BIS 2B Midterm 2 studying

Aristotle Scala Naturae

350 BCE god, angles, demons, heavens, heavens, humans, animals, plants, minerals (static species)

Zhuang Zhou

369-286 BCE all life comes from one species and depending on location becomes different things. Species change over time even into other species.

Ibn Khaldun's Muqaddimah

1377 mans relationship to the world “descent though mo“

Linneas System *names*

famous for taxonomy he loved categorizing things … problematic

Alexander Von Humbolt

“scientific geography “ Biomes fundamental and realized niche very anti slavery

George Cuvier

catastrophism famous for craneomety (measuring skulls) bad

Charles Lyell

Gradualism , in geology but not in biology [grand canyon] . he thought species didnt change

jean baptiste lamark

believed organisms passed on traits acquired through use/ disuse (giraffe neck thing)

John edmonstone Darwins mentor

really really good at takidermy cause he learned in a really humid environment taught at uni of edinburgh

Darwin

pigeons - selective breeding on the origin of species “decent though modefication“

Wallace

same ideas as darwin but no credit ☹

catastrophism

earth and life on it and are primarly shaped by major , sudden events

gradualism

earth and life on it are shaped by long slow processes

by mid 1800’s

gradual change is important in earths history , earth is old , extinction occurs

evolution

genetic change over time

adaptation

type of evolution that occurs though natural selection

micro evolution

small across generation

macro evolution

accumulation of micro evolution changes that a new group arises large scale across species change

necessary conditions for natural selection

variation

heritability (0-1)

differential success - fitness

Phenotype

is the traits it
exhibits (its physical appearance)

Genotype

Genotype is the genetic makeup of an organism

relative fitness

absolute fitness / pop mean fitness

sexual selection

Alturism

a behavior that reduces individual fitness and increases the fitness of other individuals

kin selection

selection that favors the increase the success of relatives

Negative Frequency dependent selection

the rarer phenotype have highest fitness , phenotypes ocelots

Deleterious

decrease fitness

Breeders equation

R=h²S

R is how much the phenotype shifts after selection

H is the heritability

S is the strength of selection in one generation . Og mean - new mean

Patterns of natural selection

Directional

Stabilizing

Diversifying / disruptive

Transcription

DNA → RNA

RNA polymerase

Translation

RNA → Proteins

Ribosome

DNA base pairs

C-G

T-A

In RNA the T is swapped for U

Codon

3 base pairs

Types of mutations

Substitution

Insertion

Deletion

Silent / synonymous

Law of segregation

I’m production of gametes , the two copies of a gene separate so that each gamete contains 1 copy

Law of independent assortment

Alleles of different genes sort independently of one another during gamete formation

Recombination

When meiosis happens the chromosomes Wind and switch genetic material

Considering multiple genes & probability

P(Y&R) = P(Y) * P(R)

& means multiply or means add so two expressions and add

Single / complete dominance

A single dominant allele produces the dominant phenotype. Rr same as RR in phenotype ❤

Incomplete dominance

The heterozygote phenotype is an intermediate between the homogeneous phenotypes Rr 🩷

Codominant

The heterozygote phenotype is both homogeneous phenotypes expressed fully ❤&🤍

Linkage

Genes on the same chromosome and are close together are more likely to get inheriated together

Pleiotrophy

When one gene affects multiple characteristics

Polygenic inheritance

One trait is additivley controlled by many genes (darker shards of something)

❤🧡💛

Epistasis

When multiple genes interact to determine phenotype 🐶🐕‍🦺🐶🦮

Hardy -Weinberg equilibrium

No mutations

No natural selection

No gene flow

No genetic drift

YES random mating

H-W pq shit

Frequency :

P. A1

q. A2.

Frequency of getting a A1A1 = p²

Frequency of getting a A1A2 = 2pq

Frequency of getting A2A2 = q²

Frequency of one allele

F(A) = F(AA) + ½ F(Aa)

Genetic drift

Chance events that cause allele frequencies to fluctuate unpredictably from one generation to the next. “Marbles”

Smaller pop size = stronger drift

If there is no random mating

Inbreeding 🩷x🩷

Outbreeding 🩷x💜

this reduces heterogeneity until I’m extreme cases there are no hetero left

*so much fewer Aa than we EXPECT in HW — compare to itself not others

This is why deleterious traits show up more think royal 🫅 👸 family

Reproductive barriers

Pre zygotic barriers:

Habitat isolation

Temporal isolation (time)

Behavioral 🔥🪰

Mechanical isolation

Gamete isolation

Post zygote barriers : (prevent zygote from being viable)

Reduced hybrid viability - non complete development

Reduced hybrid fertility - hybrid offspring are viable but can’t reproduce themselves

Hybrid breakdown → viable → viable → infertile

Secondary Contact

reinforcement

fusion

Stability

descent with modification

this is what causes homologous traits. the organisms are very similar because they all descended from one common ancestor

Convergent Evolution

this is what causes Analogous traits which are similar in different organisms because of similar SELECTIVE PRESSURES