Department of Biology Seminar

"The Dual Role of Parental Conflict in Speciation: Lessons from Mimulus""

Coughlan_Selfie

Dr. Jennifer Coughlan | Coughlan Lab

Bio:
See attached CV here.

Abstract:
Determining what factors generate biodiversity is a central question in evolutionary biology. Despite its long history of study, we are only beginning to understand the evolutionary drivers of reproductive barriers between species, including reproductive barriers that manifest as sterile or dead hybrids. An intriguing hypothesis is that intragenomic conflicts- or selfish evolution- can drive the evolution of alleles that cause hybrid sterility/inviability. One such source of conflict is conflict between parents over resource allocation to offspring. Under parental conflict, multiple paternity drives the evolution of paternally derived, resource-acquiring alleles, and maternally derived alleles that distribute resources equally among offspring. In hybrids, mismatches between these parent-of-origin effect alleles can cause inappropriate development of placenta or endosperm, and subsequently embryo death. Here, I test the role of parental conflict in generating one of the most common intrinsic barriers in seed angiosperms- hybrid seed inviability-using members of the evolutionary and ecological model system; the Mimulus guttatus species complex. I show that hybrid seed inviability has evolved rapidly and repeatedly in this group, and patterns of HSI conform to the predictions of parental conflict. Additionally, genetic mapping suggests that hybrid seed inviability is conferred by nuclear, parent-of-origin effect loci (i.e. loci that affect the probability of death only if maternally or paternally derived). Lastly, using a series of natural surveys and mixed pollination crosses, I find that species with different histories of parental conflict frequently co-occur and hybridize, and hybridization between species with differing histories of parental conflict can indirectly influence growth in intraspecific seeds. Overall, this work highlights a dual role of parental conflict in the speciation process; both in the origin of reproductive isolation, but also in the dynamics and outcomes of hybridization in nature.

Watch the seminar here!
 

Date:
Location:
THM 116

"The Dual Role of Parental Conflict in Speciation: Lessons from Mimulus""

Coughlan_Selfie

Dr. Jennifer Coughlan | Coughlan Lab

Bio:
See attached CV here.

Abstract:
Determining what factors generate biodiversity is a central question in evolutionary biology. Despite its long history of study, we are only beginning to understand the evolutionary drivers of reproductive barriers between species, including reproductive barriers that manifest as sterile or dead hybrids. An intriguing hypothesis is that intragenomic conflicts- or selfish evolution- can drive the evolution of alleles that cause hybrid sterility/inviability. One such source of conflict is conflict between parents over resource allocation to offspring. Under parental conflict, multiple paternity drives the evolution of paternally derived, resource-acquiring alleles, and maternally derived alleles that distribute resources equally among offspring. In hybrids, mismatches between these parent-of-origin effect alleles can cause inappropriate development of placenta or endosperm, and subsequently embryo death. Here, I test the role of parental conflict in generating one of the most common intrinsic barriers in seed angiosperms- hybrid seed inviability-using members of the evolutionary and ecological model system; the Mimulus guttatus species complex. I show that hybrid seed inviability has evolved rapidly and repeatedly in this group, and patterns of HSI conform to the predictions of parental conflict. Additionally, genetic mapping suggests that hybrid seed inviability is conferred by nuclear, parent-of-origin effect loci (i.e. loci that affect the probability of death only if maternally or paternally derived). Lastly, using a series of natural surveys and mixed pollination crosses, I find that species with different histories of parental conflict frequently co-occur and hybridize, and hybridization between species with differing histories of parental conflict can indirectly influence growth in intraspecific seeds. Overall, this work highlights a dual role of parental conflict in the speciation process; both in the origin of reproductive isolation, but also in the dynamics and outcomes of hybridization in nature.

Watch the seminar here!
 

