a woman sitting at a table with the words they say it 's genetic on the bottom Alt: a woman expressing "they say it's genetic"

HAT-TIP @acstone.bsky.social & @cegamorim.bsky.social for leading the genetics teaMMM of @n8upham.bsky.social @fervillanea.bsky.social @lucasrocm.bsky.social @carloschalicothere.bsky.social @elinork.bsky.social @afogel29.bsky.social @elliecat.bsky.social @michelle-e-white.bsky.social #2026MMM

The test for genetic admixture D(gaur, aurochs; ancient group1, ancient group2) reveals asymmetric affinities of aurochs genomes with pre-4000-yr-B.P. cattle populations. Levantine cattle show reduced genetic sharing relative to other populations with the Armenian (Gyu2) and British (CPC98) aurochs but more with the Moroccan aurochs (Th7). Balkan cattle show asymmetric affinities with the British aurochs.

Is the auroch DNA truly gone from the world? Pereira et al found that modern Anatolian, Levant, Irani, and Balkans cattle share DNA to various degrees with extinct Armenian, British, and Moroccan ancient aurochs. A small amount of auroch DNA still lives today doi.org/10.1126/scie... #2026MMM #RIP

The best fit of genetic data to a population graph of Eurasian aurochs and Sahiwal, obtained from qpGraph, involves a gene flow from Near Eastern aurochs into Holocene East Asian aurochs.

The extinct auroch had at least three subspecies, and all three contributed some ancestry to modern cattle. For example, Cai et al found East Asian cattle descend from West Eurasian cattle originally but then later admixture with the extinct East Asian auroch doi.org/10.1038/hdy.... #2026MMM

(a) Geographic locations of humpback whale genetic sampling in the North Pacific. (b) Geographic locations and mtDNA haplotype frequencies for humpback whales across 8 breeding regions and 10 feeding regions. 28 mtDNA haplotypes were identified for humpback whales in the North Pacific. Colors correspond to the 3 haplogroup designations from previous studies where A-types are colored maroon (A+) and yellow (A-), E-types are colored green, and F-types are colored blue.

Every year, humpback whales make long treks btwn where they breed & where they feed. Maternally-inherited mtDNA from >1,800 humpback whales suggest that animals annually return to where they were born to breed themselves & where they fed w/their moms early in life #2026MMM doi.org/10.3354/meps10508

A chromosome-scale genome for the honey badger doesn't yet exist. Only available genome is in 2,068,312 pieces. Honey badger don't care. www.ncbi.nlm.nih.gov/datasets/gen... #2026MMM #RIP

35 mm slide; color. African lion cub with Honey Badger. Garst, Warren, 1922-2016, photographer

Although honey badgers have a dominant male, genetic analysis revealed that subordinate males fathered about half of cubs. journals.co.za/doi/abs/10.1... #2026MMM

STRUCTURE bar plot showing the distribution of Nile crocodile populations. The most likely number of population clusters, K = 2 (based on ΔK, representing the upper hierarchical level) and K = 5 (based on all other estimates, giving a more “localised” regional evaluation of population structure). [OR-BNP-Nam: Okavango River system—Bwabwata National Park–Namibia, OR-OD-Bot: Okavango River system—Okavango Delta—Botswana, OR-OCR-Nam—Okavango Crocodile Ranch—Okavango River—Namibia, LK-Nam–Lower Kunene River—Namibia, LS-N-Mal–Lower Shire River (North)—Malawi, LS-S-Mal–Lower Shire River (South)—Malawi, Limpo-SAf–Limpopo River—South Africa, KZN-SAf–KwaZulu-Natal—South Africa].

How related are Nile crocodiles across Southern Africa? Van Asch et al. (2019) used STRs & mtDNA to examine phylogeography & genetic diversity. Primary differentiation across east/west & secondarily across major river systems #2026MMM doi.org/10.1371/jour...

In just a few minutes the penultimate #2026MMM night of battles begin & I'll be posting genetics & evolution facts from Genetics TeaMMM!

Fig 2 from Liu et al. (2024). The median-joining haplotype network and haplotype distribution obtained from sampled populations of Salamandrella genus based on the COI gene. Labels have been added to clarify species networks with Siberian salamander S. keyserlingii at the top and Schrenck salamander (Salamandrella tridactyla) at the bottom of panel a. Panel b shows diversity within each haplotype.

