Celebrating Black in STEM

I have been very fortunate to know and work with outstanding Black scientists throughout my career.  Here are a few of them.

I met Joe Graves when we were undergraduates at Oberlin College.  We took an evolution course together.  I remember discussing with Joe our mutual fascination with evolution and wondering how we might go about studying it.  I met up again with Joe at UC-Irvine, where we were both conducting evolution experiments—Joe using fruit flies, and me with bacteria.  Joe and I reconnected once more when he and I became founding members of the BEACON Center for the Study of Evolution in Action.  Joe now studies bacterial evolution, and we are becoming scientific collaborators as well.

JoAnn White was an ecologist at UNC, studying the life-history and population dynamics of periodical cicadas.  She served on my doctoral advisory committee and was a highly successful faculty member.  Unfortunately, she left academia, even though she had tenure, because it was too frustrating. I was honored that she asked me to write a reference letter when she moved to a new profession.  But it was a terrible loss for academia to lose such an outstanding scientist and role model as JoAnn White.

Paul Turner was one of my first graduate students.  He joined my lab in the Department of Ecology and Evolution at UC-Irvine, and he moved with me to MSU, receiving his Ph.D. in 1995.  Paul has impressed me in many ways, not only as a superb scientist and mentor, but also in his upbeat outlook on life.  Somehow he manages to smile and laugh about the challenges of being a departmental chair and interim dean, even while running a lab that conducts ground-breaking research.

Lynette Ekunwe was my lab manager and technician for seven years after I moved to MSU. She helped to sustain the long-term evolution experiment with E. coli after its move from UC-Irvine, and she helped run my lab group as it grew in size. Lynette moved to Jackson State University when her husband, the late Steve Ekunwe, took a faculty position there. After the move, Lynette earned a doctorate in public health, and she now works in the field of epidemiology.

I first met Scott Edwards when he was a graduate student at UC-Berkeley. I suspected that he was a rising star, and I was right.  Although Scott and I have not collaborated on actual science, we’ve worked together in other ways.  Scott and I served successive terms as Presidents of the Society for the Study of Evolution, and he has been a valued member of the External Advisory Board for the BEACON Center.

Shenandoah Oden was an undergraduate from Detroit when she joined my lab in the 1990s.  She worked with postdoc Santiago Elena on measuring the fitness effects of random insertion mutations in E. coli, leading to a paper in Genetica. What I remember best about Shenandoah is a question she asked me right after Brendan Bohannan presented his dissertation seminar: “How do scientists come up with the questions they ask?” I told her that was the best question that any student had ever asked me.  It reminded me of how Joe Graves and I, when we were undergrads, wondered how we might study evolution. To Shenandoah, I explained the importance of personal curiosity and mentors in finding questions that are both interesting and answerable.

Marwa Adewa, Maia Rowles and Kiyana Weatherspoon were three excellent undergraduate researchers in my lab, all of whom were mentored by Zachary Blount. Maia and Kiyana were coauthors on a paper in the Proceedings of the Royal Society, London B, which reported the results of what we call the “all-hands project”—one in which a generation of lab members performed a set of parallel assays to measure the subtle changes in fitness in late generations of the long-term evolution experiment with E. coli. Marwa now works in the field of veterinary medical research, while Maia and Kiyana are pursuing careers with a biomedical focus.

Judi Brown Clarke was, until very recently, the Diversity Director for our BEACON Center. In that role she generated and managed many successful programs that introduced hundreds of students at all levels to evolution and provided them with opportunities to engage in scientific research. She also was a great listener and valuable source of advice for many of us when we faced personal challenges and setbacks. An Olympic medalist, Judi recently became the Chief Diversity Officer at Stony Brook University.

I met Jay Bundy in 2013, at the Evolution meeting in Snowbird, Utah.  Who was this student who was asking so many thoughtful, insightful questions of the speakers?  I ran into Jay as we rushed between talks, introduced myself, and learned that he was a masters student at Penn State.  He wasn’t sure if he was interested in microbes, but I encouraged him to think about joining BEACON.  Jay came to MSU, first as a BEACON staff member contributing to education and outreach activities, and then as a graduate student in the Department of Integrative Biology.  He also contributed to the all-hands project.  However, he switched from studying bacteria to digital organisms, and he’s now performing and analyzing experiments to quantify how the duration of history in an evolving lineage’s previous environment influences its subsequent evolution in a new environment. Stay tuned for Jay’s findings—he’s working on a huge paper. Jay is as deeply thoughtful about science and life as I imagined when I first heard his questions at the Evolution meeting.

