Eduardo Amorim
@cegamorim.bsky.social
Assistant Professor of Biology at Cal State Northridge || Incoming Assistant Professor of Anthropological Genetics at Arizona State University || March Mammal Madness Genetics Team @mmmletsgo.bsky.social || Amateur potter || #aDNA #Evolution #PopGen
Analyses by Louis et al. (2020) also showed that narwhals have among the lowest levels of diversity of all cetaceans for which population-level mtDNA genome data are publicly available #2025MMM #RIP doi.org/10.1098/rspb...
March 28, 2025 at 1:27 AM
Analyses by Louis et al. (2020) also showed that narwhals have among the lowest levels of diversity of all cetaceans for which population-level mtDNA genome data are publicly available #2025MMM #RIP doi.org/10.1098/rspb...
Louis et al (2020) used mtDNA genome analyses to assess narwhal population history in relation to past climatic shifts. They showed narwhals had a long-term low effective population size, which increased after the Last Glacial Maximum (when suitable habitat expanded) #2025MMM doi.org/10.1098/rspb...
March 28, 2025 at 1:11 AM
Louis et al (2020) used mtDNA genome analyses to assess narwhal population history in relation to past climatic shifts. They showed narwhals had a long-term low effective population size, which increased after the Last Glacial Maximum (when suitable habitat expanded) #2025MMM doi.org/10.1098/rspb...
Southeast Greenland polar bears persist in a region with much more sea ice-free days than other polar bears! Genetic data suggest that they are also genetically distinct from other polar bears and should be considered the 20th subpopulation of the species #2025MMM doi.org/10.1126/science.abk2793
March 28, 2025 at 1:10 AM
Southeast Greenland polar bears persist in a region with much more sea ice-free days than other polar bears! Genetic data suggest that they are also genetically distinct from other polar bears and should be considered the 20th subpopulation of the species #2025MMM doi.org/10.1126/science.abk2793
Can sun bears survive modern threats?
Genomics from a 100,000-year-old polar bear reveals ancient gene flow with brown bears during climate upheaval. Maybe mixing helped them survive.
#2025MMM #RIP www.nature.com/articles/s41...
Genomics from a 100,000-year-old polar bear reveals ancient gene flow with brown bears during climate upheaval. Maybe mixing helped them survive.
#2025MMM #RIP www.nature.com/articles/s41...
March 28, 2025 at 1:04 AM
Can sun bears survive modern threats?
Genomics from a 100,000-year-old polar bear reveals ancient gene flow with brown bears during climate upheaval. Maybe mixing helped them survive.
#2025MMM #RIP www.nature.com/articles/s41...
Genomics from a 100,000-year-old polar bear reveals ancient gene flow with brown bears during climate upheaval. Maybe mixing helped them survive.
#2025MMM #RIP www.nature.com/articles/s41...
Sun bears live in the tropics and don’t need to hibernate. But in hibernating grizzlies, hundreds of genes shift expr. to protect brain, heart, and muscles. Understanding how they do this could change how we treat diseases like diabetes. #2025MMM www.nature.com/articles/s42...
March 28, 2025 at 12:48 AM
Sun bears live in the tropics and don’t need to hibernate. But in hibernating grizzlies, hundreds of genes shift expr. to protect brain, heart, and muscles. Understanding how they do this could change how we treat diseases like diabetes. #2025MMM www.nature.com/articles/s42...
Baniel et al. (2022) used 16S rRNA sequencing to assess Gelada’s gut microbiota maturation & found diversity increased rapidly after birth, followed by gradual changes in composition until weaning, when dietary changes (milk- to plant-based diet) drove shifts. #2025MMM doi.org/10.1016/j.cu...
![Part of Figure 1 from Baniel et al. (2022). Gut microbiome taxonomic assembly in the first 3 years of life in immature geladas (A) Relative abundance of the 15 and 19 most abundant phyla and families per age category. (B) Age-associated pattern of alpha diversity (Shannon index of ASVs) within samples. The dotted vertical line represents the critical point of inflexion (7.3 months, 95% CI = [6.4–8.2] in shaded gray, nonlinear quadratic plateau model [QPM]: R2 = 0.62) representing the age at which alpha diversity converges to adult-like patterns. Immatures are considered ‘‘weaned’’ when their mother has resumed reproductive cycles. The dataset was rarefied at 20,000 reads for the figure. (C) Age-associated pattern of beta diversity. A principal component analysis (PCA) was used to ordinate samples based on the Aitchison dissimilarity index. (C) represents the projection of the first principal component (PC1) that is best explained by the age of immatures. The dotted vertical line represents the critical point of inflexion (17.2 months, 95% CI = [15.5–19.4] in shaded gray, nonlinear QPM between PC1 and age: R2 = 0.55) representing the age at which immatures beta diversity (i.e., overall composition) converges to adult-like patterns.](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:s7nzp5zkte4l5vmkq6jjyobv/bafkreihchhyqpgxzgqjrynjho3po6qilqsihusho4lpcqlxkk35inj6xtq@jpeg)
March 28, 2025 at 12:47 AM
Baniel et al. (2022) used 16S rRNA sequencing to assess Gelada’s gut microbiota maturation & found diversity increased rapidly after birth, followed by gradual changes in composition until weaning, when dietary changes (milk- to plant-based diet) drove shifts. #2025MMM doi.org/10.1016/j.cu...
