يبدو أن النسخ الإضافية من المادة الوراثية قد عززت فرص بقاء النباتات الزهرية خلال الأزمات البيئية الكبرى التي شهدتها الأرض، بما في ذلك الحدث الذي أدى إلى انقراض الديناصورات.
وجدت دراسة شملت 470 نوعاً من كاسيات البذور وجود 132 حالة تضاعف جينومي قديم تركزت حول تسع فترات من الاضطرابات البيئية بين 108 ملايين و14 مليون سنة مضت. وشملت هذه الاضطرابات تحولات مناخية، وتغيرات في مستويات الأكسجين، وانقراضات جماعية، مثل اصطدام الكويكب قبل 66 مليون سنة في نهاية العصر الطباشيري.
The end-Permian extinction, which occurred 252 million years ago, eliminated over 80 percent of marine species, yet many ocean ecosystems maintained complex structures with top predators surviving. A new study of seven global marine sites reveals that despite severe losses, five ecosystems retained at least four trophic levels. This suggests ecosystems' resilience depends on their unique species compositions, offering insights for modern climate threats.
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A cache of 250-million-year-old fossils rediscovered in Australia has shown a diverse community of early ocean predators following Earth's worst mass extinction. These marine amphibians, including species from the trematosaurid group, indicate a rapid global spread in the early Mesozoic era. The findings challenge previous views that limited such creatures to a single species in the southern hemisphere.
Scientists suggest that asteroid impacts created hot, chemical-rich environments that could have kick-started life on Earth. A new review led by recent Rutgers graduate Shea Cinquemani highlights impact-generated hydrothermal systems as potential cradles for life's building blocks. These systems may have persisted for thousands of years, providing ideal conditions for early biology.
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A 20-year experiment cloning mice has revealed that clones develop significantly more genetic mutations than naturally reproduced mice, accumulating to fatal levels after multiple generations. Researchers led by Teruhiko Wakayama at Yamanashi University in Japan found over 70 mutations per clone generation on average, three times higher than in controls. The findings, published in Nature Communications, raise concerns for applications in farming, conservation and de-extinction efforts.
Researchers at Queen Mary University of London analyzed data from the BioTIME database and found species turnover in ecosystems has declined by a third since the mid-1970s. This challenges expectations that ecosystems would accelerate turnover in response to climate change and other pressures. Lead author Emmanuel Nwankwo described nature's self-repair mechanism as an engine grinding to a halt.
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Scientists have identified a 307-million-year-old fossil as one of the earliest known land vertebrates to consume plants. The creature, named Tyrannoroter heberti, featured specialized teeth for grinding vegetation. This discovery challenges previous understandings of early terrestrial diets.