evolution and the origin of life

physio psych

Darwin

naturalist —> evolution by natural selection

Darwin’s finches

• similar to species of finch in Ecuador —> theorized some event caused some to be brought to the Galapagos

• no predators and lots of food —> inc pop

self-categorization (finches)

diff groups of finches formed d/t beak differences that helped them excel in getting varying food sources —> ecological niches

favorable variation

• trait that inc odds of survival in a given env

• a favorable variation at one point in time may not remain favorable if env changes

• e.g., big beak that can crack nuts that other finches cannot eat

injurious variation

• trait that does not inc odds of survival and reproduction in a given env

• an injurious variation at one point in time may not remain injurious if env changes

• e.g., born w/o beak —> will die b/c cannot eat —> cannot survive long enough to reproduce

Chicxulub crater

• dinos survived for so long d/t ability to feed off diff plant sources (favorable trait)

• crater caused a huge change in env that killed plants —> dinos could no longer survive despite previously favorable trait —> now injurious trait

convergent evolution

• 2 somewhat related animals evolve to have similar traits OT even if not in same env

• e.g., birds in diff parts of world dev similar beaks b/c of similar food sources

• e.g., octopus and human can both solve puzzles despite our last shared ancestor (worm) which could not solve puzzles —> convergent intelligence evolution

artificial selection

humans decide “good”/”favorable” traits instead of nature

larger vs. smaller animal mutation errors

larger animals have more proofreading mechanisms b/c they have more DNA vs. smaller animals —> more prone to error —> cancer

types of DNA mutations

substitution, deletion, insertion, inversion

UV dmg to DNA

UV can cause DNA breaks that lead to improper adjacent pairings (e.g., thymine dimers)

goal-direction evolution

• humans are not the pinnacle of evolution

• however, we evolve OT from a shared ancestor as there is a need to work twds a certain goal

memetic evolution

• abstract knowledge can evolve OT

• humans survive b/c we have ideas and spread them

• we have invented things in our non-natural world to allow us to survive

• similar to behavioral regulation —> we mentally evolve all the time

how do planets form?

gravity attracts things tg —> causes rndm clumps —> they spin —> atoms fuse —> release lots of E (e.g., stars) —> OT planets form

cooling of magma oceans

• magma settles into diff rocks w/ diff densities

• volcanoes will bring heavier rocks to surface —> sink back down —> Earth fills "craters” w/ water (which likely came from ice comets)

prebiotically plausible molecules

• lots of C, H, N

• catalyze themselves into RNA under the right conditions —> can self-replicate (better survival odds) —> “when life starts”

what type of aa must be obtained from diet

9 “essential” aa

Miller and Urey exp

• tried to understand abiogenesis

• took organic cmpds and found they eventually produced aas

cell membrane

• seals cells off from external env to prevent DNA/RNA from being exposed to things that would make them inert and thus prevent replication/survival

• can form bilayers, liposomes, micelles