PLoS Genetics,
Journal Year:
2023,
Volume and Issue:
19(11), P. e1011062 - e1011062
Published: Nov. 28, 2023
Admixture,
the
exchange
of
genetic
information
between
distinct
source
populations,
is
thought
to
be
a
major
adaptive
variation.
Unlike
mutation
events,
which
periodically
generate
single
alleles,
admixture
can
introduce
many
selected
alleles
simultaneously.
As
such,
effects
linkage
may
especially
pronounced
in
admixed
populations.
However,
existing
tools
for
identifying
mutations
within
populations
only
account
selection
at
site,
overlooking
phenomena
such
as
among
proximal
alleles.
Here,
we
develop
and
extensively
validate
method
quantifying
individual
multiple
linked
sites
on
chromosome
Our
approach
numerically
calculates
expected
local
ancestry
landscape
an
population
given
multi-locus
model,
then
maximizes
likelihood
model.
After
applying
this
Drosophila
melanogaster
Passer
italiae,
found
that
impacts
important
contributor
natural
Furthermore,
situations
considered,
coefficients
number
are
overestimated
analyses
do
not
consider
sites.
results
imply
evolutionary
force
This
tool
provides
powerful
generalized
investigate
these
crucial
diverse
PLoS Genetics,
Journal Year:
2024,
Volume and Issue:
20(2), P. e1010657 - e1010657
Published: Feb. 20, 2024
A
growing
body
of
evidence
suggests
that
gene
flow
between
closely
related
species
is
a
widespread
phenomenon.
Alleles
introgress
from
one
into
close
relative
are
typically
neutral
or
deleterious,
but
sometimes
confer
significant
fitness
advantage.
Given
the
potential
relevance
to
speciation
and
adaptation,
numerous
methods
have
therefore
been
devised
identify
regions
genome
experienced
introgression.
Recently,
supervised
machine
learning
approaches
shown
be
highly
effective
for
detecting
One
especially
promising
approach
treat
population
genetic
inference
as
an
image
classification
problem,
feed
representation
alignment
input
deep
neural
network
distinguishes
among
evolutionary
models
(i.e.
introgression
no
introgression).
However,
if
we
wish
investigate
full
extent
effects
introgression,
merely
identifying
genomic
in
harbor
introgressed
loci
insufficient—ideally
would
able
infer
precisely
which
individuals
material
at
positions
genome.
Here
adapt
algorithm
semantic
segmentation,
task
correctly
type
object
each
individual
pixel
belongs,
alleles.
Our
trained
thus
infer,
two-population
alignment,
those
individual’s
alleles
were
other
population.
We
use
simulated
data
show
this
accurate,
it
can
readily
extended
unsampled
“ghost”
population,
performing
comparably
method
tailored
specifically
task.
Finally,
apply
Drosophila
,
showing
accurately
recover
haplotypes
real
data.
This
analysis
reveals
confined
lower
frequencies
within
genic
regions,
suggestive
purifying
selection,
found
much
higher
region
previously
affected
by
adaptive
method’s
success
recovering
challenging
real-world
scenarios
underscores
utility
making
richer
inferences
Genetics,
Journal Year:
2024,
Volume and Issue:
226(4)
Published: Feb. 22, 2024
Abstract
Understanding
natural
selection
and
other
forms
of
non-neutrality
is
a
major
focus
for
the
use
machine
learning
in
population
genetics.
Existing
methods
rely
on
computationally
intensive
simulated
training
data.
Unlike
efficient
neutral
coalescent
simulations
demographic
inference,
realistic
typically
require
slow
forward
simulations.
Because
there
are
many
possible
modes
selection,
high
dimensional
parameter
space
must
be
explored,
with
no
guarantee
that
models
close
to
real
processes.
Finally,
it
difficult
interpret
trained
neural
networks,
leading
lack
understanding
about
what
features
contribute
classification.
Here
we
develop
new
approach
detect
local
evolutionary
processes
requires
relatively
few
during
training.
We
build
upon
generative
adversarial
network
simulate
This
consists
generator
(fitted
model),
discriminator
(convolutional
network)
predicts
whether
genomic
region
or
fake.
As
can
only
generate
data
under
processes,
regions
recognizes
as
having
probability
being
“real”
do
not
fit
model
therefore
candidates
targets
selection.
To
incentivize
identification
specific
mode
fine-tune
small
number
custom
non-neutral
show
this
has
power
various
simulations,
finds
positive
identified
by
state-of-the-art
genetic
three
human
populations.
how
networks
clustering
hidden
units
based
their
correlation
patterns
known
summary
statistics.
medRxiv (Cold Spring Harbor Laboratory),
Journal Year:
2025,
Volume and Issue:
unknown
Published: Jan. 3, 2025
Abstract
The
Biorepository
and
Integrative
Genomics
(BIG)
Initiative
in
Tennessee
has
developed
a
pioneering
resource
to
address
gaps
genomic
research
by
linking
genomic,
phenotypic,
environmental
data
from
diverse
Mid-South
population,
including
underrepresented
groups.
