This document provides a humorous summary of key concepts from Chapters 22-23 of a biology textbook. It uses colorful language and crude humor to discuss topics like evolution, natural selection, genetic drift, and genetic variation over multiple generations. The summary touches on major figures like Darwin and Lamarck and their contributions to the theory of evolution through concepts such as adaptation, artificial selection, homologous structures, and convergent evolution.

1. Chapters 22-23 Study Guide
SO MUCH FUN ALREADY WOO LIKE
LOOK AT THIS COLOR CHOICE IT
SCREAMS HAPPY YAYOMG

2. Terms n’ Shit
I had to google
feces clip art to
find this
• Evolution (you better fucking know this or else
you’ll die): descent with modification
• Aristotle 384-322BC (was obvi a dumb mother):
viewed species as fixed…aka unchanging…
– Developed scala naturae (foreigny) which arranged
organisms on a scale of increasing complexity
• Carolus Linnaeus 1707-1778 (dat sexii ass name
got him many a biatch): sought to classify life’s
diversity  developed 2-part naming system
that’s still used today (that BAMF! Sexy and
smart..)
– Differed from scala naturae bc it grouped similar
species into increasingly general categories

3. This
one’s
called
“turd”
by
More Clipart Feces
OCAL
• Strata: superimposed layers of rock (n roll)
• Fossils: dinosaurs lol
• Paleontology: study of fossils…largely developed by Georges Cuvier
(olala tres francais)
– Cuvier noticed that the older the stratum, more dissimilar its fossils were to current life-forms; also
noticed new species appeared while some species disappeared 
– Yet Cuvier OPPOSED EVOLUTION (betchur regretting dat one now, eh buddy?)…advocated
catastrophism (principle that events in the past occurred suddenly and were caused by mechanisms
different from those operating in the present…..nice try, bro.)
– Speculated that each boundary b/w strata = catastrophe (ie. Flood)
• James Hutton (1726-1797): proposed that Earth's geologic features
could be explained by gradual mechanisms still working (take that
Cuvier!!)
• Charles Lyell…(rhymes with Niall)…(1797-1875): incorporated
Hutton’s thinking into his principle of uniformitarianism
(mechanisms of change = constant over time)
HUTTON+LYELL=BROMANCE JK I MEAN INFLUENCED DARWIN’S THINKING

4. SO Much Shit At This Point In Thyme
• Jean-Baptiste de Lamarck (1744-1829): Darn maybe
next
time, motherfuq
proposed mechanism for how life changes er
over time…but he was wrong lol.
- Came up with principles of use and
disuse, the idea that parts of the
body that are used extensively
become larger and stronger while
those that are not used deteriorate

5. Cocks*cker Mother F*cker I just got my
puryud stir my coffee with your din-a-ling why don’tya bring on the acne and
mood swings I’m ready biatch
• Charles Darwin (the big kahuna of 1809-1882):
– Adaptations: characteristics of organisms that
enhance their survival/reproduction (sexy sex) in
specific environments
– “Could a new species arise
from an ancestral form by the
gradual accumulation of adaptations
to a different environment?”
• Natural Selection: process in which
individuals w. certain inherited trairs leave
more offspring than individuals w. other traits

6. I Think I Reached My Post-Limit…How
Will I Prevail?
• Artificial Selection (can suck my d(candle
st)ick): selecting and breeding individuals that
possess desired traits Inference #1:
Individuals whose
Observation #1: harry is naked as fuq. Just the inherited traits
way I like him. I mean, wot? Members of a give them higher
population often vary greatly in their traits probability of
Observation #2: Traits are inherited surviving and
from parents to offspring Inference #2: unequal reproducing in
ability given environment
Observation #3: All species are capable of producing survive/reproduce
more offspring than environment can support leads to accumulation
tend leave more
favorable traits in offspring than
Observation #4: Owing to lack of food/resources population over other individuals
many of these offspring do not survive generations