Sequencing mtDNA COI genes in Siberian Salamander & cryptic sister species Schrenck salamander in northeast China finds high genetic differentiation among populations w/in each species in the Khingan Range & Changbai mountains doi.org/10.1371/jour... #2026MMM #2026mmm #RIP

The Gila Monster slowly moves towards the defrosting Siberian Salamander, using her flicking her tongue to assess as she steps towards the AMPHIBICICLE #2026MMM #2026mmm

Map showing sampled localities of S. keyserlingii and geographical distribution of the main mtDNA clades.

Studying mtDNA genomes from throughout Siberian Salamander's range finds highest diversity in Russian Far East & Manchuria. Population expanded in the middle Pleistocene & then bottlenecked at the Last Glacial Max. dx.doi.org/10.1016/j.ym... #2026MMM #2026mmm

Giemsa (a, b, e, f) and C-banded (c, d, g, h) metaphase chromosomes and karyotypes from a female (a–d) and a male (e–h) of Heloderma suspectum. The sex chromosomes are labelled in the C-banded female karyotype (d)

Gila monsters have 18 pairs of chromosomes (fewer than our 23), including a pair of sex chromosomes (Pokorná et al, 2014): journals.plos.org/plosone/arti... #2026MMM #2026mmm

Molecular divergence times (in millions of years with 95% highest posterior intervals on the divergence estimates of each node) for dasyuromorphian based on the analysis of partitioned concatenated DNA sequences of nuclear and mitochondrial genes.Vertical brown bars indicate timings of major phases of aridity in Australia over the last 30 Myr. (Westerman et al. 2015)

While the long-tailed planigale appeared relatively recently, its ancestors likely diversified as Australia collided with the Ontong-Java Plateau, creating the dry habitats they love today. doi.org/10.1111/zoj.... #2026MMM #2026mmm #RIP

Tree of phylogenetic relationships of dasyuromorphians obtained from the combined nuclear plus mitochondrial DNA sequences in which each gene was given its own model of sequence evolution. (Westerman et al. 2015)

Big data for small mammals! Researchers used 16 nuclear and mitochondrial genes to build the Dasyuromorphia tree. Findings confirm long-tailed planigale sits within the Planigalini tribe, having diverged from its closest relatives ~12.3 million years ago doi.org/10.1111/zoj..... #2026MMM #2026mmm

Phylogeny of the small-eared shrews of the genus cryptotis. The least shrews, which are three species, sit outside the branches containing all other small-eared shrews.

Shrews species relationships have always been difficult to resolve because their group speciated very quickly. He et al used mitochondrial genomes to create a phylogeny and identified the Least Shrew group as basal to all other small-eared shrews dx.doi.org/10.24272/j.i... #2026MMM #2026mmm

(A) Snail plot of M. giganteus scaffolded haploid genome assembly. (B) Hi-C contact map for the haploid assembly. Approximately 99% of data are scaffolded onto 14 pseudochromosomes. (C) Composition of chelicerate genome assemblies.

Kulkarni et al. (2024) assembled a chromosome-level genome of the Uropygi (Mastigoproctus giganteus) and found it is BIG. Nearly as big as the human genome (3.17Gb), with 71% consisting of repetitive DNA. doi.org/10.1093/jher... #2026MMM #2026mmm #RIP

(A) Phylogeny of Chelicerata with emphasis on the relationships between Arachnopulmonata. Tree topology is based on Ballesteros et al. (2022). (B) Live habitus of M. giganteus in lateral view. (C) Live habitus of M. giganteus in frontal view. WGD = whole genome duplication

Uropygi have looked largely the same since the Carboniferous, but their DNA tells an even older story. The Mastigoproctus giganteus genome has preserved the signature of a whole genome duplication that predates the Silurian (400+ million years old). doi.org/10.1093/jher... #2026MMM #2026mmm

Majority-rule consensus tree of combined morphological and molecular data sets for the new world rats and mice. The three species of grasshopper mice sit on their own brach outside the other new world mice showing they are very unique.

Phylogenies work best if you can combine fossil and DNA evidence! A consensus of the molecular, morphological, and paleontological evidence placed the three grasshopper mice species as a distinct and unique genus within the new world mice doi.org/10.1093/jmam... #2026MMM #2026mmm

Diagram of protoporphorin 1X showing the labeling of pyrroles and axes used in GHb. View is from the distal towards the proximal side.