Date:
Location:
THM 116

"The Dual Role of Parental Conflict in Speciation: Lessons from Mimulus""

Coughlan_Selfie

Dr. Jennifer Coughlan | Coughlan Lab

Bio:
See attached CV here.

Abstract:
Determining what factors generate biodiversity is a central question in evolutionary biology. Despite its long history of study, we are only beginning to understand the evolutionary drivers of reproductive barriers between species, including reproductive barriers that manifest as sterile or dead hybrids. An intriguing hypothesis is that intragenomic conflicts- or selfish evolution- can drive the evolution of alleles that cause hybrid sterility/inviability. One such source of conflict is conflict between parents over resource allocation to offspring. Under parental conflict, multiple paternity drives the evolution of paternally derived, resource-acquiring alleles, and maternally derived alleles that distribute resources equally among offspring. In hybrids, mismatches between these parent-of-origin effect alleles can cause inappropriate development of placenta or endosperm, and subsequently embryo death. Here, I test the role of parental conflict in generating one of the most common intrinsic barriers in seed angiosperms- hybrid seed inviability-using members of the evolutionary and ecological model system; the Mimulus guttatus species complex. I show that hybrid seed inviability has evolved rapidly and repeatedly in this group, and patterns of HSI conform to the predictions of parental conflict. Additionally, genetic mapping suggests that hybrid seed inviability is conferred by nuclear, parent-of-origin effect loci (i.e. loci that affect the probability of death only if maternally or paternally derived). Lastly, using a series of natural surveys and mixed pollination crosses, I find that species with different histories of parental conflict frequently co-occur and hybridize, and hybridization between species with differing histories of parental conflict can indirectly influence growth in intraspecific seeds. Overall, this work highlights a dual role of parental conflict in the speciation process; both in the origin of reproductive isolation, but also in the dynamics and outcomes of hybridization in nature.

Watch the seminar here!
 

Date:
Location:
THM 116

"The Dual Role of Parental Conflict in Speciation: Lessons from Mimulus""

Coughlan_Selfie

Dr. Jennifer Coughlan | Coughlan Lab

Bio:
See attached CV here.

Abstract:
Determining what factors generate biodiversity is a central question in evolutionary biology. Despite its long history of study, we are only beginning to understand the evolutionary drivers of reproductive barriers between species, including reproductive barriers that manifest as sterile or dead hybrids. An intriguing hypothesis is that intragenomic conflicts- or selfish evolution- can drive the evolution of alleles that cause hybrid sterility/inviability. One such source of conflict is conflict between parents over resource allocation to offspring. Under parental conflict, multiple paternity drives the evolution of paternally derived, resource-acquiring alleles, and maternally derived alleles that distribute resources equally among offspring. In hybrids, mismatches between these parent-of-origin effect alleles can cause inappropriate development of placenta or endosperm, and subsequently embryo death. Here, I test the role of parental conflict in generating one of the most common intrinsic barriers in seed angiosperms- hybrid seed inviability-using members of the evolutionary and ecological model system; the Mimulus guttatus species complex. I show that hybrid seed inviability has evolved rapidly and repeatedly in this group, and patterns of HSI conform to the predictions of parental conflict. Additionally, genetic mapping suggests that hybrid seed inviability is conferred by nuclear, parent-of-origin effect loci (i.e. loci that affect the probability of death only if maternally or paternally derived). Lastly, using a series of natural surveys and mixed pollination crosses, I find that species with different histories of parental conflict frequently co-occur and hybridize, and hybridization between species with differing histories of parental conflict can indirectly influence growth in intraspecific seeds. Overall, this work highlights a dual role of parental conflict in the speciation process; both in the origin of reproductive isolation, but also in the dynamics and outcomes of hybridization in nature.

Watch the seminar here!
 

Date:
Location:
THM 116

"The Dual Role of Parental Conflict in Speciation: Lessons from Mimulus""

Coughlan_Selfie

Dr. Jennifer Coughlan | Coughlan Lab

Bio:
See attached CV here.