7. How am I still on Chapter 22,
Hazza is not plzd
* We’re gonna basically
skip the rest of this shit
because fuck you that’s why
• Homology: similarity resulting from common ancestry
(think HOMO)
• Homologous Structures:
represent variations on
structural theme that was
present in common
ancestor
• Vestigial Structures: remnants structures that served
important functions in organism’s ancestors

8. • Convergent Evolution: ind. (YES I WILL
ABBRIEVIATE WHATEVER I FKIN WNT)
evolution of sim. Features in diff. lineages
– Share features bc of convergent evolution? You
aren’t homo, that’s analogous!!!!! **sad face**
• Biogeography: geographic distribution of
species
• Endemic: found nowhere else in worls

9. CHAPTER 23, MOTHER FUCKERS
• Discrete characters: classified on either-or basis
– My way or the highway, bitch
– Jk LLN :D (no I’m not)
• Quantitative characters:
vary along a continuum in
a population
Average heterozygosity: average percent of loci that
are hetero(sexual)zygous

10. Brief Fucking Interlude…
• The song I’m listening to just wished
constipation upon me…RUDE
OH SHIT (pun)
IT’S
FLOWING, BO
OK IT

11. I really don’t
I really don’t
I really don’t
• Geographic variation: diff. in genetic comp of separate
pops
• Mutation: ultimate source new alleles
Shame 
• THIS IS STARTING TO BE A PIECE O’ DEUCE
• Population: group individuals of same
species that live in same area, interbreed and produce
fertile offspring (SEEEEEEEX)
• Gene Pool: all alleles for all the loci in all individuals of
population

12. Zayn wipe that
MORE?! fucking grin off
your face or it’s
gonna get physical
• Hardy-Weinberg principle: states that frequencies
alleles/genotypes in pop. Will remain constant
generation to generation
– Equilibrium
1. No mutations
2. Random mating
3. No natural selection
4. Extremely large population size
5. No gene flow

13. Anddddd more…
• This shit ain’t funny no more, Campbell Bio Book. Just
think, Sam…Shia’s day is worse. He just discovered he’s
a cannibal :/ awk.
• Genetic Drift: chance events that
cause allele frequencies to fluctuate
unpredictably
- Founder Effect: individuals
isolated from larger population – establish new
pop. Whose gene pool differs from source pop.
- Bottleneck Effect: sudden change in environment
may drasticaly reduce pop. Size – by chance,
certain alleles over/underrepresentated or missing

14. No explanation necessary
just keeping tidy
• Effects of Genetic Drift:
– Significant in small pops
– Can cause allele frequencies change at random
– Lead to loss genetic variation w.in pops
– Can cause harmful alleles become fixed
• Gene Flow: transfer alleles into/out of population
• DIRECTIONal Selection: conditions favor one
extreme of a phenotypic range, thereby shifting
frequency curve for phenotypic character in ONE
DIRECTION or the other

15. • Disruptive selection: conditions favor
individuals at both extremes over
intermediate phenotypes
• Stabilizing Selection: favors intermediate
variants
• (my) Sexual Selection (is 1D): individuals w.
certain inherited characteristics more likely to
obtain mates

16. ALMOST DONE, FUQERS IN MY HEAD
• Sexual dimorphism: difference b/w 2 sexes in
sexual characteristics which aren’t directly
associated with reproduction/survival (SEXXX)
• Intrasexual selection: within same
sex, compete for mates of opposite sex (think:
fangirls)
• Intersexual selection: individuals of one sex
(usually female) are choosy in selecting mates
(think: NOT ME)

17. • Balancing selection: natural selection maintains
2+ forms in population
• Frequency-dependent selection: fitness
phenotype declines if too common in population
• Neutral Variation: noncoding sequences that
appear to have no selective
advantage/disadvantage
• Why Natural Selection Cannot Fashion Perfect
Organisms (LOL is this a joke? ….1D…): selection
can only act on existing variations, limited by
historical restraints, adaptations =
compromises, chance+natural
selection+environment interact

18. FUCK BITCHES GET MONEY I’M DONE