Sebastian Echeverri, PhD Student

I am a doctoral student in the Morehouse Lab, focused on understanding how eyes shape the evolution of complex visual displays in jumping spiders. I was raised on a steady diet of Bill Nye the Science Guy and Steve Irwin’s Crocodile Hunter. By their powers combined, I received a dual degree in Biology and Applied Physics from the University of Miami in 2013, and joined the Morehouse Lab in 2014. I am passionate about understanding how animals perceive the world around them, and how this shapes their behavior. When not working in the lab, I enjoy hiking, birdwatching and nature photography.

2014-present, Ph.D. Biological Sciences, University of Pittsburgh, Pittsburgh, PA

2009-2013, B.S. Biology and B.S. Applied Physics, University of Miami, Miami, FL

Current Research

My current research focuses on determining how signals are shaped by both the sensory systems of their receivers as well as the environment in which signaling occurs. While we are not often aware of it thanks to the self-deception of our brains, our sensory systems are not uniformly sensitive in all directions. Our eyes, for example, have a tiny patch where color and high acuity vision are localized – the fovea. This means that we are most sensitive to color information and most capable of discerning detail when an image falls onto our foveae. Animals also have non-homogenous sensory fields, especially in their eyes, meaning that visual signals may need to be designed differently based on which part of the receiver’s eyes they will fall upon.

The males of the North American jumping spider genus Habronattus performs energetic complex courtship displays to impress females, but these displays are seen differently by the female depending on the relative position of the male. Jumping spiders have four pairs of eyes, each specialized for different tasks. In Habronattus, only the forward-facing Anterior Median Eyes are capable of trichromatic vision, meaning that if a male strays too far to the side of the female, the colors of his display might be lost. I am investigating both how males maintain an alignment of their signal with the appropriate field of view of the female as well as how properties of the background environment, such as color or motion, may require males to adjust their signals in order to be detectable.

Prior Research

As an undergraduate, I worked with Dr. Gavin Leighton on his study of the mechanisms that maintain social behavior. Since natural selection favors traits that increase an individual’s reproductive success, a straightforward prediction would be that life should act exclusively selfishly. However, there are several well-documented examples of what appear to be altruistic behaviors that have been favored by selection, such as ant colonies. The origins and maintenance of social behavior are both ongoing questions in evolutionary biology. Dr. Leighton’s work focused on sociable weavers (Philetairus socius), small sparrow-like birds that build immense communal nests, an extremely rare behavior for birds. I spent two months in Namibia with Dr. Leighton conducting behavioral observations in order to determine exactly how and why these birds undertake such massive construction projects.

Publications

Leighton, G.M. and Echeverri, S. (2015) Population genomics of sociable weavers of limited spatial scales. In review.

Leighton, G.M. and Echeverri, S. (2015) Stable isotope signatures reveal cryptic differences in diet of sociable weavers. Avian Biology Research. In press.

Leighton, G. M. and Echeverri, S. (2014) Non-linear influence of nest size on thermal buffering of sociable weaver nests and the maintenance of cooperative nest construction. Avian Biology Research, 7(4), 255–260.