Introduction
What evolutionary process plays a major role in shaping the genetic patterns described in this article?
Genetic drift
What specific immune gene complex did the researchers analyze in this study?
The major histocompatibility complex (MHC)
Why were some genetic samples discarded in this study?
Because their DNA concentrations were too low for reliable genotyping.
What evolutionary mechanism was found to shape the genetics of the NYC urban coyote population?
Founder effects and genetic drift
What evolutionary mechanism maintains multiple alleles at immune genes because genetic diversity provides a fitness advantage?
Balancing selection
Under what environmental conditions do coyote populations tend to thrive according to the paper?
Human-modified environments with relatively low human population density
What pattern did the authors observe at MHC immune loci?
MHC genetic diversity was largely maintained and showed little reduction compared to non-urban coyotes.
What potential consequence did the authors suggest could result from the limited genetic diversity of NYC coyotes?
Reduced ability to adapt to environmental pressures or pathogens and increased risk of inbreeding
Why can urban environments like New York City provide good systems for studying genetic drift?
Urban colonization often involves a small number of individuals founding a new, partially isolated population, which increases the effects of drift and allele loss.
How did the urban and non-urban coyote samples differ in source and time period?
Urban samples were primarily scat collected between 2010–2016, whereas non-urban samples were archived tissue collected between 2000–2010.
Why did NYC coyotes show lower neutral genetic diversity than non-urban coyotes?
Because urban colonization involved a small founding population, leading to allele loss through genetic drift and bottleneck effects.
Why has natural selection likely had limited impact on MHC diversity in NYC coyotes so far?
Because the NYC population is recently founded and small, so strong genetic drift has dominated allele frequencies and limited selective change.
Why is maintaining high genetic diversity at MHC immune genes beneficial for NYC coyotes?
Because greater MHC diversity allows individuals to recognize and respond to a wider range of pathogens, improving disease resistance and survival.
Why was it important to compare urban NYC coyotes with non-urban populations in this study?
To provide a reference population so that observed genetic differences in NYC coyotes could be attributed to urban colonization processes like drift and bottlenecks rather than normal background variation.
Why does reduced diversity at neutral loci but not strongly at MHC loci suggest genetic drift as the dominant force?
Because genetic drift reduces diversity across neutral loci genome-wide, while balancing selection can maintain diversity at functional loci like MHC.
How could increasing habitat connectivity affect the genetic composition of urban NYC coyotes?
It would increase gene flow, introducing new alleles into the population and increasing genetic diversity.
In a population with small effective population size, which evolutionary force is expected to dominate genetic variation?
Genetic drift, because allele frequencies change more rapidly and alleles are lost faster than selection can maintain variation in small populations.
Heterozygosity excess relative to allele number was used as evidence for which demographic event during NYC colonization?
A population bottleneck
After correcting for sample size with rarefaction, NYC coyotes showed lower values of which measure of neutral genetic diversity compared to non-NYC coyotes?
Allele richness
What does this study conclude about the relationship between population demography and maintenance of genetic variation?
Small effective population sizes can lose genetic variation through drift faster than natural selection can maintain it.