Evolutionary constraints on physiology confound range shift predictions of two nacellid limpets

Stingless bees of the genus Melipona are subdivided into 4 subgenera called Eomelipona, Melikerria, Melipona sensu stricto, and Michmelia according to species morphology. Cytogenetically, the species of the genus Melipona show variation in the amount and distribution of heterochromatin along their chromosomes and can be separated into 2 groups: the first with low content of heterochromatin and the second with high content of heterochromatin. These heterochromatin patterns and the number of chromosomes are characteristics exclusive to Melipona karyotypes that distinguish them from the other genera of the Meliponini. To better understand the karyotype organization in Melipona and the relationship among the subgenera, we mapped repetitive sequences and analyzed previously reported cytogenetic data with the aim to identify cytogenetic markers to be used for investigating the phylogenetic relationships and chromosome evolution in the genus. In general, Melipona species have 2n = 18 chromosomes, and the species of each subgenus share the same characteristics in relation to heterochromatin regions, DAPI/CMA3 fluorophores, and the number and distribution of 18S rDNA sites. Microsatellites were observed only in euchromatin regions, whereas the (TTAGG)6 repeats were found at telomeric sites in both groups. Our data indicate that in addition to the chromosome number, the karyotypes in Melipona could be separated into 2 groups that are characterized by conserved cytogenetic features and patterns that generally are shared by species within each subgenus, which may reflect evolutionary constraints. Our results agree with the morphological separation of the Melipona into 4 subgenera, suggesting that they must be independent evolutionary lineages.

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5.1 A 1.5μW 0.135pJ·%RH2 CMOS Humidity Sensor Using Adaptive Range-Shift Zoom CDC and Power-Aware Floating Inverter Amplifier Array

2021 IEEE International Solid- State Circuits Conference (ISSCC) ◽

10.1109/isscc42613.2021.9365931 ◽

2021 ◽

Author(s):

Heyi Li ◽

Zhichao Tan ◽

Yuanxin Bao ◽

Han Xiao ◽

Hao Zhang ◽

...

Keyword(s):

Humidity Sensor ◽

Range Shift

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An Orchid in Retrograde: Climate-Driven Range Shift Patterns of Ophrys helenae in Greece

Plants ◽

10.3390/plants10030470 ◽

2021 ◽

Vol 10 (3) ◽

pp. 470

Author(s):

Martha Charitonidou ◽

Konstantinos Kougioumoutzis ◽

John M. Halley

Keyword(s):

Climate Change ◽

Climate Models ◽

Species Distribution Modelling ◽

Range Shift ◽

Last Interglacial ◽

Distribution Modelling ◽

Species Response ◽

Northwestern Greece ◽

The Last Glacial Maximum ◽

The Last Glacial

Climate change is regarded as one of the most important threats to plants. Already species around the globe are showing considerable latitudinal and altitudinal shifts. Helen’s bee orchid (Ophrys helenae), a Balkan endemic with a distribution center in northwestern Greece, is reported to be expanding east and southwards. Since this southeastern movement goes against the usual expectations, we investigated via Species Distribution Modelling, whether this pattern is consistent with projections based on the species’ response to climate change. We predicted the species’ future distribution based on three different climate models in two climate scenarios. We also explored the species’ potential distribution during the Last Interglacial and the Last Glacial Maximum. O. helenae is projected to shift mainly southeast and experience considerable area changes. The species is expected to become extinct in the core of its current distribution, but to establish a strong presence in the mid- and high-altitude areas of the Central Peloponnese, a region that could have provided shelter in previous climatic extremes.

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North Atlantic warming over six decades drives decreases in krill abundance with no associated range shift

Communications Biology ◽

10.1038/s42003-021-02159-1 ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

Martin Edwards ◽

Pierre Hélaouët ◽

Eric Goberville ◽

Alistair Lindley ◽

Geraint A. Tarling ◽

...

Keyword(s):

North Atlantic ◽

Range Shift ◽

The Core ◽

Krill Abundance ◽

The North ◽

Living Space ◽

Warming Climate ◽

Two Temperatures ◽

The North Atlantic

AbstractIn the North Atlantic, euphausiids (krill) form a major link between primary production and predators including commercially exploited fish. This basin is warming very rapidly, with species expected to shift northwards following their thermal tolerances. Here we show, however, that there has been a 50% decline in surface krill abundance over the last 60 years that occurred in situ, with no associated range shift. While we relate these changes to the warming climate, our study is the first to document an in situ squeeze on living space within this system. The warmer isotherms are shifting measurably northwards but cooler isotherms have remained relatively static, stalled by the subpolar fronts in the NW Atlantic. Consequently the two temperatures defining the core of krill distribution (7–13 °C) were 8° of latitude apart 60 years ago but are presently only 4° apart. Over the 60 year period the core latitudinal distribution of euphausiids has remained relatively stable so a ‘habitat squeeze’, with loss of 4° of latitude in living space, could explain the decline in krill. This highlights that, as the temperature warms, not all species can track isotherms and shift northward at the same rate with both losers and winners emerging under the ‘Atlantification’ of the sub-Arctic.

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