ecology notes

Chapter 6. evolutionary ecology. Process of evolution depends on genetic variation gene pool-collection of alleles from all individuals in a population. Alleles-different forms of alleles. Mutation-random change in the sequence of nucleotides in regions of DNA that either compromise a gene or control the expression of a gene. Recombination-the reshuffling of genes that can occur as DNA is copied during meiosis and chromosomes exchange genetic material. Random assortment -process of making haploid gametes in which given combination of alleles that are placed into given gamete could be any combination of those processed by the parent. Genetic drift-when genetic variation is lost because of random variation. Bottleneck affect-reduction to genetic diversity due to large reduction of the population. Founder affect-when a small number of individuals become isolated to colonize new areas bringing with them next to no genetic variation. Selection-process of favored phenotypes reproducing more often. Stabilizing selection-when individuals with regular phenotypes have a higher survival success than those with extreme phenotypes. Directional selection- one extreme phenotype is favored over those with more average phenotypes. Disruptive selection- when both sides of an extreme phenotype are favored over more average phenotypes causing species to split. Strength of selection-difference in the mean phenotypic distribution before and after a period measured in standard distribution. heritability-proportion of phenotypic variation caused by genetic variation. This is all microevolution that occurs at the population level. Industrial melanism-industrial activities causes a environment to become darker causing a population to become different colors. Macroevolution-species or higher levels of organization. Phylogenetic tree-hypothesized patterns of relatedness among different groups. Allopatric speciation-long time caused by geographic isolation. Sympatric speciation-caused rapidly by random variation. Polyploid-species that contains 3+ sets of chromosones.

Chapter 7. Life History. Life History is the schedule of an organism’s growth. Fecundity-number of offspring per reproductive cycle. Parity-number of reproductive episodes that a organism experiences. Parental investment-time and energy given to a offspring by parents. Size of offspring greatly affects dispersal seeds get bigger with dispersal mechanisms. principle of allocation- when energy is diverted to one body structure they can’t be used elsewhere. There are tradeoffs between growth and age at sexual maturity. Determinate growth-a growth pattern in which a individual does not grow anymore once reproduction is initiated. Indeterminate growth-continues to grow after sexual maturity. All organisms become senescent. Semelparous-only reproduce once. Iteroparity-reproduce multiple times. Annual-one year life span. Perineal-more the one year. Photoperiod-amount of light each day.  

Chapter 8. reproductive strategies. Can be sexual or asexual. Sexual-inherit dna from both parents. Asexual-get dna from a single parent. Vegetative=asexual reproduction from body tissues. Clones-produced asexually with the same genotype. Binary fission reproduction by duplication of genes followed by cell division ending with 2 identical cells. Parthenogenesis-asexual reproduction embryo produced without fertilization. Cost of meiosis-50 percent reduction in parent genes passed to next generation. Benefits of sexual reproduction-removal of bad mutations, increasing diversity, helps with environmental variation. Red queen hypothesis-sexual reproduction allows host to evolve at a rate that can outpace evolution of parasites. Perfect flowers-contains male and female parts. Simultaneous hermaphrodites-individuals that possess male and female reproductive functions. Sequential hermaphrodites-can switch between male and female functions. Monoecious plants that have separate male and female flowers on the same individual. Dioecious-either male or female parts on single individual. Genetic sex determination-sex is determined by inheritance of specific chromosomes. Environmental sex determination-sex being determined by the environment. Frequency dependent selection-rare phenotype becomes favored by environment. Local mate competition-when competition occurs in a small area and only few males are needed to fertilize all females. Mating system-number of mates and the permanence of said mates. Promiscuity-animal hookups no bond males and females have as many partners as desired. Polygamy-single individual makes multiple long term social bond with members of opposite sex. Polygyny-male has many females. Polyandry-female has many males. monogamy-one male one female through period required to rear offspring. Extra pair copulations-cheating social bond with a mate yet also mates with other individuals. Mate guarding-one mate prevents other partner from extra relations. Sexual dimorphism-ability to tell male from female. Primary sexual characteristics-traits directly related to fertilization. Secondary sexual characteristics-directly related to differences between male and female such as body shape. Good genes hypothesis-theory that an individual chooses a mate that possesses a superior genotype. Good health hypothesis-chooses healthiest mate runaway sexual selection-selection for preferences of a sexual trait and selection will continue to reinforce it. Handicap principle-greater the handicap the greater its ability to offset that handicap.  

Chapter 9. social behaviors-interactions with one’s own species. Dilution effect-reduced probability of predation when in a group. Lek-location of an aggregation of animals that is used to put on a display to attract mates. Bigger groups can result in larger rates of parasites and diseases as well as more internal competition. Larger territories provide more mates. Dominance hierarchy-social ranking within a group determined through fighting or other contest. 4 types of interactions between donors and recipients. Cooperation-both increase fitness. Altruism-increase in recipient decrease in donor. Selfishness-increase donor, decrease recipient. Spitefulness-decrease both. Direct fitness-fitness an individual gains by passing on genes. Indirect fitness-fitness gained by helping relatives pass on genes. Inclusive fitness-sum of direct and indirect fitness. Direct selection favors direct fitness. Indirect selection-favors indirect fitness known as kin selection. Coefficient of relatedness-probability of an individual carrying genes from a shared ancestor. Calculating direct fitness-BxR is greater than C c=direct fitness benefit. B=relative benefit to recipient r=recipient coefficient of relatedness. Caste-social group with specialized behavior. Haplodiploid-sex determination system one sex is haploid one is diploid. Queen-dominate egg laying female in eusocial societies.  

Chapter 10. population distributions. Limited to the suitability of habitats. Spatial structure- pattern of density and spacing of individuals within a population. Fundamental niche-range of abiotic conditions under which a species can persist. Realized niche-range of abiotic and biotic conditions under which a species persist. Geographic range-total area covered by population. Ecological niche modeling-process of determining suitable habitat conditions for a species. Ecological envelope-range of conditions that are PREDICTED to be suitable for a species. Characteristics:1 range. 2 abundance. 3 density. 4 dispersion. 5 dispersal. Endemic species-only occur in certain locations. Cosmopolitan-very large ranges typically across multiple continents. Dispersion-how individuals are spread within a population. Clustered dispersion-individuals are congregated into high density groups. Dispersal-movement of individuals. Census-counting every induvial in a population. Line transact surveys-surveys that count individuals observed moving across a line. Mark recapture survey-capturing induvial marking then releasing them recapturing later and finding ratio of marked to unmarked. Lifetime dispersal distance-average distance between birth and death. Larger the organism less abundance more range. Dispersal limitation-absence of a population due to barriers. Habitat corridors-strip of  favorable habitat between 2 large favorable habitats that facilitate movement. Ideal distribution-all individuals are  spaced with equal benefit