In the critical fight against extinction, conservationists use a variety of tactics to try to save the species.

One of the most essential tools is to maintain the variation of the genetic material (DNA) of a group of animals, which is called “genetic diversity”. In general, the greater the genetic diversity, the greater the chance of long-term survival.

Limited genetic changes The Tasmanian Devil’s immune system reduced genetic possibilities. Image: Chen Wu / Flickr

This technique works because a wider range of genes and variants are likely to adapt a species to unexpected conditions, including new diseases and hot climates.

Like having a small game pack of cards, if we don’t have a lot of options, our options are limited.

The Tasmanian Devil has tackled this problem by having small populations in the past, reducing genetic diversity.

This limited genetic variation has led to the Devil’s immune system reducing its genetic potential to fight and fight a contagious cancer called Devil’s Facial Tumor Disease.

WHAT IS CONSERVATION GENETICS?

The field of conservation, genetics, is about strategies for conserving or enhancing genetic diversity within species populations, promoting adaptive capacity, reducing the negative effects of inbreeding and random genetic drift, and ultimately reducing the risk of extinction.

Thus, from a genetic conservation perspective, the high genetic diversity within a species ’population (compared to other populations of the same species) generally reflects a“ healthy ”viable population.

A final view has challenged this school of thought, arguing that genetic variation in a population is not important for conservation.

Since the literature does not support this view and ignores well-established evolutionary principles, it may affect how genetic conservation strategies are applied in the future.

In flies, for example, hundreds or even thousands of genes can be part of the adaptation process. Image: Equipped

Genetic change is measured by the presence of heterozygosity different versions of the same gene – known as alleles – in different parts of the genome of individuals.

Inbreeding involves increased processes equality or homozygosity — that is, the same versions of a gene are the same allele — through linking between related individuals.

Harmful alleles (versions that negatively affect health) reduce an individual’s likelihood of reproduction and are usually expressed when they are homozygous.

As a result, the chances of individual and population survival decrease season, and has been seen in the Helmeted Honeyeater.

From a genetic perspective to make an accurate estimate of the health of the population, the diversity and “equality” of the genetic machinery must be taken into account.

In providing arguments, the authors of the final approach distinguish the effects of genetic variation that affect characteristics that are important for survival (“adaptive” or “functional” variation), not genetic variation, or “neutral” variation.

It would be considered as an adaptive variation in genes that directly affect disease susceptibility or drought tolerance, a neutral variation in genes that do not affect these traits or any other trait.

However, it is usually not possible to distinguish between these types of variations, so conservation genetics typically evaluates variation without reference to whether it is neutral or adaptive.

Helmeted Honeyeater has reduced its chances of survival due to inbreeding. Image: Getty Images

In a recently published publication, we examine the difficulty involved in identifying diversity of adaptation, especially in relation to how genomic information can be used to predict the future vulnerability of species under climate change.

Within this article, while genomics provides valuable insights into processes such as inbreeding, we emphasize the need to further develop functional gene-based approaches that allow genomics to evolve genetically in order to use genomics to address future climate change.

THE ROLE OF GENES IN THE SURVIVAL

Increasingly, the variation in conservation genetics is now based on the variation of the DNA sequence scattered throughout the thousands of nucleotides that make up an organism’s genome, called single-nucleotide polymorphisms or SNP markers.

This change is seen as a sensible approach to adaptive potential, especially because genomes with characteristics such as growth capacity, stress tolerance, and disease tolerance are also scattered throughout the genome.

Any indication of genome variation is generally taken as a sign of variation.

Studies show that when flies, birds, and other organisms adapt to new environments, hundreds or thousands of genes in the genome may be part of the adaptation process, which often do not match evolutionary events, making it difficult to identify specific genes involved. adaptation.

There is ample evidence that whether general levels of genetic variation, adaptive or neutral, affect population adaptation rates and high levels reduce the likelihood of population extinction.

The genetic rescue of the Mountain Pygmy-possum brought awareness to habitat destruction and invasive predators. Image: Equipped

The best research comes from careful laboratory experiments, where many populations derived from the same source are compared but differ in genetic variation.

The results of these experiments show that due to their larger and genetically diverse populations, they have much lower extinction rates in experimental systems – such as flies and crustaceans.

In rural conditions, there is ample evidence that injection of new genetic variants enhances the physical status of threatened species. This includes the genetic rescue strategy used to prevent the extinction of the pygmy potion on Mount Buller Victoria.

RECOVERY OF GENETIC HEALTH

The initial recovery of the “genetic health” of these populations is partly associated with a decrease in inbreeding but, in the longer term, an increase in genetic variation will be important for adaptation.

But these genetic strategies cannot be successful without tackling threats such as habitat destruction and invasive predators – both of which went hand in hand with the genetic rescue of the mountain pygmy possum.

Certainly, many species that do not have genetic variation can be very successful. This includes a large number of “weeds” of animals and plants that do not have much genetic variation – including species of pests that proliferate clonally like many polishes.

There are also some highly invasive species in Australia with limited diversity, such as foxes, carps, deer and others. But these species can reproduce rapidly, be released from predators and natural competitors, and become widespread, and as a result, populations and spreads rapidly spread to native environments.

A young Eastern Barred Bandicoot, as part of a genetic rescue program, is released at Rothwell Mount Conservation Sanctuary. Image: Equipped

Conservation genetics is not based on these species comparisons; instead, it tends to focus on native species of conservation concern, as the relative suitability of populations is directly related to their relative levels of genetic variation.

THE BEST CHANCE FOR SURVIVAL

As we move into a world of uncertainty, it is important to ensure that endangered species have the best chance of surviving changes in the environment.

There are different ways to encourage genetic variation in populations that have become genetically vulnerable, including the deliberate introduction of individuals from other populations and the restoration of habitat corridors.

All of these efforts should be aligned with conservation programs that help conservation-dependent species maintain a large population size, which will allow them to maintain high levels of genetic diversity, increasing resilience and adaptability.

These are the key principles to follow; because appropriate changes in environmental stressors remain impossible at the genetic level, the involvement of many genes is complex, and is likely to be dependent on both biological and environmental factors.

In an effort to conserve in the near future, assessing the genetic variation of the entire genome of a species must be crucial in making our decisions.

Banner: Mountain Pygmy Possum / Andrew Weeks