driving engine are the characteristics of the environment: circumstances. The reason a fish that can crawl is rewarded is that it can occupy a new circumstance: land.
What defines a new circumstance you might ask?  Any available difference to the original biophysical environment a species originated in that rewards a genetic variant of the original form. It can be a layer of colder water under a layer of warmer water. It can be a different type of food in the same layer of water. Another options is that the layer changes due to an event like tectonic plate movement.

Let's now take a look now how circumstances as opposed to just random alteration and survival of the fittest can far better explain the rate of evolution, the multitude of species and the designed appearance of life forms.

Basic setup

Suppose you have a bacteria of type B1 in environment E1. See picture 1.

-Cycle is the (random or otherwise) alteration cycle. An alteration cycle is the time it takes changes in the DNA to produce a functional difference in an organism.

-E1 is an environment at 10 meters of depth in the ocean, with rocks along the bottom of type 1.

-The bacteria of the type B1 has a flagellum to move it, pili to grip a surface and a membrane to conduct material interaction with the environment, letting food pass through but keeping out salt. These features are all adapted for survival in E1.

Adaptation and reward

If the environment remains the same what adaptation would be rewarded? There is no need for a thicker membrane, that just costs more food. The same goes for different pili. However, a faster rate of movement might get you more food. So the rewarded adaptation is:

B1 -> B2: larger flagellum.

If you follow the current focus of evolution theory, eventually you would just get bacteria with larger flagella. The other adaptations are not rewarded and lose ground in the population.

However, suppose that next to environment 1 (E1) there is another one. E2. This one has a different rock type that requires extra grip. So the rewarded adaptation is:

B1 -> B3: pili of a shape that provides more grip. In this case hook-like pili.

Similar, there could be an adjacent environment to E1 called E3. This is a deeper environment. The pressure is higher. So the rewarded adaptation is:

B1 -> B4: thicker membrane. 

picture1: click to enlarge.

Now let's continue to picture 2. We continue from E2. If everything else remains the same, B3 would evolve into B6 which has a larger flagellum to catch more food.

Suppose in the adjacent environment E4 there is more salt. That would result in B7, a bacteria that can survive the higher salinity via a thicker membrane. If everything else again remains the same, B7 would evolve to B8 with a larger flagellum during Cycle 3.

If you now look back at picture 1, do note that the bacteria B1 from E1 would just be the same always if no circumstances changed, except with larger and larger flagellum. In E4 B8 has this larger flagellum but also pili that provide more grip and a thicker membrane.

picture2: click to enlarge.

The evolution rate

We can surmise that environmental changes over space contribute greatly to the outcomes of the random alteration reward system. Many more alterations are rewarded. So you have more change with the same amount of random alteration cycles.

In picture 1 B1 does not die out, because E1 continues, it just grows faster. However E2 and E3 produce a fundamentally different species. These in turn also grow faster, if everything remains the same.

There is a famous example in evolution where butterflies with black wings survived better in certain areas during the early industrial revolution in England, because the trees were covered with soot. Do note that here no such catastrophe was needed, just slightly different adjacent circumstances.

Features that appear designed

Let's continue with picture 2. Suppose that E5, adjacent to E4, has less food. In order to guide more food to the membrane, the pili develop more substructures. So the rewarded adaptation is:

B8 -> B9: increased surface area of the pili.

Now suppose that adjacent to E5 there is an environment that has still water. The current is none existent. In E5 the flagellum and the movement of the water were enough to ensure that enough food passed along the membrane. But in E6 it's a different story. Through random alteration, pili that happen to get movement parts attached to them are rewarded. Now the bacteria can not not only swim but also move water towards its membrane laterally. It's adapted to E6 (B11).

To the casual observer it might seem that the bacteria has a very useful device. A sort of fan that pushed food to its membrane. Somewhat similar to the mechanical arm of a digger. It must be designed, what else could explain it? There is no way that natural selection through survival of the fittest and random alteration could have produced it in the old environment E1. There is no reason for B1 in E1 to evolve such a device and have it be rewarded. This complex device must have been purposely designed by God to operate in E6.