Thinking about boosting wild Addax populations w/ individuals from ex-situ groups?
That’s called genetic rescue!
Simulations by @ckyriazis.bsky.social show that choosing individuals from smaller source populations may reduce extinction risk more effectively.
#2025MMM #RIP doi.org/10.1002/evl3...
That’s called genetic rescue!
Simulations by @ckyriazis.bsky.social show that choosing individuals from smaller source populations may reduce extinction risk more effectively.
#2025MMM #RIP doi.org/10.1002/evl3...
March 28, 2025 at 12:40 AM
Thinking about boosting wild Addax populations w/ individuals from ex-situ groups?
That’s called genetic rescue!
Simulations by @ckyriazis.bsky.social show that choosing individuals from smaller source populations may reduce extinction risk more effectively.
#2025MMM #RIP doi.org/10.1002/evl3...
That’s called genetic rescue!
Simulations by @ckyriazis.bsky.social show that choosing individuals from smaller source populations may reduce extinction risk more effectively.
#2025MMM #RIP doi.org/10.1002/evl3...
Fewer genetic studies have been completed on Central & S. American pumas than N. American pumas. However, mtDNA sequencing has shown that Central & S. American pumas form distinct groups and that N. American pumas are genetically homogenous. #2025MMM doi.org/10.3109/1940...
March 28, 2025 at 12:30 AM
Fewer genetic studies have been completed on Central & S. American pumas than N. American pumas. However, mtDNA sequencing has shown that Central & S. American pumas form distinct groups and that N. American pumas are genetically homogenous. #2025MMM doi.org/10.3109/1940...
Only ~300 Addax remain in the wild & ~1000 in ex-situ groups. The latter are vital for preventing extinction, but genetic data show wild Addax hold more diversity than all ex-situ combined. Enhancing genetic management in captivity is crucial to preserve the species. #2025MMM doi.org/10.1111/eva....
March 28, 2025 at 12:28 AM
Only ~300 Addax remain in the wild & ~1000 in ex-situ groups. The latter are vital for preventing extinction, but genetic data show wild Addax hold more diversity than all ex-situ combined. Enhancing genetic management in captivity is crucial to preserve the species. #2025MMM doi.org/10.1111/eva....
Spotted Gar retinas reveal ancestral traits lost in teleosts—like retinal exo-rhodopsin expression and a lack of crystalline cone mosaics. Their opsin diversity helps trace how genome duplication reshaped ray-finned fish vision. #2025MMM #RIP doi.org/10.1002/jez....
March 28, 2025 at 12:23 AM
Spotted Gar retinas reveal ancestral traits lost in teleosts—like retinal exo-rhodopsin expression and a lack of crystalline cone mosaics. Their opsin diversity helps trace how genome duplication reshaped ray-finned fish vision. #2025MMM #RIP doi.org/10.1002/jez....
Enamel likely evolved ON SCALES, *not* teeth!
Fossil and genetic data show ganoine in gars is enamel-like, with shared genes. Ancient fishes like Psarolepis had enamel on scales but dentine-only teeth. Enamel later spread to teeth via patterning shifts. #2025MMM
doi.org/10.1038/natu...
Fossil and genetic data show ganoine in gars is enamel-like, with shared genes. Ancient fishes like Psarolepis had enamel on scales but dentine-only teeth. Enamel later spread to teeth via patterning shifts. #2025MMM
doi.org/10.1038/natu...
March 28, 2025 at 12:09 AM
Enamel likely evolved ON SCALES, *not* teeth!
Fossil and genetic data show ganoine in gars is enamel-like, with shared genes. Ancient fishes like Psarolepis had enamel on scales but dentine-only teeth. Enamel later spread to teeth via patterning shifts. #2025MMM
doi.org/10.1038/natu...
