If we had the threat upon us of a new devastating flood that could wipe out life on earth, we would need a different kind of Noah’s ark, and a new way of selecting passengers, just picking up any two animals and plants of the same type would not do the trick for a new beginning.
It would be conservation geneticists, and not Moses, who would be choosing which animals and plants are better equipped to survive human and environmental threats based on their DNA.
If that animal or plant possesses the right DNA, that has proven how well it can deal with extreme temperatures, scarce food and water, changes in its habitat, fight back or elude predators and be capable of reproducing offspring, then it will be chosen. At the same time it is necessary to have the right number of members of the same species to ensure diversity and success, not having enough members will drive them to extinction.
Life seems immensely interconnected and diverse than first thought and such complexities are part of every living organism on the planet.
That complexity is written in our DNA. It is the collected and collective historical memory of our biology since life originated on earth. It is also the cause for individuality and uniqueness even though we belong to one species and share the majority of our DNA.
This is the daunting task that conservation geneticists are facing today, with limited resources in an ever developing scientific field of genomics, where uncertainty is a common challenge and the goals for predictability and control seem elusive and at times unattainable, these concerned scientists are trying to save living organisms from oblivion.
This new devastating flood endangering our environment and life is not the kind of rapid and swift natural destruction, but one created across time and generations of people, so close to us that makes it difficult to see or believe in its existence.
Human activities are destroying animal and plant habitats, and over exploitation of resources are creating mass extinctions.
For many years people did not believe in climate change. This is considered one of the greatest threats ever faced by humanity, not because of its effects, but because solving it requires a complete change in our values. Values that are driving our economy and the way we relate to our environment.
Everyday animals and plants go extinct at a rate never seen before
According to an article by Paul Brown, an environmental reporter for the Guardian, in the year 2004, a full report coming from global research initiatives on the first comprehensive study into the effect of higher temperatures in the natural world ever made drew the conclusion that by the year 2050, due to global climate changes, more than one quarter of animals and plants of the planet will be driven to extinction.
They estimated that more than one million species will be lost. Chris Thomas, a lead author of the research from four continents stated that much of that loss, 1 in 10 animals and plants are irreversible because of the extra global warming gases already discharged into the atmosphere.
The last report from the Global Diversity Outlook 3 in 2010 made assessments to populations of animals, plants and other organisms. The majority of animal species populations have fell almost 31% in 2006 since 1970.
According to Sally Aitken et al. living organisms are going extinct between 50 to 500 times faster than the natural rate, approximately between 3 thousand to 30 thousand species go extinct annually due to human activities. Currently “over 50% of all animals species are considered to be critically endangered or vulnerable to extinction.”
If plant and animal species are interconnected what happens when one of them goes extinct?
Many plant and animal species are directly dependent on each other either providing food, shelter, protection, and many other supporting activities that allow animals and plants to live and reproduce.
According to the CBC one recent study conducted among Canada, U.S.A. and Singapore found, with the use of mathematical models, that approximately 6,300 species will be affected or driven to extinction when its related plant or animal goes extinct: This is known as co-extinction.
Perhaps the most important factors driving animal and plant extinctions are: loss of habitat, invasive species, over-exploitation-hunting and climate change.
Loss of habitat can occur as a result of the effects of climate change in natural environments that are affected by fluctuations in temperature. It may seem exaggerated to think that a couple of degrees Celsius in temperature change can have such a negative impact, especially when we cannot truly tell or feel the difference it makes a variation of 2 degrees Celsius.
According to a report prepared by Dr. Jim Pojar in 2010, titled “A New Climate for Conservartion” changes of temperature in B.C. will have grave consequences. For the populations of Fraser River sockeye salmon changes in water temperature are bad news. About 4 degrees above the normal water temperature will put them right into the lethal range when Fraser River temperatures reach 20-21 degrees Celsius. “In October 2008, many populations of Pacific sockeye salmon were placed on the IUCN Global Red List of Threatened Species. One quarter of the world’s sockeye salmon populations are at risk of extinction.”
