Researching Evolutionary Development
(Evo Devo)
Ciera Martinez, PhD
UC Berkeley
The study of comparing species to understand how developmental processes evolve.
Evo Devo
Did these structures originate from a common ancestor? i.e.
For example:
Homologous
How do you determine if
structures are homologous?
development the same
look the same
have same relation to other features
source: evolution.berkeley.edu
Then you can map features on a phylogenetic tree to understand the evolutionary history of any organism
Alternatively, structures
may look the same AND function the same, but are not derived from the same ancestral structure. These structures are
analogous.
Source: evolution.about.com
So if your interested in insect wing evolution, you look at only insects.
Source: From DNA to Diversity. Carrol and Weatherbee.
Do these organisms use the same genetic toolbox to achieve the same shape?
Genetic Toolbox
Genetic material that directs development.
Modern Molecular Evo Devo researchers ask:
How do we know if organisms use the same genetic toolbox to build similar looking structures?
1. The genes look the same
2. The genes act the same
How do we know if they are the same genes?
- The genes look the same.
Source: Ronshaugen et al., 2002
How do we know if they are the same genes?
- The genes act the same.
Source: From DNA to Diversity. Carrol and Weatherbee.
Most exciting: Sometimes genes that look the same, make very different structures when you zoom out on the phylogenetic tree.
For example, you can ask: Does this Ubx gene exist in mammals? If yes, how does it act? If no, do they share genes that function similarly?
Source: From Pang and Thompson. 2011.
Evo Devo research spans different time scales.
Evolutionary Time
Source: From coast.noaa.gov
Developmental Time
By: Michael Richardson
Then compares across species
Scientific Method
1. Observation
2. Question
3. Research
4. Hypothesis
5. Experiment
6. Data
7. Conclusion
Observation: Woa. That is weird/beautiful.
Question: WTF? How did that come to exist? Why is it like that?
Research: Has anyone else ever noticed this? What did they do?
Hypothesis: If I compare this species and this species, I will understand how that weird/beautiful thing evolved.
How the scientific method for evo devo researchers (like me)
($$$: Please give me money I am now obsessed and will spend it wisely.)
Experiment: Measure. Observe. Measure, Observe. Listen to music. Measure.
Data: Organize. Program. Make pretty graphs. Repeat.
Conclusion: Hypothesis supported/rejected and I have a thousand more questions. Can I please keep researching this?
How I became an evo devo Researcher?
I love form, design, and function
Evo Devo research I have been fortunate to be part of...
Evolution of Wood
Source: Du et al., 2011, Spicer and Groover 2010.
Evolution of flower symmetry
Source: Preston, Martinez, Hileman. 2013.
How do leaves evolve?
Source: Martinez, unpublished.
Me Now:
I study how a fly embryo becomes a fly across 50 closely related species. But not looks at single genes, but whole genomes.