The Theme of Evolution in Conservation Biology
All living things are shaped by evolution, but anthropogenic changes to habitats and ecosystems can happen faster than evolutionary change. Conservation biology has to take evolutionary processes into account. This means conserving genetic diversity, preserving land in a way that allows gene flow to happen.
Part of the problem with losing populations of species, even if other populations exist, is the loss of genetic diversity. With fewer populations, inbreeding (individuals mating with relatives) can increase. Inbreeding can lead to reduced survival and reproductive success, a term known as inbreeding depression, and can lead to extinction.
Experiments of lizards on Caribbean islands showed that small populations could increase their genetic diversity over several generations. Other research shows that they way humans interact with other animals has evolutionary consequences; Northeast Arctic cod have started maturing at younger ages because of fishing's selective pressure.
Conservation biologists have developed breeding programs designed to increase genetic variation. The Florida panther was facing extinction because of inbreeding depression. Biologists developed a way of increasing genetic diversity in the Florida panther: breed Florida panthers with a different subspecies, the Texas panther. Conservation biologists were able to maintain the genetic identity of the two subspecies while increasing the genetic diversity of the Florida panther enough to save it from extinction.
Fire is an evolutionary process. In some fire-adapted plants, seeds only open after a fire. Fire can also clear out competing plants, leaving more resources and space for fire-adapted plants. In North America, humans have historically suppressed fires because of the damage they can do to our worldly possessions. This allows understory plants to grow dense and leaf litter to accumulate, which can make wildfires worse.
However, recognizing that fire is an important part of certain ecosystems, land managers have recently adopted the practice of "prescribed burns." You won't need aloe for these burns—they are controlled, small-scale fires that help restore ecosystems to their natural states. A benefit of small regular fires is that they burn up plant matter on the ground, reducing the fuel load for future, non-planned fires.
Additionally, it would be a shame to lose genes that make a species better able to adapt to climate change, or protect against disease. By using conservation strategies that include evolutionary processes, biologists hope to maintain genetic diversity of the organisms on our planet.
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