What Darwin Never Knew | Notes & Review

Posted on November 20, 2010


NOVA Production, December 29, 2009. http://www.pbs.org/wgbh/nova/evolution/darwin-never-knew.html. Based on the books: Endless Forms Most Beautiful and The Making of the Fittest by Sean Carroll.

While Darwin’s idea was brilliant, there was one big problem: How does evolution actually work? Science is uncovering answers to this question, and ultimately the question of what makes us human.

There are 9,000 species of birds, 350,000 kinds of beetles, 28,000 types of fish; 2,000,000 living species and counting. And we are just one of them.

Watching a developing embryo is truly the most glorious miracle of nature. No baloney. – Michael Levine, UC, Berkeley

We understand the concept of “Descent with Modification.” But what was making species change? Variation is the starting point. Over many generations, these tiny variations would make the fit fitter, and the less fit would die off. This is evolution by natural selection. One of the keys to how new species are formed. But there were holes in this theory. Darwin didn’t actually know how it worked. What was inside a creature’s body that makes it change?

Modern science is providing the answers to a hidden mechanism that Darwin knew nothing about.

The rock pocket mouse is the snicker’s bar of the desert. – Michael Nachman, U.Arizona. (I just liked this quote)

The linking molecules of DNA are G, A, T, and C. DNA is found in every living thing on earth. With a small number of letters you can say almost infinite words. This forms the code. DNA doesn’t stay the same. Half the DNA is from mom and half from dad. This creates whole new sets of combinations. Another way to change is mutation. Mutations happen when DNA copies itself. Letters can replace itself with different letters.

Humans have 23,000 genes–the same as a chicken; more than some animals, but less than some plants. The human genome project opened up a whole new set of puzzles. There has to be something more going on. How do you get so many differences with so similar sets of genes?

There is something profound about what the embryo is telling us. We have rediscovered what Darwin has been telling us all along, that the embryo is the platform for diversity. It’s not the number of genes you have, but how you use them that determines the great diversity in the Animal Kingdom.

There are “switch genes,” that turn other genes “on” and “off.” Old genes can make new pathways. Human DNA is only 0.4% difference between humans and chimpanzees.

— VIA —

While I appreciate the production, there was far too much drama and “producing,” than there was of education. The platform of these kinds of shows are always dramatic, “knowing now what Darwin never knew.” Oooh. Makes you want to tune in. Then, after 45 min., you want to tune out.

Sure, genetics has transformed our understanding. But again, as with everything else this is not the explanation as to how evolution works but rather another step in the journey of discovering the processes and events behind our current understanding. Every step along the path of understanding, however, only leads to other questions and new arenas of mystery that are simply deeper.

How does a switch gene know that it is a switch gene? How do they communicate with the production genes?
How do the letters of DNA inform the protein production?
How do chemicals become conscious?

I have a high level of respect for this kind of scientific discovery. I find it fascinating, and beautiful. However, regarding helping to answer the question of what makes us human, I’m not sure genetic discovery, much less this production, accomplished much towards addressing this answer.

I look forward to the next discovery…

Posted in: Science