BSCI 160 Shapiro Spring 2022

Deserts are common at -30 deg latitude north and south

Hadley cells moves air typically bring hot dry air to this region

earth's latitudinal temp gradient is due to

tilt of the earth relative to is axis of rotation,

add a billion people to the planet most recently took x years

10 years

pop with logistic growth model, N>K

R is going to be negative

n=K

r=0

n

r=positive

if doubling time is getting shorter than

r is increasing, because per capita growth rate is increasing

west side of mountains is dry due to rain shadow, where are prevailing winds blowing?

from east to west, air cools and drop moisture before crossing peaks

if age structure is a triangle

pop will increase

if fertility rate drops to 2 per female but large number of females in population will start reproducing when they reach sexual maturity

population momentum will sustain growth

max # of individuals sustained in a habitat

carrying capacity

earth is home to how many people

7.9 billion people

if r decreases but population increases

density dependent

Coriolis effect

westward deflection of air currents as they move towards the equator

Coriolis effect is due to earth's

shape and rotation speed

spring and fall equinox day length is

12 hours at all latitudes, angle is like parallel to sun

pop size 200, 50 born, 40 die, per capita death rate (d) =?

40/200 = 0.2

pop size 200, 50 born, 40 die per capita pop growth rate (r) =?

r=b-d or 50/200=b, 0.5 =r

if r = 0 "stable over time" "constant"

b = d

demographic transition

decrease in b and d due to industrialization, decrease in d first

antibiotic resistance

mutation is random, chance, only survivors are resistant and they reproduce

Darwin + Wallace

species related by shared ancestry, split and diverge, decent w/ modification

d x n=

D = total death in pop

r x n

number of people added to original n

temp and percipitation

summer months are in the middle of x axis, growing season (temp > 0, precipitation > temperature)

ideal population growth

exponential

Susceptible-Infected-Resistant (S-I-R) model

disease spreads in pop: sus # declines, infected # increases, resistant # increases

R0 (basic reproductive rate) of disease drops to 1

# infested indivi in pop not growing

in ant-plant mutualism

plant feeds ant, ants protects plants from herb insects, ants protect plants from plant

# species of in an area (Y) vs area (x)

logarithmic

if # species of in an area (Y) vs area (x) log transformed

linear positive graph

half of the earth's primary production from

tropical forests and ocean

species diversity

evenness (distribution) and species richness (diversity)

keystone

bigger impact than biomass and abundance suggests

trophic cascade

Eco phenomenon triggered by add or sub of top predators

eggs in host and eat host alive with only one host

parasitoid

interaction that benefits both

mutualism

defensive response

thicker shells living with predators

if species evolve to have less similar niches (increase niche differentiation) on competition

less intense interspecific, intraspecific (same species) more intense

if species evolve to have less similar niches (increase niche differentiation) on coexistence

increase likelihood of long-term coexistence (intra comp > inter comp)

mechanisms for competition:

Exploitation: depletion of resources

Interference: decreasing someone else's ability to use a resource

fundamental niche

all the possibilities of where an organism can occupy

realized niche

where do they actually land in their niche (competition)

parasitism

one organism hurts another to benefit itself (living off of it)

predation

One eats the other

deleterious allele more likely to become fixed if

population is very small (genetic drift) or tightly linked to a highly beneficial allele

mieosis vs mitosis

homologous chromosomes pair up in tetrads during meiosis but not mitosis

complete dominance

Aa same phenotype as AA

imcomplete dominance

can result in offspring with phenotypes that are intermediate relative to their parents

antagonistic pleiotropy hypotheses of aging

old ladies might get cancer BUT they have higher fertility when young

late in life has ___ selection

weaker (natural selection thinks about survival and reduction)

paraphyletic groups

almost all (double snip)

clade (monophyletic group)

snip test

pop has 50 AA, 20 Aa, 30 aa f(A) f(a)

(2(AA)+1(Aa)/tot) = .6 and (2(aa)+1(Aa) / tot)= .4 (check p + q = 1.0

pop has 50 AA, 20 Aa, 30 aa geno freq HWE

P^2+2pq+q^2 = 1) if observed match expected then yes

pop has 50 AA, 20 Aa, 30 aa f(AA) f(Aa) f(aa)

50/100=0.5f(AA)

20/100 = 0/2 f(Aa)

30/100 = 0.3f(aa)

(check: P^2+2pq+q^2 = 1)

pop has 50 AA, 20 Aa, 30 aa why/why not HEW

observed doesn't match expected frequency

recessive allele causes disease with frequency 1/25, at HWE, expected frequency of carriers

.32 or 32%

D= no disease f(D) = p, d = disease f(d) = q, f(dd) = (1/24) ^1/2, 1-q=p

phylogeny diagram that represents relationships no info on time or amount of change

cladeogram

alternate forms of a gene (normal vs disease causing)

alleles

phenomenon of one gene having an effect on multiple traits

pleiotropy

if the phenotypic effect of the genotype at one locus depends on the genotype at another locus

epistasis

polygenic

multiple genes affecting one trait

four mechanisms of evolutionary change

natural selection, gene flow/migration, mutating, genetic drift

natural selection

alleles that improve sexual reproduction and survival increase in frequency

gene flow/migration

alleles transfer from one pop to another

mutating

random changes in gene create new alleles

genetic drift

random changes in allele frequency

Heterozygous

Aa or A1A2

homozygous

AA aa A1A1 A2A2

parsimony

least changes

mitosis and meiosis

1) diploid cell

2) Mit (one long line) Mei (all next to each other tetrad)

3) Mit: one copy of each and they are identical Mei: 2 identical cells split and become haploid with 1/2 info

loci on same chromosome

how the parents alleles are aligned tells about gametes

sex traits in bird on Z allele

male: ZtZT

Femal: ZTW

all males T, femals 50/50

biological species concept

potential to interbreed under natural conditions and produce viable, fertile offspring

Sexual reproduction predominates because

deleterious mutations are more easily purged (removed) from sexually reproducing populations

Mutational meltdown

s the accumulation of harmful mutations in a small population, which leads to loss of fitness and decline of the population size, which may lead to further accumulation of deleterious mutations due to fixation by genetic drift.

associative learning

acquired ability to associate an environmental feature with another (i don't eat pasta)

Imprinting

rapid irreversible learning during a critical period

alopatric speciation

speciation because a population diverges due to a physical barrier

shifting baseline

normal for each generation keeps moving up or down

sexual selection

natural selection for access to mates

inclusive fitness

combo of direct and indirect fitness that increases genetic representation in future gens

externalities

costs that affect a party who did not choose to incur those costs

what is a pre-zygotic reproductive barrier

prevents formation of a zygote, sperm wont fertilize egg (also post-mating)

pre mating reproductive barrier

prevents mating from happening

Mechanical Reproductive barriers

sex organs don't match up in a population

temporal Reproductive barriers

different times when they mate

behavioral Reproductive barriers

different mating calls and dances

why do males typically have sexually selected characters

sperm are cheap eggs are expensive, females are more picky, males fight for mates, males show they have good genes or attractive

when would sexual selection in females be stronger than males

mating is more costly to males, males invest more in offspring (seahorses)

tradgedy of the commons

individual behave in self interest and degrade the population and community and environment

addressing tragedy of the commons

create public policies that incentivize acting for the collective

disruptive selection

favoring both extremes and avoiding the middle, gametes produce at different loci create alleles that are new phenotypes, and mutations

directional selection

favors one extreme trait (IE super long beak)

when meiosis produces gametes

it creates and new combos of alleles

Michael Carmichael

University of Maryland's first Stormwater Management and Maintenance Inspector