TWiEVO 8 letters

Pengfei writes:

Dear Vincent and Nels,

I have just finished listening to episode 6 of TWiEVO.  Great podcast and thank you for the opportunity of free professional development.  I am an associate professor at Thomas Nelson Community College in Hampton VA, and have previously worked as a postdoc at Harvard University and the Medical University of South Carolina, so I recognized quite a few people that you brought up in the show.  I was trained as a microbiologist and a molecular biologist, so I listen to TWiM all the time.  I was really excited to meet Michael and Michelle at last year’s ASM meeting, and was a little disappointed that you were not there.  I hope to meet you this year in Boston in June!

 In this episode of TWiEVO, you and Nels talked about whether the genes of one organism have been put into another organism, and Nels thought it was a Helicobacter species that Craig Ventor’s institute used as the host, but in fact it was the Mycoplasma genitalium species.  His institute joined together a minimum set of genes and injected the artificial genome to Mycoplasma.  It was successful, and they named it Synthia. I believe the work was done in August of 2010.

 I look forward to the next episode!  

Best regards,

-Pengfei

@berlinbuggirl (Hannah Davis) Bug nerd, biology masters student, and amateur photographer, Berlin, Germany

Butterflies lay eggs! Viviparous insects e.g. aphids, tsetse flies exist and they’re super cool.

Ross writes:

Hi TWiEVO gang! Loving the podcast so far. The discussion in the last episode about the evolution of Ebola and its host receptor was probably my favourite yet, having the senior authors on the show to discuss the paper was excellent. Anyway, I came across a really bad creationist misunderstanding of evolution on twitter today (pictured below) which inspired me to tweak it a bit to make it hopefully more accurate, let me know what you think.

Evolution is sort of like photocopying a photocopy for millions of years. Maybe you start out with a painting that vaguely resembles a cow. Each time you photocopy the previous photocopy the resulting picture looks more or like a cow. The ones that look less like a cow get thrown away, the ones that look more like a cow are kept as the next copy to be photocopied until eventually the picture looks more and more like a cow. Over time though people tastes in paintings change, so then the copies that get accepted and rejected change over time.

This then is evolution, constant refinement depending on the changing environment.

Tweet: DNA entropy, think of it this way: a copy of a photo copy of all life for 600,000+ years, LIE to yourself if it gives you comfort?

Regards, Ross Balch (Virology PhD student at QUT, Australia)

Adam writes:

In regards to some discussion on TWiEVO 5 about the “arms race” between viruses and mammals, it may be useful to look at it from a slightly different perspective. The mammalian immune system engages in a sort of asymmetric warfare in that much of immune surveillance is targeted toward altered or damaged self, in contrast to pathogen-targeted T and B responses to specific viral peptides and proteins. For example, IL-1 family members are immunologically potent indicators of cell stress or death detectable by diverse groups of immune cells. Some of these mediators (IL-1b, IL-18) are produced in a pro- form requiring activation by cellular caspases downstream of inflammasome activation; others are sequestered inside the cell and likely released as a result of necrosis (IL-33). Danger-associated molecular patterns (DAMPs) are also an example, such as cell-free chromatin and ATP.

While pathogenic viruses are/are likely capable of interfering with these types of immune surveillance, perhaps it is a bit more challenging to commandeer host cells without disturbing healthy biology than it is to mutate an amino acid critical for T or B cell recognition. And if they could do the former, they wouldn’t be very good pathogens.

Thanks for the great science.

Adam Savage (not the Myth-ic one)

*raining in SF

Steve writes:

Hello Nels and Vincent,

Thank you for the great new podcast! I’ve a question to which I’ve tried to learn the answer, but have been largely unsuccessful to this point. TWiEVO seems to be a good platform for this question.

Do we think that sexual reproduction has one, or multiple beginnings? I ask this because it seems like the ancestors of plants, animals, and fungi all diverged fairly early in our history, perhaps before our common ancestors were fully multicellular. Yet the similarities, especially meiosis, between all sexually reproducing organisms, cannot be ignored.  Are there enough molecular similarities involved in all sexually reproducing organisms to assume a common beginning for sexual reproduction?

Thanks! The last few weeks went from being warm and spring-like here in the Eastern Sierra, back to sub-zero mornings and chilly afternoons. I’m looking forward to spring!

Best Regards,
Steve