Alexa Sadier

Assistant Project Scientist (or postdoc) at UCLA



Don't stop because someone tells you your dream is too big.


My work focuses on this weird and fun question: does evolution produce all the animals we can possibly imagine, or are there rules (such as gravity in physics) that limit their evolution to only a few shapes? In other words, is it possible to evolve a shark with a giraffe neck and long legs or is it impossible because of the way evolution works?

To answer this question, I use the some of the most fascinating animals, BATS! Why bats? Because they are incredibly diverse and that diversity provides us the material we need to understand if there are rules behind the evolution of animals: some bat faces look like pigs, others like dogs, or foxes. Others are even so weird that you would think of them as aliens. They also live in different environments such as caves, trees, hollow trees or abandoned buildings..

So how to study bats? We have to go where they live, which is in the field, everywhere in the world except Antarctica! We go in the caves of Puerto Rico, the forests of Trinidad, the jungle of Cameroon, the Mayan temples of Belize and down to the deep caves of Dominican Republic. How to catch a bat? We use mist nets, butterfly nets and harp traps to safely get a lot of samples from them (such as DNA or tissues). I then go back to the lab to study the differences between species. How do I do it? I measure them or their embryos under the scope but I also look at their DNA, RNA and protein using molecular biology techniques such as cool fluo markers. Finally, I also use mathematical modelling to simulate the evolutionary processes behind the diversity of their shapes.

I also study color vision in bats (if you thought that bats are blind, you were wrong! They can see many things, some of them in color!), bat diet and bat echolocation!


I choose research because I love to explore. I grew up in the mountains and I am a backcountry skier as well as a mountaineer. What I love in life is exploring and finding new territories. By doing research, I do the same, except that I explore knowledge and discover new things every day!

I have always been fascinated by evolution because it is like traveling in the past to understand how species evolve. I came to bats because they are so diverse and incredible that we can explore and discover many things about them and their evolution. In addition, as an outdoor person, I love to be in the field which brings other exploratory challenges.

I realized that I wanted to explore when I was a kid. I wanted to be an astronaut, I wanted to explore the stars or rocks, I was fond of geology. I used to keep my personal collection of rocks, flowers, skulls when I was a kid! In college, I realized that physics was not my strength (and it is needed for astrophysics and geology) but I felt in love with evolutionary biology. When I started to work in a lab as an undergrad, I realized that research would allow me to explore science and knowledge, find new things as well as having a key role in the society by helping building knowledge.


I was lucky to have parents who never told me "you won't be able to do it" or "as a girl, it is not for you". For a very young age, my dad initiated me to mountaineering and I was never told that a certain career would be too difficult. At the same time, I always thought I was not good enough despite entering the best universities. To my younger me, I would say: “believe in your dreams, be confident in yourself, you are doing great, this is just tough for everyone. You will get there if you do what you want without thinking about what other people think about you.” This lack of confidence and impostor syndrome dragged me down many times.


I love working in STEM because I love exploring new things. I love being in front of an unexplored map and imagine new ways to discover the unknown and/or solve new problems. Research and what we do in STEM is central to our societies. Fundamental research is at the base of so many things, from new technologies to a better understanding of where we come from and where we are going. I like the idea of participating in creating a better world by helping to understand it.

In addition, I love to share what I find to the public.I am involved in a lot of outreach activities because I love to communicate the excitement of finding new discoveries. We are mostly funded by public institutions and I believe it is aslo part of our mission, as scientists, to explain what we do.


Find a topic that you love, and never let anyone tell you that you can't do it. Find people (nice but also honest to you), who you can rely on (regardless of gender or origin) and who will support you and advance together with your peers. If an environment seems deleterious (university, lab, etc.), find a new one until you find a place you feel comfortable in. Sometimes you have to be with the right people and it is not your fault if it does not work.

Don't stop because someone tells you your dream is too big. If somebody would have told me that I would travel the world to study bats for a living, I might have laughed 10 years ago, but now this is what I do! When I was stressed right after my PhD, a good friend who was more advanced than me in my field of research told me "you'll get in there, remember, this is like a game as long as you enjoy it."


Why did you want to climb Mount Everest"Because it's there" Georges Mallory