However if you follow the history you can see that B1 changed into B11 through B3, B7, B8, B9 and B10. The pili received functional change upon functional change, eventually resulting in the mechanical fan.

We can now surmise that changing circumstances also contribute greatly to the rate of functional change over time. And thus to the creation of species that are fundamentally different (not just bigger better faster), or in other words to biodiversity. Changes randomly build on top of each other, producing functionalities for the organism that to the casual observer might seem designed.

Changing circumstances across time

Now that we looked at space, we can look at time. Changing circumstances across time are far better known, since they have been popularized in the media. For example: extinction events like the fall of the dinosaurs. When circumstances change in the same environment the effect on evolution is much more dramatic. Suddenly individuals find themselves possessing the right adaptations or not.

Let's look at picture 3. In environment 1 random alteration produces B2, B3 and B4. B3 and B4 are alterations that survive better than B1 in the adjacent environments of E2 and E3 (picture 1 & 2). However in environment 1 they are of little use. So the bacteria of type B3 and B4 that remain in E1 have small numbers. The successful adaptation for E1 is B2, with the larger flagellum that allows it to move faster and thus catch more food.

Now let's suppose that E1 suddenly changes. Due to volcanic activity the ocean floor of E1 sinks several meters. Suddenly the large number of B2 and small number of B3 die out due to the increase in water pressure. The small number of B4 flourish to become dominant.

Similar to the changing circumstance over space, we can see that changing circumstances over time also contribute to the process of natural selection, drawing the mainstream focus of evolution theory even further from survival of the fittest via random alteration as the engine behind evolution, in favor of changing circumstances.

picture3: click to enlarge.

Evolution via survival of the fittest in a non changing environment

Lets now take a look at what the mechanisms from the popular media focus accomplish on their own, via picture 4. Supposedly the main cause behind evolution is that the genes that are best adapted to the enviroment (including sexual selection) survive via competition.

Suppose you have bacteria B1 in environment E1. Through random alteration it develops three variations, a thicker membrane (B4), different shapes of pili (B3) and a larger flagellum (B2). In Cycle 1 the rock type did not change and neither did the pressure. There is no benefit to the alterations of B3 and B4, and these types eventually die out. B2 however can gather food more quickly than B1, B3 and B4 and therefore becomes dominant.

We can surmise that if the enviroment does not change and we solely rely on competition, species do not change functionally, or at least not very fast. The change is not in the function of body parts, but rather their efficiency. A good example are ever more exotic birds of paradise, larger and larger crocodiles, etc. No really new species are created. A bird of paradise remains a flying bird, it doesn't become an ostrich.

picture4: click to enlarge.

Conclusion

It maybe clear that the environment provides the main evolutionairy pressure that rewards functional change in an organism and genetic alteration is just the mechanism (quote: James Feston). And it is not only change in the current environment that drives evolution. Alterations may allow individuals of a species to occupy adjacent environments to the one occupied by non mutated members. The original focus as stated in the introduction can now be replaced.

Our new paradigm states:

Natural selection via changing circumstances.

Focus:

Changing circumstances over time and space.

Mechanisms:

Circumstantial selection of adaptations gained through random genetic alteration.

Mobility of individuals across space.
Some individuals have traits that provide a better combination of survival chances, fertility and reproductive succes in the circumstances they find themselves in. Succesive generations of these individuals gradually replace the old population or colonize new territory. In this succesion all traits are passed on, not just the ones that gave the competitive edge.

Theory:

Evolution is change in the heritable characteristics of biological populations over successive generations by the mechanism of natural selection. Natural selection is based on the change or absence there off, of circumstances across space and time. These changes reward those specific alterations that are best adapted to a new enviroment.

Media support:
https://www.youtube.com/watch?v=plVk4NVIUh8 (added 29-1-17)

Obviously none of the scientific content mentioned in this article is news. The point is that popular discourse should shift its focus towards changes in circumstances in favor of competition, alteration, adaptation and sexual selection.