Abstract:
Determining what factors generate biodiversity is a central question in evolutionary biology. Despite its long history of study, we are only beginning to understand the evolutionary drivers of reproductive barriers between species, including reproductive barriers that manifest as sterile or dead hybrids. An intriguing hypothesis is that intragenomic conflicts- or selfish evolution- can drive the evolution of alleles that cause hybrid sterility/inviability. One such source of conflict is conflict between parents over resource allocation to offspring. Under parental conflict, multiple paternity drives the evolution of paternally derived, resource-acquiring alleles, and maternally derived alleles that distribute resources equally among offspring. In hybrids, mismatches between these parent-of-origin effect alleles can cause inappropriate development of placenta or endosperm, and subsequently embryo death. Here, I test the role of parental conflict in generating one of the most common intrinsic barriers in seed angiosperms- hybrid seed inviability-using members of the evolutionary and ecological model system; the Mimulus guttatus species complex. I show that hybrid seed inviability has evolved rapidly and repeatedly in this group, and patterns of HSI conform to the predictions of parental conflict. Additionally, genetic mapping suggests that hybrid seed inviability is conferred by nuclear, parent-of-origin effect loci (i.e. loci that affect the probability of death only if maternally or paternally derived). Lastly, using a series of natural surveys and mixed pollination crosses, I find that species with different histories of parental conflict frequently co-occur and hybridize, and hybridization between species with differing histories of parental conflict can indirectly influence growth in intraspecific seeds. Overall, this work highlights a dual role of parental conflict in the speciation process; both in the origin of reproductive isolation, but also in the dynamics and outcomes of hybridization in nature.

Watch the seminar here!
 

Date:
Location:
THM 116

"The Developmental Basis of Phenotypic Diversity"

Dr. Ricardo Mallarino | Mallarino Lab

Bio:
Ricardo Mallarino is an Assistant Professor of Molecular Biology at Princeton University. Originally from Bogota, Colombia, he graduated with a B.S. in Biology from Universidad de los Andes. He completed his graduate studies at Harvard in Organismic and Evolutionary Biology in 2011, working with Arhat Abzhanov on developmental mechanisms underlying beak shape diversity in Darwin’s finches and their close relatives. After completing his PhD. he joined Hopi Hoekstra’s lab at Harvard, where he established a new model species and developed tools for studying the molecular basis of pigment pattern formation in mammals. Research in the Mallarino lab focuses on understanding the genetic and developmental mechanisms by which form and structure are regulated during vertebrate embryogenesis and elucidating how these processes get modified during evolutionary time to produce phenotypic diversity.

Abstract:
The evolution of metazoan organisms over millions of years has led to remarkable complexity of form and function. While biologists have long studied the ultimate causes of biological diversity (i.e., why it originates), the proximate mechanisms underlying its emergence (i.e., how it arises) remain largely unknown. The goal of my lab is to uncover the genetic and developmental mechanisms underlying the establishment of phenotypic traits and to understand how these mechanisms have evolved to generate diversity across species. We achieve this by harnessing naturally evolved phenotypic variation in ‘non-traditional’ species and integrating multiple disciplines, including developmental biology, computational biology, and evolutionary genetics. For the past six years, our research has focused primarily on patterning and evolution of novelty in mammalian skin. In this talk, I’ll describe how my lab has developed new model systems to study two distinct spatially patterned phenomena during skin development - stripe pattern formation in rodents and gliding membrane formation in marsupials. Through the use of experimental embryology, transcriptomics, comparative genomics, and functional genetics, our work has yielded insights into the mechanisms by which phenotypic novelty is generated at the molecular level.

Watch the seminar here!