We
analyzed
13,152
genomes
BIG
found
significant
genetic
diversity,
with
50%
of
participants
inferred
have
non-European
or
several
types
admixed
ancestry.
Ancestry
within
the
cohort
is
stratified,
distinct
geographic
demographic
patterns,
as
African
ancestry
more
common
urban
areas,
while
European
suburban
regions.
observe
ancestry-specific
rates
novel
variants,
which
are
enriched
for
functional
clinical
relevance.
Disease
prevalence
analysis
linked
factors,
showing
higher
odds
ratios
asthma
obesity
minority
groups,
particularly
area.
Finally,
we
discrepancies
between
self-reported
race
ancestry,
related
individuals
self-identifying
differing
racial
categories.
These
findings
underscore
limitations
biomedical
variable.
proven
be
an
effective
model
community-centered
precision
medicine.
integrated
genomics
education,
fostered
great
trust
among
contributing
communities.
Future
goals
include
expansion,
enhanced
analysis,
ensure
equitable
healthcare
outcomes.
Molecular Ecology,
Journal Year:
2025,
Volume and Issue:
unknown
Published: Feb. 28, 2025
Admixture
is
the
exchange
of
genetic
variation
between
differentiated
demes,
resulting
in
ancestry
within
a
population
coalescing
multiple
ancestral
source
populations.
Low-latitude
killer
whales
(Orcinus
orca)
populations
typically
have
higher
diversity
than
those
more
densely
populated,
high
productivity
and
high-latitude
regions.
This
has
been
hypothesized
to
be
due
episodic
admixture
with
distinct
backgrounds.
We
test
this
hypothesis
by
estimating
local
whole
genome
sequences
from
three
genetically
differentiated,
low-latitude
whale
comparing
them
global
variation.
find
'Antarctic-like'
tracts
genomes
southwestern
Australia
(SWA)
including
recent
(within
last
2-4
generations)
admixture.
Admixed
individuals
had,
on
average,
shorter
fewer
runs
homozygosity
unadmixed
increased
effective
size
(Ne).
Thus,
connectivity
demes
results
maintenance
Ne
relatively
small
at
level
comparable
sum
across
demes.
A
subset
admixed
regions
was
inferred
evolving
under
selection
SWA
population,
suggesting
that
may
contributing
population's
adaptive
potential.
study
provides
important
rare
empirical
evidence
can
maintain
sporadic
different
backgrounds
promote
long-term
stability
Ne.
Systematic Biology,
Journal Year:
2023,
Volume and Issue:
72(5), P. 1171 - 1179
Published: May 31, 2023
We
consider
the
evolution
of
phylogenetic
gene
trees
along
species
networks,
according
to
network
multispecies
coalescent
process,
and
introduce
a
new
model
with
correlated
inheritance
flow.
This
generalizes
two
traditional
versions
coalescent:
independent
or
common
inheritance.
At
each
reticulation,
multiple
lineages
given
locus
are
inherited
from
parental
populations
chosen
at
random,
either
independently
across
positive
correlation
Dirichlet
process.
process
may
account
for
locus-specific
probabilities
inheritance,
example.
implemented
simulation
under
these
models
in
Julia
package
PhyloCoalSimulations,
which
depends
on
PhyloNetworks
its
powerful
manipulation
tools.
Input
phylogenies
can
be
read
extended
Newick
format,
numbers
generations
units.
Simulated
written
way
that
preserves
information
about
their
embedding
within
network.
used
downstream
purposes,
such
as
simulate
species-specific
processes
like
rate
variation
species,
other
scenarios
illustrated
this
note.
should
useful
studies
simulation-based
inference
methods.
The
software
is
available
open
source
documentation
tutorial
https://github.com/cecileane/PhyloCoalSimulations.jl.
bioRxiv (Cold Spring Harbor Laboratory),
Journal Year:
2023,
Volume and Issue:
unknown
Published: Feb. 7, 2023
A
growing
body
of
evidence
suggests
that
gene
flow
between
closely
related
species
is
a
widespread
phenomenon.
Alleles
introgress
from
one
into
close
relative
are
typically
neutral
or
deleterious,
but
sometimes
confer
significant
fitness
advantage.
Given
the
potential
relevance
to
speciation
and
adaptation,
numerous
methods
have
therefore
been
devised
identify
regions
genome
experienced
introgression.