I also met Nkrumah Grant in 2013, when he visited MSU while exploring possible graduate programs.  He immediately impressed me with his personal story of overcoming obstacles.  Nkrumah explained to me his love of science as a child, and how he had gotten discouraged and derailed before undertaking a concerted effort to pursue his dream of science and scholarship.  And pursue it he did … and continues to do.  From a G.E.D. to a Ph.D.  Co-author on the all-hands project, co-first-author on a paper just published in eLife, and three more papers posted to bioRxiv in the last few weeks.  He also just defended his dissertation, giving a beautiful public seminar followed by an engaging, collegial exam.  Nkrumah has done all this and more while being a dedicated father and working tirelessly to promote equity and inclusion in science.

Last but not least, Ali Abdel Magid and Jalin Jordan are two of the current generation of superb undergraduate researchers in the lab. Ali is working with Nkrumah on the evolution of bacterial cell size, while Jalin works with Kyle Card on the evolution of antibiotic resistance.  Both Ali and Jalin are also working toward future careers in medicine. This summer, they are reading work that integrates evolution and medicine including the landmark book, Why We Get Sick, by Nesse and Williams, and the path-breaking paper by Tami Lieberman et al. on the evolution of bacteria in the lungs of CF patients.

My science is better, and my life richer, because of all these people, and many more.  How much better science would be, and how much richer all of our lives would be, if we would open more doors, listen more carefully, and live, learn, and work together.

***

After reading a draft of this essay, Nkrumah Grant, Joe Graves, and Jay Bundy all asked me to say more about this:  How can we achieve the aspirations expressed in my closing sentence above? 

I plan to reflect more on their vital question.  In the meantime, I invite readers who have ideas to put them in the comments below.

EDIT: I should also acknowledge two other influences: A high-school teacher, Mrs. Clayton, who taught a Black History class that I took, and who introduced me to Frederick Douglass, whose autobiography I read with awe and admiration.

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Bacterial Niche Finally Defined

The following scholarly contribution comes from my wife Madeleine Lenski after conversing with her “sister” (my former postdoc) Valeria Souza.

For those with an itch for criteria,

Scratch this: What’s a niche for bacteria?

Don’t take me to task

If I answer “a flask” –

It’s a bitch from warm broth to Siberia.

Thirty Years

No, the LTEE did not suddenly jump forward by almost 3 years. That milestone will be reached on February 24, 2018.

Next Friday is the end of the semester at MSU and, for me, it will mark 30 years that I’ve been on the faculty: six at UC-Irvine, and 24 here at MSU. (I also taught for one semester at Dartmouth as a sabbatical replacement, while I was doing a postdoc at UMass.)

Holy cow: 30 years. Where did all that time go?

Well, a lot of it was spent advising, supervising, and mentoring graduate students. And those have been some of the most interesting, enjoyable, and rewarding professional experiences that I can imagine.

In fact, this afternoon Caroline Turner defended her dissertation – congratulations Dr. Turner! Her dissertation is titled “Experimental evolution and ecological consequences: new niches and changing stoichiometry.” It contains four fascinating and meaty chapters, two on the interplay between evolutionary and ecological processes in the LTEE population that evolved the ability to grow on citrate, and two on evolved changes in the elemental stoichiometry of bacterial cells over experimental time scales.

Caroline is the 20th student to complete her Ph.D. with me serving as the advisor or co-advisor. Here they all are, with links to their professional pages or related sites.

1. Felisa Smith, Ph.D. in 1991 from UC-Irvine.
2. John Mittler, Ph.D. in 1992 from UC-Irvine.
3. Mike Travisano, Ph.D. in 1993 from MSU.
4. Paul Turner, Ph.D. in 1995 from MSU.
5. Greg Velicer, Ph.D. in 1997 from MSU.
6. Brendan Bohannan, Ph.D. in 1997 from MSU.
7. Phil Gerrish, Ph.D. in 1998 from MSU.
8. Farida Vasi, Ph.D. in 2000 from MSU.
9. Vaughn Cooper, Ph.D. in 2000 from MSU.
10. Danny Rozen, Ph.D. in 2000 from MSU.
11. Kristina Hillesland, Ph.D. in 2004 from MSU.
12. Elizabeth Ostrowski, Ph.D. in 2005 from MSU.
13. Bob Woods, Ph.D. in 2005 from MSU.
14. Dule Misevic, Ph.D. in 2006 from MSU.
15. Gabe Yedid, Ph.D. in 2007 from MSU.
16. Sean Sleight, Ph.D. in 2007 from MSU.
17. Zack Blount, Ph.D. in 2011 from MSU.
18. Justin Meyer, Ph.D. in 2012 from MSU.
19. Luis Zaman, Ph.D. in 2014 from MSU. (Charles Ofria was the primary advisor.)
20. Caroline Turner, Ph.D. in 2015 from MSU.

