Graphical abstract showing effect of deletion compared to wild-type coloring

Orange cat mystery solved! Orange cats lack ~5,100 bases of DNA that normally regulate the gene ARHGAP36. The gene is still there, but switched on when it should be off. www.cell.com/current-biol... #2026MMM #RIP

Images of non-charcoal (left) and charcoal (center and right) Bengal cats, with corresponding genotypes at Asip and Mc1r. lc and dom superscripts, refer to the normal leopard cat and normal domestic cat alleles, respectively, and a refers to the Asip nonagouti allele.

Bengal cats (house cats that are ~4% Asian leopard cat) look wild, but domestic cat controls the coat color. Leopard cat color genes are suppressed. Genome version of home habitat advantage www.cell.com/current-biol... #2026MMM

Principal component analysis of modern lions (blue square), modern tigers (green diamonds), and cave lions (red circles) showing the position of the japanese tigers (yellow stars). Cluster positions indicate that japanese "tiger"s are actually cave lions.

Lions & tigers & bears? Genomic work from Sun et al. (2025) found the Japanese Archipelago housed lions, not tigers, during the Late Pleistocene. Originally, all big 🐱 fossil remains were attributed to tigers. Oh my! doi.org/10.1073/pnas... #2026MMM

Admixture bar plot showing genetic structure across 27 named dromedary camel-types from Asia and Africa at multiple clustering levels (K = 2, 3, 5, 10, 16). Each vertical bar represents one individual, colored by proportional membership in genetic clusters. Vertical white lines separate camel-types labeled above, with country abbreviations below (on x-axis). At K = 2, individuals broadly separate into two main groups corresponding to African camel-types (e.g., Borena, Rendille, Turkana, Gabbra) versus most others, with Omani camels already distinct. At K = 3, three main clusters emerge: a unique Omani group, a distinct African group, and a third group containing remaining camel-types. At higher K values, additional substructure appears within some camel-types (e.g., Hadana, Awarik, Awadi, Pakistani Kohi and Raidi, and Majaheem), but many individuals show mixed ancestry, with colors spread across camel-types. Overall, the plot illustrates that genetic clustering aligns more strongly with geographic origin than with named camel-types, which often do not form clearly distinct genetic groups.

Across 27 dromedary camel-types, DNA analysis showed that names based on coat color often didn’t match real genetic boundaries. The strongest pattern was geography: camel-types cluster broadly by origin (Asia vs. Africa). #2026MMM #RIP doi.org/10.1093/jher...

Map of Europe showing the complete mtDNA genomes in modern cattle breeds reported as blue branches (lineages T, Q and R) and ancient auroch mtDNA genomes reported as green branches (lineages T, P and E). The Northern European Aurochs have lineages P and E but the Southern European aurochs also have liineage T, which is the most common lineage in modern cattle.

Aurochs used to live in Northern and Southern Europe and carried many mitochondrial genome lineages. Lari et al found that Southern Italy aurochs have similar lineages as modern cattle unlike northern Europe Aurochs, suggesting a role in domestication for Italy doi.org/10.1186/1471... #2026MMM

Schematic diagram of a camel kidney medullary collecting duct cell showing molecular responses to dehydration. The cell is bordered by tight junctions, with the urinary lumen on the left and renal interstitial fluid on the right, where osmotic stress occurs. Red labels indicate upregulated genes (relative to the mammal standard), green indicate downregulated, and white indicate unchanged expression. Water reabsorption occurs through aquaporins (AQP2 on the lumen side and AQP3 on the interstitial side). Sodium is reabsorbed via ENaC and potassium is secreted via ROMK, while Na⁺/K⁺ ATPase maintains electrolyte balance. Inside the cell, increased glucose uptake through GLUT1 fuels glycolysis and ATP production, supporting ion transport. Glucose is also converted into sorbitol via aldose reductase (AR), contributing to osmotic balance. NFAT5 regulates osmotic stress responses, but transporters for taurine, betaine, and myo-inositol (TauT, BGT1, SMIT) are downregulated, indicating reduced osmolyte import. Instead, organic osmolytes such as sorbitol and glycerophosphocholine (GPC) accumulate through metabolic pathways. Additional components include antioxidant responses (Nrf2), reactive oxygen species (ROS), and metabolic enzymes (SDH), all contributing to maintaining water and osmotic homeostasis under dehydration. Source: Wu et al. (2014) DOI: 10.1038/ncomms6188

To protect their kidneys during extreme dehydration, camels use a unique metabolic strategy. Rather than importing osmolytes like most mammals, they increase glucose uptake in renal cells, fueling osmolyte production to balance osmotic stress. #2026MMM www.nature.com/articles/nco...

