---
res:
bibo_abstract:
- This thesis is concerned with the inference of current population structure based
on geo-referenced genetic data. The underlying idea is that population structure
affects its spatial genetic structure. Therefore, genotype information can be
utilized to estimate important demographic parameters such as migration rates.
These indirect estimates of population structure have become very attractive,
as genotype data is now widely available. However, there also has been much concern
about these approaches. Importantly, genetic structure can be influenced by many
complex patterns, which often cannot be disentangled. Moreover, many methods merely
fit heuristic patterns of genetic structure, and do not build upon population
genetics theory. Here, I describe two novel inference methods that address these
shortcomings. In Chapter 2, I introduce an inference scheme based on a new type
of signal, identity by descent (IBD) blocks. Recently, it has become feasible
to detect such long blocks of genome shared between pairs of samples. These blocks
are direct traces of recent coalescence events. As such, they contain ample signal
for inferring recent demography. I examine sharing of IBD blocks in two-dimensional
populations with local migration. Using a diffusion approximation, I derive formulas
for an isolation by distance pattern of long IBD blocks and show that sharing
of long IBD blocks approaches rapid exponential decay for growing sample distance.
I describe an inference scheme based on these results. It can robustly estimate
the dispersal rate and population density, which is demonstrated on simulated
data. I also show an application to estimate mean migration and the rate of recent
population growth within Eastern Europe. Chapter 3 is about a novel method to
estimate barriers to gene flow in a two dimensional population. This inference
scheme utilizes geographically localized allele frequency fluctuations - a classical
isolation by distance signal. The strength of these local fluctuations increases
on average next to a barrier, and there is less correlation across it. I again
use a framework of diffusion of ancestral lineages to model this effect, and provide
an efficient numerical implementation to fit the results to geo-referenced biallelic
SNP data. This inference scheme is able to robustly estimate strong barriers to
gene flow, as tests on simulated data confirm.@eng
bibo_authorlist:
- foaf_Person:
foaf_givenName: Harald
foaf_name: Ringbauer, Harald
foaf_surname: Ringbauer
foaf_workInfoHomepage: http://www.librecat.org/personId=417FCFF4-F248-11E8-B48F-1D18A9856A87
orcid: 0000-0002-4884-9682
bibo_doi: 10.15479/AT:ISTA:th_963
dct_date: 2018^xs_gYear
dct_language: eng
dct_publisher: IST Austria@
dct_title: Inferring recent demography from spatial genetic structure@
...