Search

Smithsonian National Museum of Natural History
A cluster of orange branching soft corals growing against a black background of the deep sea floor.

Population Genomics

Population genetics is the study of the structure of genetic diversity within and across a species' populations. Groups of individuals of the same species that interbreed form populations, and within each population genetic characteristics vary between individuals. The genetic variation between individuals makes up a population’s genetic diversity. In general, populations with a higher genetic diversity are more resilient to changes in their environment and isolated populations with low genetic diversity are more vulnerable to stress and injury. For example, if ocean conditions change, the more genetic variety a species has, the more likely there will be individuals with a trait that helps them deal with the changing environment.  

An increasingly important aspect of restoration work is understanding the genetic diversity of species being restored because it can impact a population’s ability to respond to disturbances, like oil spills, or changing environmental conditions. Scientists sample the DNA from hundreds of individuals of a species across its habitat range to see how they are related to one another, and to find out if and how groups are connected across that habitat range. Understanding the population structure of key benthic organisms – such as corals – and their close invertebrate associates in the mesophotic and deep Gulf of Mexico will allow scientists to determine if and how communities are connected and whether certain populations are the source of genetic diversity found in other areas. This information in turn will help MDBC partners understand how to restore injured habitat and how to devise and prioritize management and restoration actions.

NMNH-MDBC scientists are assisting in population genetic studies of corals and their associated invertebrate taxa. Data derived from specimen genome skimming (see Biodiversity Characterization) contains hundreds to thousands of DNA regions useful for reconstructing how individuals are related and how populations are connected across space and time.

To the left, a map of a section of the Gulf of Mexico with circles indicating different populations. Arrows emanating from the east-most circle point to circles north and west. To the right, a picture of a yellow deep-sea coral colony.
A map of the northern Gulf of Mexico displaying migration patterns among Paramuricea biscaya populations. Results indicate that populations in the east are sources of genetic exchange to populations in the west. In particular, the Desoto Canyon area is seeding larvae to the Mississippi Canyon area where coral population were injured from the spill. These results, published in Galaska et al. 2022 Frontiers in Marine Science can help managers make decisions as to where to protect coral habitat from further human activities.