Unlike most, bloodworm hemoglobin swaps distal histidine for leucine. This hydrophobic pocket stops iron oxidation, keeping "blood" functional in the toxic mud where these animals live. doi.org/10.1016/0022... #2026MMM #2026mmm #RIP

Best maximum-likelihood (ML) tree from gene cyt b sequences of shrikes. Bootstrap-support values from a 100-replicate bootstrap are included at the nodes, if above 50%.

The Northern Shrike is not just one species: genetic data suggests New World and Old World populations have been on separate paths for a long time (1.1–1.8 my) doi.org/10.1525/cond... #2026MMM #2026mmm

Transcriptomic profile of toxin genes expressed in the venom glands of Glycera dibranchiata. (A) Contig diversity for the different toxins. (B) Abundance of sequence reads for the different toxins. Relative contig diversity and relative abundance of reads are expressed as percentages followed by the numbers of contigs and reads in parentheses

Genetic profiling of bloodworm venom gland reveals a lethal cocktail of 20 different toxin classes, including "stonustoxin" previously only found in deadly stonefish. It’s a cool case of convergent evolution! doi.org/10.1093/gbe/... #2026MMM #2026mmm

Conserved sequence features in redulysin proteins. Amino acid sequence alignment of redulysins with the cytolytic domain of trialysin. The consensus sequence of the redulysin proteins is shown at the bottom. Lys residues are shown in bold black, positively charged residues in red, and hydrophobic residues in blue.

The venom gland of the assassin bug is a specialized factory. Using RNA-Seq, researchers identified 127 unique protein sequences, including "redulysins", pore-forming toxins that help melt prey tissues from the inside out. doi.org/10.1074/mcp.... #2026MMM #2026mmm #RIP

Evolution of CUB domain proteins. Sequence names in blue indicate P. plagipennis sequences determined in Walker et al. (2017). (A) alignment of CUB domain venom proteins from P. plagipennis and the anthocorid O. laevigatus with the N-terminal portion (including CUB domain) of P. plagipennis venom S1 protease 8. (B) phylogeny according to Bayesian inference showing support for monophyly of cimicomorphan venom CUB domain proteins (highlighted yellow). (Walker et al. 2017)

Research shows the CUB domain protein family, among the most abundant proteins in the Assassin bugs' venom, likely evolved from digestive enzymes ~190 million years ago. This coincides with the ancestral switch from eating plants to becoming predators! doi.org/10.1074/mcp.... #2026MMM #2026mmm

The effects of venom from four Naja species against the honey badger (Mellivora capensis) native and mutant mimotope sequences. (a) Amino acid sequences of native and mutant mimotopes. (b) Bar graphs represent the mean area under the curve (AUC) values of the adjacent curve graphs. Curve graphs show the mean wavelength (nm) shift in light with increased binding of venoms over a 120 s association phase. Each venom was tested in triplicate (n = 3). Error bars on all graphs represent the SEM. AUC values were statistically analysed using a one-way ANOVA with a Dunnett's multiple comparisons post hoc test comparing to the native mimotope. Statistical significance is indicated by an asterisk above the corresponding bar with a significance threshold of p < 0.01.

Honey badger has a specific protein coding mutation that reduces the binding capacity of neurotoxins in the venom of snakes it preys upon. royalsocietypublishing.org/rspb/article... #2026MMM #2026mmm

Osedax’s metabolic adaptations to bone digestion. a Summary table of the presence (filled circles) and absence (empty crosses) ofamino acid biosynthetic pathways in 7 annelid genomes and O. frankpressi endosymbiont (symbiont Rs 1). While Vestimentifera and asymbiotic annelids can synthesise all amino acids that are non-essential and conditional for humans, O. frankpressi shows incomplete pathways to synthetise proline, arginine, and serine (in red). Some of these amino acids are abundant in the bone (e.g., proline) and all can be produced by the symbiont (tyrosine biosynthetic pathway is truncated in the symbiont; dotted & lighter circle). b–d Schematic representation (as in MetaCyc database) of the biosynthetic pathways for proline (b), serine (c) and arginine (d) indicating with red and violet circles the enzymes present in O. frankpressi and its endsymbiont, respectively. Osedax frankpressi cannot produce serine from glycolytic metabolites but can either produce serine from collagen-derived glycine or take it from the diet. In addition, O. frankpressi can only convert arginine into ornithine, producing urea as a result. e, f Heatmaps of normalised mRNA expression levels for amino acid biosynthetic enzymes (e) and glycine catabolising enzymes (f) in the body & roots of O. frankpressi. Biosynthetic enzymes (e), including the two copies of serine hydroxymethyltransferase (SHMT-a and SHMT-b) that convert glycine into serine, are more expressed in the roots than in the body of O. frankpressi.

