lec 1 Flashcards

Question

What could Darwin Not explain

Answer 1

1) how a given traist is transmitted from parent to offspring 2) Where and how new traits suddently emerged GREGOR MEDEL: -Conducted experiments (1856-1863 !!!!!) in plant hybridization using common peas and was credited for laws of heredity (Basics for all meodern genetics) -signficiance of his work not realized until 1900

Answer 2

Pisum sativum -used pod shape, colour, and seed shape colour and flower colour to figure this out Discovered 1) Traits are passed from parent to offspring through gametes in specific discrete units or factors -these factors can be assorted differently in different indivduals -factors are GENES now 2) Individuals have 2 copies of each gene -one each parent -alternate forms of the genes are called ALLELLES What are the principles `1) Principle of Segregaton -each gamete can only carry one allele from a parent at a given gene 2) Independent assortment -segregation of members of one pair of alleles occurs INDEPENDETNLY of the segregation of the members of another pair of allele in gamete formation

Answer 3

Evidence and patterns of evolution

Answer 4

1858 published in 1859

Answer 5

1967; when the book was written 1859 in other countries alike japan and europe had more acceptance for evolution iceland had the most acceptance for evoution whereas USA did not only 40% in uSA thought it was true that humans developed from earlier species of animals After 2007, there was an increase in the acceptance if evolution after release of paper in2006

Answer 6

Biological first definition: "one species never springs from the seed of another"

Answer 7

a) Species do change (microevolution) Selective Breeding (ie artificial selection) -you put mice on wheel: some run fast, some run slow, some run for long time -measured how long mice ran voluntarily, and number of revolution per day -created 8 populations of mice: 4 fastest (highest revolutions per day), and 4 at random -mated 4 pairs of fast and fast -did for 24 generations then measured how much the offspring run : average 14000 revlutions for the fast offspring, for the random: average was 5k -SUGGESTS: by seelcting the individuals that ran alot, they were able to cause microevolution in the population in over 24 generations -the individuals didnt EVELOVE, the population evolved Vestigial Structures: a useles or rudimentary structure or version of a body art that has an important funcition in other closesly allied species, cannot be explaine by theory of special creation but makes sense for theory of descent (mexican tetra (eyes), brown kiwi (Wings), boa (legs), humans (tail bone, arrector pilli muscle), Threespine Stickleback (marine vs freshwater armor, test) b) lineages do diverge (SPECIATION) Speciation is: the concept that describes the situation where new species arise from pre-existing species -starts from a single population where there is variation among individuas What is a species: Biological Species Concept: Species are populations, or groups of populations within and among which individuals actually or potentially interbreed, and outside of which they do not interbreed (ernst mayr) Example 1: Threespine Stickleback Example again: Single population with 3 variations: blue, purple, green, all can interbreed with eachother because same species -over time, they divide more inot subpopulations (can still interbreed but more distinguishable) -over more time: we get distinct populations with limited interbreeding (still can but much less often) -finally, become reproductively isolated populations = different species So basically u can have a population with variation and it will al still be the same species, but over time, if they become more isolated, then they will become distinctly different species Example 2: Ring Species (siberian greenish warbler) -Ring species: series of populations of a species that geographically arrange around a barrier like a mountain or lack of forest -adjacent populations may be able to interbreed, but geogrraphically seperated ones wont be able to For Siberian Greenish Warbler: -differences in genetics and song (mating call) is strong for populations that are more geographically isolated (they do not recognize eachtoerhs mating call) -shows how they are slowly reproductively isolated c) new life forms are derived from older life forms (MACROEVOLUTION) - Goerge Cuvier: Published list of species only known from fossils (1801) -Clift noted that extinct mammals from australia were like extant marsupials (Slot, irish elk) -darwin noted the same things with sloths and armadillos in south america -SHOWE THAT fossils and living org in the same geographical area resembled eachother and are distinct from organisms elsewhere (LAw of Succession) EXAMPLR : Transitional Forms: Pacific Leaping Blennies: Transitional meaning u can see the transition states in evolution Aquatic ones: cant leave water Amphibious ones: double life -there was a point in time where a common ancestor that was aquaitc transitions to amphibious and from there there was a transition to Teresstial: can persist in water but for short term, will jump out, preferes moist environment -can survive on land , and also respire across gills, o2 crosses and enters blood stream Example 2: What is a bird : Archaeopteryx and phylogeny: -Bird: flight and feathers -but share many traits with crocodiles and dinosaurces because there is a common ancestor of all of these -vestigial features are seen on sinosauropteryx (short feathers that are no flight feathers but used for insulation and thermal regulation) -similicaudipteryc : long feathers, more similar to birds but not for flight From Dinos to birds: sinosauropteryx and similicaudipteryx d) All life forms are related (common ancestory) -All organisms have a common ancestor -Richard Dawkins "the Ancestor's tale". -Humans are connected all the way back to Protocells/unicellular life -protocells -> multicellular life - > animals - > fish and tetrapods -> malla s -> great apes -> and homo sapiens (NOT THE END THUOGH< evolution is still happening) -Homologoy is crucial line of evidence : traits are homolougs if they are derived evolutionarily, and a developmentarily from the same source structure. (ie 4 limbs) A) Structural Homology: -each structures adapteed to specific environemtns (Whale, horse, humans,moles, bat) -the genes that control the evelopmentof these is the same but they are different in function and stucture Darwin and Orchids Analogus: similar function but derived volutionarily and evelopmentally from a DIFFERENT source structure ie whales and sharks : whales have strong tail from terrestiral form, sharks from aquatic Molecular Homology: -Flaw shared between humans and chimpanzees and bonobos but not gorillas , orangutans or others -chimps , humans and bonobos all have an error in their gene , showing that they inherited this gene error from a commmon ancestor -both have cahrcot-marie-torth disease and hereditary neuropathy (pressive palsies) -Finally : the fact that all species have a universitality of genitic code and triplet nucleotides that code for AA (codons universal) e) Earth is old Catastrophism (biblical) / univormitarianism -alot of time was needed to build mountains and create the geoloical stata observed in nature - based on evidence, 6000 year old earth (arch bishop usher) and catastrophism is not consistent with evidence -calendar divded into Eons, Eras, Periods, Epochs

