Before You Debate Evolution Make Sure You Understand It and How It Has Evolved

[TB2]

There are so many strawman arguments (on both sides!) in the 'creation-evolution debate' that results in a lot of wasted time. For example, individuals don't gradually "evolve into" something else (anagenesis); populations split (cladogenesis, speciation).

The standard Neodarwinian/Modern Synthesis view is basically gradual evolution by "natural selection and random mutation." This is what most people (on both sides) argue over. But advances in microbiology, molecular genetics, and genomics over the past fifty years has revolutionized our understanding of evolutionary biology. Here is a run down:

1. Most mutations are neutral or nearly so in terms of fitness.

2. Most genomic evolution is not the result of positive, directional natural selection.

3. Small scale genetic tinkering can result in large scale macroevolutionary "leaps."

4. "Random" mutations aren't as "random" as we once thought.

5. Most mutations are not "accidents" but under biological control. For example, starvation triggers the SOS response in bacteria where bacteria purposely switch to low fidelity replication enzymes that make more errors in DNA replication (a sort of "Hail Mary" last ditch effort to produce variants that might be better adapted to the environment). That is, instead of mutations being accidental, living cells have mechanisms that induce mutations in their genomes.

6. Cells have in built "evolvability" mechanisms that enable rapid genome restructuring and genetic changes.

7. Genetic change is not limited to (vertical) inheritance from ancestors but includes (horizontal) gene transfer.

8. A great amount of genomic evolution occurs via "jumping genes" (transposable elements). It turns out that there is a whole world of "natural genetic engineering" going on around us within and between species, including the sharing and exchange of genetic material. Cells have mechanisms to splice and edit DNA. About two-thirds of the human genome is the result of "jumping genes."

9. And much, much more....

Here is more on the subject of how our understanding of evolution has dramatically changed in just the past few decades. The evidence for evolution and common ancestry has never been stronger (while conversely the origin of life has never been more difficult to explain).

"THE EXTENDED EVOLUTIONARY SYNTHESIS"

"EVOLUTION WITHOUT ACCIDENTS"

And here's a more technical companion to the link above for those who want it:

Nothing in Evolution Makes Sense Except in the Light of Genomics: Read–Write Genome Evolution as an Active Biological Process​

Genomes contain abundant and functional repetitive components in addition to the unique coding sequences envisaged in the early days of molecular biology. Combinatorial coding, plus the biochemical abilities cells possess to rearrange DNA molecules, constitute a powerful toolbox for adaptive genome rewriting. That is, cells possess “Read–Write Genomes” they alter by numerous biochemical processes capable of rapidly restructuring cellular DNA molecules. Rather than viewing genome evolution as a series of accidental modifications, we can now study it as a complex biological process of active self-modification.

 

[CrowCross]

5. Most mutations are not "accidents" but under biological control. For example, starvation triggers the SOS response in bacteria where bacteria purposely switch to low fidelity replication enzymes that make more errors in DNA replication (a sort of "Hail Mary" last ditch effort to produce variants that might be better adapted to the environment). That is, instead of mutations being accidental, living cells have mechanisms that induce mutations in their genomes.

How did the bacteria evolve the ability to purposely switch to low fidelity replication enzymes that make more errors in DNA replication (a sort of "Hail Mary" last ditch effort to produce variants that might be better adapted to the environment)?

How did the living cells evolve the mechanisms that induce mutations in their genomes?