Genetic diversity and demographic history of vultures. (A) Comparison of genome-wide heterozygosity in birds. (B) Demographic history of the two vultures (G. himalayensis and G. barbatus). Genomes of three individuals of G. himalayensis and one individual of G. barbatus were analyzed. Tsuf, atmospheric surface air temperature.

#RIP Genome-wide heterozygosity of the ossifrage: 0.0011 sites/bp, roughly half the avian average. Zou et al. 2021 traced this genetic impoverishment to the Last Glacial Maximum (~20 kya), suggesting vultures were never genetically diverse to begin with. doi.org/10.1093/molb... #2026MMM

Summary of the 33 microvirus genomes identified in this study and their distribution across 14 Gila monster fecal samples. The solid dark-gray and black circles indicate 95% to 99% and 100% raw read genome coverage, respectively, per Gila monster fecal sample. The number of reads that mapped to the microvirus genome sequence and the depth of the read coverage are summarized, and the sample containing the highest number of reads for each microvirus is denoted by a black circle with a yellow outline. The genome organization is provided on the right with color-coded, open reading frames with details of putative protein families.

Gila monsters get viruses, like other species. 33 microvirus genomes were discovered from studying fecal samples from 14 Gila monsters. pmc.ncbi.nlm.nih.gov/articles/PMC... #2026MMM

Map showing the past (grey) and current (black) distribution of the species, based on Mundy et al. (1992) and Heredia & Heredia (1991). Pie diagrams depict the proportions of clade A (black) and clade B (white) haplotypes in different bearded vulture populations. Numbers in parenthesis refer to sample size.

The ossifrage hides Ice Age history in its mtDNA! Godoy et al. used museum specimens of now-extinct populations to reveal 2 lineages: one from W. Europe, one from Africa & C. Asia, shaped by separate glacial refugia. doi.org/10.1046/j.13... #2026MMM

(A) Phylogenetic tree of 12 mammals used in this comparative analysis with red lines corresponding to the branches of long-lived mammals that are less prone to cancer (Asian elephant, African bush elephant, greater horseshoe bat, and naked mole rat). (B) Alignment of the ALDH6A1 protein sequence across species, where Asian elephant, African bush elephant, greater horseshoe bat, and naked mole rat have one mutation (asterisk) in the Aldehyde dehydrogenase domain (in red) that differs from other mammals that all the T (Threonine) residue (in black). (C) 3D structure of ALDH6A1 protein in long-lived mammals vs. short-lived mammals.

Asian elephant (🐘) lost tonight but it often wins against cancer! The Asian 🐘 genome + those of other mammals that are also less prone to cancer have a mutation in the ALDH6A1 gene that differs from other mammals and may help explain how they suppress cancer #2026MMM #RIP doi.org/10.1111/acel.13917

A graph showing probability distribution curves for fossil remains from different species: hippos in red and yellow, mammoths in grey, woolly rhinos in blue. Time since the present is on the x-axis. Hippo fossils cluster between 47k and 31k years ago.

Hippos were present in central Europe until around 31,000 years ago at the same time as mammoths and woolly rhinos. This was likely a small and isolated population in the Upper Rhine Plain. #2026MMM doi.org/10.1016/j.cu...

Sampling locations of Asian elephants included in the study (colored dots) as well as the geographic distributions of elephants in India (grey shading) and potential geographic barriers to elephant dispersal in India (blue and black lines). Sampling locations include northern populations in Northwestern India (NW; pink) and Northeastern India (NE; red); a central population in the Central Indian landscape (CI; blue); and southern populations in the north of Palghat Gap (NPG; orange), south of Palghat Gap but north of Shencottah Gap (SPG; green), and south of Shencottah Gap (SSG; yellow).

60% of the 🌏's wild Asian elephants (🐘) reside in India. Whole genome data from 34 Asian 🐘 reveal patterns of genetic divergence, diversity, inbreeding, + costly mutations that suggest 🐘 serially founded new populations as they moved north ➡️ south in India. #2026MMM doi.org/10.1016/j.cub.2024.08.062

Photos by Rebecca Raymond/National Park Service and Dan Stahler/National Park Service: Both of these Yellowstone wolves display the hair loss and skin lesions associated with mange. By analyzing 25 years of wolf observations and genetic samples from 408 Yellowstone wolves, a Princeton-led research team found that genetics play a role in the severity of the mite-borne disease. They found support for the “monoculture theory”: wolves with severe mange, like the one on the left, tend to have less genetic variation than wolves with mild symptoms, as seen on the right.

#RIP Grey fox. Sarcoptic mange devastates wolves, coyotes & red foxes. In wolves, immunity & skin barrier genes explain who survives. Grey foxes are remarkably mange-resistant. With the new grey fox reference genome, we have the tools to discover why! #2026MMM pmc.ncbi.nlm.nih.gov/articles/PMC...

