
ブラジルのリオグランデドスル・カトリック大などの国際研究チームが、南米各地のジャガーネコのDNAを解析し、ボリビアの森林に生息する集団が新種であることを明らかにした。体格は家猫並みで、現地の呼び方から「ティルカヨ」と命名された。ティルカヨはジャガーネコなどの祖先とは約140万年前に分かれたと推定され、ペルーにも新亜種の可能性がある集団がいることが分かった。森林の伐採や密猟などで絶滅が懸念されており、正確な種の分類が保護や繁殖に役立つと指摘している。
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ジャガーネコはオセロット属の一種で、大型のジャガー(ヒョウ属)とは異なる。これまでの研究で、ジャガーネコは多数の種に分類される可能性が指摘されてきた。
南米各地のジャガーネコのDNAを解析したところ、ボリビアの森林に生息する集団は新種に分類されることが分かったと、ブラジルのリオグランデドスル・カトリック大などの国際研究チームが19日までに米科学誌カレント・バイオロジー電子版に発表した。体格はペットのイエネコ並みで、現地の呼び方から「ティルカヨ」と命名された。
ジャガーネコはオセロット属の一種で、大型のジャガー(ヒョウ属)とは異なる。調査が進むにつれて多数の種に分類されるとの見方が強まっていた。
研究チームが博物館の標本を含む計38匹について、細胞核DNAを網羅的に調べる「全ゲノム解析」を行ったところ、ティルカヨの存在が判明。ジャガーネコなどの祖先とは約140万年前に分かれたと推定した。
ペルーにはジャガーネコの新亜種に分類すべき集団がいることも分かった。いずれも森林の伐採や密猟などで絶滅が懸念されており、正確な種の分類が適切な保護や繁殖に役立つという。

During the extended mission of the asteroid explorer Hayabusa2, the only ion engine (B) that was operating normally broke down. JAXA's policy is to continue operation through "cross operation," which combines normal parts from different engines, with the aim of reaching the destination in 2031.

A research team from Syracuse University and other institutions announced in the American journal Science that they have discovered a new species of single-celled amoeba that grows at temperatures as high as 63 degrees Celsius in California's Lassen Volcanic National Park. This is the highest growth temperature ever recorded for a eukaryotic organism with a cell nucleus.

Stone tools believed to be the oldest in Japan were discovered in 2024 at the Yoshiwa-no-Kan Ruins in Hatsukaichi City, Hiroshima Prefecture, and excavations are continuing led by Sadakatsu Kunitake, a senior researcher at the Nara National Research Institute for Cultural Properties. The stone tool, called a point tool, was found to be 42,300 years old by radiocarbon dating, which could be about 5,000 years earlier than the conventional time that humans arrived in the archipelago. Many citizens visit the public exhibition, which leads to the development of related products and regional revitalization.

Keio University announced that it has selected Professor Seiji Ogawa of Kyoto University and Professor Ulrich Hartl of Germany's Max Planck Institute for Biochemistry as this year's Keio Medical Prize recipients. Dr. Ogawa was recognized for elucidating genetic abnormalities in cancer, and Dr. Hartl was recognized for elucidating the function of molecular chaperones.

A research team from the University of California, Los Angeles and other institutions announced that they analyzed carbon-13 and oxygen-18 isotopes in the tooth enamel of a Tyrannosaurus rex excavated in Montana and estimated that the animal's body temperature was approximately 36.3 degrees Celsius. This is the first concrete estimate of body temperature that supports the idea that dinosaurs were at least partially homeothermic rather than poikilothermic.

A research team from the University of California, Los Angeles and other institutions analyzed a Tyrannosaurus rex fossil unearthed in Montana and measured carbon-13 and oxygen-18 isotopes in tooth enamel to estimate body temperature. The researchers found that their body temperature was approximately 36.3 degrees Celsius, similar to that of humans, suggesting that at least some dinosaurs may have been homeothermic like mammals.