Date:
Location:
THM 116

"The Developmental Basis of Phenotypic Diversity"

Dr. Ricardo Mallarino | Mallarino Lab

Bio:
Ricardo Mallarino is an Assistant Professor of Molecular Biology at Princeton University. Originally from Bogota, Colombia, he graduated with a B.S. in Biology from Universidad de los Andes. He completed his graduate studies at Harvard in Organismic and Evolutionary Biology in 2011, working with Arhat Abzhanov on developmental mechanisms underlying beak shape diversity in Darwin’s finches and their close relatives. After completing his PhD. he joined Hopi Hoekstra’s lab at Harvard, where he established a new model species and developed tools for studying the molecular basis of pigment pattern formation in mammals. Research in the Mallarino lab focuses on understanding the genetic and developmental mechanisms by which form and structure are regulated during vertebrate embryogenesis and elucidating how these processes get modified during evolutionary time to produce phenotypic diversity.

Abstract:
The evolution of metazoan organisms over millions of years has led to remarkable complexity of form and function. While biologists have long studied the ultimate causes of biological diversity (i.e., why it originates), the proximate mechanisms underlying its emergence (i.e., how it arises) remain largely unknown. The goal of my lab is to uncover the genetic and developmental mechanisms underlying the establishment of phenotypic traits and to understand how these mechanisms have evolved to generate diversity across species. We achieve this by harnessing naturally evolved phenotypic variation in ‘non-traditional’ species and integrating multiple disciplines, including developmental biology, computational biology, and evolutionary genetics. For the past six years, our research has focused primarily on patterning and evolution of novelty in mammalian skin. In this talk, I’ll describe how my lab has developed new model systems to study two distinct spatially patterned phenomena during skin development - stripe pattern formation in rodents and gliding membrane formation in marsupials. Through the use of experimental embryology, transcriptomics, comparative genomics, and functional genetics, our work has yielded insights into the mechanisms by which phenotypic novelty is generated at the molecular level.

Watch the seminar here!

Date:
Location:
THM 116

"The Developmental Basis of Phenotypic Diversity"

Dr. Ricardo Mallarino | Mallarino Lab

Bio:
Ricardo Mallarino is an Assistant Professor of Molecular Biology at Princeton University. Originally from Bogota, Colombia, he graduated with a B.S. in Biology from Universidad de los Andes. He completed his graduate studies at Harvard in Organismic and Evolutionary Biology in 2011, working with Arhat Abzhanov on developmental mechanisms underlying beak shape diversity in Darwin’s finches and their close relatives. After completing his PhD. he joined Hopi Hoekstra’s lab at Harvard, where he established a new model species and developed tools for studying the molecular basis of pigment pattern formation in mammals. Research in the Mallarino lab focuses on understanding the genetic and developmental mechanisms by which form and structure are regulated during vertebrate embryogenesis and elucidating how these processes get modified during evolutionary time to produce phenotypic diversity.

Abstract:
The evolution of metazoan organisms over millions of years has led to remarkable complexity of form and function. While biologists have long studied the ultimate causes of biological diversity (i.e., why it originates), the proximate mechanisms underlying its emergence (i.e., how it arises) remain largely unknown. The goal of my lab is to uncover the genetic and developmental mechanisms underlying the establishment of phenotypic traits and to understand how these mechanisms have evolved to generate diversity across species. We achieve this by harnessing naturally evolved phenotypic variation in ‘non-traditional’ species and integrating multiple disciplines, including developmental biology, computational biology, and evolutionary genetics. For the past six years, our research has focused primarily on patterning and evolution of novelty in mammalian skin. In this talk, I’ll describe how my lab has developed new model systems to study two distinct spatially patterned phenomena during skin development - stripe pattern formation in rodents and gliding membrane formation in marsupials. Through the use of experimental embryology, transcriptomics, comparative genomics, and functional genetics, our work has yielded insights into the mechanisms by which phenotypic novelty is generated at the molecular level.

Watch the seminar here!

