front 1 eukaryotes reproduce | back 1 sexually |
front 2 hermaphrodite is | back 2 individual that produces both female and male gametes |
front 3 banana slugs | back 3 hermaphrodites and can receive sperm from other slugs, deliver sperm to them, or fertilized their own eggs |
front 4 parthenogenesis is a mode of | back 4 reproduction in which the female sex cells undergo meiosis but are not fertilized by sperm |
front 5 in parthenogenetic species females produce | back 5 only daughters |
front 6 strawberries reproduce ___ and breadmold reproduce ___ | back 6 asexually, sexually/asexually |
front 7 sex does not always genrate | back 7 more variable offspring |
front 8 asexual linegaes multiply | back 8 faster than sexual lineages because all progeny produce offspring (sexual lineage, half males that cannot produce by themselves, halving rate of replication) |
front 9 disadvantages of sex: twofold cost of sex | back 9 asexual lineages grow more rapidly each generation, sexual cannot |
front 10 disadvantages of sex: search cost | back 10 males and females must locate each other in order to mate, takes time, energy, and risk of predation |
front 11 disadvantages of sex: reduced relatedness | back 11 sexually reproducing organisms pass half of alleles to offspring from meiosis, halves the relatedness between parents and progeny |
front 12 disadvantages of sex: risk of sexually transmitted infections | back 12 mating provides effective means of transmission for many pathogens, asexual avoid this risk |
front 13 advantages of sex: combining beneficial mutations | back 13 combining alleles of genes can bring separate beneficial mutations together in a single individual faster than would be expected if they had to arise spontaneously in the same genome |
front 14 advantages of sex: generation of novel genotypes | back 14 thru recombination, meiosis provide chromosomes to cross over, creating gametes with unique combinations of alleles |
front 15 advantages of sex: faster evolution | back 15 offspring of sexual parents are more genetically variable than asexual. speed evolutionary response to selection (red queen effect) |
front 16 advantages of sex: clearance of deleterious mutations | back 16 sexual populations can purge themselves of harmful mutations, exclude deleterious mutations. asexual cannot, they steadily accumulate mutations until extinct (Muller's ratchet) |
front 17 muller's ratchet | back 17 genomes of asexual population accumulate irreversible, deleterious mutations over generations |
front 18 genetic load | back 18 the burden of accumulated deleterious mutations increases over time |
front 19 yeast can reproduce | back 19 either asexually or sexually |
front 20 McDonald found that deleterious alleles "hitchhike" to | back 20 fixation in asexual populations but are purged from sexual populations due to recombination |
front 21 the red queen effect makes | back 21 sex beneficial |
front 22 red queen effect | back 22 to maintain relative fitness, coevolving populations must constantly adapt to each other. |
front 23 sex evolves when selection changes over time | back 23 more readily when a species' environment changes rapidly |
front 24 sex evolves when selection changes over space | back 24 can be favored when selection varies over space, as long as the genetic associations created by migration are locally disadvantageous. |
front 25 sex evolves when organism are less adapted to their environment | back 25 organism both sexually and asexually tend to switch to sex under stressful conditions |
front 26 sex evolves when populations are finite | back 26 with limited number of individuals in population, selection erodes and leaves only hidden variation. recombination then reveals hidden variation, improving response to selection |
front 27 in the absence of sex, the only variation that remains after several rounds of selection is | back 27 hidden in the sense that plus alleles at the first site are found with minus alleles at the second site (or vice versa) (this problem is irrelevant in an infinitely large population) |
front 28 anisogamy results in | back 28 differential investment in reproduction |
front 29 anisogamy | back 29 sexual reproduction involving the fusion of two dissimilar gametes |
front 30 limitations on reproductive success | back 30 differ for the sexes |
front 31 females are limited by | back 31 fecundity (number of eggs produced) |
front 32 males are limited by the | back 32 number of mates they can obtain |
front 33 investment differences can | back 33 extend past fertilization |
front 34 uncertain paternity may explain why | back 34 male parental care is less common |
front 35 certainty of paternity | back 35 the probability that a male is the genetic sire of the offspring his mate produces |
front 36 females have | back 36 certain maternity |
front 37 asymmetrical parental care | back 37 alters operational sex ratio |
front 38 fisher's principle | back 38 a 1:1 sex ration is an evolutionarily stable strategy |
front 39 slower rat eof reprodction by females leads to male-biased operational sex ratio (OSR): | back 39 ration of males to females capable of reproducing at a given time |
front 40 intrasexual selection | back 40 competition between members of the same sex (usually males) for access to mates |
front 41 intersexual selection | back 41 members of one sex (usually females) choose members of the opposite sex |
front 42 sexual selection | back 42 differential reproductive success resulting from competition for mates (intrasexual and intersexual selection) |
front 43 sexual selection is commonly a stronger effect for | back 43 males (male biased OSR leads to males outcompete other males for access to females) |
front 44 ornaments | back 44 attractive traits that incerase mating success |
front 45 arnaments | back 45 weaponry used to outcompete other individuals |
front 46 high variance in male reprodutive success leads to | back 46 intense sexual selection |
front 47 some males compete for | back 47 territory |
front 48 direct benefits | back 48 benefit the female directly |
front 49 indirect benefits | back 49 benefits that affect the genetic quality of the female offspring |
front 50 voluntary self sacrifice in redback spiders | back 50 male redback spiders will sacrifice their lives to copulate longer with female (higher chance in passing their genes and break the female's reproductive system) |
front 51 some males display | back 51 elaborate ornaments |
front 52 honest sexual signaling | back 52 level of advertisement reveals mate quality |
front 53 zahavi's handicap principle proposes | back 53 females prefer males with handicaps (mating characters that reduce survival chances) because they are indicators of heritable viability |
front 54 male mannikins peform in a lek | back 54 an assemblage of rival males who cluster together to perform courtship displays in close proximity |
front 55 female preferences may arise from | back 55 pre existing sensory bias |
front 56 arbitrary choice (fisher's positive feedback cycle) | back 56 certain male traits are advantageous not because they indicate good quality, but but simply because they are attractive to females. |
front 57 good genes | back 57 elaborate or bright male ornaments signal underlying good quality (good genes) |
front 58 fisher- good genes process (combination) | back 58 alleles for female preferences can coevolve with alleles influencing expression of costly indicator traits in mates |
front 59 costly ornaments can be | back 59 honest signals of better health |
front 60 monogamy | back 60 one male pairs with one female (sexual: exclusively, social: pair but may cheat) |
front 61 polygyny | back 61 males mate with multiple females |
front 62 polyandry | back 62 females mate with multiple males |
front 63 pair-bonding species are not neccesarily | back 63 sexual monogamous |
front 64 polyandry selects | back 64 for male traits that increase paternity rates |
front 65 sperm competition | back 65 occurs when females mate multiply and ejaculates from different males overlap and compete for fertilization |
front 66 sperm competition drives evolution of | back 66 larger testes in primates (males testes are larger in species where females regularly mate with multiple males) |
front 67 cryptic female choice | back 67 a form of sexual selection that arises after mating, when female store and separate sperm from different males and thus determine which sperm they use to fertilize their eggs |
front 68 sexual conflict | back 68 traits that confer a fitness benefit to one sex but a cost to the other (traits cevevolve antagonistically) |
front 69 coevolution of male and female genitalia in waterflow has been hypothesized to occur | back 69 through sexual conflict |
front 70 eviednce for antagonistic coevolution in Drosophila | back 70 Drosophila were experimentally forced to mate monogamously, had lost their defenses against seminal proteins, so females died at much higher rate when mated with normal males |