EvoBIO

It's true.
~ Ryan A. Chavez

This remarkable event is known as the endosymbiotic event, a turning point in the history of life on Earth. It took place roughly 1.5 to 2 billion years ago, when ancestral cells engulfed free-living bacteria, eventually giving rise to the mitochondria in our cells today.

~ Ryan A. Chavez

Did you know that if a species were to theoretically evolve too quickly, they can go extinct? If the species evolves too quickly, their genetic load can become too high, and a phenomenon called "error catastrophe" can occur, where deleterious mutations accumulate in the genome faster than they can be removed by natural selection. But you might reply, "Well, HIV evolves extremely fast—why hasn't HIV gone extinct?" Well, this rule mostly applies to animals.

HIV actually gets around this error catastrophe wall. HIV's mutation rate is so high that it increases the genetic load, reducing the average fitness of the viral population. The virus operates near the threshold of error catastrophe, a delicate mutation-selection balance. However, HIV compensates by producing massive numbers of virions, ensuring that even if most are defective. A small fraction remains highly fit. This strategy allows the virus to maintain high overall fitness and makes HIV remarkably adaptable and persistent!

~ Ryan A. Chavez

(Image credits: alionaprof/Shutterstock)

The only real critique of evolutionary theory that I've encountered was from an early television actor named Milton Berle:

“If evolution really
works, how come
mothers only have
two hands?”

~ Ryan A. Chavez

Whales and hippos are closely related! They share a common ancestor that lived about 60 million years ago. Whales and hippos both belong to the order Artiodactyla (even-toed ungulates). Both groups communicate using sounds underwater.

~ Ryan A. Chavez

~ Ryan A. Chavez

🏳️‍🌈

Creationists often fail to grasp the fundamental nature of information, which can arise from intelligent design or natural processes. From the perspective of information theory, biological information is the measurable difference between the maximum and actual entropy of a system, making it highly dependent on context. The introduction of new sequence variations through mutation can either increase or decrease informational content based on statistical methods and population models. A creationist might assert that a chihuahua genome contains less information—using some ill-defined metric for information—since dogs ultimately evolved from ancient grey wolf ancestors, the chihuahua genome can't be found in the grey wolf, so the chihuahua genome contains unique or more “information.” ... Claude Shannon is perhaps rolling in his grave at this point.

(Image credit: biomodal)

~ Ryan A. Chavez

The trichromatic vision of Old World
primates is based on three cone types: long-wavelength (L) medium-wavelength (M), and short-wavelength (S) cones. L cones are most sensitive to longer wavelengths (often associated with red), M cones to medium wavelengths (green), and S cones to shorter wavelengths (blue).

~ Ryan A. Chavez

Even if tomorrow we were to discover that the literal Genesis creation narrative were true, evolutionary biology would still be a field—we'd still have stochastic fluctuations in allelic and genomic frequencies, we'd still have gene flow, we'd still have natural selection, we'd still have genetic drift, and we'd still have mutation. That's all you need for biological evotouching.

~ Ryan A. Chavez