Archive for the ‘Darwin’ Category

Part I here.

After this post, we’ll gather on Wednesday’s and Saturdays for new posts in this series.

Charles Darwin never knew about DNA, or genes, or genetics. DNA and protein, as well as the debate about which was the genetic material came after Darwin. The definitive experiment showing DNA as the genetic material was performed in 1952 by Hershey and Chase, a mere eight years before I was born. No, Darwin didn’t have any of the knowledge that contaminates our perspective on him. We can be so smug and self-assured when we look back on Darwin and his contemporaries.

To do this conversation justice, we must enter into Darwin’s world as it was, and see that world through his eyes.

Young Darwin was actually a medical student who became taken with the field of natural history. It was a dynamic age in naturalism and, contrary to popular belief, Darwin was NOT the first to propose that life evolved. There were actually many before him, many who backed down under threats of excommunication from civil society and some from their churches. The most prominent proponent who advanced a scientific hypothesis of evolution was Jean-Baptiste Pierre Antoine de Monet, Chevalier de la Marck. We know him today simply as, Lamarck.

Lamarck lived from 1744-1729, dying two years before twenty-two year-old Charles Darwin would set sail on his famous five-year voyage aboard the HMS Beagle. Lamarck proposed that life evolved by organisms developing adaptations to their environment and then passing them on to their offspring. Today he is remembered in most biology classes as the fool who got it wrong. In reality, Lamarck was a brilliant invertebrate biologist who coined both the terms invertebrate and biology. Lamarck established most of the taxonomic trees for invertebrates, and is widely regarded in the field as one of the fathers of the field. Back to Darwin.

As a young and budding naturalist, Darwin was afforded the opportunity to sail aboard the HMS Beagle in 1831 (Recall that Darwin would not publish Origin of the Species until 1859). It was a time of great exploration and scientific documentation of the flora and fauna of distant lands, of geology and anthropology. The discovery of fossils and the observations of sedimentary rock containing those fossils was a hot topic. It was observed that sediments form at certain rates, and that sedimentary layers of rock could not have formed in the time since Sunday, 23 October 4004 BC, which was Bishop Usher’s biblical calculation of when the world was created.

The concept of geologic time outside of Bishop Usher’s frame was pointing toward a planet that was hundreds of millions of years old, at the least. Fossil evidence, it was further noted, indicated that the deepest sedimentary layers had the most primitive looking organisms, while organisms generally increased in size and complexity in the newer, more surface sedimentary layers.

Darwin carried with him on the Beagle Volume 1 of Principles of Geology, by the foremost geologist of the day, Charles Lyell. Darwin received Volume 2 when he reached South America. Lyell had Darwin do investigations for him, and it is fair to say that Darwin came away much more convinced of evolution based on the geology than did Lyell. In fact, Lyell disagreed with Darwin, and only gave grudging and tepid acceptance of modification by natural selection after Origin of the Species was published. Lyell would write in his 1863 book, Geological Evidences of the Antiquity of Man that it remained a profound mystery how man bridged the evolutionary divide between himself and the beasts. So not all scientists were of one accord in Darwin’s day, not even his great friend Lyell.

Regarding Darwin’s famous voyage on HMS Beagle, I’m rereading it for the first time in years. However, there is an excellent site with an interactive map of Darwin’s voyage that nicely summarizes each phase of the journey.

Get it here.

It’s worth doing a little reading at that site, as we’ll begin to systematize Darwin’s findings in our next post.

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It’s time that this blog tackle the issue of Charles Darwin, evolution, and the Culture of Death as they relate to one another. I’ll probably succeed in pleasing nobody on any side of this debate, but it’s a discussion that needs to be had by pro-lifers. The issue of Darwinian evolution evokes rather strong sentiments, and I welcome them all. In the words of Churchill, “We can disagree without being disagreeable.”

So, where do we begin? I’d like to begin with the science and then proceed to the philosophical and anthropological consequences.

First, I am a molecular biologist, and I thank God every day for the window into His creative mind that science has given me. If there is one thing that I can say with absolute certitude it is this:

Life Evolves!

That is a wholly separate issue from the question of how life began, and we’ll tackle those issues as well in later posts. However, for now it suffices to say that Darwin and I both happened on the scene quite some time after the appearance of life on this planet and that we both see the evidence for change over time.

It’s hard to see the evidence for change in humans over time, if only because we don’t live long enough to witness it first-hand. That’s why biologists who study evolution like to use organisms with short generation times. Fruit flys have generation times that are mere weeks, and bacteria such as E. coli reproduce every 20 minutes in liquid growth medium when grown at human body temperature.

It’s much easier to see genetic changes over the generations in an organism that reproduces every 20 minutes than in organisms that reproduce every 20 years.

At the cellular and molecular level, we see that DNA recombines in sexually reproducing organisms to create a riot of uniquely different members of the species. This enables the species to survive if some lethal threat arises that some members happen to be resistant to. We see this with antibiotic resistance in bacteria (which do not reproduce sexually).

Perhaps one in a billion bacterial cells might have acquired a mutation, or a gene from another species, that makes the cell resistant to a certain antibiotic (which are made by other organisms). When we take antibiotics, the drug kills the cells that are susceptible and leaves behind the ones that have developed resistance. These cells grow back in the presence of the drug. Over time, with excessive use of that antibiotic in a community, we see that almost all people coming to the hospital with an infection to be afflicted with antibiotic resistant strains.

The resistant strain has become the new norm.

That’s evolution, the endless cycle of mutation, adaptation, reproduction.

The evidence for evolution is so abundant that evolution has become biology’s prism through which all else is filtered. And that leads to evolution rising to the level of a Theory.

In everyday language, the words opinion, theory, idea, belief, hypothesis, conjecture, all tend to be used interchangeably to denote the cognitions of a single individual. In science, the same words have vastly different meaning.

A well-informed idea is called a Hypothesis. We design experiments to test the hypothesis, and the experiments must be designed in such a way that the hypothesis is open to being disproved.

When the same hypothesis is proven repeatedly and universally, it rises to the level of scientific Theory. There are only a handful of ideas that have risen to that level. Einstein’s Relativity is one.

When Theory has all of the wrinkles ironed out, it rises to the level of a scientific Law, and there are only a handful of those: The laws of Thermodynamics and Gravity being examples.

So when we say that Darwinian evolution is a scientific theory, we mean that there is a mountain of evidence to support that idea.

Was Darwin a racist or eugenist? We’ll consider that separately as we tease apart the science of evolution from the philosophical and political consequences that flow from the misapplication of the scientific reality. Today’s blog was just the opening round.

Next time: The core biological ideas surrounding evolution by means of natural selection. It would help if people posted comments here, and not just on FB, as not everyone reading the blog comes through FB. Thanks.

Also, Darwin is getting his own Category in the box on the right.

{Serendipity moment. After publishing this post, WordPress tells me it was the 666th post published on my blog. That ought to mean something to Darwin’s detractors 😉 }

Part II here.

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