Jump to content

Vertical and lateral evolution


Recommended Posts

There is a logical way, using only simple genetic considerations, to separate evolution into its vertical and lateral components. Vertical evolution could be seen as evolutionary progress. Whereas lateral evolution is more concerned with perturbations of existing systems.

 

This distinction is easier to see with an example. Let us compare a single cell with a hypothetical multicellular life form composed of only two differentiated cells that integrate. To differentiate, maintain, connect, and integrate these two cells requires additional DNA support that is not needed by the single cell. All the extra DNA requirement would make this vertical evolution.

 

If we had two birds of the same species, one is yellow and other red, one color may provide selective advantage. But this would be more of a lateral evolution since it may only require tweaking proteins within an existing integration.

 

If we go from our simple hypothetical two cell critter to a hypothetical critter with ten types of differentiated cells, the genetic control system will need to evolve vertically to differentiate, maintain, connect and integrate all those cells for the integrity of the integrated whole. Once that system is in place, tweaking that design is more lateral evolution.

 

The dividing line between vertical and lateral is not always clear cut, so we may need to define something in the middle, which is oblique evolution, or a combination of vertical and lateral evolution.

 

To put it all together, with a more realistic example, animals that bear their young live require additional genetic differentiation support compared to animals that lay eggs. At the very least, one has to add generic induced plumbing for the shared blood supply. This was vertical evolution. Lateral, may only change some outward coloring characteristics within the litter, but may not change any integrated systems. Oblique evolution may add additional functional optimization. This may go up and out.

Link to comment
Share on other sites

Vertical evolution could be seen as evolutionary progress.
I am having real problems getting past this. Progress implies direction and better. Such terms are frowned upon in an evolutionary context.

 

If we had two birds of the same species, one is yellow and other red, one color may provide selective advantage. But this would be more of a lateral evolution since it may only require tweaking proteins within an existing integration.

------------

If we go from our simple hypothetical two cell critter to a hypothetical critter with ten types of differentiated cells, the genetic control system will need to evolve vertically to differentiate, maintain, connect and integrate all those cells for the integrity of the integrated whole.

Please correct me if I am wrong - this is not my strongest field - but surely all that is required for your two cell critter to go to a ten cell critter is to tweak the hox genes. How then do you distinguish that from a similar tweak for your bird colouration?

 

I shall be interested to see what others think, but for me you have introduced an unnecessary complication that adds nothing to our understanding of the process of evolution.

Link to comment
Share on other sites

Your entire premise, the distinction between "progressive" evolution and "non-progressive" evolution, is entirely false.

 

You have made similar mistakes before, and I suggest you take some time to read works on evolution before continuing, particularly the works of Gould, who addresses this issue in many of his popular essays.

Link to comment
Share on other sites

Replicators are often seen as the beginning of life. Was this a vertical evolutionary milestone, or did a variety of mechanisms occur under the differing conditions?

 

Replicators are one area where enough attention was given to a vertical milestone. Other vertical changes haven't been thought out, so they come under a different standard. In the case of replicators, the design is the most flexible for almost all environments. This vertical milestone was proactive and not just reactive.

Link to comment
Share on other sites

Pioneer, could you address the points I raised in my earlier post.

First (and this is echoed by Mokele's first post in the thread) how do you justify the implication of progress in your thesis?

Second, expressed more generally, why do you seem to believe that large phenotype changes always require large genotype changes?

Link to comment
Share on other sites

Are you actually going to answer questions, or just continue to spew a mish-mash of random technical-sounding words?

 

This is what pioneer does... I'm surprised you're not used to it by now. No offense to the user, but why has no action been taken?

Link to comment
Share on other sites

Yeah, like a permanent ban. He contributes nothing but obfuscation and misguided ideas based on faulty premises.

 

He posts as "HydrogenBond" at other fora where they're dealing with the same nonsense, non-response to specific questions, and endless repetition of points repeatedly and flatly debunked.

Link to comment
Share on other sites

Intentional or not, Pioneer seems to be saying that genetic changes that cause a species to diverge should be called vertical evolution whereas genetic changes that simply lead to variations within a species be called lateral evolution. I think the lack of an understanding of how a species is defined is part of the reason Pioneer is having a lot of trouble expressing himself.

 

Anyway, why add more words to the dictionary when no one even reads it anyway?

 

Pioneer, if you have time, I recommend: http://en.wikipedia.org/wiki/Species#Definitions_of_species

Link to comment
Share on other sites

He posts as "HydrogenBond" at other fora where they're dealing with the same nonsense, non-response to specific questions, and endless repetition of points repeatedly and flatly debunked.
:doh:

If only I had known.

