jueves, 10 de septiembre de 2020
domingo, 6 de septiembre de 2020
sábado, 5 de septiembre de 2020
Lactose tolerance happened quickly in Europe
Summary
Lactase persistence (LP), the continued expression of lactase into adulthood, is the most strongly selected single gene trait over the last 10,000 years in multiple human populations. It has been posited that the primary allele causing LP among Eurasians, rs4988235-A [1], only rose to appreciable frequencies during the Bronze and Iron Ages [2, 3], long after humans started consuming milk from domesticated animals. This rapid rise has been attributed to an influx of people from the Pontic-Caspian steppe that began around 5,000 years ago [4, 5]. We investigate the spatiotemporal spread of LP through an analysis of 14 warriors from the Tollense Bronze Age battlefield in northern Germany (∼3,200 before present, BP), the oldest large-scale conflict site north of the Alps. Genetic data indicate that these individuals represent a single unstructured Central/Northern European population. We complemented these data with genotypes of 18 individuals from the Bronze Age site Mokrin in Serbia (∼4,100 to ∼3,700 BP) and 37 individuals from Eastern Europe and the Pontic-Caspian Steppe region, predating both Bronze Age sites (∼5,980 to ∼3,980 BP). We infer low LP in all three regions, i.e., in northern Germany and South-eastern and Eastern Europe, suggesting that the surge of rs4988235 in Central and Northern Europe was unlikely caused by Steppe expansions. We estimate a selection coefficient of 0.06 and conclude that the selection was ongoing in various parts of Europe over the last 3,000 years.
sábado, 29 de agosto de 2020
martes, 25 de agosto de 2020
domingo, 23 de agosto de 2020
sábado, 22 de agosto de 2020
domingo, 16 de agosto de 2020
lunes, 10 de agosto de 2020
martes, 4 de agosto de 2020
RECIDA
Ministerio para la transición ecológica y el reto demográfico
REDISCOVER Nature - Photo competition 2020
Isn’t nature full of wonders? No matter where we are, we can always appreciate its beauty. Have you ever sat near a quiet lake in a mountain, watched sparrows nesting in your garden or a tiny herb seedling grow on your kitchen windowsill? Taking in nature in all its beautiful shapes and forms can bring us a lot of joy – now possibly more than ever.
The European Environment Agency is inviting you to reconnect with nature and capture all its wonders on camera. So grab your cameras and go for a hike on a local trail or relax in your garden and observe the tree leaves bending or the fluffy clouds floating in the sky. Be curious and discover the parts of nature you have never noticed before, both small and large.
Every year, the EEA organises a photo competition to raise awareness about an environmental theme and invites Europeans to share their takes on it. This year’s competition ‘REDISCOVER Nature’ is a call for all of us to look around us and let ourselves be amazed by nature.
The competition is open for submissions until 30 September 2020.
European environmental agency
jueves, 30 de julio de 2020
martes, 28 de julio de 2020
Cáncer, la pista olvidada
Ya en los años 70 la labor de gente como Mina Bissell tiende a probar que el cáncer nace de una interacción entre las células y su entorno. La bióloga americana fue una de las primeras en poner en tela de juicio la teoría de que la genética del cáncer sea la única causa de esta enfermedad.
Laurent Schwartz también propone adoptar una visión más global. Para comprender mejor la célula cancerosa hay que estudiar sus recursos, y la forma en que los utiliza. Es lo que se conoce como "metabolismo".
viernes, 17 de julio de 2020
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