Answer 8

NO populations do

Answer 9

group of same species that live in a specific area at a specific time, so that the individuals have the potential to mate with eachtoher OR -most cases: there are multiple populations of a different species (several independent moose, or galapagos turtles (darwin))

Answer 10

change in alellele frequencies in alele frequency in a population over time -for the mice, we measure the traits and it changed in the popylation over time, so it is the population evolving

Answer 11

Tetrapoda (four feet)

Answer 12

Usually becaue homologous if they are derived, evolutionarily and evelopmentally from the same source

Answer 13

Tailbone -dont have tails but have this Errector Pilli Muscles -next to hair follicles -think about cats, when scared or threatened, hairs stand up, it is a behavioural response to threat -for these animals, the ahir is also insulation, not for us Thermal Regulation: we and chimps are homeotherms (we maintain the same body temp regardles of external temperature), if my body temp drops, it means we will be sick -homeotherms have adaptations to maintain temps then -our hairs still stand up but it doesnt provie thermal protection but we still have this thing but for other mammals the hair standing up provides warmth and insulation

Answer 14

ancestral form is marine: these are fully armored with pelvic fins modified into spines FreshwaterL Ligher armor, vestigial pelvic structure both are from one genotype, each is a different allele -each trait controlled by a single gene, with two alleles (one for light armour, one for heavy) Test: -all fish in Lobery lake Alaska were poisoned in 1982 for restocking -lake was colonized by threespine sticklebacks from marine inlet (1988) -from 1990-2001, freuqencu of individuals with ifferent traits forms recorded Results: Lightly plated increased in population, and armour decreased. (POPULATION CHANGED DRAMATICALY) -individuals didnt evolve, but POPULATION CHARACTERISTICS DID Why did the fuly armoured ecreased: less predators, so decrease in this phenotype -shows us how the less armoured are modified descendantsof marine populations NOTE: Need does not drive evolution or change : For change to happen, gene variants need rto have already existed, an only the frequency of this changes (lightly plated already existed ie)

