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Well today was a first. I got choked up and barely kept it together during an academic talk. What the heck happened you say? I am an easy crier but also I agreed to spend a part of my talk on tree thinking. A thread..
I started off with the fact that if you google evolution, the vast majority of the images will be some version of that cartoon of the & #39;ascent of man& #39;. This cartoon is a perfect manifestation of all sort of misconceptions about evolution..
That some living species (e.g. chimps) are ancestors of other living species (e.g. humans), that evolution is a march of progress from primitive to advanced, that evolution is a linear (not a branching) story, that humans are the pinnacle of evolution.
Many great articles and blogs have been written attempting to debunk these misconceptions, like this blog about the & #39;ascent& #39; by @fabiokmendes ( https://blogs.iu.edu/sciu/2017/09/26/why-are-there-still-apes/)">https://blogs.iu.edu/sciu/2017... and this recent paper by @mcdaniellab ( https://nph.onlinelibrary.wiley.com/doi/full/10.1111/nph.17241)">https://nph.onlinelibrary.wiley.com/doi/full/...
So why then do we still see these misconceptions all over the place? Centuries after Darwin& #39;s spoke of the grandeur of the view of life as a branching tree, decades after such simple and clear articulations like this one by Krell and Cranston ( https://onlinelibrary.wiley.com/doi/full/10.1111/j.0307-6970.2004.00262.x)">https://onlinelibrary.wiley.com/doi/full/...
We the reason is us, us evolutionary biologists who could do better. Who let the progressive stories slip in. Who could actively push back against misconceptions when we write, when we speak, when we teach. I described three areas where it is us and we can do better.
First, we show trees that look more like timelines, where some taxa are drawn closer to the root, and many appear as pitstops on the way to some most advanced taxon. https://en.wikipedia.org/wiki/Plant_evolution">https://en.wikipedia.org/wiki/Plan...
We know that all of the tips of this tree have evolved the same time since their common ancestor, have each evolved unique traits. We know this but we don& #39;t draw it like we do. And do we teach like we do? Not if the textbooks are any indication.
Second, we have gotten so used to ladderized trees in phylogenetics, we& #39;ve come to feel like there is some meaning in the order of the tips. We know that& #39;s not true ( http://www.csun.edu/~dgray/Evol322/OmlandTreeThinking.pdf),">https://www.csun.edu/~dgray/Ev... but who among us doesn& #39;t have that gut reaction that an unladderized tree "looks wrong"?
Finally, we use words to describe taxa that suggest they are lower or more primitive forms, the "basal" whatever relative to whichever sister group is the one we have decided is worthy to discuss without such a qualifier. Whichever group we deem the advanced one.
I& #39;ve heard often that this is just semantics. But it plays into the science we do ( https://www.researchgate.net/publication/274406871_The_hidden_biology_of_sponges_and_ctenophores).">https://www.researchgate.net/publicati... If our view of biological diversity is biased, so too will be our science.
You& #39;re probably thinking oof, she& #39;s worked up. Well yes, but I made it this far while relatively keeping my cool. Where I lose it is thinking about the broader implications of our sloppy tree-thinking.
If we let the notion slide that some living species are primitive, ancestral, less evolved, it& #39;s all too easy for those ideas to seep into society and be extrapolated to humans. http://for-the-love-of-trees.blogspot.com/2016/12/the-phylogenetics-of-equality.html">https://for-the-love-of-trees.blogspot.com/2016/12/t...
So yes, I get emotional when I talk about tree-thinking. How we as evolutionary biologists draw and talk about trees will trickle out, into other fields, into textbooks, into popular media and into our deep-seated notions about ourselves relative to the rest of the natural world.
And if you really feel that& #39;s its just semantics, challenge yourself to use other words, words that are worthy of the awesome diversity of life and the specialness of every single lineage and the story they have to tell us.
While I& #39;m here, I want to acknowledge that decades of evolutionary education researchers have devoted their time and energy to understanding how the ways we teach tree-thinking can propagate or undo misconceptions.
So none of this is conjecture on my part -- this is their science. Look up the wonderful work on teaching tree-thinking by Kefnyn Catley, Laura Novick, @richmeisel, @keomland, Sarah Eddy and others.
I have more references to the literature in my blog and some figures and examples that might be additional food for thought. http://for-the-love-of-trees.blogspot.com/ ">https://for-the-love-of-trees.blogspot.com/">...
Thank you everyone -- I am so deeply heartened the positive responses to this thread. It& #39;s not at all what I expected but I feel more hopeful about this than I have in years. Good chance though that I& #39;ll still cry if I make a public plea for tree-thinking again 
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