Perspectives on Evolution

[Thumpalumpacus]

Yearp.  Changes in gene frequency over time is evolution, and evolution + a shit ton of time = speciation.

Is this really how evolution is defined?

Yes, that is the definition of evolution I learnt in PhysAnthr101.

 

How would changes in gene frequency over time be measured?

Before modern technology, agrarians measured it very roughly by phenotype -- that is, the physical expression of the dominant genes in one's heredity. This is exactly how they genetically engineered animals such as domesticated cattle, or plants such as wheat or corn. The old MkI eyeball can see one hell of a lot of detail.

 

Certainly, very much or even most of the evolutionary narrative is based on fossils, no?

Not any more, not since the time of Mendel, and then Watson/Crick.

Definitely need to read up on this, Ben. The Modern Synthesis blends Darwin's original theory with Mendel's insights into genetics, and then a few decades after that happened Watson and Crick discovered the architecture of DNA and the exploration of its components started, which knowledge was then folded into the Modern Synthesis. Fossils are good clues, no doubt, but modern biochemistry is by far the more powerful tool for understanding evolution by natural selection.

---

[...] natural selection cannot happen within the lifetime of one organism.

Selection happens depending on whether death occurs before or after reproduction, and whether death was caused or avoided by one or more mutations. The changes in alleles in a population -- the statistical changes which result in speciation -- take lifetimes. Do not confuse the two.