By Alliance Intern Kaitlyn Downer from Oregon State University ‘25
Whether it’s elephants being born without tusks or bighorn sheep growing smaller horns, wildlife evolution is being forced to change in real time due to human impact. While some might believe that this is just nature doing its thing, these rapid changes can fundamentally alter ecosystems in unpredictable ways and set off a disturbing domino effect.
I’ve always had a deep connection with animals and nature. Growing up in Hawai’i, nature and endangered species not only surround the community, they are talked about all the time. We are conditioned to know that many of the beautiful creatures that surround us are endangered. If you go on a boat ride down the Na Pali coast, the crew will tell you “that’s a honu (green sea turtle), and it’s endangered. That’s a Hawaiian monk seal, and their numbers are dwindling.”
I felt drawn to write a piece about wildlife, and I was searching for news after seeing that there are only 2,500 wild Bengal tigers left. Though I knew humans were changing the pace of wildlife evolution, I didn’t realize how far we had gone until I sat down and read a disturbing article.
“Oh, God,” I thought to myself. When I saw the facts laid out, I was shocked, but also not. When I spoke with friends about this, they pretty much said, “Oh, yeah,” but didn’t seem very surprised either.
It should be unacceptable that we aren’t shocked.
Nature is always changing, but humans action has forced some animals to evolve faster than ever before. It’s not just about survival of the fittest anymore — it’s survival of the ones who can protect themselves from us the best. It doesn’t have to be this way, and I’ll share what you can do about it.
Can Human Activity Dramatically Impact Animal Evolution?
A wide range of animals are evolving quickly to try and keep up with the world that humans are so rapidly changing. Bighorn sheep, African elephants, and Puerto Rican crested anoles are a few significant examples.
In the Canadian Rockies, hunters prefer to shoot Bighorn sheep with large, curled horns. Over time, rams started evolving smaller horns because the big-horned ones were getting killed before they could reproduce.
One ram with tiny horns not only survived by being “less impressive” to hunters, but was able to father an unusually high number of 25 lambs. It’s like if humans only dated people over 6 feet tall, and within a few generations, everyone just got taller.
A similar thing happened with elephants in Mozambique’s Gorongosa National Park. Years of poaching during a civil war meant that elephants with big, beautiful tusks were killed off, while tuskless elephants survived and had more babies, according to National Geographic.
Now, many female elephants are born in Gorongosa without tusks. It’s another disturbing example of evolution happening right in front of us, but it also shows how much humans are shaping the future of wildlife — often without meaning to.
National Wildlife Federation found that some Puerto Rican crested anoles evolved to survive in the city by growing longer legs and bigger toe pads in order to move across buildings and concrete more swiftly.
Why This Actually Matters
At first, it might not seem like a big deal. So what if sheep have smaller horns or elephants don’t have tusks? But the thing is, every species is connected in some way. When one changes, it can set off a domino effect.
For example, elephants use their tusks to dig for water and strip bark from trees. Without tusks to help with these actions, it could potentially lead to overgrowth of certain plants and reduced biodiversity.
Researchers from Princeton University, along with workers at Mozambique, found that “a population-wide increase in tusklessness may have downstream impacts, such as reduced bioturbation (reworking of soil), shifts in plant species composition, reduced spatial heterogeneity and increased tree cover — any of which could affect myriad other ecosystem properties. Elsewhere, evolution in species that perform key ecological functions has exerted potent effects.”
In the case of bighorn sheep, smaller horns might mean weaker males that struggle to defend themselves, affecting population dynamics. These small shifts can have big consequences, rippling through food chains and entire ecosystems.
Wildlife isn’t just nice to look at — it plays a crucial role in keeping nature balanced. Predators keep prey populations in check and pollinators help plants grow. Everything is connected in ways we don’t always realize.
If one species evolves too fast (or disappears), it can throw everything off, leading to unpredictable changes that could even affect things like agriculture, climate and the availability of natural resources.
Can We Do Anything About It?
Since we’re the ones influencing these rapid changes, we also have the power to slow them down. One way is by rethinking the big picture. For example, protecting animals like elephants from poaching doesn’t just save individual creatures — it helps maintain the natural traits they’ve had for thousands of years.
We also need to think about conservation in a way that considers evolution. Nature isn’t static, and protecting ecosystems means understanding how different species adapt to change. We clearly need to create protected spaces where animals can evolve naturally without the intense pressure of human interference.
Certain communities have taken steps to reduce harmful aspects of our artificial environment to protect wildlife. On the island of Kaua’i, certain public areas in the community turn off industrial lighting from late September to mid-December in order to reduce light pollution so shearwaters can migrate more peacefully.
In light of all these concerns, I hope you’ll join me in learning more, taking action and celebrating World Wildlife Day on March 3.
The Bigger Picture
The fact that animals are evolving so quickly because of us is both fascinating and deeply concerning. It’s proof that humans aren’t just part of the natural world — we’re actively shaping it, sometimes in ways we don’t even notice until it’s too late.
While nature is resilient, it’s not invincible. If we want to keep ecosystems thriving, we need to start thinking about conservation as more than just saving individual animals — it’s about protecting the entire, delicate web of life that keeps our planet running.