 

Nevertheless, Pioneer if you will make an honest attempt to address my two points you may have an advocate at the hearings that cannot be too far away.

Link to comment
Share on other sites

Maybe I am not explaining myself well enough. I am not trying to create confusion, but I see things in a different way, which may be helpful. I think I found a better example of vertical evolution.

 

Consider the heart or that pump that circulates the environment around the cells within a multicellular animal. As far as I know, there is no other basic mechanism, other than a pumping action, that could be substituted, within a large animal. Trees use capillary action. But without the pump, plants are stuck without mobility. The heart-pump appears to be a milestone for the progress of animal without any substitute. Even at the time of only replicators, this was a predefined milestone that had to be achieved or else animal progress on earth would have been stuck.

 

Where this vertical thinking came from was looking at how an animal grows from conception to birth. This is not done randomly, but have a basic schema that lays foundations and builds upon these. As each milestone is set in place, there is further differentiation both laterally and vertically.

 

If we start of a fertilized ovum all is does is divide to a point and then stops. This is conceptually the simplest type of multi-cellular. It is analogous to a dividing cell that sticks daughter cells. Once that milestone is reached, life builds on that.

Link to comment
Share on other sites

You're renaming something that's already known - adaptations. It's already well-known that some adaptations allow organisms to diversify into previously unavailable niches and forms. There's no need for a new word for it.

 

Also, you seem to be repeating Haeckel's mistake of assuming that embryonic growth mirrors evolution, which was disproven about 100 years ago.

Link to comment
Share on other sites

Pioneer, milestones are arbitrary points on a continuum, placed there by humans for their convenience in understanding the spectrum and because of our innate tendency to classify.

 

Now could you address the two points I asked you to address. Just to remind you:

 

Point 1: Progress implies direction and better. Such terms are frowned upon in an evolutionary context.

Point 2: surely all that is required for your two cell critter to go to a ten cell critter is to tweak the hox genes. How then do you distinguish that from a similar tweak for your bird colouration?

Edited by Ophiolite
Correct typo
Link to comment
Share on other sites

Point 1: Progress implies direction and better. Such terms are frowned upon in an evolutionary context.

 

I understand the convention. It is difficult to argue against this without making people frown. I don't wish to hurt feelings. All I was doing was trying to order some of the data as a function of changes in base systems which build up each other. Is there data that shows a more advanced version of a body system appearing before a simpler system? I would happy to see this data so I could put this to rest.

 

surely all that is required for your two cell critter to go to a ten cell critter is to tweak the hox genes. How then do you distinguish that from a similar tweak for your bird colouration?

 

The difference has to do when the gene is being expressed. If the multicellular occurs earlier for the same critter it is a base genetic effect that forms a platform onto which a wide range of change build. They can both be vertical, but one will take a bigger step and provide a larger platform for lateral change.

Link to comment
Share on other sites

I understand the convention. It is difficult to argue against this without making people frown. I don't wish to hurt feelings. All I was doing was trying to order some of the data as a function of changes in base systems which build up each other. Is there data that shows a more advanced version of a body system appearing before a simpler system? I would happy to see this data so I could put this to rest.

 

Consider fish living in lakes in caves. They have lost their eyes because they don't need them anymore - there is no light to see anything, so it's a waste of resources to grow and develop eyes and the ability to process visual information. They have lost relatively complex organs and much of the neural material needed to process the information those organs would have gathered - so you could argue that this is a decrease in complexity.

 

The point of the issue of "progress" is that it implies that certain traits are better than all other traits in any environment. And this is simply untrue. No trait is optimally adaptive in all environments. Eyes are great when there is light to see by. They are useless energy sinks where there is no light.

 

The difference has to do when the gene is being expressed. If the multicellular occurs earlier for the same critter it is a base genetic effect that forms a platform onto which a wide range of change build. They can both be vertical, but one will take a bigger step and provide a larger platform for lateral change.

 

It sounds to me like you're trying to draw a line between the evolution of new species, in other words speciation, and the evolution of within-species variation. The only real biological difference between these two is that in the first case you have two or more populations that do not transfer genes between them, and in the second you have gene transfer between all the populations in question. Other than that there is no difference between the mechanisms you are trying to differentiate. Even the differences I described above will no longer apply if you have one population slowly evolving new traits to the point where we humans might decide they have become different enough to warrant naming them a new species. But it would be an arbitrary designation. As are the designations you're trying to draw.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.