Marta Martínez
Wells,
Research Scientist (Ph.D., Connecticut)
- Contact Information:
Dr. Marta Martínez Wells
- Department of Ecology and Evolutionary Biology
- University of Connecticut
- 75 N. Eagleville Road, U-43
- Storrs, CT 06269-3043
- Tel: (860) 486-3947/4550
- Fax: (860) 486-6364
- E-Mail: marta.wells@uconn.edu
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At Yale, where I am currently a lecturer, contact marta.wells@yale.edu
I also have a website
at Yale, where you can find additional information.
Current Areas of Research:
Evolutionary Biology, molecular evolution, speciation on green lacewings
(Neuroptera), courtship song behavior.
For the past 10 years I have been working with Charles
Henry on green lacewings (Neuroptera, Chrysopidae). We are interested in
understanding the role of mating signals in reproductive isolation among cryptic
species of insects. Even though, it is not clear whether the changes in courtship
song features precede, induce, or develop after speciation, courtship songs
become a very important factor in the process of speciation, because they result
in the formation of swarms of sibling species distinguished only by differences
in their songs.
Green lacewings of the order Neuroptera, are a good case study to look
at the role of courtship songs in reproductive isolation and at evolutionary
changes in song features among closely related species.
Male and female green lacewings establish duetting behavior through a low
frequency tremulation courtship song, that always precedes copulation. If you
would like to hear what these vibrational signals sound like, click HERE.
A combination of playback experiments, laboratory hybridization, electrophoretic
and mitochondrial DNA studies has shown that many species of green lacewings
are really groups of cryptic sibling biological species previously unknown.
In organisms that use acoustic signals, there are some features that are used
in species recognition. In many insects, it has been shown that the temporal
features of songs such as pulse rate or inter-chirp interval play a key role
on species recognition. In Chrysoperla plorabunda, the temporal features of
the courtship song (volley duration and interval) seem to be very important
features to elicit duetting responses in females.
The process of speciation must frequently involve the evolution of novel signals
and preferences and the problem is to understand how this occurs. Data on behavioral
responses of hybrid green lacewings to both hybrid and parental songs, suggest
that the mechanisms of production and reception of songs may be coupled. Then,
changes on song features during speciation could be accompanied by changes in
the receiver's signal, allowing for populations to diverge through assortative
mating.
Currently, I am doing a study using mitochondrial and nuclear DNA sequence
data, in Chris Simon's Laboratory,
to reconstruct the phylogenetic relationships among several closely related
species within the genus Chrysoperla. The objective is to enhance the
understanding of the evolution of courtship songs, and try to clarify the relationship
between song divergence and rapid speciation within certain of its species lineages,
such as the C. plorabunda complex, C. downesi complex
and C. carnea complex. Some of the preliminary results show the
song species within each complex as being more close related to each other than
to any other species in the other complexes. This results agree with the prediction
that if speciation trough song divergence is the evolutionary process occurring
in these insects, the song species should be sister taxa within each complex.
Selected Publications:
Henry, C. S., and M. M. Wells. 1990. Geographical variation in the
song of Chrysoperla plorabunda (Neuroptera: Chrysopidae) in North
America. Ann. Entomol. Soc. Amer. 83:317-325.
Wells, M. M. and C. S. Henry. 1992a. The role of courtship songs
in reproductive isolation among populations of green lacewings of the genusChrysoperla
(Neuroptera: Chrysopidae). Evolution 46(1): 31-42.
Wells, M. M. and C. S. Henry. 1992b. Behavioral responses of green
lacewings (Neuroptera: Chrysopidae: Chrysoperla) to synthetic mating
songs. Anim.Behav. 44:641-652.
Henry, C. S., M. M. Wells, and R. J. Pupedis. 1993. Hidden taxonomic
diversity within Chrysoperla plorabunda (Neuroptera: Chrysopidae):
two new species based on courtship songs. Ann. Entomol. Soc. Am 86:1-13.
Wells, M. M. 1993. Laboratory hybridization in green lacewings (Neuroptera:
Chrysopidae: Chrysoperla): evidence for genetic incompatibility.
Can. J.Zool. 71:233-237
Wells, M. M. and C. S. Henry. 1994. Behavioral responses of hybrid
lacewings (Neuroptera; Chrysopidae) to courtship songs. J. Insect Behav.
7:649-662.
Wells, M. M. 1994. Small genetic distances among populations of
green lacewings of the genus Chrysoperla (Neuroptera: Chrysopidae):
implications for speciation. Ann. Entomol. Soc. Amer. 87(6):737-744.
Wells, M. M. and C.
S. Henry. 1998. Songs, reproductive isolation and speciation in cryptic
species of insects: a case study using green lacewings. Pp. 217- 233 in: D.
Howard, ed. Endless Forms: Species and Speciation. (n/a), Oxford,
New York.
Henry, C., M. Wells, and C. Simon. 1999. Convergent evolution
of courtship songs among cryptic species of the carnea-group of green lacewings
(Neuroptera: Chrysopidae: Chrysoperla). Evolution 53(4):1165-1179.
Henry, C.S., Wells, M.L.M. & Holsinger, K.E. (2002) The inheritance
of mating song in two cryptic, sibling lacewing species (Neuroptera: Chrysopidae:
Chrysoperla). Genetica, 116, 269-289.
Henry, C.S. & Wells, M.L.M. (2004) Adaptation or random change? The
evolutionary response of songs to substrate properties in lacewings (Neuroptera:
Chrysopidae: Chrysoperla). Animal Behaviour, 68, 879-895.
Courses Taught: Evolution, General Ecology, Introductory Biology, Biology
of Terrestrial Arthropods, Animal Behavior, Laboratory on Evolutionary Biology,
Diversity of Life.
Collaborators: Charles
Henry,
Chris Simon