There are also 8 doctoral students at various stages currently in my group at MSU including Brian Wade (Ph.D. candidate), Mike Wiser (Ph.D. candidate), Rohan Maddamsetti (Ph.D. candidate), Alita Burmeister (Ph.D. candidate), Elizabeth Baird, Jay Bundy, Nkrumah Grant, and Kyle Card.

My own advisor – the late, great Nelson Hairston, Sr. – said that he expected his graduate students to shed sweat and maybe even occasional tears, but not blood. I would imagine the same has been true for my students.

Thirty years, holy cow. Time flies when you’re working hard and having fun!

Added November 4, 2015:  And now #21 in my 31st year, as  Mike Wiser successfully defended his dissertation today!

An Absence of Posts, an Abundance of Talks, and More

Dear Reader:  No, I have not given up on this blog.  But I’ve been busy, busy, busy!

In the last four weeks alone, I have traveled to the University of Arizona, Harvard University, Duquesne University, and Princeton University.  Besides giving talks at each place (two public lectures and two academic seminars, with cumulative audiences of well over a thousand people), I have met with dozens and dozens of amazing scientists, from graduate students and postdocs to faculty both young and old.  It’s been a blast:  an exhausting blast, but a blast all the same!

And next week?  I’m hosting four terrific colleagues from two continents who will work with me to begin making sense of hundreds of newly sequenced genomes from the LTEE.

Oh, and we have some more job searches starting next week.

And did I mention?  We just had a fascinating (if I may so myself) and complex paper come out today in Science (on-line express for now) on the most deeply divergent (i.e., oldest sustained polymorphism) of the 12 LTEE populations.  And no, it’s not about the citrate eaters from population Ara–3.

Plucain, J., T. Hindré, M. Le Gac, O. Tenaillon, S. Cruveiller, C. Médigue, N. Leiby, W. R. Harcombe, C. J. Marx, R. E. Lenski, D. Schneider.  2014.  Epistasis and allele specificity in the emergence of a stable polymorphism in Escherichia coli.  Science.

It’s population Ara–2 instead, where two lineages—dubbed the Larges (L) and Smalls (S)—have coexisted for several tens of thousands of generations.  In superb research led by Dr. Jessica Plucain that she did in the lab of my long-time collaborator (and dear friend!) Prof. Dom Schneider (Grenoble, France), Jessica led the work to identify—out of hundreds of mutations—three that are sufficient to allow a “constructed” S ecotype (i.e., the ancestor plus three derived alleles) to invade and stably coexist with the evolved L ecotype.  Ecological context and specific genetic interactions are key to establishing this “half” of the polymorphism … and the other “half” of the story— what makes the L ecotype special—might well turn out to be just as complex, or perhaps even more so.

The S and L types are especially challenging (even painful!) to work with because this population became a mutator very early on—before the two lineages diverged—and so there are many, many mutations to contend with; moreover, they make colonies on agar plates that are quite challenging to score and count.  So congratulations to Jessica, Dom, and other members of Dom’s lab for their perseverance in studying this extremely interesting population.

Also on the list of authors are Prof. Chris Marx and two members of his lab.  They performed metabolic analyses showing how the carbon fluxes through the central metabolism of the S ecotype have diverged from both the ancestor and the L ecotype.  Chris was a postdoc in my lab almost a decade ago, but most of his work (then and since) has been on experimental evolution using Methylobacterium, and so this is the first paper we’ve co-authored.

There was a production error, though, in the on-line version of our paper; the final sentence of the abstract was dropped (except for one word).  The abstract, in total, should read as follows:

“Ecological opportunities promote population divergence into coexisting lineages. However, the genetic mechanisms that enable new lineages to exploit these opportunities are poorly understood except in cases of single mutations. We examined how two Escherichia coli lineages diverged from their common ancestor at the outset of a long-term coexistence. By sequencing genomes and reconstructing the genetic history of one lineage, we showed that three mutations together were sufficient to produce the frequency-dependent fitness effects that allowed this lineage to invade and stably coexist with the other. These mutations all affected regulatory genes and collectively caused substantial metabolic changes. Moreover, the particular derived alleles were critical for the initial divergence and invasion, indicating that the establishment of this polymorphism depended on specific epistatic interactions.”

