Bio286 Terminologies Latest Update Graded A+

Bio286 Terminologies Latest Update Graded A+ Life History - Answers Pattern of how organisms allocate time and energy among the various activities throughout its life that affect survival, maturation, and reproduction Life History Traits - Answers Longevity, growth rate, age at sexual maturation, age at first reproduction, number of reproductive bouts per lifetime, number of offspring per reproductive bout Ecdysis - Answers periodic shedding of the cuticle in arthropods or the outer skin in reptiles (cicadas in lecture example) Subimago - Answers A life stage of certain insects that is NOT sexually mature, comes before the imago stage. Imago - Answers Sexually mature version certain insects molt into after the subimago stage; Imagos don't have well-developed mouthparts, so their main goal is to breed before they die. Iteroparous - Answers Species that reproduce multiple times during their lives (ex: humans, dogs, frogs, etc) Semelparous - Answers Species that reproduce only once in their life, but may produce MANY offspring during that one time (ex: mayflies, tussock moths) Iteroparity - Answers A survivorship pattern related to reproductive patterns; often typical of organisms whose survival chances increase once they reach maturity (type 1 or 2 survivorship, but iteroparous organisms may have type 3 survivorship curves as well) Semelparity - Answers A survivorship pattern related to reproductive patterns; often typical of organisms with type 3 survivorship (high early life stage mortality), including many fish, insects, all annual plants, etc Phylogeny - Answers a synonym for 'evolutionary tree,' a hypothesized diagram showing the history of divergence and change from single ancestral lineage to its descendants, Parsimony - Answers used when constructing evolutionary trees; choice among alternatives that require fewest number of evolutionary changes; the least complex explanation to explain data. Also explains relationships among organisms: similarities and differences (appearance, function, DNA, proteins), tips of branches (different species), and common ancestors (branch points) Homologous characters - Answers those that are similar in different organisms because they were derived from a common ancestor. Ex: vertebrate forelimbs Analogous characters - Answers traits that serve a similar function but have separate evolutionary origins, a result of convergent evolution. Ex: bird and bat wings. Convergent evolution - Answers similarity between species in certain traits that is caused by similar, but evolutionary independent, responses to common environmental problems. Homoplasy - Answers similarity in the characters found in different species NOT inherited from a common ancestor. Ex: cacti and euphorbs Parallel evolution - Answers similar phenotypes arise form similar developmental origins in different species. Ex: attachment organs in larval stages of blind cave fish Taxon (taxa) - Answers any group of species that we designate or name (like vertebrates) Clade - Answers a taxon that consists of all the descendants of a common ancestor Vertebrate clade - Answers having an embryo that develops within an amnion (an adaptation to laying eggs on land) includes reptiles, birds, and mammals General events leading to speciation - Answers populations become isolated physically, beahviorally, etc; populations diverging in 1+ traits (mating behavior, etc); reproductive isolation Why do rates of speciation vary? - Answers habitat specialization, diet specialization, changes in ploidy Ploidy - Answers an organism doubling their own chromosome number or being fertilized by another species and then doubling chromosome number 2 commonly recognized modes of speciation - Answers Allopatric and Sympatric Allopatric Speciation - Answers among populations with discontinuous distributions; dispersal, peripatric, and vicariance Allopatric dispersal - Answers new populations established in area and subjected to unique selective pressures Peripatric - Answers small isolated population drifts to become reproductively isolated Vicariance - Answers existing populations divided by physical barriers, ex: snapping shrimp in Panama Sympatric Speciation - Answers among populations with overlapping distributions; reproductive isolation must occur without geographic isolation Migration - Answers Physical movement from one area to another and back again; allows organisms to track resources and habitat quality; carries risks of predation and starvation; may be under genetic control (like Monarch butterflies) Dispersal - Answers The one-way movement of an individual from the natal area; results in gene flow if dispersers breed in new habitat; introduces mortality risk associated with movement Natal dispersal - Answers Moving away from where born prior to reproduction; may be independent of environmental conditions, thus minimizing the probability of inbreeding (ex: male belding's ground squirrels leaving after reaching a certain weight) Pre-saturation dispersal - Answers occurs before resources become sparse Saturation dispersal - Answers the dispersal to avoid the shortage of important resources such as food or nest sites Phylopatry - Answers the lack of dispersal; organisms mature in the habitat in which they were born Polyandry - Answers one female is mating with multiple males in her territory Polygyny - Answers one male is mating with multiple females in his territory Reproductive isolation - Answers caused by habitat fragmentation and sexual selection Polyploidy - Answers changes in chromosome number. between 30-70% of today's angiosperms are thought to be polyploid. polyploidy is especially extensive among fish, but known examples among amphibians and reptiles Types of Polyploidy - Answers Autopolyploidy and allopolyploidy Autopolyploidy - Answers genome duplication within a species (like coffee, potatoes, etc) Allopolyploidy - Answers genome duplication associated with hybridization (mating among different species). Ex: grey tree frog Biological Species - Answers A group of interbreeding organisms that produce fertile offspring and have an isolated gene pool (Ernst Mayr's Biological Species Concept)/groups of interbreeding populations that are evolutionary independent of other populations; the base unit of taxonomic classification consisting of an ancestor-dependent group of populations of evolutionary closely related similar organisms; the number of recognized species is constantly changing What it takes to recognize a new species - Answers a description of the new species (their features, behaviors, anatomy, and genetics) that makes it unique and new and distinguishable from close relative; a description of the origins of the species type and subtypes; how the species was collected and where? Subspecies - Answers A group of phenotypically similar populations of a species inhabiting a geographic subdivision of the range of that species but differing taxonomically from other populations of that species; not distinct enough to become reproductively isolated, but may be on that path and one to speciation; indicated by another scientific name added on as a trinomen