Sampling the insects of the amber forest [Ecology]
Amber, which is fossilized tree resin, is full of surprises. The tail of a feathered dinosaur was recently recovered from mid-Cretaceous (∼99 Ma) amber from Myanmar (1), and anole lizards in Miocene Dominican amber (2) showed that lizard communities have persisted for at least 16 My. Carnivorous plants of the family Roridulaceae, presently confined to South Africa, have been discovered in Eocene amber from the Baltic (3). The great majority of creatures in amber, however, are insects, and they often preserve the finest 3D details. A fly and a mite were discovered trapped in a spider web in Early Cretaceous amber from Spain (4), and a scale insect in mid-Cretaceous Burmese amber is associated with eggs and freshly hatched nymphs, showing that brood care in insects dates back at least 100 My (5). Some amber insects even retain the cellular structure of internal soft tissues, such as muscle (6, 7). However, amber does not trap all of the animals in the forest, and even the insects are subject to sampling bias. This is an important consideration when we use the evidence of fossils entombed in amber to interpret terrestrial environments and ecosystems of the past. A study in PNAS by Solórzano Kraemer et al. (8) compares the range of insects trapped in modern tree resin in a Madagascar forest with the diversity of insects that live there, which represents a major step in determining the extent to which inclusions in amber represent the diversity and ecology of ancient forest communities.
Many different plants exude resin. Some of them are extinct, and some living resin producers are not found in the fossil record. Resins harden and darken over time through a process that usually involves polymerization. The rate of this transformation varies with resin chemistry and environmental conditions. Hardened resin …
*UPDATE: On June 18, 2018, after this article went to press, the Supreme Court of the United States ruled on two high-profile cases related to partisan gerrymandering. In effect, the rulings sidestepped the issue of when partisan gerrymandering is unconstitutional. Both cases—one concerning ... more
It is not known whether the fossil content of amber accurately represents the arthropod biodiversity of past forests, and if and how those fossils can be compared with recent fauna for studies and predictions of biodiversity change through time. Our study of arthropods (mainly insects and s ... more
The existence of a chemosynthetic subseafloor biosphere was immediately recognized when deep-sea hot springs were discovered in 1977. However, quantifying how much new carbon is fixed in this environment has remained elusive. In this study, we incubated natural subseafloor communities under ... more