Ani Talwar gives us the stark science on how we’re altering the planet on a genetic level. In this article, we learn about the science behind ecosystem destruction on a biological scale.
You’re in a cabin, on an island with a calm breeze, soft songbirds and sunny skies. WHAM! Out of nowhere a wave descends, 30 metres high, created by a creature 10,000km away. Your cabin doesn’t stand a chance. Within seconds, it’s gone, destroyed by some creature who sent that wave on purpose. Unfair? Now, replace that island for an ecosystem, the cabin with a habitat, and the person inside for an animal. And that malevolent cabin killer: that’s you.
You, me, humans. But it’s not just cabins anymore, it’s the actual qualities of the people inside them. “The effects of rural homes on native species can be felt tens to hundreds of kilometres away,” Animals who won’t even interact with us, are paying the price for our ‘comfort’.
Take fish for example. They’re hunted for their size; bigger fish make more food. But now, they’re evolving to shrink. Their size, once an evolutionary advantage; bigger fish’s offspring can swim, grow and survive better, is now the complete opposite. Big fish are now the hunted ones, small ones survive. The outcome: fish are shrinking.
That’s a very large example, maybe you won’t ever experience unless you sit for years watching and measuring fish all around the world, so let’s talk about something that’s easier to notice and measure: Lake Windemere, UK, and Perch fish.
These fish once normally lived up to around 20 years of age, until a disease in 1976 wiped out 99% of their population. Now, Perch have evolved to become more sexually mature and reproduce before the disease hits them, and they have never been found older than 7 years. The shocking bit is that scientists now believe many diseases like this one are caused by humans. Us. You and me.
This isn’t a new development. Most students will probably have heard of the change in peppered moths around the industrial revolution in England. But it’s not just moths, it’s rhinos, and bears, and birds and fish.
Does this mean that humans are the ones causing the genetic change? Well out of every other living thing on the planet, which of us produce most noise, density and pollution?
So, we’ve established that humans can have an impact on even the genes of a species and how they evolve, but is it always bad? It has been found that bacteria can thrive in places that wouldn’t be suitable for larger organisms, so humans have created new environments suitable for microorganisms like sewage, contaminated water and deforested soil. That’s good right? It means we’ve helped something… but if we’re at the stage where water contaminated with effluent is good, is it really that good?
These examples all result from major change, so let’s look at one resulting from a change of just 3°C in the Yosemite National Park: alpine chipmunks. As the park heated up over the years, the chipmunks were reported to have moved to higher altitudes and decrease in number. Scientists analysed the species and they found what they termed ‘genetic erosion’ due to global warming. The chipmunks were losing their genetic diversity, which lowers their stability as a species, so they could go extinct. Not only that, us heating up the planet is causing other genetic changes for other animals too.
But what about resistance in animals instead of extinction?
Resistance stems from an organism getting clever and becoming immune to something designed to kill them. You’ll have probably heard of antibiotic resistance; when harmful bacteria are no longer killed by an antibiotic anymore. This occurs when a gene mutates in an individual, giving the organism immunity to allow it survive and multiply. As other individuals in the population die without this advantageous gene mutation, eventually the whole population becomes immune to the threat. Whilst antibiotic resistance will be a huge global problem we will face in the near future, resistance can also occur in animals to save a species from extinction.
An example of resistance in animals are fish in Mexico. Through ancient tribes poisoning the river, the fish have genetically adapted to become immune to the poison. This has only happened through human activities.
The science is clear, we have inadvertently altered the whole genetic makeup of our ecosystems and species through our increased pressure.
Almost in retaliation, the ice melting is releasing diseases that we are not immune to, so it’s at the point where as a species, we have gone full circle. We have impacted nature, genes, and now we’re having a detrimental impact on ourselves as well.
So, let’s go back to your cabin that is decaying and ruined by disaster after disaster that hits it and you have no power to stop it. We wouldn’t condone genetic manipulation of our children or sibling so we shouldn’t allow it of animals, especially if only for our comfort.
So, are we changing nature’s genes?
Yes, yes we are.
About the Author: Ani Talwar can be found at @Mischief.weavers, she wrote the book ‘ATRO- CITY THE FLOOD’ and cares passionately about sustainability.