front 1 biological species concept | back 1 species are groups of potentially interbreeding populations that are reproductively isolated from other such groups (work pretty well for sexually reproducing animals) |
front 2 phylogenetic species concept | back 2 smallest possible group descending from a common ancestor and recognizable by unique, derived traits (useful for systematics; focuses on phylogenetic history) |
front 3 general lineage species concept | back 3 species are metapopulations that exchange alleles frequently enough to compreise the same gene pool |
front 4 metapopulation | back 4 group of spatially separated populations of the same species that interact at some level |
front 5 biologist generally agree that | back 5 no single definition of a "species" will fit all taxa |
front 6 speciation | back 6 evolutionary process by which new species arise (key step in the evolution of new species is the splitting in two of an original population) |
front 7 isolating barrier | back 7 an aspect of the environment, genetics, behavior, physiology, or ecology of a species that reduces or impedes gene flow from individuals of other species (geographic or reproductive) |
front 8 geographic | back 8 extrinsic properties of landscape that prevent gene flow (allopatry) |
front 9 reproductive | back 9 features of organisms that prevent interbreeding (barriers effective even in sympatry) |
front 10 prezygotic barriers pre-mating: | back 10 -behavioral isolation -ecological isolation: habitat, temporal, pollinator -mechanical isolation |
front 11 prezygotic barriers post-mating: | back 11 -copulatory behavioral isolation -gametic isolation |
front 12 prezygotic barriers intrinsic: | back 12 -hybrid inviability -hybrid sterility: physiological and behavioral |
front 13 prezygotic barriers extrinsic: | back 13 -ecological inviability -behavioral sterility |
front 14 elk and red deer | back 14 two populations are geographically isolated but will reproduce when brought together |
front 15 total population of free-ranging elk in trans-pecos as estimated in 1995 at | back 15 330 but 2014 was 3.5k |
front 16 premating barriers | back 16 timing of reproduction |
front 17 corals reproduce by releasing gametes into the water, the graph shows | back 17 two species of Montastraea corals remain reproductively isolated due to spawning times |
front 18 some animals have | back 18 distinct courtship rituals |
front 19 some rituals reinforce recent speciation events for | back 19 closely related animals |
front 20 females only respond to | back 20 specific courtship displays for mating |
front 21 premating barriers | back 21 pollinator isolation (two species of partially sympatric monkey flowers are pollinated, not hybridized in nature as pollinators aren't interested in the other species) |
front 22 copulatory behavioral isolation | back 22 mating between species results in damage to the female reproductive tract; different species males' copulatory courtship results in eggs not fertilized by deposited sperm |
front 23 gametic incompability | back 23 sperm or pollen from one species fails to penetrate and fertilize the egg of another species |
front 24 hybrids are produced but have | back 24 low fitness |
front 25 hybrid inviability | back 25 the hybrid embryos of sheep and goats, for example, die in the early developmental stages birth |
front 26 hybrid sterility | back 26 mules |
front 27 ecological inviability (outbreeding depression) | back 27 outbreeding depression can lead to coadapted gene complexes being broken apart without the forging of new coadapted gene complexes to take their place |
front 28 behavioral sterility | back 28 e.g., behavioral sterility of hybrid males in acoustically communicating grasshoppers |
front 29 bateson-dobzhansky-muller incompability | back 29 genetic incompatibility in hybrid offspring arising from epistatic interactions at two or more loci |
front 30 dobzhanksy-muller incompatibility arises if | back 30 one population evolves the A1B0 genotype and the other evolves the A0B1 hybrids if the populations were to come into contact |
front 31 Example of B-D-M incompatibility (epistatic interaction) | back 31 QTL was used to identify Hms1 on chromosome 6 and Hms2 on chromosome 13. Hybrids with M. guttatus alleles for Hms1 produce viable pollen if they also inherit at least one M. guttatus allele at Hms2. if they get M. nasutus the pollen is sterile. |
front 32 allopatric speciation | back 32 result of geographic isolation, after a geographic boundary separate them, the populations become increasingly divergent |
front 33 reinforcement refers to | back 33 the increase of reproductive isolation between populations through selection against hybrid offspring |
front 34 consequences of secondary contact | back 34 -fusion of incipient populations back into one species -reinforcement -stable or transient hybrid zone formation -speciation of hybrids |
front 35 reinforcement increases | back 35 prezygotic reproductive isolation |
front 36 reinforcement (definition) | back 36 natural selection favors prezygotic isolation mechanisms that prevent the formation of hybrids with reduced fitness (postzygotic isolation must evolve in allopatry) |
front 37 reinforcement outcomes | back 37 -extinction of one of the initial populations -the initial populations can hybridized -the initial populations can speciate, are determined by both initial divergence and level of fitness of the hybrids |
