Post-ice age recolonization and differentiation of FucusNorthern Europe
ABSTRACT REWRITE
Fucus serratus, a seaweed, is assumed to have evolved in the North Atlantic, and current
populations represent recolonization from a southern refugium since the last glacial maximum 18
000–20 000 years ago. By analyzing seven microsatellite loci in populations taken from 21
locations across the species’ range, we were able to evaluate genetic structure at many spatial
scales. Despite restricted gamete dispersal in F. serratus of less than 2 m from parental
individuals, spatial auto-correlation analysis of seven microsatellite loci found no evidence for
spatial clustering of alleles on a scale of 100 m. The minimal panmictic unit for F. serratus,
according to pairwise analysis, was 0.5 to 2 kilometers. Along some adjacent beaches, isolation
by distance was significant. Despite a brief history of 7500 years, population differentiation was
substantial within the Skagerrak–Kattegat–Baltic Seas (SKB) (global = 0.17) A neighbor-joining
tree based on Reynold’s distances computed from microsatellite data revealed a central
assemblage of populations on the Brittany Peninsula, which was surrounded by four wellsupported clusters: the SKB, the North Sea (Ireland, Helgoland), and two populations from the
northern Spanish coast. Icelandic and Nova Scotian samples were most closely related to
samples from northwest Sweden and Brittany, respectively. Allelic diversity was twofold higher
in Brittany groups than in populations to the north and threefold higher in southern populations
when sample sizes were standardized (N = 41). The Brittany region could represent a refugium
or a recolonized area, but the Spanish populations are most likely present-day edge populations
that have gone through several bottlenecks as a result of thermally induced recolonization and
extinction cycles.
Abstract
The goal of this research is to look into the impact of post-LIA Neoglacial retreat on the
slope instability in 19 alpine reservoirs in British Columbia’s upper Lillooet River Valley. The
study investigates the effects of scouring and glacial retreat on the shape and stability of
hillslopes. The research is designed through the creation of a flow chart that compares the
landslide hazards associated with glacier melting. The analysis employed field mapping, GIS
analysis, landslide statistic comparison, landscape characteristics, and a comparison of
landscapes with and without a history of landslides.
The extent of landslide response to glacial retreat is primarily determined by rock
characteristics, and the variation of glacial scour below the LIA trim line. There is intense terrain
activity, aggressive rock and landslides in hillsides engraved in frail rock formations. Post-LIA
retreat, on the other hand, rarely causes increased bedrock instability in stronger granitic rock,
except in cases of shallow-seated rock slides and unstable slopes. Landslides caused by post-LIA
retreat begin as debris slides or debris avalanches from unstable deposits and cluster in bedrock
components along directional glacial ice or glaciation trim lines.
The findings of the study revealed a highly significant relationship between the landslide
hazard, gravitational slope displacement, and over-steeped hillsides caused by glacial erosion.
The results indicated that 8/10 dangerous rock slope failures occurred just above deep valley
terrains and in areas associated with deep landslides, implying that this type of instability was the
starting point for dangerous landslides.
Your presentation (Week 7, 8, or 10) should be about 7 minutes long, and have three main
components:
1. a summary of your book
2. a brief summary of your abstracts and a discussion of how they relate/contribute to your
book’s message
3. your thoughts on the book (such as: Is it worth reading? What made you choose it?)
These components do not have to be in this order, and you can blend them together if you like.
As a presenter, you will be graded on the content, organization, clarity, design, and delivery of
your presentation.
Book: After the Ice Age: The Return of Life to Glaciated North America by E.C. Pielou