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Joanna Masel @joannamasel.bsky.social · 22d

The same difference in exploitative ability yields more coexistence when created by search speed differences than via handling times. 7/9

Series of phase diagrams showing when coexistence vs one type winning occurs, and via which mechanism. Each phase diagram has the hawkishness of the two types as its axes, based on the rate at which they give up during contests. Different panels vary in their search and/or handing rates, changing both exploitation and interference.

Joanna Masel @joannamasel.bsky.social · 22d

Faster search yields more opportunities to interfere, and faster handling yields fewer opportunities to be interfered with. This mechanistic connection between exploitative and interference abilities is core to our results, and how they differ from past work. 6/9

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Joanna Masel @joannamasel.bsky.social · 22d

Other parameters yield the “dominance-discovery” trade-off described in ants, where the Dove loses at contests but is better at finding new resources. We also find a new “Dove-discovery” trade-off, where Hawks search better, but the opportunity costs from contests is too high. 5/9

Table showing the conditions for six different outcomes: the R* rule, Hawk victory, Dove victory, Hawk-Dove coexistence, the Dominance-discovery trade-off, or the Dove-discovery trade-off. Terms for the strength of Exploitative differences vs Interference differences enable us to distinguish among the scenarios.

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Joanna Masel @joannamasel.bsky.social · 22d

Some parameter choices yield something like the Hawk-Dove game, with a trade-off between the benefits of interfering with the other type and the costs of interfering with one’s own type. The Hawk’s cost need not be direct – an opportunity cost from time spent fighting is enough. 4/9

Joanna Masel @joannamasel.bsky.social · 22d

We develop a mechanistic model in which consuming a resource takes time, and Handlers can be interrupted by Searchers who find them rather than free Resource. This initiates a Contest, distracting the consumers, thus allowing the resource to grow to higher levels. 3/9

Ball and stick diagram showing mass action kinetics by which Searchers find Resources and coming Handlers, Searchers find Handlers to begin a Contest, Contests end when one side dies or gives up, Handling ends with consumption, or Handlers or Searchers die.

R* rule (ecology) - Wikipedia

Joanna Masel @joannamasel.bsky.social · 22d

R* theory assumes no direct interactions at the same trophic level, and that resources are consumed down to the level at which only one species can persist. en.wikipedia.org/wiki/R*_rule... 2/9

en.wikipedia.org

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Joanna Masel @joannamasel.bsky.social · 22d

Our new paper @asn-amnat.bsky.social develops a Grand Unified Theory including both exploitative and interference competition doi.org/10.1086/737628. The R* rule of ecology (that 2 species cannot coexist on a single resource), is widely broken, including via a new trade-off we describe. 1/9

A Mechanistically Integrated Model of Exploitative and Interference Competition over a Single Resource Produces Widespread Coexistence | The American Naturalist

Abstract Many ecological models treat exploitative competition in isolation from interference competition. Corresponding theory centers around the R* rule, according to which consumers that share a si...

Trump Deals A New Immigration Blow To International Students

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Reposted by Joanna Masel

Joshua Weitz @joshuasweitz.bsky.social · Sep 2

The House discretionary budget bill is now out for FY26, including a proposed *slight boost* in NIH funding & many other components that will take time to unpack.

Bill text:
appropriations.house.gov/sites/evo-su...

A few key points including IDC analysis in a provisional 🧵

appropriations.house.gov

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Reposted by Joanna Masel

Catherine Rampell @crampell.bsky.social · Aug 29

Trump admin planning to change student visas from lasting for duration of academic program to fixed 4-yr term, and then much harder to renew
Could destroy US ability to attract global talent, particularly those seeking advanced degrees in STEM. The median time to complete a PhD is 5.7 yrs per NSF.

Trump officials have proposed a new rule limiting international students to fixed periods of entry, making a U.S. education more precarious.

www.forbes.com

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Reposted by Joanna Masel

Matt Yousefzadeh @mattyousefzadeh.bsky.social · Aug 14

Very sad to see.
www.thetransmitter.org/community/ha...

Exclusive: Harvard University lays off fly database team

The layoffs jeopardize this resource, which has served more than 4,000 labs for about three decades.

www.thetransmitter.org

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Joanna Masel @joannamasel.bsky.social · Aug 5

I think the strongest evidence for pervasive adaptive substitutions comes from @denard.bsky.social eg elifesciences.org/articles/12469 and subsequent work. The reason is pathogens, although other arms races might contribute.

Viruses are a dominant driver of protein adaptation in mammals

Viruses drive adaptation at the scale of the whole proteome and not only in antiviral proteins in mammalian hosts.

elifesciences.org

Joanna Masel @joannamasel.bsky.social · Aug 5

I think there is a drift barrier in all cases. But allele frequencies trajectories are different, affecting the site frequency spectrum. We found that the Ne reduction stems from interactions between beneficial and deleterious alleles: bsky.app/profile/joan...

Joanna Masel @joannamasel.bsky.social · Oct 30

Our new preprint changes the way we look at an “extinction vortex” in which a small population loses fitness, causing it to become even smaller.
doi.org/10.1101/2024...
@wmawass.bsky.social @uliseshmc.bsky.social 1/n

Extinction vortices are driven more by a shortage of beneficial mutations than by deleterious mutation accumulation

Natural populations are increasingly at risk of extinction due to climate change and habitat loss and fragmentation. The long-term viability of small populations can be threatened by an extinction vor...

Joanna Masel @joannamasel.bsky.social · Aug 5

Whoops, I just realized what you were pointing to. I was quoting @nicolasgaltier.bsky.social that time. It's really about the effects of sites that the focal allele is in LD with: either fewer of them and linked, or potentially weakly the whole genome.

Joanna Masel @joannamasel.bsky.social · Aug 5

Also, I think what I wrote about linked selection in that thread was a direct quote from the authors.

Joanna Masel @joannamasel.bsky.social · Aug 5

You are asking why in a thread I wrote 2 years ago, I wasn't yet aware of all the results that came from our 1-year-old paper!!! I think you can guess the reason...

Joanna Masel @joannamasel.bsky.social · Aug 5

The quality of genetic background has temporal autocorrelation. Neutral theory cannot capture the resulting colored noise. www.cell.com/current-biol...

Redirecting

Joanna Masel @joannamasel.bsky.social · Aug 5

The theory of background selection from linked sites is very different to that from unlinked sites. Charlesworth actually started with the latter, although most current work is the former.

Joanna Masel @joannamasel.bsky.social · Aug 5

The paper finds var(#del mut per individual) < mean. This implies non-independent evolution. Think of selection as taking out the worst quadrant given two arbitrary axes - you'll get a negative correlation after, ie LD among unlinked sites.