A recent paper tackled a mystery that has puzzled scientists for years;  how the world’s only winged mammals carry viruses that cause severe disease while rarely becoming seriously ill themselves?

One prominent lab that studied them was in Wuhan, China, but they took their database of coronavirus samples offline in late 2019 so scientists in the rest of the world are stuck redoing a lot to try and figure out how it happens. Researchers from the U.S. Centers for Disease Control and academia found that the world’s largest family of bats carry two copies of the genes that produce antibodies that help the immune system recognize and fight infections. Their model was vesper bats, because that family includes over 500 species found on every continent where bats can survive. Antibodies are Y-shaped proteins consisting of two heavy protein chains and two light protein chains. In every other mammal, those heavy chains are built from a single set of gene. Vesper bats instead possess two separate heavy-chain gene systems, which makes it possible for them to generate enhanced antibody diversity. 

The discovery of two distinct copies of proteins that prevent infection opens new avenues for understanding the evolution of immunity and how we respond to disease. Preventing human disease is a key reason why the Obama administration helped fund gain-of-function research in Wuhan back in 2014. They had bat and other animal samples from all across Asia and the world. They were looking closely at adaptive immune systems.

(A) Schematic of Ig gene annotations for A-IGH locus. (B) Pie chart of functionality and (C) gene family distribution for functional variable (V) genes for A-IGH locus. (D) Density plot of AID hotspots per kilobase in the constant gene encoding regions for A-IGH locus. (E) Schematic of Ig gene annotations for B-IGH locus. (F) Pie chart of functionality and (G) gene family distribution for functional variable genes for B-IGH locus. (H) Density plot of AID hotspots per kilobase in the constant gene encoding regions for B-IGH locus. (I) Nearest neighbor-joining tree of functional and ORF V genes for A-IGH and B-IGH with human V genes collapsed by V-gene family for reference. Created in BioRender. Pursell, T. (2026) https://BioRender.com/rru8vm2.

Genes along can't explain why they are effective viral reservoirs that give disease without catching it but because bats are pollinators and pest controllers their ability to serve as natural hosts for many viruses leads to worry about disease spillover. But bats aren't like Aedes Egyptii mosquitoes, disease vectors that could be wiped out and their ecological value taken up by a million other species, they are important enough we would benefit from coexisting with viruses the way they do.

After an asteroid slammed into Earth 66 million years ago, now called the Cretaceous-Paleogene (K-Pg) extinction, fish in the fossil record went dark for about 10,000,000 years. When they have been found again, any species that look different than those that came before, leaving scientists to wonder what evolutionary paths fishes took between about 66 and 56 million years ago. A new paper describes marine fishes dated to 62.2 million years ago, helping to fill that interval, including the earliest known fossil skeletons of jack, a type of sportfish, moonfish and pipefish, the family to which seahorses belong.

In total, they discovered 21 kinds of fishes across nine orders of fish. Most of the fishes are percomorphs, a major group in today's oceans but which were relatively uncommon during the age of dinosaurs

The researchers also wondered what their findings meant in the broader context of the fossil record early after the K-Pg extinction. Comparing their findings to information from other fossil deposits, the researchers found that most of the percomorphs found just after the extinction event were mostly in the tropics. There appeared to be fewer percomorphs in higher latitudes. Only long after the extinction did percomorphs seem to become common everywhere.

The researchers say there could be many reasons why the 10-million year gap has occurred. One reason could be that the majority of paleontological work has been concentrated in Europe and North America, missing valuable deposits that might be present elsewhere.

Citation: Sanaa El-Sayed et al., Rise of modern marine fishes captured in an early Paleocene Lagerstätte.Sci. Adv.12,eaec8978(2026). https://www.science.org/doi/10.1126/sciadv.aec8978

Laser-assisted electron scattering (LAES) is a tool for understanding how electrons interact with matter under the influence of strong fields. When electrons are fired at atoms or molecules, they are scattered in all directions; the presence of strong light can change the way in which the scattering takes place due to an exchange of energy with the surrounding light field. The amount of energy exchanged is precisely governed by quantum mechanics and yields characteristic shifts in the energies held by scattered electrons.

Now, researchers have succeeded in detecting laser-assisted electron scattering using circularly polarized light for the first time. The use of circularly polarized light promises valuable insights into how atomic scale “helicity” impacts how electrons interact with matter and light. Using synchronized femtosecond laser pulses and electron pulses directed at argon atoms, they succeeded in detecting a  laser-assisted electron scattering  signal showing excellent agreement with theory.
 

Recent experiments have used LAES measurements to show how strong electromagnetic fields can fundamentally change the behavior of matter. Examples include “light-dressing,” where strong laser light modifies the distribution of electrons around atoms.

A key challenge in recent work on LAES is the use of circularly polarized light. As a wave of oscillating electric and magnetic fields, light can have a “polarization” direction in which the electric fields oscillate. In circularly polarized light, the polarization direction rotates as the wave propagates forward. Since it has a characteristic “handedness,” of whether it rotates left or right, the way in which it interacts with matter may be sensitive to any intrinsic “chirality” in the structure, the “handedness” of the structure itself. Importantly, measuring the difference between left and right-handed light in LAES gives access to the “phase” of scattered electrons, an inaccessible quantity using linearly polarized light. However, the gold standard measurement of LAES using circularly polarized light in single atoms has not yet been achieved.

The team successfully demonstrated LAES in argon using femtosecond circularly polarized laser pulses in the near-infrared range, and simultaneous electron pulses. They were able to measure the energy and angular distributions of electrons scattered by argon in the presence of femtosecond laser pulses, finding peaks characteristic of the LAES process. While the signal was weaker than with linearly polarized light, the scattering signal agreed with a form expected from seminal extensions to LAES theory (Kroll-Watson theory). At this point, they were unable to measure the minute difference between LAES with left and right-handed light.

While there is further work to be done to improve detection efficiency and statistical accuracy, the team’s work demonstrates how LAES with circularly polarized light might illuminate new aspects of electron-matter interaction in strong fields.