Figure 6. (Sacks et. al 2022) Schematic representation of a hypothesis explaining the origins of island foxes (Urocyon littoralis) from a mainland ancestor replaced by expanding populations of gray foxes (U. cinereoargenteus). Island foxes and their immediate mainland ancestors (green) are distinguished from gray foxes (blue) 15,000 years ago (YA), prior to their introduction to the northern super-island, Santarosae 13,000–9500 YA, followed by their independent introductions to each of the southern islands 6000–200 YA, and finally their extirpation and replacement by expanding gray foxes on the mainland during the late Holocene. Overlapping time intervals reflect uncertainty in timing of extirpation and replacement. Putative introductions of foxes to the Channel Islands are indicated by green arrows and putative expansion routes of gray foxes are indicated by black arrows. Dashed lines indicate boundary to the California Floristic Province and dotted line bounds the Central Valley.

Grey foxes colonized California's Channel Islands ~13,000 years ago and evolved into an entirely new species, the island fox! DNA shows all island foxes trace back to a now-extinct mainland grey fox population replaced by expanding grey foxes. #2026MMM www.mdpi.com/2073-4425/13...

Table 3. Population Aggregation Analysis (PAA) Assigning Archival Specimens to Western or Eastern Clade. Diagnostic nucleotide positions within the short 12s (11 sites) and d-loop (14 sites) sequences. Specimens in bold represent archival material. Eight mummy specimens are highlighted in grey, all correspond to the western lineage. Sequences with question marks across one marker represent failed amplification success for that specimen. D-loop site 206 is an indel event in the eastern clade. The miscoding error observed at d-loop site 226 due to DNA degradation

Hekkala et al. (2011) used DNA to id cryptic diversity finding that both C. niloticus & C. suchas historically inhabited the Nile River! DNA of 8 croc mummies from Thebes & Samoun showed all were C. suchas, consistent w/priests' preference for the smaller croc! doi.org/10.1111/j.13... #2026MMM

Venn diagram of candidate loci identified by multiple outlier detection techniques. Shown are the number of candidate loci identified by each software. LFMM approach is colored in yellow for the abiotic variables and in green for the biotic variables.

European sea lampreys look well-mixed across the Atlantic, but seascape genomics tells a finer story. Baltazar-Soares et al. found local adaptation to ocean oxygen & river runoff, plus hints of selection driven by prey fish abundance. doi.org/10.1111/eva.... #2026MMM #RIP

(A) FACS analysis of blood leukocytes before and after antigen/mitogen cocktail immunostimulation. (B) Immunostimulated leukocytes. Scale bar, 10 µm. (C) VLR Virtual northern blot. Amplified cDNA from larval tissues, or sorted cells from unstimulated and immunostimulated blood and haematopoietic organs. Molecular size is indicated in kilobases. (D) VLR stick model. Sections from left to right are: signal peptide, N-terminal LRR, nine LRRs, connecting peptide, C-terminal LRR, threonine/proline-rich stalk, GPI anchor and hydrophobic tail (E) Epitope-tagged VLR and FcγRIIb (control) expressed in mouse thymoma cells, treated with (+ PLC) or without (- PLC) GPI-phospholipase C. (F) Three-dimensional model of VLR diversity region (two rotations).

Evolution invented adaptive immunity TWICE. Lampreys have no antibodies, yet Pancer et al. showed they build 10¹⁴+ unique immune receptors using leucine-rich repeats, a completely different molecular toolkit from our own. Convergent evolution! doi.org/10.1038/natu... #2026MMM

Figure 3. Phylogenetic analysis of RABVs analyzed in this investigation. A 592-nucleotide region encompassing the cytoplasmic domain of the glycoprotein and the G-L intergenic regions of the RABVs included in this study together with other previously characterized viruses was used in the analysis. A neighbor-joining tree of the G-L intergenic region sequences illustrating the genetic relationships of canid rabies viruses from the Kromdraai region of Gauteng. The virus sequences were compared with those from jackals from the 2016 rabies outbreak [14]. The virus sequence of the honey badger RABV is highlighted in red. The horizontal lines are proportional to the evolutionary distances between sequences and the scale bar represents nucleotide substitutions per site.

Honey badger is also susceptible to viruses - one honey badger attacked three people. Using molecular analyses, it was later confirmed that the honey badger was infected with rabies that it contracted from a dog www.mdpi.com/2414-6366/8/... #2026MMM

Demographic reconstruction of Baiji populations over time show that their populations had declined up to 10,000 years ago, at the beginning of the Holocene, and then had began to recover until human activity drove them extinct.

Using coalescent demographic reconstructions, Zhou et al found that the extinct Baiji had undergone a bottleneck at the beginning of the Holocene but populations were recovering in the last 10,000 years until recent extinction from human activities doi.org/10.1038/ncom... #2026MMM #RIP

Phylogeny of the river dolphins, where the East Asian Baiji was more closely related to the genus Inia, the South American river dolphins, including the La Plata river dolphin in the genus Pontoporia than to any of the Eurasian dolphins.