Date:
Location:
THM 116

"The Developmental Basis of Phenotypic Diversity"

Dr. Ricardo Mallarino | Mallarino Lab

Bio:
Ricardo Mallarino is an Assistant Professor of Molecular Biology at Princeton University. Originally from Bogota, Colombia, he graduated with a B.S. in Biology from Universidad de los Andes. He completed his graduate studies at Harvard in Organismic and Evolutionary Biology in 2011, working with Arhat Abzhanov on developmental mechanisms underlying beak shape diversity in Darwin’s finches and their close relatives. After completing his PhD. he joined Hopi Hoekstra’s lab at Harvard, where he established a new model species and developed tools for studying the molecular basis of pigment pattern formation in mammals. Research in the Mallarino lab focuses on understanding the genetic and developmental mechanisms by which form and structure are regulated during vertebrate embryogenesis and elucidating how these processes get modified during evolutionary time to produce phenotypic diversity.

Abstract:
The evolution of metazoan organisms over millions of years has led to remarkable complexity of form and function. While biologists have long studied the ultimate causes of biological diversity (i.e., why it originates), the proximate mechanisms underlying its emergence (i.e., how it arises) remain largely unknown. The goal of my lab is to uncover the genetic and developmental mechanisms underlying the establishment of phenotypic traits and to understand how these mechanisms have evolved to generate diversity across species. We achieve this by harnessing naturally evolved phenotypic variation in ‘non-traditional’ species and integrating multiple disciplines, including developmental biology, computational biology, and evolutionary genetics. For the past six years, our research has focused primarily on patterning and evolution of novelty in mammalian skin. In this talk, I’ll describe how my lab has developed new model systems to study two distinct spatially patterned phenomena during skin development - stripe pattern formation in rodents and gliding membrane formation in marsupials. Through the use of experimental embryology, transcriptomics, comparative genomics, and functional genetics, our work has yielded insights into the mechanisms by which phenotypic novelty is generated at the molecular level.

Watch the seminar here!

Date:
Location:
THM 116

"The Developmental Basis of Phenotypic Diversity"

Dr. Ricardo Mallarino | Mallarino Lab

Bio:
Ricardo Mallarino is an Assistant Professor of Molecular Biology at Princeton University. Originally from Bogota, Colombia, he graduated with a B.S. in Biology from Universidad de los Andes. He completed his graduate studies at Harvard in Organismic and Evolutionary Biology in 2011, working with Arhat Abzhanov on developmental mechanisms underlying beak shape diversity in Darwin’s finches and their close relatives. After completing his PhD. he joined Hopi Hoekstra’s lab at Harvard, where he established a new model species and developed tools for studying the molecular basis of pigment pattern formation in mammals. Research in the Mallarino lab focuses on understanding the genetic and developmental mechanisms by which form and structure are regulated during vertebrate embryogenesis and elucidating how these processes get modified during evolutionary time to produce phenotypic diversity.

Abstract:
The evolution of metazoan organisms over millions of years has led to remarkable complexity of form and function. While biologists have long studied the ultimate causes of biological diversity (i.e., why it originates), the proximate mechanisms underlying its emergence (i.e., how it arises) remain largely unknown. The goal of my lab is to uncover the genetic and developmental mechanisms underlying the establishment of phenotypic traits and to understand how these mechanisms have evolved to generate diversity across species. We achieve this by harnessing naturally evolved phenotypic variation in ‘non-traditional’ species and integrating multiple disciplines, including developmental biology, computational biology, and evolutionary genetics. For the past six years, our research has focused primarily on patterning and evolution of novelty in mammalian skin. In this talk, I’ll describe how my lab has developed new model systems to study two distinct spatially patterned phenomena during skin development - stripe pattern formation in rodents and gliding membrane formation in marsupials. Through the use of experimental embryology, transcriptomics, comparative genomics, and functional genetics, our work has yielded insights into the mechanisms by which phenotypic novelty is generated at the molecular level.

Watch the seminar here!

Date:
Location:
THM 116