Project 1a 

This fish has legs — and it uses them for more than just walking. 

Sea robins’ legs are not only crablike but also like tongues.

 Some sea robins, a group of fish with two wing-like fins and six crablike legs, use their legs to dig in sand and find buried prey with a sense much like taste, researchers report in two papers published September 26 in Current Biology. Most sea robins seem to use their legs only for walking. However, an ancient gene important for the formation of limbs in humans and other animals and a gene involved in building taste buds helped a few species develop legs that taste.

“New things came from old parts,” says David Kingsley, a developmental biologist at Stanford University. A walking fish with taste organs on its limbs may look “really new and cool and different, but when you dig in… the new things have come by taking a tool kit of preexisting genes and deploying them in new ways.”

Northern sea robins (Prionotus carolinus) are skilled at finding buried crabs or shrimp to snag a meal. So skilled that other fish seem to follow along to take advantage of any spoils. Previous studies suggested that northern sea robin legs could pick up chemical cues, but it was unclear if the limbs could sense anything as they dug into the seafloor.

Most sea robins, including a non-digging species called the striped sea robin (P. evolans), have smooth, rod-shaped legs that probably can’t taste, the team discovered. That difference suggests that northern sea robins and another digging relative, the leopard sea robin (P. scitulus), are among a few species benefitting from an “evolutionary innovation,” says Amy Herbert, a developmental biologist at Stanford University. 

www.sciencenews.org/article/fish-legs-taste-prey-sea-robin 

This fish has legs - and it uses them for more than just walking.

 Besides looking like crabs, sea robins' legs also look like tongues. 

Researchers describe in two publications published September 26 in Current Biology that some sea robins, a group of fish with six crab-like legs and two wing-like fins, use their legs to dig in sand and find buried prey using a sense similar to taste. The majority of sea robins appear to only walk on two legs. However, a few species were able to generate taste-producing legs thanks to an ancient gene involved in the development of limbs in humans and other animals, as well as a gene related to the construction of taste buds.

Stanford University developmental scientist David Kingsley asserts that "new things came from old parts." Even while a walking fish with taste organs on its limbs appears to be "really new and cool and different," closer examination reveals that the new features are the result of repurposing preexisting genes in novel ways. 

Prionotus carolinus, or northern sea robins, are adept at locating buried crabs or shrimp to obtain food. So proficient that other fish appear to trail behind to share in the spoils. It was unknown if the legs of northern sea robins could sense anything when they sank into the seafloor, despite earlier research suggesting that they could detect chemical cues. 

The team found that the majority of sea robins, including the striped sea robin (P. evolans), are non-digging species, and have smooth, rod-shaped legs that are most likely incapable of tasting. According to Amy Herbert, a developmental biologist at Stanford University, this distinction shows that northern sea robins and another digging relative, the leopard sea robin (P. scitulus), are among a select few species benefiting from an "evolutionary innovation." 

Huellas de los primeros pobladores de América

En 2021, arqueólogos del Parque Nacional de White Sands, en Nuevo México, anunciaron un descubrimiento: huellas humanas inconfundibles, dejadas en la orilla fangosa de un antiguo lago hace entre 21.000 y 23.000 años.

Las pisadas fosilizadas se formaron en lodo blando en los márgenes de un lago poco profundo que ahora forma parte de Alkali Flat, una gran zona de dunas.

David Bustos, administrador del programa de recursos del parque nacional, fue el primero en descubrir estas huellas en el año 2009. Bustos, junto a Matthew Bennett, un geólogo de la Universidad de Bournemouth (Reino Unido) y otros científicos del USGS comenzaron a estudiar más detalladamente el lugar en 2019. 

Si las fechas son correctas, las huellas se dejaron en el punto álgido de la última glaciación, cuando los glaciares cubrían Canadá, lo que sugiere que los humanos debieron de hacer el viaje a América antes de que se formaran esas capas de hielo. 

www.agenciasinc.es/Noticias/Los-diez-avances-cientificos-de-2023-segun-la-revista-Science 

Las huellas de los primeros colonos  Americanos 

En el Parque Nacional de White Sands en Nuevo México, los arqueólogos descubrieron en 2021 que habían dejado huellas humanas inconfundibles en la orilla fangosa de un lago antiguo hace entre 21.000 y 23.000 años.

En el Parque Nacional de White Sands en Nuevo México, los arqueólogos descubrieron en 2021 que habían dejado huellas humanas inconfundibles en la orilla fangosa de un lago antiguo hace entre 21.000 y 23.000 años.

En el año 2009, David Bustos, administrador del programa de recursos del parque nacional, fue el primero en encontrar estas huellas. En 2019, Busto comenzó a investigar más a fondo el lugar junto a Matthew Bennett, un geólogo de la Universidad de Bournemouth (Reino Unido), y otros científicos del USGS.

Si las fechas son precisas, las huellas se dejaron en el punto más alto de la última glaciación, cuando los glaciares cubrían Canadá, lo que indica que las personas debieron viajar a América antes de que se formaran esas capas de hielo.