Welcome back to Nature League!

In a rapidly changing world, it's fascinating to think about how much has changed in our lifetimes. For example, the human population was barely above five billion when I was born, and that number has increased by about 50% in just my lifetime.

And of those people currently alive on Earth, more than half live in urban areas, which is definitely different compared to when I was born. And in terms of technology, oh man! In my lifetime, the world has seen the premiere and development of the internet -- so, you know, there's that.

Not to mention personal cell phones and the myriad changes that have happened to human society because of this tech. Those changes are just for the world and human society in general; however, what's really fun for me is to think about the biggest changes that have happened within my own areas of scientific and personal interest. [CHEERY INTRO MUSIC]. Recently, Dr.

Lindsey Doe of Sexplanations started the #NowNotThen tag, where she discussed four positive changes she's noticed during her lifetime in the field of human sexuality. She tagged me and three other creators and challenged us to do the same for our areas of interest. So, here are my four #NowNotThen positive changes for wildlife biology and conservation!

Number 1: The use of genetics in conservation. While technological advances have fundamentally changed human society, they've also fundamentally changed wildlife biology research projects and methods. One of these tech advancements is the use of genetics in conservation and the application of molecular data to actual management decisions around the world.

This is my specific field of research and has been for a while, but when I first heard of conservation genetics in undergrad, it gave me a sense that something was fundamentally changing. Imagine a population that's being monitored to see how it's doing. One of the most basic things you'd need to know is: how many individuals are there?

During my lifetime, scientists have gone from manually counting individuals in the field to using genetic data. Nowadays, analyzing this kind of data from a small number of individuals can give more information about population numbers than manually counting ever could, and a lot of the time, using genetics is both faster and cheaper than previous methods. And right now, another change is happening -- that's the progress from genetic data to genomic data.

Instead of studying several genes, wildlife biologists are now investigating the entire set of genetic material in organisms and populations. This is exciting because we can now answer previously unanswerable questions about things like genes under the process of natural selection and how these genes can interact with the environment. This information will be really important when it comes to assessing how populations might respond to global changes in climate and habitat.

Thinking about the use of genetics and genomics in conservation brings me to. Number 2: non-invasive sampling. In the past, researchers obtained DNA samples from individual organisms by taking tissue in the form of blood, biopsies, or small clips on the outside of the body, like on the edge of a fish's fin.

While some might argue that the benefit of the conservation-driven research outweighs the harm or discomfort to the organism, there are definitely ethical issues with this methodology. During my lifetime alone, an entirely different approach has been created and refined. This approach is called “non-invasive” genetic sampling, and it's distinct from the other methods because to qualify as “non-invasive,” the source of the DNA has to be left behind by an individual and is collected without catching or disturbing them.

DNA can now be extracted from non-invasive samples of hair, scat or feces, and feathers, without ever seeing the individual, much less majorly disturbing it. Let's be honest, though -- a lot of people that go into wildlife biology do so because they want to experience wildlife up close and personal. With non-invasive genetic sampling, this is becoming a thing of the past.

And while that might be seen as a negative by some, there are several major positives. We already touched on the reduction in disturbance, pain, and/or suffering, but the benefits of non-invasive sampling extend past ethical considerations. There are also some gains on the science side of things as well.

For species that are naturally rare, endangered, or cryptic, it can be incredibly hard to ever get close enough to study them, much less take a tissue sample. However, non-invasive sampling has totally changed the game. Take snow leopards.

This species is listed as Vulnerable on the IUCN Red List, but in the past it's been really difficult to study them and draft conservation guidelines because they're so hard to capture. I mean, cats are already ridiculously good at not being found when they don't want to be found, so imagine that trait but in a population that's sparse and distributed across mountains and rugged terrain. Yeah… total sampling nightmare.

And yet… scientists have recently been able to estimate snow leopard population numbers and spatial connectivity by extracting DNA from snow leopard scats left behind by the cats. Everyone wins -- the snow leopards can remain elusive and out of sight while scientists obtain information about snow leopard populations. #catscats #conservation. Number 3: Epigenetics.

