Evolutionists: Describe your conceptual understanding of evolution.

[pitabread]

One of the biggest gaps in discussions around evolution seems to be a result of differing understanding of the very subject of evolution.

To try to get a handle on different understandings, I've created two thread: one for creationists and one for evolutionists to describe their respective conceptual understanding of evolution. The companion creationist thread is here: Creationists: Describe your conceptual understanding of evolution.

Areas for discussion of conceptual understanding can include:

• the scope of the theory of Evolution;
• the process of evolution;
• evolutionary history of life on Earth; and,
• evolution of biological complexity.

For the context of these threads, "creationist" refers to anyone who does not fully accept the current scientific understanding of evolution. Likewise, "evolutionist" refers to anyone who does accept the current scientific understanding thereof.

 

[pitabread]

Short version:

Biological evolution is an observable process by which populations of organisms change over time. The phrase "change in allele frequencies over time" refers to the changes in gene variations over time in said populations.

The Theory of Evolution is the body of scientific knowledge that seeks to explain this process we observe. It includes descriptions of both the mechanisms of the process and descriptions of the natural history of life on Earth as shaped by the same process.


Longer version:

The process of evolution is the same now as in the past

The process of evolution over time hasn't changed. As long as you have populations of organisms that reproduce, the process of evolution will always continue.

Evolution occurs in populations

Since evolution is a change in populations over time, evolution takes place at the population, not individual level.

All modern organisms are equally "evolved"; evolution has no "levels"

There are no levels to evolution. There is no ladder of evolutionary progress by which organisms are predestined to evolve through.

Rather, all modern organisms are equally evolved. The only real measure in this context is time. And since all lineages go back to the same starting point, all organisms are effectively equal in that respect.

Evolution is like a recursive process

I conceptualize the process of evolution as similar to a recursive process. Essentially the output of one generation becomes the input of the next. Thus there is no real starting point or baseline when talking about the process (save for the origin of life itself). The baseline is constantly changing.

I also recognize that all of the biological categories we assign to organisms are strictly artificial. Species designations and other taxonomical assignments are human invented categories. We do it because it makes organisms easier to talk about. But the actual organisms are not biologically confined to a particular "type" or category in that manner.

I think this represents a fundamental difference with how creationists conceptualize biology and the process of evolution. Creationists seem to conceptualize organisms as having these fixed types and therefore organisms are confined to these types in the context of the process of evolution. However, these types do not exist in nature (which is why you can never get a consistent definition of "kind" from creationists).

Evolution produces genetic information

The process of evolution is constantly producing new genetic information. Studying the process at the molecular level reveals that virtually every type of change to genomes, including the production of novel protein functions is possible. By any definition of information as applicable to genetics, it's demonstrable that evolution produces genetic information through variation during reproduction.

Evolution produces complexity

Evolution produces complexity through functional dependence. This especially seems to be the case with functional specialization that can occur through loss of function. E.g. if you have a multi-functional protein with redundancy, removal of that redundancy creationists greater functional dependence. Learning about protein function and how proteins can serve multiple purposes was a revelation in understanding evolution of complexity. Similarly with functional organs, since many organs serve multiple purposes. Studying the history of organ evolution shows how functions can change and become more specialized over time.

 

[durangodawood]

Thumbnail version:

Evolution by natural selection describes the main biological process for change in forms of life (and their genomes).

Basically, any change in the genome that provides an advantage in reproduction will itself get reproduced at the expense of non-advantaged individuals. Over time this can lead to significant qualitative changes (like fins to feet) and novel species.

 

[Tree of Life]

Thumbnail version:

Evolution by natural selection describes the main biological process for change in forms of life (and their genomes).

Basically, any change in the genome that provides an advantage in reproduction will itself get reproduced at the expense of non-advantaged individuals. Over time this can lead to significant qualitative changes (like fin to feet) and novel species.

As you've stated it, this is not at all incompatible with a literal seven day creation.

 

[durangodawood]

As you've stated it, this is not at all incompatible with a literal seven day creation.

Thats correct.... because I limited my post to the process of evolution by natural selection.

If I had talked about the evidence for the particular history ("the evolution") of life on earth, that would not be compatible.

 

[Tree of Life]

Thats correct.... because I limited my post to the process of evolution by natural selection.

If I had talked about the evidence for the particular history of life on earth, that would not be compatible.

Do you only understand evolution to be referring to the process?

 

[durangodawood]

Do you only understand evolution to be referring to the process?

No. Strictly speaking "the evolution" is the actual record of change over time.

"Evolution by natural selection" is the main biological process that drives that change.

 

[FrumiousBandersnatch]

I understand biological evolution as the process by which populations change over time as a result of reproduction with heritable variation and selection.

One can argue about whether artificial selection (i.e. deliberate human selection as in selective breeding), qualifies as evolution. But the underlying principle can be extended to non-biological processes such as computational evolutionary design, and - often less convincingly - social processes such as the development and spread of cultural ideas, beliefs, stories, music, memes, etc.

 

[essentialsaltes]

It's a huge subject, obviously, but to try to distill things into concepts.

Evolution is the change of living things over time.
The theory of evolution is the explanation for this change.
Evolution is enabled by 'imperfect replication'. Children are not exact duplicates of their parents, but vary in characteristics that are inherited.
Given this variation in a population, the environment will favor certain varieties. This results in change over time, i.e. evolution.
This effect is sufficient to explain what we see in the historical record of evolution, from goo to you.