Answer 15

micro : over generations' macro: more major changes

Answer 16

Vestigial Structures 1) Mexican tatra (Eyes) 2) Brown Kiwi (wings) 3) BOa (hindlimb) 4) Humans (tailbone, arrector pilli muscle 5) Threepine stickleback (armour and pelvic fin) Microevolution: Vestigial features and threepine stickleback Speciation: Threepine stickleback and 3 coloured variation thing b) Ring species (Siberian greenish warbler) MAcroevolution: ex 1: Pacific leaping blennies : they are the transitional state between fully awuatic and fully terrestrial. -show evolution because live double life ex : 2 What is a bird : Archaeopteryx and phylogeny: -Bird: flight and feathers -but share many traits with crocodiles and dinosaurces because there is a common ancestor of all of these -vestigial features are seen on sinosauropteryx (short feathers that are no flight feathers but used for insulation and thermal regulation) -similicaudipteryc : long feathers, more similar to birds but not for flight From Dinos to birds: sinosauropteryx and similicaudipteryx

Answer 17

Analogus: similar function but derived volutionarily and evelopmentally from a DIFFERENT source structure ie whales and sharks : whales have strong tail from terrestiral form, sharks from aquatic Molecular Homology: -Flaw shared between humans and chimpanzees and bonobos but not gorillas , orangutans or others -chimps , humans and bonobos all have an error in their gene , showing that they inherited this gene error from a commmon ancestor -both have cahrcot-marie-torth disease and hereditary neuropathy (pressive palsies) -Finally : the fact that all species have a universitality of genitic code and triplet nucleotides that code for AA (codons universal)

Answer 18

-muticellular organisms appear in the ocean late June -Land plants appears late november -the swamps that formed the world's coal deposits during the pennsylvanian thrived for 4 days in dec -dinos: mid december, but extinct boxing day , rocky mountains formed -human-like animals appear in evening of dec 31 -most recent galciers receded from waterloo area 75 seconds before midnight on 31st -the Roman empire ruled western world for 5 seconds, from 11;59:45 ro 59:50 on 31st -Columbus arrived 3 seconds before midnight

Answer 19

Natural Selection

Answer 20

1) Change/MOdification 2) Genetics/Allele frequencies 3) Population 4) Time

Answer 21

1. Natural Selection 2. Mutatino 3> Gene flow 4. Genetic Drift 5. Non random mating

Answer 22

All must be true for nautral selection: 1) Individuals of a population differ from one another (if everyone is a genetic clone, natural selection cant happen) 2) THe differences are , at least in part, passed from parent to offspring (phenotypical differences) 3) Some individuals are more successful at surviing and reproducing than others 4) The more sucessful individuals are not just lucky, hey suceed bebcause of variant traits they have inherited an will pass to offspring In another way: a) organisms produce more offspring that can be supported _as population size increases, the amount of food goes down, then survival and reprouction become compromised - as more food available, it increases population size, so less food, so less growth b) There is constant struggle for existance c) Invidiaus in population vary in phenotypes d) Some of this phenotypic variation is heritable (genotypes) e) Those individuald that have phenotypes that are most adapted to current conditions are most lkely to surive and reproduce f) if rthese are heritable, it will be passed on to offspring Natural selecrion acts deirectly on phenotypes of individuals, but only if there is a change in allele frequencies in a populat occurred If all of these postualiteds hold true, then population will change gradually over time Evolution in population results from natural selection on individuals; requires change in frequency distribution of a trait in population (statistical thinking)

Answer 23

study of allele and genotype frequencies and the variation in these frequences acrosss space and through time and evolutionary factors that explain this variation

Answer 24

if all the autral selection postualates hold true, then populations will gradually change over time evolution o a populatinn results from natural selection on individuals

Answer 25

these generational changes are usually small and it might take hundreds of generations to detect meaningful difference

Answer 26

ability of an organism to survive and reproduce in its environment -relative term, relatice to the fitness of other members of the population -lifetime reproductive stress

lec 1 Flashcards

(53 cards)