Field of Science

A plea to bridge a chasm
Why should cell biologists care about evolution?

Our department seems rather heavy on molecular biology, and thus I get plenty of opportunity to hang out with with the molecular evolution and phylogenetics folk. They taught me to appreciate good phylogeny and the importance thereof to work in other fields of biology. Developmental/cell biology is becoming increasingly more 'interphyletic' as the findings in other clades often turn out to be quite relevant throughout the distant tips of the tree.

Chancing upon this many evolutionary protistologists and the likes has led me to read a bit of literature in the field and familiarise myself with some of the works. But being a cell biologist, I've also wandered across some rather interesting developmental/cellular protistology stuff; strangely enough, the evolutionary protistologists seem much less familiar with it.

I've spent the last couple of weeks in the company of cell biologists, mostly metazoan but some fungi, plant and protist people as well. Strangely enough, the protistan cell biologists seemed unfamiliar with many of the evolutionary protistology literature and people! We're talking about what is quite possibly one of the smallest fields in biology in population -- protistology! Shouldn't they really get to know each other and work in an integrated manner?

Furthermore, I had a chat with a prof working on yeast who had the misfortune of revealing himself to be of the crown eukaryote camp (the animals-plants-fungi vs. unicellular organisms model). I politely informed him animals-plants-fungi were not a natural monophyletic group by any means, and that multicellularity evolved upwards of 16 times in the eukaryote kingdom, at at least one other time among the prokaryotes... his response was along the lines of: 'Why should I care? I'm a cell biologist'

Grrr. I am too! Why should we care??? Well, let's see:

- Perhaps we could avoid publically embarassing ourselves by comparing homologous genes between animals, plants and yeasts in that order, and then wondering why the fuck the outter genes share more homology than the crap in the middle!? Every time I see a chart like that being published, I wonder if anyone could please bring those people up to date by about 30 years? It's messy and confusing to use haphazardly organise genes... the subject is a mess by nature, why not use every tool available to clean it up a bit?

- Those of us in the less popular fields often get ideas from the yeast and animal people. Working on the plant cell cycle, for example, requires one to read plenty of opisthokont literature, and even cancer research papers, since much of the work was done in those fields. We're finding some fundamental differences from the opisthokont system, but many principles and gene pathways still apply. Wouldn't it be rather crucial for a plant biologist to be aware that we're more distant from yeasts and animals than the latter are from each other?

- Some of the lesser-known organisms conceal a goldmine of genetic and cellular data. Some of them present us with the special cases we couldn't even dream of. Germline and somatic nuclei within one cell? Ciliates. Unicellular vision? Chlamydomonas, Warnowiid dinoflagelates, Euglenids to name a few. Cells alternative rapidly between amoeboid and flagellate forms with de novo centriole formation? Heteloboseans. A capsule with a coiled up tube that shoots outward at extreme speeds to penetrate the host? Microsporidia. A Martian creature with cortical plates that are opened up by subcellular muscle tissue to engulf prey? Acanthometra. A 'dispersing' 'multicellular' 'colony' of amoebae? Cellular slime moulds. Oh yeah, and a thing that goes plasmodial and then turns inside out to let out dinospores - Amoebophrya (Grell 1973 pp.143-146). Chainmail genomes with RNA editing on crack? Trypanosomes.

Let's stop there. The prof claiming irrelevance of evolution works on post-transcriptional mRNA processing. He should really care about Trypanosomes. Some of their genomes have polycistronic gene clusters, with one promotor to express them all. Well, within a cluster anyway. Traditional promotor-activation focused gene regulation mechanisms more or less fall apart there - the regulation of Trypanosome gene regulation depends largely on mRNA-level and protein-level control. Post-transcriptional mRNA regulation seems to be largely ignored by most, but perhaps it may play a large role outside the Trypanosome clade?

Now, one must be aware of Trypanosome evolution and where the are in the tree to be able to properly generalise and hypothesise from there. If the tree truly does root between unikonts and bikonts, then plant mRNA processing would be expected to be more similar to that of Trypanosomes than that of animals. Or if Tryps were rather distant from everything, then there may be a high likelihood of their regulatory mechanisms being unique...

- Evolutionary biologists need cell biology!!! Organisms are more than just genomes in a lipid bag... cytoplasmic/cortical inheritance (and therefore evolution) happens too, although it is much harder to trace than genomic evolution. So far eukaryotic cellular evolution seems to be dominated by Tom Cavalier-Smith, and that's a sign that it's wild territory desperately in need of hard core research! (According to sources (former student of his), TC-S makes outrageous claims just to make people investigate the topic for him...)

So, in short, cell/developmental and evolutionary biologists - TALK TO EACH OTHER SOMETIME, K?

This gaping chasm is a detriment to progress in both fields. Tribalism has never been of much use to anything but itself, and academic tribalism even more so...

Now there's also medical 'biologists'... but that's a rant for another day.

No comments:

Post a Comment

Markup Key:
- <b>bold</b> = bold
- <i>italic</i> = italic
- <a href="">FoS</a> = FoS