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Nature and biology2–3 minSome autumn colors were present in the leaf before autumn arrived. As green chlorophyll breaks down, yellow and orange pigments can become easier to see, revealing a change in what dominates the leaf's appearance.

Nature and biology3–7 minA promising chemical trace in a Mars sample would mean less if it arrived from Earth on the spacecraft. Perseverance’s witness tubes make contamination part of the evidence by recording materials that could accompany the sampling process.

Nature and biology5–7 minDeveloping an apple variety involves more than waiting for one tree to bear fruit. Washington State University’s WA 38, sold as Cosmic Crisp, began with a 1997 cross and required evaluation of the resulting tree, its fruit and the conditions in which it would be grown.

Nature and biology5–7 minCalling spider silk stronger than steel leaves two questions unanswered: which silk, and what does stronger mean? A web contains materials with different jobs, and resistance to breaking, stretchiness, and energy absorbed before breaking are different properties.

Nature and biology3–7 minA tree count records an activity. A carbon claim asks what changed compared with what would otherwise have happened, including changes in soil, vegetation, and project emissions. The UK Woodland Carbon Code makes those accounting questions explicit. A planting total alone cannot answer them.

Nature and biology3–5 minAn ant colony can gain future workers by taking another colony’s young. A laboratory study of Diacamma indicum followed brood theft during nest relocation, when a colony’s possessions are especially exposed.

Nature and biology5–7 minA larger animal has more cells in which cancer might begin. That makes comparisons between species an interesting test of a simple prediction. Researchers investigate cancer deaths, longevity, and body size together, while asking how the available records shape what can be concluded.

Nature and biology3–5 minA tree can gain a great deal of wood without removing the same mass of soil from beneath it. Photosynthesis brings carbon from atmospheric carbon dioxide into sugars that help build the plant. Water and mineral nutrients still have their own essential roles.

Nature and biology3–5 minA mouse's heart and an elephant's heart run at very different rates, and their lifespans differ too. Multiplying heart rate by lifespan produces an intriguing cross-species comparison, but the result depends on which rate, lifespan, and animals were measured. An approximate pattern is a long way from a personal countdown.

Nature and biology3–5 minWeaver ants bring leaves together, but the adults do not produce the silk that fastens them. In Oecophylla smaragdina, appropriately developed larvae provide the silk, making nest construction a partnership between life stages.

Nature and biology3–5 minThe roots and the fruiting branches of a grafted tree can come from different plants. Growers choose a rootstock and a scion for different jobs, joining them without creating the same kind of new plant as a seed cross.

Nature and biology3–7 minA fossil in a museum has survived more than time. Remains had to escape destruction, become preserved, survive changes in the rock, and eventually be found. One route involves rapid burial and minerals entering hard tissues. Each step filters what survives, so the fossil record is a selective record of life.