Fossil and genetic data show ganoine in gars is enamel-like, with shared genes. Ancient fishes like Psarolepis had enamel on scales but dentine-only teeth. Enamel later spread to teeth via patterning shifts. #2025MMM
doi.org/10.1038/natu...
A Ginkgo genome provides new insights into the evolution of gymnosperms! Liu et al (2021) found functioning genes associated with the formation of sperm flagellum, which has been lost in all seed plants EXCEPT ginkgo & cycads, as pollen carries immobile sperm instead doi.org/10.1038/s414... #2025MMM
March 28, 2025 at 12:07 AM
A Ginkgo genome provides new insights into the evolution of gymnosperms! Liu et al (2021) found functioning genes associated with the formation of sperm flagellum, which has been lost in all seed plants EXCEPT ginkgo & cycads, as pollen carries immobile sperm instead doi.org/10.1038/s414... #2025MMM
A genome assembly for the Tayra by Derežanin et al. (2022) revealed that the Tayra split from other mustelids in the late miocene, and comparative analyses revealed genes putatively under selection for seasonal breeding. #2025MMM #RIP doi.org/10.1111/mec....
March 13, 2025 at 2:03 AM
A genome assembly for the Tayra by Derežanin et al. (2022) revealed that the Tayra split from other mustelids in the late miocene, and comparative analyses revealed genes putatively under selection for seasonal breeding. #2025MMM #RIP doi.org/10.1111/mec....
The Tayra belongs to a clade that also contains fishers, martens, and wolverines. Nuclear genetic analyses have shown that this group diverged from other mustelids between 10 and 15 million years ago. #2025MMM doi.org/10.1016/j.ym...
March 13, 2025 at 1:47 AM
The Tayra belongs to a clade that also contains fishers, martens, and wolverines. Nuclear genetic analyses have shown that this group diverged from other mustelids between 10 and 15 million years ago. #2025MMM doi.org/10.1016/j.ym...
The Spotted-necked Otter (Hydrictis maculicollis) of Africa is sister to the Sea Otter (Enhydra), with a relatively short (530,000-year) interval separating them, which has led to discordance in genome-wide analyses of their history-- let's get along sisters!!
#2025MMM www.cell.com/current-biol...
#2025MMM www.cell.com/current-biol...
March 13, 2025 at 1:46 AM
The Spotted-necked Otter (Hydrictis maculicollis) of Africa is sister to the Sea Otter (Enhydra), with a relatively short (530,000-year) interval separating them, which has led to discordance in genome-wide analyses of their history-- let's get along sisters!!
#2025MMM www.cell.com/current-biol...
#2025MMM www.cell.com/current-biol...
Mountain Beavers have weird skulls! They are "protrogomorphous" which means that their jaw muscle (superficial masseter) originates on the upper palate (maxilla) and inserts along the back of the jaw (angular process) as compared to other rodents #2025MMM #RIP animaldiversity.org/collections/...
March 13, 2025 at 1:43 AM
Mountain Beavers have weird skulls! They are "protrogomorphous" which means that their jaw muscle (superficial masseter) originates on the upper palate (maxilla) and inserts along the back of the jaw (angular process) as compared to other rodents #2025MMM #RIP animaldiversity.org/collections/...
Among the weirdest rodents, the Mountain Beaver (Aplodontia rufa) is not to be confused with true beavers, to which it is not closely related -- instead, it is the only living member of the rodent family Aplodontiidae and is more closely related to squirrels!! #2025MMM doi.org/10.1644/12-M...
March 13, 2025 at 1:36 AM
Among the weirdest rodents, the Mountain Beaver (Aplodontia rufa) is not to be confused with true beavers, to which it is not closely related -- instead, it is the only living member of the rodent family Aplodontiidae and is more closely related to squirrels!! #2025MMM doi.org/10.1644/12-M...
The 3 species of peccary (Chacoan, white-lipped, and collared) have different numbers of chromosomes (10, 13, and 15 pairs). Recent work has found that the Chacoan peccary has a more similar chromosome arrangement to the white-lipped peccary. #2025MMM doi.org/10.1007/s133...
March 13, 2025 at 1:35 AM
The 3 species of peccary (Chacoan, white-lipped, and collared) have different numbers of chromosomes (10, 13, and 15 pairs). Recent work has found that the Chacoan peccary has a more similar chromosome arrangement to the white-lipped peccary. #2025MMM doi.org/10.1007/s133...
