Preface to the Princeton Landmarks in Biology Edition vii Preface xi Symbols Used xiii 1. The Importance of Islands 3 2. Area and Number of Speicies 8 3. Further Explanations of the Area-Diversity Pattern 19 4. The Strategy of Colonization 68 5. Invasibility and the Variable Niche 94 6. Stepping Stones and Biotic Exchange 123 7. Evolutionary Changes Following Colonization 145 8. Prospect 181 Glossary 185 References 193 Index 201

The Theory of Island Biogeography

Insects are the most speciose group of animals, but the phylogenetic relationships of many major lineages remain unresolved. We inferred the phylogeny of insects from 1478 protein-coding genes. Phylogenomic analyses of nucleotide and amino acid sequences, with site-specific nucleotide or domain-specific amino acid substitution models, produced statistically robust and congruent results resolving previously controversial phylogenetic relations hips. We dated the origin of insects to the Early Ordovician [~479 million years ago (Ma)], of insect flight to the Early Devonian (~406 Ma), of major extant lineages to the Mississippian (~345 Ma), and the major diversification of holometabolous insects to the Early Cretaceous. Our phylogenomic study provides a comprehensive reliable scaffold for future comparative analyses of evolutionary innovations among insects.

https://science.sciencemag.org/content/sci/346/6210/763.full.pdf

Phylogenomics resolves the timing and pattern of insect evolution

Worldwide decline of the entomofauna: A review of its drivers

Floods and droughts are important features of most running water ecosystems, but the alteration of natural flow regimes by recent human activities, such as dam building, raises questions related to both evolution and conservation Among organisms inhabiting running waters, what adaptations exist for surviving floods and droughts? How will the alteration of the frequency, timing and duration of flow extremes affect flood- and drought-adapted organisms? How rapidly can populations evolve in response to altered flow regimes? Here, we identify three modes of adaptation (life history, behavioral and morphological) that plants and animals use to survive floods and/or droughts The mode of adaptation that an organism has determines its vulnerability to different kinds of flow regime alteration The rate of evolution in response to flow regime alteration remains an open question Because humans have now altered the flow regimes of most rivers and many streams, understanding the link between fitness and flow regime is crucial for the effective management and restoration of running water ecosystems

/pdf/adaptation-to-natural-flow-regimes-1z55ndwrg2.pdf

Adaptation to natural flow regimes

Perturbations in ecosystems consist of a sequence of 2 events: the disturbance, marked by the application of the disturbing forces, and the response shown by the biota to the damage inflicted by the disturbance. The disturbance must be effectively characterized, without confounding it with the response, for progress to be made in the study of the disturbance ecology of streams. A disturbance may take the form of a pulse, a press, or a ramp, and the consequent trajectory of the response may be a pulse, a press, or a ramp.Floods and droughts are the major forms of natural disturbance in flowing waters and, although the effects of floods have been relatively well studied, those of droughts have been largely neglected. Floods accentuate downstream and lateral transport links, often with damaging consequences, whereas droughts fragment the continuity of streams. Both floods and droughts destroy and generate habitat patchiness and patchiness of the biota. During recovery, there are changes in the biotic...

Disturbance, patchiness, and diversity in streams

Biodiversity is undisturbed rhithral streams in central Europe is high, with about 1000 resident metazoan species; over 600 insect species occur in the Fulda river (Germany) Longitudinal downstream shift of dominance from rheobiontic to rheophilous and finally to ubiquituos rheoxenic taxa in the potamal is described Present downstream importance of ubiquituous species probably results from replacement of original potamal communities, present faunas being surrogates Species losses through human impact are well documented for fish The case of Plecoptera (10 potamal species either altogether extinct, extinct in Central Europe or extremely endangered) suggests that potamal invertebrates suffered as severe losses as did fish

Stream habitat fragmentation - a threat to biodiversity

Key to the West Palaearctic genera of stoneflies (Plecoptera) in the larval stage

Stoneflies (Plecoptera) of 5 families belonging to at least 33 different species are recorded from Bhutan, from where Plecoptera had not been known previously. Only 6 of these could be identified with formerly known species while 18 species are first named. The identity of several additional species remains doubtful for lack of adequate material or descriptions of taxa named earlier. Nemoura auberti is proposed as replacement name for N. schmidi AUBERT, 1967, (nec N. schmidi AUBERT, 1959); Leuctra indica NEEDHAM, 1909, is transferred to genus Nemoura. New diagnoses are given for the leuctrid genera Rhopalopsole and Perlomyia and placement of several of their species is changed.

