Unit 3: Natural Selection Flashcards
why is pandorina multicellular?
it swims with certain cells at the front (cell specialization)
2 aspects of multicellular organism
- cell specialization
- cells can’t live seperately
3 factors of evolution, how they apply to viruses
- variability, among virus particles
- heritable, have genes
- fitness, certain gene means more likely to attach to bacteriophage
can species without a favorable gene still have better evolutionary fitness?
yes, if they produce more offspring
3-spined stickleback male
male parental care, more typical of external fertalization
bee-eaters
male helps siblings
probability of helping correlated with relatedness to chicks
genetic mutation
random change in genes between generations
ultimate source of new genes
does natural selection require mutations?
not in the short run, does in the long run
artificial selection
natural selection where humans do the selecting
heritability depends on…
variation in environment
leaf cutter acts
mutualistic relationship with fungus
ant only eats fungus, fungus only found in ants nest/spread by ants
workers (females) give up reproduction to look after siblings
sexual selection
natural selection on traits that increase quantity or quality of mates
factors consider for male sexual selection traits
want more mates
1. competition w/ other males
2. attract more females
factors considered for female sexual selection traits
want better mates
1. better resources (mate provides)
2. better genes
genetic drift
change in genetic makeup of population caused by random chance
only in small populations, leads to loss of genetic diversity
