BIOL 112 CHAPTER 18 September 2 2021 Homologous same anatomical structure internal anatomy evolving into different lineages ex humerus ulna radius metacarpal phalanges Analogous same trait that is inherited but different structure ex wings convergent evolution and analogous traits go hand in hand same trait different functions ex not all birds can fly Vestigial if you look at the evolution of the structure it is diminishing in the functionality ex pelvic bones in whales they lose functionality but it has not lost function Nature tends to evolve towards an increase in surface level ex camouflage We live on an unstable rock with a lot of unstable genetics If the environment changes selection pressures are going to change in order to adapt Prior to industrial revolution plants had a certain trait and after the industrial revolution they ve been lost Evolution differences in genetics changes in environment and dominoes start to fall If the trait is selected the certain species stays in the population Fossils are a big deal western Africa has the same fossils in south America they originated in the same place Plates moving leads to changes in weather patterns changes to changes in the natural world plates shift more warm shallow seas oxygen levels go up When elements of science gets mixed with popular culture things get mixed up Molecular Biology Thomas Kuhn Paradigm shifting in science we are not afraid to change our mind but the paradigm does shift Taxonomy and Cladistics they are constantly changing women and men are constantly surveying genomes Misconceptions of Evolution evolution is just theory individuals evolve teleological evolutions explains the origin of life organisms evolved on purpose nature is NOT teleological tele last teleological means to NOT operate with a plan Speciation Formation of New Species Ernst Mayr biological species a group that can interbreed and do interbreed they have viable offspring and choose NOT to interbreed with other groups hybrid a cross between two species gene pool a collection of all variants of genes in a species Speciation allo other sym together patric area or space how species come to be long distances are geographical divides how do these species come to be Allopatric speciation involves geographic isolation Sympatric speciation occurs in the same geographical area same area but we start to see isolation from each other despite the fact that they are still technically there together chromosomal errors in cell division MUTATION different starting genetics different environmental pressures different genetics that come to be over time Bacteria mutate antibiotic resistance all the time Reproductive Isolation EXAM 1 INFORMATION AND FINAL EXAM Reproductive Isolation Hybrids TWO TYPES 1 Certain hybrids that do well 2 Certain hybrids that don t exist for maybe a couple generations hybrids are either sterile or through later generation fail to exist how species are maintained Prezygotic Barriers they have the same traits but want nothing to do with them impeding different species from attempting to mate Habitat isolation live in different places Temporal isolation temporal time they are reproductively viable at different times of the year Behavioral isolation courtship rituals Anthropocentric Mechanical isolation morph form anatomically they are unable to perform well in order to mate Gametic isolation species specific bindin protein has to fit specifically to fit the receptor like a key in a lock in order to mate the protein has to fit the receptor on the egg zona pellusta Postzygotic Barriers maintain species hybrids do not do well when these 3 are in play Reduced hybrids viability Extinction 99 of all living things in this world have become extinct Concept 24 2 Speciation can occur in basically 2 ways allopatric speciation sympatric speciation VARK learning styles survey Allopatric Speciation Allopatric speciation gene flow is interrupted or reduced when a population is divided in geographically isolated subpopulations Long distances the greater the divide the greater the degree that speciation will take place over the years Mosquito Fish Slide under high predation vs under low predation Fundamental Element of Evolution just because a trait is there doesn t mean that it has this fabulous function Sympatric Speciation polyploidy poly many ploidy chromosome autopolyploid made my humans ex bananas auto self replicates its own DNA allopolyploid allo other simpolyploid Allopatric Speciation dispersal when a few members of a species move to a new geographical area aka founder effect vicariance when a natural situation barrier arises to physically divide organisms not seen as much with great geographical distances Adaptive Radiation when a founder species in a short period of time becomes a new species that can be tracked back to one ancestral species Sympatric Speciation when you count chromosomes count centromeres nondisjunction an unequal division of the DNA during miotic goings on monosomies will be at the 23rd spot in humans but you ll see that an nothing else autopolyploidy Reproductive Isolation Presygotic Postzygotic Allo and sym forming species Pre and post maintains species Gametic barrier species specific bindin proteins coevolution Reconnection these are the hybrids that do well hybrid fusion when the hybrid out competes both parent A and B reinforcement parental species just kind of move away stability both the parents and hybrids does well started out with two and ended up with 3 Postzygotic example sterile mule Rates of Speciation gradual speciation species forming over time punctuated equilibrium where there is all of a sudden a radical departure based on a rapid change in environment steven j goule the individual from Harvard he did his research on islands islands are good biological laboratories Rates of Speciation speciation happens more often on islands CHAPTER 10 September 7 2021 What is Genetic Drift In a population can lead to the elimination of an allele from a population by chance The smaller the population the greater effects of genetic drift randomness Anthropocentric seeing the entire natural as being humans and humans alone The Biological Species Concept A species can interbreed A species does interbreed A species produces viable offspring The species does NOT interbreed with other groups Ernst Mayer EXAM 1 PEOPLE Steven J Goule Charles Darwin The way an individual looks is not the same as a population evolving
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