Mike the Mad Biologist

In the midst of the kerfuffle about atheism, religion, and teaching evolution in high school, the NY Times article made me wonder if focusing part of the curriculum on molecular evolution would be a better way of teaching evolutionary biology* (and ScienceBlogling Sandra describes some good ways of doing so).

I pose this as a question–it could be a dreadful idea, but here are some things to consider:

  1. Molecular biology is viewed as more ‘scientific.’ Like it or not (and I don’t), molecular biology is viewed as more rigorous than organismal biology.
  2. DNA sequence is pretty easy to understand. A, T, C, and G, which then gets translated into proteins. This is not ‘fuzzy’, nor does it require extensive organismal knowledge (yes, I realize molecular evoluiton is far more complex than this, but we don’t teach string theory to fifteen year-olds either).
  3. If students have access to the internet (and perhaps computers), they can do their own analyses. Between Genbank and most analysis programs either being very cheap or freeware, students could design their own projects (although cutting open a fetal pig is kinda cool…).
  4. There are some very good natural history and laboratory examples of molecular evolution.
  5. Teaching basic phylogenetics is a lot easier with molecular data than with fossil data. Again, it’s that four-character state thing.
  6. I think it’s harder to ‘explain away’ the molecular evidence for evolution than the organismal evidence (or at least, the creationists have less practice at it).

Mind you, I’m not saying we should get rid of the organismal approaches to teaching evolution, but do you think more of an emphasis on the molecular evidence for evolution would work?

Update: More thoughts on the topic here.

*Unlike PZ, I don’t see ‘religion’ as a problem, but particular religions as problematic, and they should be called out, although not in a public school. A government institution has no business directly telling students that their religion is hooey (as long as there is no imminent harm to students, etc.).


  1. #1 Martijn
    August 26, 2008

    I think it is, because for me it always felt very natural that a lot of small changes can make really big changes over millions of years. You might have to include stuff like the existence of introns and exons and pseudogenes from the start, to escape the “there are only loss of function mutations” strategy of creationists.

  2. #2 Sigmund
    August 26, 2008

    It’s by far the best way to provide the most convincing evidence for common descent. It also fits in with real life techniques that many people are familiar with – namely DNA evidence from legal proceedings. Once students realize that the same principles that tie a murderer or rapist to a crime scene or determine paternity of a child, are used by evolutionary biologists to show how various species are related it will be hard for creationists to throw out the entire technique – as they seemingly can do with impunity with radioisotopic dating.

  3. #3 KsBioteacher
    August 26, 2008

    This is exactly how I introduced evolution in my last few years teaching biology in the high school classroom–we went from DNA structure and function to mutations to sequence analysis using the Biology Workbench. Specifically, we followed a number of case studies from the Bioquest project: Molecular phylogenies, The Florida Dentist HIV case, West Nile virus origins and then some work with molecular evidence for vertebrate and mammalian phylogenies. Then we went organismal with artificial selection demonstrations and other labs before we ever brought up Darwin. Easier transition for the students, they are doing the work and it also tends to counter any anti-evolution propaganda they may have encountered. The anti-evolution/science folks are pretty scripted based on what they think is a standard classroom approach–this approach throws them for a loop.

  4. #4 Bio613
    August 26, 2008

    I don’t disagree with you, far from it. The State has NO business making a comment on any religion, thus the ‘separation of church and state’. But, you said:
    “… that their religion is hooey (as long as there is no imminent harm to students, etc.).”. I think this does damage to the concept of science as a way of knowing the world, a way that has shown to be extremely productive. Religion, any religion, relies on the ‘I said so’ body of evidence. That arguement I think is a harm to students.

  5. #5 MartinB
    August 26, 2008

    I strongly doubt that it works well, because the genetics seems very remote from the actual happenings in animals. Take the classical example of a giraffe, for example – how does changing some bases on the DNA (and thus some amino acids in a protein) account for a change in neck length. To really understand this, you would need to delve deeply into evo-devo. I freely admit that I never really understood how proteins shape lifeforms, despite a lifelong interest in evolution, until I read “Endless forms most beautiful” this summer (If you don’t know this book, order it NOW! – no, I don’t get royalties.).

    So I don’t see how the students will ever be able to connect the DNA changes with actual evolution, and creationists will just say that this is just micro-evolution and does not matter.

  6. #6 Coturnix
    August 26, 2008

    This is how I connect the levels when I start my evolution lecture:

    “Imagine a small meadow. And imagine in that meadow ten insects. Also imagine that the ten insects are quite large and that the meadow has only so much flowers, food and space to sustain these ten individuals and not any more. Also imagine that the genomes of those ten insects are identical, except for one individual: that one has a mutation in one gene (due to an error in DNA replication, or due to crossing-over during meiosis). That mutation, during development led to the induction of the production of more mitochondria in each muscle cell.

    Normally, that mutation is not obvious – the insect flitters from flower to flower just like anyone else. However, if the situation arises, the mutant individual is just a tiny little bit faster because the additional mitochondria in muscles allow it to switch from aerobic to anaerobic sources of energy later than in other individuals. Thus, the normal individuals can fly one yard in one second, while the mutant can fly one yard plus one inch in one second.”

    Then I go from there. But I have covered the cell, DNA, heredity, genotype-phenotype mapping, and embryonic development by that time already….

  7. #7 Clark
    August 26, 2008

    It seems to me that teaching DNA to understand evolution makes a ton of sense. Much like statistical mechanics makes thermodynamics make sense.

  8. #8 abb3w
    August 26, 2008

    …except the focus on Molecular Evolution of DNA is likely to bring us back to the ignorant “that’s only MICROevolution” argument.

  9. #9 Peter
    August 27, 2008

    This makes sense if what you want to bring them is a lesson as to why evolution matters in their lives. Much of medical research and Oncology in particular base the research on a detailed understanding of the workings of evolution on the molecular level. Many people will pray for a cure for cancer but most will go to the doctor as well.

    But if all you want to do is avoid offending the people who have overstepped the bounds of their religion you are probably mistaken. They are easily offended and will continue to make stuff up.

  10. #10 David Marjanovi?, OM
    August 27, 2008

    except for one individual: that one has a mutation in one gene (due to an error in DNA replication, or due to crossing-over during meiosis). That mutation, during development led to the induction of the production of more mitochondria in each muscle cell.

    Would some cdesign proponentsists insist that this cannot happen because mutations are always bad?

  11. #11 RBH
    August 28, 2008

    There are some very good natural history and laboratory examples of molecular evolution.

    Got a few examples of those (with references) that one could adapt for a couple of lectures to a general lay audience?

  12. #12 Sigmund
    August 28, 2008

    A classic human example is lactose tolerance mutations that have developed on least three separate occasions in societies that use milk production as part of their culture. It is such a useful survival advantage that it rapidly spread through these populations. Razib on gene expression has done some posts on this.

  13. #13 RBH
    August 28, 2008

    Thanks — I should have thought of that myself. 🙁

  14. #14 Irradiatus
    August 28, 2008

    Added to the new blog carnival Carnival of Evolution #1

  15. #15 azdırıcı
    April 2, 2009

    thanks for all

  16. #16 biber hapı
    July 30, 2009

    biber hapı

  17. #17 biber hapi
    September 8, 2009

    biber hapi

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