# Winston Ewert: The Dependency Graph of Life

**URL:** https://discourse.peacefulscience.org/t/winston-ewert-the-dependency-graph-of-life/728
**Category:** Office Hours
**Tags:** Design
**Created:** [July 21, 2018, 2:51am UTC](https://discourse.peacefulscience.org/t/winston-ewert-the-dependency-graph-of-life/728 "2018-07-21T02:51:30Z")
**Posts on this page:** 1
**Showing post:** 34

<div class="post-metadata">

### Author: ![swamidass](https://sea2.discourse-cdn.com/flex016/user_avatar/discourse.peacefulscience.org/swamidass/32/3_2.png) [@swamidass](https://discourse.peacefulscience.org/u/swamidass)
#### Post date: [July 22, 2018, 1:50am UTC](https://discourse.peacefulscience.org/t/winston-ewert-the-dependency-graph-of-life/728/34 "2018-07-22T01:50:19Z")

</div>

> [@Winston\_Ewert](#):
>
> I’ve acknowledged the limitations of what I’ve done so far. You’ve pointed out the limitations and the sorts of issues that need to be dealt with. They largely correspond to what I’d already thought would be the concerns with a few surprises. Now I need to go ponder these things for a while.

I agree.

> [@swamidass](#):
>
> The real question, it seems, is different. You have to show that this model works better than the current best models of common descent, which right now are undirected graphs.

> [@swamidass](#):
>
> Why exactly? I can produce strong evidence that human diversity does not follow a tree, even though we all agree it arises from a process of common descent. That is de facto evidence that common descent does not produce DNA that fits a tree perfectly.

Just to help you out, here is on example of a study that shows human diversity (which obviously results from common descent) does not show a tree pattern ([https://doi.org/10.1534/genetics.115.182626](https://doi.org/10.1534/genetics.115.182626)). I can produce more examples when you are ready to engage on that. Alan Templeton, a leading population geneticist, argues that not a single human diversity dataset he has examined survives a statistical test to see if it is a tree (private communication).

As I stated earlier, human variation data serves as an excellent negative control. If you solve the technical problems in this approach, the signal should disappear when you look at human diversity data. Gnomad ([http://gnomad.broadinstitute.org/](http://gnomad.broadinstitute.org/)) should provide more than enough data to test this. When that analysis is done, whatever the results, please let us know. Even if it does not work out, you get credit for being upfront about the negative results.

> [@Winston\_Ewert](#):
>
> Thanks everyone

Thank you too. It has been a pleasure having you here. Whenever you would like to re-open the conversation, let us know. I will reopen it for you. It seems like many of us are looking forward to seeing how this develops.

* * *

**Cite this exchange with DOI: [10.5281/zenodo.1318762](https://doi.org/10.5281/zenodo.1318762).**

## This thread is closed but the side conversation continues. Join us here with your questions: [https://discourse.peacefulscience.org/t/side-comments-on-the-dependency-graph-of-life/743](https://discourse.peacefulscience.org/t/side-comments-on-the-dependency-graph-of-life/743).

---

_[View the full topic](https://discourse.peacefulscience.org/t/winston-ewert-the-dependency-graph-of-life/728)._