True river dolphins across the world's rivers are not all related. The extinct Baiji from East Asia was more closely related to the South American river dolphins in the genus Inia than to the Ganges river dolphin or Susu from South Asia doi.org/10.1371/jour... #2026MMM

Figure showing 2 phylogenetic trees of Tethytheria (Steller's Sea Cows and relatives) based on complete mitochondrial genomes: (A) top plot shows a Neighbor-Joining tree and (B) the bottom plot a Maximum Likelihood tree. In both trees, the extinct Steller’s Sea Cow (Hydrodamalis gigas) clusters most closely with the dugong (Dugong dugon), forming a sister group within Sirenia, while manatees (Trichechus manatus) branch off earlier. More distantly related species (Asian and African elephants, as well as woolly mammoth), form separate lineages. Branch lengths represent genetic divergence, and nodes on the Neighbor-Joining tree are supported by high bootstrap values. Procavia capensis is used as an outgroup in both cases. Source: Sharko et al. (2019) Genomics.

Scientists sequenced the mitochondrial genome of the extinct Steller’s Sea Cow from a museum bone, reconstructing its evolutionary history centuries after it went extinct. Data show it was most closely related to the dugong, found across the Indo-Pacific Ocean. #2026MMM doi.org/10.1016/j.yg...

This bar graph displays the variety of different repeat lengths found within the pSS(R)2 sequence. It shows that the fragment is composed of short sequences of DNA ranging from 2 to 17 nucleotides long

Indian rhino genomes contain a fragment called pSS(R)2 composed of repetitive units. It is unique to this species and could be used to identify horns, hooves, and other tissues to prevent poaching. #2026MMM #RIP doi.org/10.1016/s037...

A map of sites where samples of greater one-horned rhinoceros (Rhinoceros unicornis) dung were collected in Gorumara National Park, West Bengal.

A noninvasive census of an animal population is possible by analyzing dung samples. Researchers extracted DNA from rhino droppings in Gorumara National Park. They identified 43 unique rhinos and a 3.8:1 male to female ratio in this region #2026MMM doi.org/10.1017/S003...

A diagram showing for six species of whale (humpback whale colored in light orange) the enrichment of mammalian phenotype categories for positively selected genes in each species.

Despite their extremely large body size, humpback whales are well-known for their agility. Signatures of positive natural selection surrounding some genes related to reflexes and movement might hold clues to this awesome agility! #2026MMM doi.org/10.1016/j.gene.2024.148822

Featuring skeets by @acstone.bsky.social @afogel29.bsky.social @carloschalicothere.bsky.social @cegamorim.bsky.social @elinork.bsky.social @elliecat.bsky.social @fervillanea.bsky.social @sexchrlab.bsky.social @michelle-e-white.bsky.social and me!

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Tonight our final 16 species battle. Let's see whose genome wrote the better survival story. 🧬🎖️

I'll be posting genetics & evolution facts from Genetics TeaMMM #2026MMM

Heterozygosity of the various mink and weasels painted as a heat map. More genetic diversity is painted yellow, less is painted blue. The American mink, the closest relative to the Sea Mink, has internediate to low levels of heterozygosity.

Was the Sea Mink its own species or a variant of the American Mink? DNA from the American mink shows that it is not a very genetically diverse species, making less likely that cryptic variation exists within the living representatives doi.org/10.1093/gbe/... #2026MMM #RIP

Current distributions for all weasels in the western hemisphere : (A) M. erminea, (B) M. frenata, M. africana , M. felipei , (C) M. vison, (D) M. nigripes , M. nivalis

American mink have a history of being difficult to place in the Mustelid tree of life. Mink in the genus Neogale, including the extinct sea mink, used to be part of the weasels in the genus Mustela but DNA found the two branches to be distant cousins doi.org/10.1016/j.ym... #2026MMM

Line graph showing historical effective population size (y-axis) over time in years before present (x-axis) for 3 camel species: Camelus bactrianus (black), C. dromedarius (blue), and C. ferus (red). All three species show a similar pattern: population sizes increase in the distant past, then decline sharply by up to ~70% during the last glacial period (LGP, shaded), with a minimum around the last glacial maximum (LGM). Afterward, populations partially recover, with C. bactrianus reaching the highest recent values, C. ferus intermediate, and C. dromedarius remaining lowest. Small camel illustrations appear next to each trajectory.

Genetic data show that the Camelus dromedarius, C. ferus, and C. bactrianus lost ~70% of their populations in the last glacial period. Domestication hit C. dromedarius again around 4-5 kya. The Wild Dromedary survived the Ice Age… then humans took over. #2026MMM doi.org/10.1007/s112...