Ben Moran
@ben-moran.bsky.social
Ph.D. candidate in Biology at Stanford University - speciation, conservation, and population genomics
9/ Many thanks to the collaborators without whom this work wouldn’t have been possible, especially to Chelsea Rochman's lab, @gilrosenthal.bsky.social, and the CICHAZ field station in Calnali, HGO, Mexico, which has supported 20+ years of genetic and environmental measurements.
May 1, 2025 at 1:15 PM
9/ Many thanks to the collaborators without whom this work wouldn’t have been possible, especially to Chelsea Rochman's lab, @gilrosenthal.bsky.social, and the CICHAZ field station in Calnali, HGO, Mexico, which has supported 20+ years of genetic and environmental measurements.
8/ Take-home: our results are consistent with human impacts on water chemistry disrupting mate choice in swordtails, weakening reproductive isolation between them.
It was encouraging to identify populations where isolation between these species is still relatively strong!
It was encouraging to identify populations where isolation between these species is still relatively strong!
May 1, 2025 at 1:15 PM
8/ Take-home: our results are consistent with human impacts on water chemistry disrupting mate choice in swordtails, weakening reproductive isolation between them.
It was encouraging to identify populations where isolation between these species is still relatively strong!
It was encouraging to identify populations where isolation between these species is still relatively strong!
7/ We use ancestry information from mothers & embryos to show that assortative mating by ancestry in a downstream Calnali population is weakened, but still significant.
Through histology, we also see signs of olfactory irritation (cilia loss, goblet cell hyperplasia) in the downstream population.
Through histology, we also see signs of olfactory irritation (cilia loss, goblet cell hyperplasia) in the downstream population.
May 1, 2025 at 1:15 PM
7/ We use ancestry information from mothers & embryos to show that assortative mating by ancestry in a downstream Calnali population is weakened, but still significant.
Through histology, we also see signs of olfactory irritation (cilia loss, goblet cell hyperplasia) in the downstream population.
Through histology, we also see signs of olfactory irritation (cilia loss, goblet cell hyperplasia) in the downstream population.
6/ Repeated water chemistry measurements show differences between rivers, but also a unique signature in the downstream Rio Calnali.
Many chemicals elevated there are known disruptors of olfaction and behavior in fishes!
Many chemicals elevated there are known disruptors of olfaction and behavior in fishes!
May 1, 2025 at 1:15 PM
6/ Repeated water chemistry measurements show differences between rivers, but also a unique signature in the downstream Rio Calnali.
Many chemicals elevated there are known disruptors of olfaction and behavior in fishes!
Many chemicals elevated there are known disruptors of olfaction and behavior in fishes!
5/ GIS analysis confirmed that this section of the Rio Calnali has the highest anthropogenic impact (measured as proportion of land area with built infrastructure) of any river reach in our study area.
The Calnali stands out even more in terms of infrastructure built close to the water.
The Calnali stands out even more in terms of infrastructure built close to the water.
May 1, 2025 at 1:15 PM
5/ GIS analysis confirmed that this section of the Rio Calnali has the highest anthropogenic impact (measured as proportion of land area with built infrastructure) of any river reach in our study area.
The Calnali stands out even more in terms of infrastructure built close to the water.
The Calnali stands out even more in terms of infrastructure built close to the water.
4/ Hybrid population structure varies drastically across rivers.
The coolest case is in the Calnali River, where a structured hybrid zone (two ancestry clusters, Xbir-like and Xmal-like) collapses into an unstructured one (one admixed cluster) as the river passes through the town of Calnali.
The coolest case is in the Calnali River, where a structured hybrid zone (two ancestry clusters, Xbir-like and Xmal-like) collapses into an unstructured one (one admixed cluster) as the river passes through the town of Calnali.
May 1, 2025 at 1:15 PM
4/ Hybrid population structure varies drastically across rivers.
The coolest case is in the Calnali River, where a structured hybrid zone (two ancestry clusters, Xbir-like and Xmal-like) collapses into an unstructured one (one admixed cluster) as the river passes through the town of Calnali.
The coolest case is in the Calnali River, where a structured hybrid zone (two ancestry clusters, Xbir-like and Xmal-like) collapses into an unstructured one (one admixed cluster) as the river passes through the town of Calnali.
3/ Our hypothesis was that human impacts drove hybridization between the swordtails X. birchmanni and X. malinche — specifically, that water pollution might disrupt their preference for the mating pheromones of their own species. We tested this idea across four rivers near Calnali, Hidalgo, Mexico.
May 1, 2025 at 1:15 PM
3/ Our hypothesis was that human impacts drove hybridization between the swordtails X. birchmanni and X. malinche — specifically, that water pollution might disrupt their preference for the mating pheromones of their own species. We tested this idea across four rivers near Calnali, Hidalgo, Mexico.
2/ We were motivated by the growing problem of anthropogenic hybridization: when humans modify the environment in ways that cause species which were previously separate to hybridize and homogenize.
We know such hybridization exists, but it’s unclear how common it is, and exactly what can cause it.
We know such hybridization exists, but it’s unclear how common it is, and exactly what can cause it.
May 1, 2025 at 1:15 PM
2/ We were motivated by the growing problem of anthropogenic hybridization: when humans modify the environment in ways that cause species which were previously separate to hybridize and homogenize.
We know such hybridization exists, but it’s unclear how common it is, and exactly what can cause it.
We know such hybridization exists, but it’s unclear how common it is, and exactly what can cause it.