front 38 sympatric speciation | back 38 reproductive isolation evolves without geographic isolation (requires nonrandom mating based on genetic or phenotypic factors ) |
front 39 parapatric speciation | back 39 geographic barrier only partially separates populations (some gene flow possible), for example, grass Agrostis tenuis, individuals are tolerant to heavy metals, a heritable trait, survive well on contaminated soil, but poorly on non-contaminated soil (the reverse occurs for intolerant populations) |
front 40 isolation by distance | back 40 populations tend to breed with those in close proximity (causes variation across the range of the species) |
front 41 ring species | back 41 is a connected series of neighboring populations, each of which interbreed with closely sited related populations, but for which there exist at least two "end" populations |
front 42 ecological speciation | back 42 selection for different ecological traits in different niches creates reproductive barriers (can lead to pre- ad postzygotic isolation |
front 43 magic traits | back 43 traits that simultaneously confer divergent local adaptation and act as reproductive barriers |
front 44 a species population of pink-petal flowers becomes isolated in allopatry or parapatry. novel pollinators drive the selection of new traits (purple petals) in the isolated populations eventually leading to | back 44 speciation of the flower populations |
front 45 phylogentic evidence for allopatric speciation | back 45 a land bridge from north america to south america only arose 3mya. allopatric speciation resulted. |
front 46 palm trees evolved due to soil types (one liked basic while the other liked acidic), therefore | back 46 there was also a shift in flowering times |
front 47 islands provide | back 47 opportunity for allopatric speciation |
front 48 colonization leads to | back 48 speciation |
front 49 (Laupala crickets only found in hawaii) QTL mapping suggests that | back 49 loci associated with male pulse rate also maps to female song preference populations on the same island often differ in male songs and female preferences for the songs |
front 50 polar bears evolved into a distinct species beginning | back 50 500,000 years ago |
front 51 ecological speciation and interspecies gene flow between polar bears and brown bears | back 51 polar bears and brown bears |
front 52 genes under strong selection in polar bears linked to ecological niche | back 52 -APOB proteins (to handle high levels of cholesterol from diet rich in fatty acids) -heart function (long-distance swimming) -hair pigmentation (interbreeding has occurred since divergence) |
front 53 when D=1 Drosophila spp. can | back 53 no longer interbreed, using molecular clocks, it takes hundreds of thousands of years for them to diverge into new biological species. |
front 54 allopolyploidy can lead to | back 54 extremely rapid speciation |
front 55 allopolyploid | back 55 an individual having two or more complete sets of chromosomes derived from different species |
front 56 cryptic species | back 56 compromise two or more taxa that are grounded under a single name because they are more-or-less indistinguishable morphologically (important for detailed biodiversity assessments) |
front 57 skippers in costa rica has caterpillars with different patters, and were apparantly | back 57 cryptic species |
front 58 cryptic meadowlarks (eastern meadowlark, western meadowlark, and chihuahuan meadowlark) in | back 58 texas |
front 59 16S rRNA genes vary by up to | back 59 3% in microbial species |
front 60 is microbes are 97% similar to 16S rRNA, they are the | back 60 same species |
front 61 single spoonful of soil may contain | back 61 10,000 different species of bacteria (soil has one trillion species by locey and lennon 2016) |
front 62 horizontal gene transfer in | back 62 E.coli, however, core genome is only 3188 genes, but there are 90,000+ gene across the entire E.coli genome |
front 63 horizontal gene transfer makes classification difficult | back 63 the mixing genes makes it difficult, if not impossible, to delineate species boundaries |
front 64 horizontal gene transfer is | back 64 common |
front 65 bacterial species often defined by | back 65 specific adaptations |
front 66 stable ecotype model | back 66 species concept for microbes, species is long-lived population of genetically related individuals that share a stable set of adaptations for hte same ecological niche, yet scientist criticize this method |
front 67 taking horizontal gene transfer into account | back 67 shapiro et al. suggests that gene acquired from other lineages can be important for the emergence of lineages with new adaptations |
front 68 geographic barriers to gene flow | back 68 physically separate populations (important for all species concepts) |
front 69 reproductive barriers are | back 69 intrinsic features of organisms that reduce likelihood of interbreeding |
front 70 separation of populations over time will | back 70 reduce gene flow |
front 71 divergent floral traits can cause | back 71 pollinator isolation and reduce interbreeding |
front 72 genetic incompabilities that reduce hybrid fitness can be | back 72 important barriers to gene flow |
front 73 specitation can occur in symatry when | back 73 populations rarely interbreed |
front 74 identifying cryptic species is important for | back 74 measures of biodiversity |
front 75 cryptic species may diverge from ancestral populations without | back 75 easily distinguishable morphologies |
front 76 microbial organisms present challenges to species concepts | back 76 developed eaukaryotes |