Evolutionary biology, population genetics, botany, bioinformatics and phylogenetics.
A number of organismal groups have been identified by biologists as groups which have experienced a recent and rapid evolutionary radiation.
These groups are characterized as containing exceptional amounts of diversity (genetic, phenotypic, or otherwise).
Examples include the Hawaiian Silversword alliance, Cichlids and others.
Biologists study these exceptionally diverse groups in an attempt to better understand the process of speciation.
The legume genus Astragalus is the most species rich genus of vascular plant on the planet, containing approxiametly 2,500 species.
Notable within the genus is the species A. lentiginosus, which contains more taxa (taxonomic varieties) than any other species in the U.S. flora.
My Ph.D. dissertation sought to characterize this infra-specific diversity from a morphologic and molecular context, as well as propose mechanisms to explain this diversity.
Through the study of diverse groups such as this, and the integration of theory and empiricism, we can begin to better describe the diversity we observe on this wonderful planet, and begin to understand the processes which have led to it.
Ground breaking work by Richard Lewontin and colleagues during the late 1960s demonstrated a dramatic abundance of intra-specific enzyme polymorphism (i.e., within species genetic diversity).
Frederick Sanger developed the 'dideoxy' method of DNA sequencing during the 1970s.
Kary Mullis improved the efficiency of DNA amplification and subsequent sequencing methodologies with the advent of the polymerase chain reaction (PCR) during the 1980s.
These advancements have provided the foundation for the field of molecular genetics.
Current advancement in DNA sequencing technologies, such as sequence-by-synthesis, have facilitated the sequencing of millions of base-pairs of DNA.
This technology has spawned genome scale projects such as the 1000 genomes project (Homo sapiens) and the 1001 genomes project (the model plant Arabidopsis thaliana) which hope to not only characterize genetic diversity within these organisms but provide mechanistic explanations for phenotypes (i.e., traits).
While this unprecedented amount of data is stunning, it is also humbling to realize that emerging technologies may soon make these methods obsolete.
The age of genomic biology is here and one day soon you may be able to have your genome sequenced affordably.
We've recently sequenced the mitochondrial genomes (~16 kbp) of 34 fishers (Martes pennanti).
Through the use of existing softwares and custom tools developed in perl and R we've begun to bring genomic information to population and conservation biology.
Although this group appears to have less molecular diversity than Native American humans (estimated to have arrived in the New World ~40 thousand years ago), we have managed to infer evolutionary relationships with unprecedented precision.
Some of these relationships are very recent, perhaps as recent as 500 years ago.
Because this predates Euro-American settlement it suggests that these lineages predate modern land management decisions. This information is of great importance to conservationists whom have recently considered the Californian populations (M.p. pacifica) as candidates for listing as protected organisms.
Land management requires the necessary compromise between ecosystem management and anthropogenic development.
In order to mitigate the effects of large ungulate grazing, wildland fire, mineral extraction and other anthropogenic impacts on our publicly owned lands, important decisions need to be made on the structure of natural populations.
Science-based management promises an attempt to maintain current structure and natural processes for future generations to enjoy.
Antelope bitterbrush (Purshia tridentata, Rosaceae) is a woody shrub distributed throughout the Great Basin, which is important forage for large ungulates, such as deer and elk.
As such, it is of interest to landmanagers for use in restoration projects, such as post-fire or post-road building activities.
It appears intuitive that local seed sources should be employed in revegetation projects, but how local is local?
We've employed nuclear microsatellites (a diploid, bi-parentally inherited marker), chloroplast microsatellites (a haploid, maternally inherited marker) and quantitative traits measured in a common garden to characterize genetic diversity within this plant species, throughout its range.
Products from this work hope to provide seed transfer guidlines for land managers, as well as infer evolutionary processes which have led to the diversity we observe.
Systematics
In order to facilitate a conversation on the world's biota, biologists strive to provide a standardized system of names which is readily applicable by other biologists.
The fundamental unit of these systems is often considered to be the species.
The 'system' employed is that of evolutionary relationship.
Because no one has ever observed the evolutionary processes which have led to the world's current biota, application of an evolutionary system may always be an artifact of current technologies and analytical methodologies.
In order to provide the best understanding of evolutionary relationships among the world's biota biologists present updates to our current understanding of this diversity as these data become available.
In the context of the naming of organisms this takes the form of nomenclatural revision.
Research conducted during my Ph.D. project led to a new understanding of the most taxon rich species in the U.S. flora, Astragalus lentiginosus (Fabaceae/Leguminosae).
This work has inspired a monographic work on Astragalus section Diphysi.
This new information promises to shed light on the nature of A. lentiginosus, as well as the question of what is an infra-specific group.
Astragalus resources:
Astragalus lentiginosus
Copyright (c) 2009 Brian J. Knaus