[Edited on 07-Mar-2014:  The on-line PDF at Science Express now has the complete abstract.]

~~~

The picture below shows Dom Schneider and Richard Lenski in Paris in 2013.  They are holding a petri dish that Jessica Plucain made to celebrate the 25th birthday of the LTEE.

Blogging’s Long Reach, Updated

At WordPress, I can see statistics showing where the visitors to my blog have come from.  I first posted on this topic back in September, and the total then was 72 countries.  Now, it’s a nice round: 100.  Wow!

The US has the lead by a large margin – no surprise there – followed by the UK, Canada, Germany, Australia, Switzerland, Sweden, The Netherlands, France, and India making up the top 10.  New Zealand has dropped out of the top 10, being replaced by India.

The US has had over 10,000 visitors.  Three others have each had over 1,000 visitors to my blog.  Twenty-two countries – including India, Brazil, Romania, South Africa, and Taiwan – have produced more than 100 visitors, while 46 countries have generated more than 10 visitors each.

Fifteen countries (or territories) have had one visitor to this blog so far including: Belarus, Cuba, Cyprus, Ethiopia, Fiji, Guam, Jordan, Kuwait, Lebanon, Nicaragua, Qatar, Rwanda, Saudi Arabia, Serbia, and Uganda.

Not a single visitor, though, has come from China …

Whoever you are, and wherever you come from, welcome to this blog!

What We’ve Learned about Evolution from the LTEE: Number 4

This is the fourth in a series of posts where I summarize what I see as the most important findings and discoveries from the LTEE.  The previous entries are listed here:

Number 1.  The LTEE offers a simple, compelling demonstration of adaptation by natural selection.

Number 2.  Although the rate of improvement decelerates, it appears that fitness can increase indefinitely even in a constant environment.

Number 3.  The LTEE has produced many striking examples of both parallel and divergent evolution across the replicate populations.

Number 4.  The LTEE provides fascinating cases of the origin and subsequent evolution of both a novel function (citrate utilization) and complex ecologies (cross-feeding interactions).

These examples are particularly interesting—and surprising—because I chose the environment of the LTEE to be as simple as possible, thereby limiting the opportunity for novel functions and complex ecologies to emerge.  However, the evolving bacteria have proven me wrong by discovering new ways of making a living in the simple flask worlds where they live.

Novel function

• Blount, Z. D., C. Z. Borland, and R. E. Lenski. 2008. Historical contingency and the evolution of a key innovation in an experimental population of Escherichia coli. Proc. Natl. Acad. Sci. USA 105: 899-7906.
• Blount, Z. D., J. E. Barrick, C. J. Davidson, and R. E. Lenski. 2012. Genomic analysis of a key innovation in an experimental Escherichia coli population. Nature 489: 513-518.

Complex ecology

• Rozen, D. E., and R. E. Lenski. 2000. Long-term experimental evolution in Escherichia coli. VIII. Dynamics of a balanced polymorphism. American Naturalist 155: 24-35.
• Le Gac, M., J. Plucain, T. Hindré, R. E. Lenski, and D. Schneider. 2012. Ecological and evolutionary dynamics of coexisting lineages during a long-term experiment with Escherichia coli. Proc. Natl. Acad. Sci. USA 109: 9487-9492.

This photo shows the increased turbidity (cell density) of the population that evolved the ability to use citrate in the middle, along with two others from the LTEE.  Brian Baer and Neerja Hajela took this picture in my lab in 2008.

Remembering Barbara McClintock’s Laugh

A twitter conversation about women scientists who should be honored with Bobbleheads reminded me of the time I met Barbara McClintock.  My postdoctoral advisor, Bruce Levin, had brought me along to a small discussion meeting on the possible ecological and evolutionary effects of genetically modified organisms being released into the environment.

The meeting was held at the Cold Spring Harbor Laboratory in 1984.  There were two Nobel Prize winners there, at least part of the time, along with seven ecologists and evolutionary biologists.  The Nobelists were James Watson, who was then director of the Laboratory, and Barbara McClintock.  The ecologists and evolutionary biologists were Jim Brown, Rob Colwell, Monte Lloyd, Phil Regal, Dan Simberloff, Bruce Levin, and myself. I think there were also a few participants from the EPA and other agencies with an interest in the issues.  As I recall, Barbara McClintock was the only woman at the meeting.

The meeting was held in an old house.  There were two small restrooms, one for men and one for women; each had just a single toilet and a sink.

Because there were many men at the meeting, there was a line for the men’s room at the coffee breaks.  Bruce Levin, being the smart guy that he is, decided during one break that it would be faster and more efficient to use the women’s room.  The door was open, and so he went in.  Meanwhile, Barbara McClintock also had to use the facilities.  Seeing that the door was closed, she waited her turn.

As Bruce came out, he was already a bit embarrassed to see Barbara waiting.  And then she said, in a serious, almost scolding, tone, “Did you put the seat down?”  Bruce – who usually has a quick comeback – was befuddled and didn’t know what to say.  After a comic pause, Barbara just laughed heartily and went on in.

So there was a warm and funny person, as well as a visionary scientist, behind that Nobel Prize!

[This picture is from the Wikipedia entry for Barbara McClintock; it has no known copyright restrictions listed there.  It comes from the Smithsonian Institution.]