In the realm of conservation for endangered species, genomic advancements have introduced complex dilemmas. With the capability to sequence entire genomes, some ponder the validity of examining species' genetic diversity using any other means. Conversely, there are concerns about the resources involved in genome sequencing, especially when traditional measures of neutral genetic diversity are more cost-effective.
A recent study indicates that transitioning to modern genomics from traditional genetics for conservation may not be imperative in every situation.
Through an in-depth analysis of gene variations in 90 fully sequenced genomes of eastern massasauga rattlesnakes, scientists discovered that the functional genetic diversity matched the neutral genetic diversity observed in expansive portions of those genomes that did not contain protein-coding genes. This mirrors the kind of genetic material historically used for evaluating genetic diversity.
H. Lisle Gibbs, a professor of evolution, ecology, and organismal biology at The Ohio State University, remarked, “If we’re worried about the genetic health of populations, neutral diversity can give us a pretty good answer, as has long been argued. We have directly tested that for this species.”
He added, “Hopefully for many other small species that live in small, isolated populations, it’s a good news story in that neutral genetic diversity measured using much less expensive and more easily accessible techniques than sequencing their whole genomes gives us important information about their genetic health.”
The study's findings are scheduled for publication in the journal Proceedings of the National Academy of Sciences.
Assessing genetic diversity in isolated animal or plant groups helps determine their ability to adapt to changes through beneficial mutations. It also establishes the conservation requirements necessary to ensure their continuity. Small population sizes can lead to inbreeding, which could increase harmful gene mutations, thus decreasing the species' chances of survival.
Historically, this diversity was determined by examining DNA sections not connected to protein-coding genes. A high diversity level in these areas indicated potential genetic variation in protein-encoding genes, suggesting a capacity for future environmental adaptation.
Gibbs stated, “With genomic information, we can now for the first time do things like go after specific variants in specific genes across the entire genome, which we’ve never been able to do before. And that’s what we were able to do.”
Gibbs' team was the first to sequence the eastern massasauga rattlesnake's genome, a species listed as threatened in 2016 due to habitat loss. They contrasted 90 of these sequences with genomes of 10 western massasauga rattlesnakes, a more prevalent species.
Utilizing their previous analysis, the team classified eastern massasauga mutations into two categories: mutations that indicated strong positive or negative selection. For reference, the neutral region was identified as areas of the genome distant from functional genes.
Gibbs explained their predictive model on population size's influence on the two mutation types. In larger populations, natural selection efficiently removes negative mutations and retains positive ones. However, in dwindling populations, random processes could undermine this efficiency, increasing harmful mutations or maintaining beneficial ones.
Nevertheless, Gibbs cautioned that neutral genetic diversity might not always be a reliable predictor. Current conditions might not yet be reflected in species' genes. He commented, “When we study patterns of diversity that we see in nature, we’re looking at what I call the ghost of evolution past over many previous generations. But humans have started to have an impact within the last 200 years, so when you do genetics and conservation, you have to be aware of this lag. The patterns may no longer be relevant to what is going to happen in the future. You can still use neutral variation, but be aware it may not be as predictive as it used to be.”
A recent study indicates that transitioning to modern genomics from traditional genetics for conservation may not be imperative in every situation.
Through an in-depth analysis of gene variations in 90 fully sequenced genomes of eastern massasauga rattlesnakes, scientists discovered that the functional genetic diversity matched the neutral genetic diversity observed in expansive portions of those genomes that did not contain protein-coding genes. This mirrors the kind of genetic material historically used for evaluating genetic diversity.
H. Lisle Gibbs, a professor of evolution, ecology, and organismal biology at The Ohio State University, remarked, “If we’re worried about the genetic health of populations, neutral diversity can give us a pretty good answer, as has long been argued. We have directly tested that for this species.”
He added, “Hopefully for many other small species that live in small, isolated populations, it’s a good news story in that neutral genetic diversity measured using much less expensive and more easily accessible techniques than sequencing their whole genomes gives us important information about their genetic health.”
The study's findings are scheduled for publication in the journal Proceedings of the National Academy of Sciences.
Assessing genetic diversity in isolated animal or plant groups helps determine their ability to adapt to changes through beneficial mutations. It also establishes the conservation requirements necessary to ensure their continuity. Small population sizes can lead to inbreeding, which could increase harmful gene mutations, thus decreasing the species' chances of survival.
Historically, this diversity was determined by examining DNA sections not connected to protein-coding genes. A high diversity level in these areas indicated potential genetic variation in protein-encoding genes, suggesting a capacity for future environmental adaptation.
Gibbs stated, “With genomic information, we can now for the first time do things like go after specific variants in specific genes across the entire genome, which we’ve never been able to do before. And that’s what we were able to do.”
Gibbs' team was the first to sequence the eastern massasauga rattlesnake's genome, a species listed as threatened in 2016 due to habitat loss. They contrasted 90 of these sequences with genomes of 10 western massasauga rattlesnakes, a more prevalent species.
Utilizing their previous analysis, the team classified eastern massasauga mutations into two categories: mutations that indicated strong positive or negative selection. For reference, the neutral region was identified as areas of the genome distant from functional genes.
Gibbs explained their predictive model on population size's influence on the two mutation types. In larger populations, natural selection efficiently removes negative mutations and retains positive ones. However, in dwindling populations, random processes could undermine this efficiency, increasing harmful mutations or maintaining beneficial ones.
Nevertheless, Gibbs cautioned that neutral genetic diversity might not always be a reliable predictor. Current conditions might not yet be reflected in species' genes. He commented, “When we study patterns of diversity that we see in nature, we’re looking at what I call the ghost of evolution past over many previous generations. But humans have started to have an impact within the last 200 years, so when you do genetics and conservation, you have to be aware of this lag. The patterns may no longer be relevant to what is going to happen in the future. You can still use neutral variation, but be aware it may not be as predictive as it used to be.”