1 14 Notes 20 04 2014 12 26 00 SCIENTIFIC THEORY SHOWN ABOVE belief doesn t require a test for it to be true must be able to do an experiment to use the scientific method needs to be tested many times to be a theory ex Lo Kal lunches prove to reduce weight prove it by must have a control group have to control behavior lifestyle genetics if something CAN be life threatening you let everyone do it rather than deny someone HUMAN EXPERIMENT ISSUES hard to control because individuals vary so much can study identical twins but they are STILL different in life style could cloning provide identical controls use stats to evaluate survey results but still have placebo effects people in distressed situations get sicker than they should because their emotions are messed up placebo effect can be seen when people s emotions effect health so you think you are sick when you aren t ETHICS need humans to give informed consent Cells cell theory 1 all living organisms have cells unicellular or multi cellular 2 cell basic unit of life 3 cells arise from pre existing cells divide to create new cells cells have a plasma membrane to separate inside and out DNA contains genetics for growth reproduction ribosomes synthesize proteins prokaryotic cells bacteria no membrane internalized bacterium became mitochondria but they still have DNA that s isolated sequenced used for energy in the cell eukaryotic cells animals plants and has a DEFINED nucleus and a nuclear membrane cell membranes impermeable barrier lipid bilayer phospholipids form two layers and create an have a hydrophilic and hydrophobic side if you take chemicals it has to go through the barrier and go inside of your cells it does this through a pore membranes have pores different proteins and medicine reacts with those proteins to get through the pore and into the cell Measurements 1m 1cm 1mm 1um micrometer x 10 7 small cells have large surface area to volume ratio things are small b c the S V ratio surface area to volume ex 1 cube 6 2 cube 3 4 cube 1 5 bigger it gets the lower the s v ratio so things stay small to have a high ratio Cell type stem cells can change into different cell types all cells have the same structure but come from different places and do different things EXCEPT for sperm cell have no cystoplasm mitochondria doesn t have the same structure Organs Systems lots of different organs make up an organ system and create an organism ex digestive organ system cell tissue organ organ system organisms many levels of cells lymphatic system returns liquids back into blood after they get loose respiratory urinary reproductive lymphatic digestive different in your body systems Brain Human Characteristics largest brains relative to body mass NOT largest brains ever birth canal limits newborn brain size so our babies are immature and can t survive without parental care human babies are useless very long developmental program must be to survive on your own Bipedal movement its been around for a while that people walk with two feet and use hands for other things Opposable thumbs and fingers easy tool manipulation Upright stance eyes forward front of face not side so we have good depth vision and control heat more easily Rapid Communication vocal structure permits complex communication using language codes are local so babies must relearn Human Taxonomy taxonomy science of classification humans mammals primates hominids family homo genus homo sapiens species the wise hominid 4 4 million years ago sometimes bi pedal males have canine teeth 4 ft opposable toes not a chimp gorilla ancestor Fossil of Lucy is from 3 million years ago southern ape 4 ft tall gorilla sized brain bi pedal and human teeth 2 million years ago Homo habilis handy 4 ft tall legs and arms are same length share work food communicate have communities 1 7 million yrs ago Homo erectus use fire communication pair bonding divide work family unit fire is important because you can cook and do things longer modern human how many species did there used to be 1 human species homo sapiens 1 16 Notes 20 04 2014 12 26 00 species you can reproduce with others of the same species and have babies that are fertile died out Neanderthals had a bad rep but existed at the same time as homo sapiens very similar to us 5 dna is similar we interacted Half a million years ago DIVERGENCE between what became from the neander river valley name Neanderthals and what became us all humans EXCEPT those in Africa have Neanderthal background INTERACTION Human history is NOT just homo sapiens OTHER SPECIES HAVE EXISTED AND INTERACTED WITH US TOO third group Denisovans existed same time as Neanderthals and humans but died off Homo Floresiensis hobbit found in Indonesian caves 10 000 years ago very recent separated on an island caused a debate Today most of human evolution occurred in Africa Mitochondria remnants of a bacterial invasion easy to isolate many per cell has small DNA molecule in egg but not sperm b c sperms too small DNA changes at rate or 1change 10 000 years USE DNA SEQUENCE CHANGES TO TRACK RELATEDNESS AND WHEN THINGS SPLIT shows common ancestor and how when it breaks off 7 european clusters Native Americans have some European sequences caused by interaction b w settlers and natives shows global migration paths over time Charles Darwin Beagle voyage 22 yrs old On the Origin of Species book not a definitive statement this way using on the explains HOW evolution could occur argument many are born size of population constant competition to survive individuals VARY randomly and that s heritable can inherit some of it POPULATION EVOLVES NOT INDIVIDUAL SURVIVAL OF FITTEST CHANGE fittest means fittest to reproduce and contribute genes to future generations society goes to extreme lengths to decrease competition b w ppl accommodate handicapped give medicine to ppl must not only live but also succeed in passing on your genes Culture Life Spans culture changes quicker than biology way people behave DOES differ today based on where you live income and education directly correlates to life span US has life expectancy much lower than the western countries accidents violence cause 50 deaths expect ppl alive to go down as you get older but with the us most problem with retirement is that we are paying in and there s more of people die in middle age them than us so we ll pay more 1 21 20 04 2014 12 26 00 Chromosomes numbered from biggest to smallest 23 pairs last pair determines sex men XY women XX 46 y chrom