Boneworm genomes are so metal! O. frankpressi has reduced genome & adaptations for bone digestion, w loss of amino acid biosynthetic pathways abundant in bones & expansion of matrix metalloproteases used in bone digestion. doi.org/10.1038/s414... #2026MMM #2026mmm #RIP

"Fig. 3B. Phylogenetic reconstructions of Siboglinidae based on concatenated nucleotides of the 13 mitochondrial protein-coding and 2 ribosomal RNA genes. Majority rule (50%) consensus phylograms from Bayesian analyses of the concatenated data matrices are shown. Values are shown next to nodes with posterior probabilities left and ML bootstrap support values right. Filled circles indicate fully supported nodes "

Are boneworms more closely related to Vestimentifera (living at hydrothermal vents) + Sclerolinum (decaying matter) or Frenulata (muddy sediments)? Li et al. (2015) sequenced the mtDNA & found boneworms are sister (& branch basely) to Vestimentifera. dx.doi.org/10.1016/j.ym... #2026MMM #2026mmm

Neighbour-joining trees based on genetic distance using the following subsets of loci: (a) 4439 SNPs, (b) 4068 putatively neutral loci and (c) 162 adaptive SNPs that were determined to be candidates of positive selection. Branch nodes are labelled with the per cent of bootstrap support that was generated with 1000 replicates. Dotted lines were used to label branch tips for clarity in high-density regions of the tree. Brackets around particular branches indicate the bootstrap support of the branch node.

The Pacific Lamprey is a master of dispersal, mixing genes across thousands of miles. To the naked eye, it looks like one giant, uniform population. Using genomic data, Hess et al. found 162 adaptive loci drive differences in body size & migration timing. doi.org/10.1111/mec.... #2026MMM #2026mmm

Figure 3 Bar plot graph of estimated membership coefficient of Trachops cirrhosus from Bayesian analysis generated using Structure and the Locprior option for (a) dataF+JUV (females + all juveniles irrespective of their sex; K = 3) and (b) dataM (only adult males; K = 2). BCI, Barro Colorado Island; BO, Bohio; GA, Gamboa; GI, Gigante; CUL, Culebra Cut. Additionally, the maps display an overview of the netting sites and the cluster assignment of the sampled individuals. Sizes in the map are proportional to sample size

Short tandem repeat DNA data collected by Halczok et al. (2018) show Fringe-lipped bat (unlike other Neotropical bats) has mostly male-mediated gene flow & that human impacts like widening of the Panama Canal are acting as recent barriers to gene flow. doi.org/10.1002/ece3... #2026MMM #2026mmm #RIP

Figure 6 from Clare (2011). Haplotype maps and phylogenetic reconstruction of COI and the 7th intron of the Dby gene in Trachops cirrhosus with sampling distributions. In the statistical parsimony networks each circle represents a single haplotype with circle size scaled by haplotype frequency. Squares indicate the most common haplotype in the network. The COI tree represents the maximum likelihood phylogeny of mitochondrial lineages. Branch supports represent non-parametric Shimodaira-Hasegawa-like (SH-like) values, those equal or greater than 95% are indicated with an asterisk. Y-chromosome intron data is depicted using a UPGMA diagram. Colour coding of branches and haplotype networks matches the sampling distribution.

Do Fringe-lipped bats have cryptic (hidden) species? Divergent mtDNA data (COI gene) suggest maybe. But what about the Y chromosome? Clare (2011) compared the data in 127 bats from across Central & South America, but no Y variation found (need more data?) doi.org/10.1371/jour... #2026MMM #2026mmm

Maximum likelihood (ML) phylogeny of all Sauromalus based on concatenated double-digest restriction site-associated DNA sequencing data. Numbers at nodes indicate bootstrap support. Major groups and currently recognized taxa are labelled.

Genomic evidence shows the Common Chuckwalla is actually two distinct lineages, separated when the northern Gulf of California first flooded. This event set the stage for the evolution of the unique giant island chuckwallas we see today. doi.org/10.1093/biol... #2026MMM #2026mmm