Ergebnisse der Bhutan-Expedition 1972 des Naturhistorischen Museums in Basel. Plecoptera

Upstream oviposition flights of several Plecoptera species of the genera Leuctra, Nemoura, Isoperla and Siphonoperla along the Breitenbach, Hesse, Germany are inferred from 1. oviposition occuring upstream from emergence areas; 2. size differences and size-shifts between emerging and egg-laying females; 3. concentration of oviposition in upstream sections of the emergence area. The last point relies on direct catches of egg-laying females with sticky traps, and on over-representation of old, mature females in upstream emergence traps towards the end of, or even after actual emergence periods. Criteria for age class discrimination of the respective taxa are described. The validity of the present and of other indirect evidence for directed adult flights and the significance of adult upstream displacement are discussed. Optical orientation cues are suggested.

Emergence, maturation and upstream oviposition flights of Plecoptera from the Breitenbach, with notes on the adult phase as a possible control of stream insect populations

1. Temperature dependence of egg development of Dinocras cephalotes (Curtis) (three German and one Norwegian population) and Slovenian D. megacephala (Klapalek) was studied under a constant 14 : 10 light : dark photoperiod and constant temperature ranges of 4–24 °C and 4–18 °C, respectively. D. cephalotes was also incubated under seasonal field conditions; natural daylength and fluctuating temperatures had no modifying effect.



2. Both species have very similar lower threshold temperatures (4 and 3.5 °C, respectively), thermal demand for development (c. 600 degree days) and high dependence of mean incubation period on temperature (exponents of regressions near 1.5). Present data on D. cephalotes agree with the literature on British and Norwegian material of the same species.



3. Development occurs only at cue temperatures above the lower threshold. Cue temperatures range from 6 °C (some D. megacephala) to 14 °C (some D. cephalotes) and vary strongly within and between egg masses of D. cephalotes. Variation is not random, but seems to be genetically determined.



4. The variable temperature response renders study of effects of particular experimental regimes, and comparisons between local populations, difficult.



5. A latitudinal gradient in cue temperatures for development from 6 °C at c. 46 °N to 12 or even 14 °C at c. 61 °N seems to reflect reduced diversity at high latitudes.



6. Average success of spontaneous hatching exceeded 90% between 12 and 20 °C, but declined towards higher and lower temperatures.



7. Unhatched eggs were not dead but in parapause; development at other, higher or lower, temperatures was induced. Spontaneous plus induced hatching success approached 90%. Developing eggs rarely died; most dead eggs were apparently unfertilized.



8. Dormant plecopteran eggs are proposed to form a seed bank in stream bed sediments. Highly successful development after up to 220 days of dormancy was ascertained in Dinocras, and survival for up to 3 years is reported for other Perloidea.



9. Only systellognathan egg morphology provides options for long dormancy; the other plecopteran superfamilies, notably Nemouroidea, follow different strategies.

Peter Zwick

Papers

Stream habitat fragmentation - a threat to biodiversity

Key to the West Palaearctic genera of stoneflies (Plecoptera) in the larval stage

Ergebnisse der Bhutan-Expedition 1972 des Naturhistorischen Museums in Basel. Plecoptera

Emergence, maturation and upstream oviposition flights of Plecoptera from the Breitenbach, with notes on the adult phase as a possible control of stream insect populations

Variable egg development of Dinocras spp. (Plecoptera, Perlidae) and the stonefly seed bank theory