A third major positive change during my life is the study of epigenetics and the ongoing restructuring of the way we think about evolution. While this one doesn't solely belong in the wildlife biology bin, it's important enough that I just have to talk about it. We've discussed evolution and natural selection here on Nature League, as well as briefly touched on the concept of epigenetics.

Epigenetics can be broadly defined as heritable changes to an organism's genome that affect things like gene expression or packaging but don't change the actual DNA sequence itself. These changes can be caused by the environment. Basically, gene expression can be altered chemically because of something like diet, or exposure to a chemical, or trauma.

When I was growing up and taking biology in high school, we were taught that development was a product of “nature vs nurture.” Basically, the jury wasn't out on whether an organism's DNA or an organism's environment determined the majority of that organism's development. But with the arrival of epigenetics, the biological sciences have evolved, if you will, into a new idea, which is “nature via nurture.” Yes, genes do determine many things about an organism, but the expression of genes can be determined by non-genetic factors. What's more controversial is whether epigenetic changes can actually work as an evolutionary force.

While several studies have provided evidence that epigenetic changes can be passed on to the next generation, scientists are still figuring out how just how many generations these changes can last throughout. If we find that epigenetic changes can be passed on and persist for thousands of generations, well... that would add a brand new chapter to Darwin's theory of evolution. So while epigenetics as a concept or emerging field of research isn't a positive or negative thing in itself, the fundamental reshaping and rethinking of core principles in biology is a great thing for rationalism.

Number 4: Citizen science. The last positive change I'd like to highlight in wildlife biology is citizen science and the general sharing of knowledge. A citizen scientist can be anyone who volunteers to collect or process data and contributes that data to a scientific project.

The job of “scientist” only became a regularly paid profession toward the end of the 19th century, so technically, citizen science isn't anything new to humankind. However, citizen science during my lifetime has absolutely exploded, particularly within the fields of ecology and biodiversity research. For example, take the U.

S. National Park Service. They have an entire portion of their website dedicated to citizen science projects within their parks, including things like surveying bees to inform the Park Service about prairie dynamics, rock climbing Devils Tower National Monument to record information about bat roosting, and monitoring plants and animals throughout the Appalachian Trail.

And it's not just a few government agencies and non-academic organizations teaming up with citizens. Citizen science is a global phenomenon, and the contributions extend into the scientific, peer-reviewed literature. A 2016 paper reviewed the use of citizen science data by analyzing datasets in the Global Biodiversity.

Information Facility, which is the world's largest database of information about where species occur on Earth. The analysis found that approximately 349 million species occurrence data points came from projects that include a majority of contributions from citizen scientists. A lot of the recent explosion in citizen science has been empowered by improvements in technology and the advent of social media.

However, citizen science is, at its core, driven by everyday citizens being fascinated by the world around them and interested in data collection. I think this is a huge positive change for biodiversity research and science as a whole, because it serves as a reminder that science isn't about lab coats and academia. Instead, science is and has always been the common human endeavor of asking questions about the world around us.

And while issues do exist regarding citizen science data consistency and accuracy, citizen science itself gives me hope about the future of my field of study. The current state of biodiversity on Earth is troubling, but there are amazing advancements in the fields of wildlife biology and conservation, and I'm so glad I took some time to think about them and share them here. Thank you for watching this episode of Nature League, and thanks especially to Dr.

Lindsey Doe of Sexplanations for tagging me in her #NowNotThen video. I'd like to continue the conversation and tag the following creators and ask them to talk about some positive changes they've noticed in their areas of interest during their lifetimes:. Hank Green, Taylor Behnke, Jackson Bird, and Craig Benzine.

If you would like to continue this conversation, you can make your own #NowNowThen video and share it with me on Twitter @Nature_League. Heads up! Today is the last day to pre-order the Critically Endangered Sharks poster because after today, it will be gone forever… Hopefully, unlike these critically endangered sharks.

Get yours at DFTBA.com! The link is in the description.