Biodiversity 1. avoid direct quotations 2. support arguments with - PDF document

Matt Schrader Comments to assignment BSC 3052 February 5, 2004 Newman, D., and D. A. Tallmon. 2001. Experimental evidence for beneficial fitness effects of gene flow in recently isolated populations. Conservation Biology. 15(4): 1054- 1063. 1. Goals of the study In small populations, extinction risk may be increased by genetic factors such as drift and inbreeding depression. Simple genetic models predict that a few migrants per generation can counteract 2. Method(s) inbreeding depression and maintain genetic variation in small populations, but there have been few 3. Results or conclusions empirical tests of their predictions. Newman and Tallmon (2001) experimentally manipulated migration into small plant populations in order to test (1) whether migration decreases the effects of inbreeding 4. Strengths and Weaknesses depression in small populations, (2) whether the amount of migration matters, and (3) how migration 5. Overall evaluation (do strengths outweigh weaknesses, affects the distribution of phenotypic variation, within and among populations. contribution to field) The experiment consisted of three migration treatments (0-migrants per generation, 1-migrant per 6. If you use work of others, include a Reference section generation, and 2.5 migrants per generation) applied to 10 replicate lab-populations of the annual plant Brassica campestris (rapa) for 5 generations. Each of the thirty populations was founded from 5 seeds 7. Questions that paper raises or future work needed collected from a wild population, and the pool of migrants came from the same wild population. 8. Questions for summary/discussion Inbreeding coefficients were calculated for each individual using pedigrees, and expected inbreeding coefficients for each treatment were calculated using Wright’s equations. Fitness traits were measure in the lab on seeds that produced the 2 nd , 4 th , and 6 th generation (germination rate, # of seeds per capsule, and seed weight), and in the field on 6 th generation plants (cotyledon width, flowering date, stem diameter, Biodiversity 1. avoid direct quotations 2. support arguments with DATA or LOGIC. “The paper was convincing." “Their sampling seemed biased." 3. Be specific. “Biodiversity is the structural and “The authors looked at papers over many years." functional variety of life forms at 4. Your personal opinion is not informative without saying why. "I found this paper interesting" genetic, population, community, 5. Focus on CONTENT not style. and ecosystem levels”. “This paper was well written” [Sandlund, Hindar, and Brown, 1992] Species Domain: Eucarya Kingdom: Animalia Phylum: Chordata Class: Amphibia Order: Anura Family: Ranidae Genus: Rana Species: cretensis

Species concepts Typological, morphological species concept Linné, described according to morphology Biological species concept Ernst Mayr popularized this concept: A group of individuals that is reproductively isolated from other groups. Cladistic species concept Donoghue and others: A species is a monophyletic group (a group including all descendents of an ancestor). What is the cladistic species concept? Every group of populations that are distinct from other groups by a common character (monophyletic group) is a species. monophyletic group monophyletic group Problematic (Cladistic) species concept Phylogenetic relationship A1 Electrophoretic mtDNA marker Linné Bio Clad A1 Rana lessonae Rana shqiperica Rana ridibunda (Poland) A2 Rana kurtmuelleri (Greece) Rana bedriagae (Turkey) A2/A4 Rana epeirotica Rana cretensis ? A3 ? Rana saharica Rana perezi Rana nigromaculata (Korea) A4

Why does the species concept matter? Why does the species concept matter? http://www.wildherps.com/species/C.constrictor.html#paludicola http://www.wildherps.com/species/C.constrictor.html Everglades Black Racer Southern Black Racer Species is a difficult unit, others? The category Species is natural, but sometimes EVOLUTIONARY SIGNIFICANT UNITs are difficult to specify, see other species concepts on populations with an independent evolutionary page 83, Table 4.2 [There are more: e.g. Recognition dynamics. species concept] DEMOGRAPHIC UNIT are populations with The Biological Species Concept (BSC) is most often independent demographic dynamics. These used for legal purposes, although the populations fluctuate in size independent of others and are often isolated. Endangered Species Act has a wider definition: subspecies and distinct population considered CONSERVATION UNIT definition depends on the different units. conservation goal: often keeping variability, minimal viable population, maintaining ecological function. CITES: regulates trade using species designations Luck, G. W. et al. 2003. Population diversity and ecosystem services. Trends in Ecology and Evolution 18: 331-336. www.cites.org How to measure Biodiversity? Taking into account abundance We could count species in an area of Shannon - Wiener index interest n We could take into account numbers of H � = − � p i ln ( p i ) individuals i We could take into account position in means the fractional abundance p i phylogeny (or biomass or productivity,....)

Taking into account abundance Behavior of Shannon-Wiener relative abundance Species Site A Site B n H � = − Common yellowthroat 0.46 0.04 � p i ln ( p i ) Field sparrow 0.16 0.09 i Dickcissel 0.07 0.07 Species 1 Species 2 H’ Red-winged blackbird 0.02 0.03 Brown-headed 0.11 0.06 0.1 0.9 0.325 cowbird American goldfinch 0.08 0.34 0.5 0.5 0.693 Ringneck pheasant 0.03 0.05 Mourning dove 0.07 0.02 Eastern kingbird - 0.05 Grasshopper sparrow - 0.15 Shannon-Wiener measures eveness Northern bobwhite - 0.09 Shannon diversity 1.64 2.07 Behavior of Shannon-Wiener Measuring Biodiversity n H � = − � p i ln ( p i ) We could count species in an area of interest ~RICHNESS i We could take into account numbers of Species 1 Species 2 Species 3 H’ individuals ~EVENESS 0.5 - 0.5 0.694 Indicator species: often we are not able to 0.79 0.11 0.11 0.672 to quantify biodiversity, but know that a ‘rare’ species is an indicator for species richness. Alpha diversity refers to the diversity within a particular area or ecosystem, and is usually expressed by the number of species (i.e., species richness) in that ecosystem. If we examine the change in species diversity between these ecosystems then we are Different levels of biodiversity measuring the beta diversity. We are counting the total number of species that are unique to each of the ecosystems being compared. Gamma diversity is a measure of the overall diversity for the different ecosystems within a region. Alpha, beta and gamma diversity for hypothetical species of birds in three different ecosystems Hypothetical Woodland habitat Hedgerow habitat Open field habitat species α Diversity in an ecological community A X B X C X β Rate of change of species diversity among D X E X similar communities F X X G X X γ H X X Diversity over all communities in a landscape I X X J X X K X L X X M X N X Alpha diversity 10 7 3 Woodland vs. hedgerow: Hedgerow vs. open field: Woodland vs. open field: Beta diversity 7 8 13 Gamma diversity 14