Recently,
supervised
machine
learning
approaches
shown
be
highly
effective
for
detecting
One
especially
promising
approach
treat
population
genetic
inference
as
an
image
classification
problem,
feed
representation
alignment
input
deep
neural
network
distinguishes
among
evolutionary
models
(i.e.
introgression
no
introgression).
However,
if
we
wish
investigate
full
extent
effects
introgression,
merely
identifying
genomic
in
harbor
introgressed
loci
insufficient-ideally
would
able
infer
precisely
which
individuals
material
at
positions
genome.
Here
adapt
algorithm
semantic
segmentation,
task
correctly
type
object
each
individual
pixel
belongs,
alleles.
Our
trained
thus
infer,
two-population
alignment,
those
individual's
alleles
were
other
population.
We
use
simulated
data
show
this
accurate,
it
can
readily
extended
unsampled
"ghost"
population,
performing
comparably
method
tailored
specifically
task.
Finally,
apply
Cultural
and
socioeconomic
differences
stratify
human
societies
shape
their
genetic
structure
beyond
the
sole
effect
of
geography.
Despite
mating
being
limited
by
sociocultural
stratification,
most
demographic
models
in
population
genetics
often
assume
random
mating.
Taking
advantage
correlation
between
stratification
proportion
ancestry
admixed
populations,
we
sought
to
infer
former
process
Americas.
To
this
aim,
define
a
model
where
individual
proportions
genome
inherited
from
Native
American,
European,
sub-Saharan
African
ancestral
populations
constrain
probabilities
through
ancestry-related
assortative
sex
bias
parameters.
We
simulate
wide
range
admixture
scenarios
under
model.
Then,
train
deep
neural
network
retrieve
good
performance
predicting
parameters
genomic
data.
Our
results
show
how
shaped
socially
constructed
racial
gender
hierarchies,
has
constrained
processes
Americas
since
European
colonization
subsequent
Atlantic
slave
trade.
bioRxiv (Cold Spring Harbor Laboratory),
Journal Year:
2023,
Volume and Issue:
unknown
Published: March 8, 2023
Understanding
natural
selection
in
humans
and
other
species
is
a
major
focus
for
the
use
of
machine
learning
population
genetics.
Existing
methods
rely
on
computationally
intensive
simulated
training
data.
Unlike
efficient
neutral
coalescent
simulations
demographic
inference,
realistic
typically
requires
slow
forward
simulations.
Because
there
are
many
possible
modes
selection,
high
dimensional
parameter
space
must
be
explored,
with
no
guarantee
that
models
close
to
real
processes.
Mismatches
between
data
test
can
lead
incorrect
inference.
Finally,
it
difficult
interpret
trained
neural
networks,
leading
lack
understanding
about
what
features
contribute
classification.
Here
we
develop
new
approach
detect
relatively
few
during
training.
We
Generative
Adversarial
Network
(GAN)
simulate
The
resulting
GAN
consists
generator
(fitted
model)
discriminator
(convolutional
network).
For
genomic
region,
predicts
whether
"real"
or
"fake"
sense
could
have
been
by
generator.
As
includes
regions
experienced
cannot
produce
such
regions,
probability
being
likely
selection.
To
further
incentivize
this
behavior,
"fine-tune"
small
number
show
has
power
simulations,
finds
under
identified
state-of-the
art
genetic
three
human
populations.
how
networks
clustering
hidden
units
based
their
correlation
patterns
known
summary
statistics.
In
summary,
our
novel,
efficient,
powerful
way
bioRxiv (Cold Spring Harbor Laboratory),
Journal Year:
2023,
Volume and Issue:
unknown
Published: Nov. 18, 2023
The
availability
of
large
genotyped
cohorts
brings
new
opportunities
for
revealing
the
high-resolution
genetic
structure
admixed
populations
via
local
ancestry
inference
(LAI),
process
identifying
each
segment
an
individual
haplotype.
Though
current
methods
achieve
high
accuracy
in
standard
cases,
LAI
is
still
challenging
when
reference
are
more
similar
(e.g.,
intra-continental),
number
too
numerous,
or
admixture
events
deep
time,
all
which
increasingly
unavoidable
biobanks.
Here,
we
present
a
method,
Recomb-Mix.
Recomb-Mix
integrates
elements
existing
site-based
Li
and
Stephens
model
introduces
graph
collapsing
trick
to
simplify
counting
paths
with
same
label
readout.
Through
comprehensive
benchmarking
on
various
simulated
datasets,
show
that
accurate
than
diverse
sets
scenarios
while
being
competitive
terms
resource
efficiency.
We
expect
will
be
useful
method
advancing
genetics
studies
populations.