User:K.Darcy/Hybridization

Introduction

Hybridization is a naturally occurring genetic process where individuals from two genetically distinct populations mate. It occurs both intraspecifically, between different distinct populations within the same species, and interspecifically, between two different species. Hybrids can be either sterile/not viable or viable/fertile. This affects the kind of effect that this hybrid will have on its and other populations that it interacts with. It can have beneficial and detrimental effects on populations and Biodiversity. Scientists recognize hybridization as a key factor in evolution, helping to create new species or advance existing species when it occurs naturally. But it has been known to contribute to many species' extinctions.

Anthropogenic Hybridization

Anthropogenic caused changes such as fragmentation and Introduced species are becoming more and more widespread. This is allowing another kind of hybridization that is more of the focus of Conservation genetics. This anthropogenically caused hybridization increases the challenges in managing certain populations that are experiencing introgression.

Habitat Fragmentation

When habitats become broken apart, one of two things can occur, genetically speaking. The first is that populations that were once connected can be cut off from one another, preventing their genes from interacting. Occasionally, this will result in a population of one species breeding with a population of another species as a means of surviving such as the case with the red wolves. Their population numbers being so small, they needed another means of survival.

The Continuum

There is a kind of continuum with three semi-distinct categories: hybridization without Introgression, hybridization with widespread introgression, and essentially a Hybrid swarm. Depending on where a population falls along this continuum, the management plans for that population will change. Hybridization is currently an area of great discussion within Wildlife management and habitat management fields. Global climate change, which is also anthropogenically caused, is creating other changes such as difference in population distributions which are indirect causes for an increase in anthropogenic hybridization.

Consequences

Hybridization can be a less discussed way toward Extinction then within detection of where a population lies along the hybrid continuum. The dispute of hybridization is how to manage the resulting hybrids. When a population experiences hybridization with substantial introgression, there still exists parent types of each set of individuals. When a complete hybrid swarm is created, all the individuals are hybrids.

Management of Hybrids

Conservationists disagree on when is the proper time to give up on a population that is becoming a hybrid swarm or to try and save the still existing pure individuals. Once it becomes a complete mixture, we should look to conserve those hybrids to avoid their loss. Most leave it as a case-by-case basis, depending on detecting of hybrids within the group. It is nearly impossible to regulate hybridization via policy because hybridization can occur beneficially when it occurs "naturally" and there is the matter of protecting those previously mentioned hybrid swarms because if they are the only remaining evidence of prior species, they need to be conserved as well.

Hybridization in Agriculture

Hybridization does not only occur in natural wildlife populations. Hybrids are used extensively in agricultural, often in the creation of Genetically modified organisms such as crops altered to be pest resistant, etc.

It is a well-known fact that it is occurring. The key is to figure out to what extent it is occurring and how to manage that after because each case is separate. No one side of the argument seems to be stronger than the other because it is nearly impossible to implement policies surrounding hybrids because they would either prevent natural hybridization from occurring or allow species to be lost to the hybrid swarm effect. Cases of each type of anthropogenic hybridization are well documented and research is going into how to manage each of them. There are proponents for the hybrid problems being addressed and the hybrids removed. There are also proponents of leaving them alone because, after all, it is a natural process and with all the up-coming changes, how else are species supposed to survive.

Public Perception

The majority of the public does not understand the urgency of hybrid situation. To most, hybrids are simply cool creations like the grolar bear, a mix between a grizzly and polar bear. However, in certain communities, it has become important such as the ag field, ornithology, particularly bird watchers, and in the fishing communities. Whether people know it or not, hybrids occur daily in our agriculture in order to create super plants to accelerate growth or provided the plant with some form of protection. These are mostly contained but still occasionally have the chance to escape our artificial environments and become an introduced species within the natural communities. More often then not, hybrids only reach the media in terms of our advanced bioengineering, particularly the creation of new one of a kind species. Anthropogenic hybridization makes distinguishing hybrids from parent generations difficult because when species or even populations begin to mix their genes and form hybrids, the hybrid individuals often develop a phenotype that can be indistinguishable from one of the parent populations/species or have characteristics from each.