Genetic data from mitochondrial & microsatellite loci showed that Muskrats were introduced to the Isles of Shoals, off the coast of Maine, in the early 1900s (Mychajliw and Harrison 2014). The Muskrats were likely introduced from New Hampshire for the fur trade. doi.org/10.1371/jour... #2025MMM #RIP
March 13, 2025 at 1:31 AM
Genetic data from mitochondrial & microsatellite loci showed that Muskrats were introduced to the Isles of Shoals, off the coast of Maine, in the early 1900s (Mychajliw and Harrison 2014). The Muskrats were likely introduced from New Hampshire for the fur trade. doi.org/10.1371/jour... #2025MMM #RIP
How many subspecies? Genetic analyses using microsatellites have contributed to our understanding of subspecies designations, where Laurence et al. (2011) revealed only 3 distinct clusters across the Muskrat's North American range. #2025MMM academic.oup.com/jhered/artic...
March 13, 2025 at 1:22 AM
How many subspecies? Genetic analyses using microsatellites have contributed to our understanding of subspecies designations, where Laurence et al. (2011) revealed only 3 distinct clusters across the Muskrat's North American range. #2025MMM academic.oup.com/jhered/artic...
Patterns of genetic variation in present-day species can shed light on their historical population size extending 1000s of years into the past. This is what González et al. did for the Maned Wolf. DNA data recovered a signal of population expansion ~24K years ago. #2025MMM doi.org/10.1093/jher...
![Population structure in Maned Wolves based on mitochondrial DNA (mtDNA) sequences. The figure has three panels. [top-left] Minimum-spanning network of mtDNA genes. Circles represent the different haplotypes and circle sizes are proportional to the haplotype’s frequency in the population. [right-hand side] Map of South America highlighting the sampling localities. Argentina (Blue), Bolivia (Red), Brazil (Yellow), and Uruguay (Purple). [bottom-left] Table showing numbers and distribution of mtDNA haplotypes within each of the four geographic groups/countries.](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:s7nzp5zkte4l5vmkq6jjyobv/bafkreiabqlp5sbpa247uldvtu5usxyyyb3fk4rzkqxk4yqlkgqkfqdrsi4@jpeg)
March 13, 2025 at 1:22 AM
Patterns of genetic variation in present-day species can shed light on their historical population size extending 1000s of years into the past. This is what González et al. did for the Maned Wolf. DNA data recovered a signal of population expansion ~24K years ago. #2025MMM doi.org/10.1093/jher...
Two distinct rabies virus strains (one adapted to canids and one adapted to mongoose) have been found in southern Africa. A molecular study from Zyl et al. (2010) showed that the mongoose strain likely arrived prior to the arrival of the canid strain. #2025MMM #RIP doi.org/10.1016/j.vi...
March 13, 2025 at 1:19 AM
Two distinct rabies virus strains (one adapted to canids and one adapted to mongoose) have been found in southern Africa. A molecular study from Zyl et al. (2010) showed that the mongoose strain likely arrived prior to the arrival of the canid strain. #2025MMM #RIP doi.org/10.1016/j.vi...
Our smiley friends, the Quokkas (Setonix brachyurus), live in Western Australia near Perth. But DNA data shows that mainland populations fragmented < 6,000 yrs ago, likely due to reduced rainfall and the loss of Quokka's preferred wet forest habitat. #2025MMM link.springer.com/article/10.1...
March 13, 2025 at 1:12 AM
Our smiley friends, the Quokkas (Setonix brachyurus), live in Western Australia near Perth. But DNA data shows that mainland populations fragmented < 6,000 yrs ago, likely due to reduced rainfall and the loss of Quokka's preferred wet forest habitat. #2025MMM link.springer.com/article/10.1...
A molecular study using nuclear and mitochondrial markers have shown that the Marsh Mongoose is sister species to another African mongoose, the long-nosed mongoose, and both are within the monophyletic non-social mongoose clade (Patou et al. 2009). #2025MMM doi.org/10.1016/j.ympev.2009.05.038
March 13, 2025 at 1:10 AM
A molecular study using nuclear and mitochondrial markers have shown that the Marsh Mongoose is sister species to another African mongoose, the long-nosed mongoose, and both are within the monophyletic non-social mongoose clade (Patou et al. 2009). #2025MMM doi.org/10.1016/j.ympev.2009.05.038
Here's an example of what those stop codons and insertions/ deletions look like in the retinal protein genes of the Star-nosed Mole's cousins in the Afrotheria -- indeed evolution has a way of enforcing that "if you don't use it you lose it" mentality. #2025MMM #RIP doi.org/10.1016/j.ym...
March 13, 2025 at 1:03 AM
Here's an example of what those stop codons and insertions/ deletions look like in the retinal protein genes of the Star-nosed Mole's cousins in the Afrotheria -- indeed evolution has a way of enforcing that "if you don't use it you lose it" mentality. #2025MMM #RIP doi.org/10.1016/j.ym...