B.C. has had a stable climate over the past 4,000 to 4,500 years and now because of human activities climate is changing at a rapid pace, in most instances faster than animals and plants can adapt to it, increasing their vulnerability and risk of extinction.
Next to climate change, loss of habitat is also the result of urban developments, logging, mining, agriculture and live stock farming.
By destroying animal and plant habitats they no longer have the necessary food, conditions and shelter to live.
Over-exploitation, this effect is easily observed in fisheries, where some regions have seen the complete disappearance of commercial fisheries because of decreased populations of fish, like the Atlantic Menhaden, according to Daniel Pauly, professor at UBC.
The Atlantic Menhaden is a good example of how one declining population of a particular fish can have such an impact on hundreds of other species in the ocean that feed on this tiny fish. It is also now known that by feeding on microscopic algae, Menhaden keep algal blooms in check.
We are in a path of irreversible ecological degradation; we use increasingly more resources everyday while our population continues to grow with no significant changes in the horizon. The number of animals and plants going into extinction continues to grow everyday.
Conservation geneticists have found that the level of adaptability and success of a species, this is, how easy animals and plants can survive challenges posed by the environment and other living organisms, and still be able to produce offspring, is determined by the amount of DNA diversity within a population of animals or plants.
This diversity in the DNA is the one responsible for making living organisms of one species different between them, minute divergence in the coded genetic information gives every individual a level of variation in perhaps weight, height, speed, tolerance to temperature, dry environments and so on, thus making some more easily adaptable to different scenarios that might present threats to their survival. And this is how natural selection works favouring individuals differences that are more successful in adapting to changes and producing offspring.
The more genetic diversity within one population the more chances they have to successfully overcome, for example, the risks of climate change. Usually big populations are considered to have adequate genetic diversity, but when this population is threaten with rapid changes to their environment they will possibly fail to reproduce and replace the following generation, and when their numbers decrease so does their genetic variability.
When the number of individuals in one population are very low, this will lead to what conservation geneticists call genetic stochasticity, this effect will lead the population to increase the probability of individuals to mate with siblings and parents ( inbreeding), causing genetic drifting and because of the random nature of stochasticity there is also greater probability of harmful genetic information to be passed on to the new generation.
These set of harmful conditions are what geneticists in conservation call extinction vortex.
When small populations are experiencing extinction vortex it is believed they have lost their capacity to continue living successfully and eventually they will die out.
For conservation geneticists the number of individuals of an animal or plant population are as important as their genetic diversity and both are essential to their research to make the right management decisions to save them from potential extinction.
What is the conservation path?
Giving the complexity and intricate relationship between the environment and all living organisms, genetic knowledge will not be enough, it is argued that the right combination of conservation genetics and ecosystems preservation is the most appropriate measure to avoid extinctions and loss of our biodiversity.
Indeed conservation geneticists focus on analyzing what is inside the genes of living organisms, tiny samples of these creatures are taken, searching for immense information catalogued with strict chemical rules in their DNA telling stories of failure, survival and brotherhood. From these microscopic observations they have reached one important truth: All living organisms are important and they are all related in different degrees at different levels of the evolutionary process, that all of them, including us, humans, are a big family sharing the same boat on this ark called life.
Sources
http://www.davidsuzuki.org/publications/downloads/2010/NewClimate_report_DSF.pdf
http://www.genetics.forestry.ubc.ca/cfcg/projects.html#develop_strat
http://news.nationalgeographic.com/news/2001/04/0403_genetics.html
http://www.cbd.int/gbo3/?pub=6667§ion=6673
Dr. Daniel Pauly, UBC, Zoology Department.
Dr. Sally Aitken, UBC, Forestry Department.
Allendorf, W. Fred, Luikart Gordon, Aitken, N. Sally, 2012 “Conservation and the genetics of populations”, second edition.
All photographs by Alberto Mendoza Galina
