Week 6 Speciation Extinction Systematics 03 04 2014 Classification Systems tel us about culture of origin Linneaus binomial nomenclature taxonomic classification o Grouped things together in terms of physical traits Phylogeny patterns of evolutionary ancestry and the speciation that produced these patterns How did speciation produce these patterns how do we construct evolutionary trees o Visual representation of relationships between taxa species at the end of a branch there is a species If two branches connect that means they had a common ancestor o Ancestral traits a trait shared with species below it unless it is lost in mutation o Derived traits shared good for figuring out how to group organisms together Comes about after primary ancestral trait o Unque traits specific for a certain species Splitting v Lumping Cladistics o Cladistics looking at evolutionary relatedness through DNA Do you like to split up or do you like to clump together o Research questions how many branches are there among a group of organisms Which branch connects to which other branch What is the branching sequence o Cladograms show ancestor dependent relationships through branching o Maximum parsimony greatest amount of splitting you could possibly do Powerful analysis of large data set How much can you split it apart Splitting v lumpting phonetics o The phonetic tree is usually more square o Not looking at time looking at increasing similiarities The furher you go to the ends of the branches the more similar two species are o Study of relationships based on degree of similiarity Molecular DNA mtDNA Phenotype Anatomical morphology o Linneaus used phonetic trees o Doesn t necessarily explain ancestral evolutionary relationships o Maximum likelihood use entire sequence analysis of many trees postulates most likely Lumping together similarities What is a species viable offspring o Old definition two organisms that can interbreed and produce o Biological definition groups of organisms with a shared closed gene pool under natural conditions o Morphological groups of organisms that share physical features important for fossils o Genetic clusters of organisms that share genes important for asexual reproduction or those lacking shared morphology Nature s rules for producing offspring o Occupy the same territory o Both be fertile at the same time o Use appropriate signaling pheromones mating calls courtship rituals behaviors visual stimuli o Be attractive to potential partner o Having appropriate equipment Different specie have different o Match physiology and genetic system of potential partner ph o Sexual selection female primates exercise choice Island Biography and Evolutionary Genetics o What factors impact species richness of speices and shaped pensis DNA etc speciation o Biogeogprahy theory more speices on mainland areas but if there is an island near the mainland the species that inhabits that island may be able to fly back and forth o Island any ecosystem completely surrounded by unlike ecosystems Consider the roles of gene flor and gene drift in contributing to speciation o Chimps and bonobos very closely related but separated by island biogeographic theory an original population separated by the congo river gene flow was disrupted between the two Extinction going on all the time whether big massive event or small o Background organismal death rate exceeds birth rate o Mass near simultaneous loss of many lineages Occur in inervals of tens of millions of years Associated with ecological catastrophes dinosaurs o Opens new areas for species to exploit When a species doesn t inhabit an area anymore someone else can move in o Reduces competition survivors of the events can multiply rapidly and diversify to fill out open space Primate conservation o Habitat loss o Bushmeat trade Primates What are primates Adaptive dietary plasticity long lived o Differences between priamtes and non primates Short snout eyes front Big brain relative to body mass Shoulder movement Opposable thumbs old world pirmates have them new world have little or non Brain devoted to sight Long gestation and developmental period Aboreal adaptation humans do not do this but other primates do o Opposable thumb precision grip o We as humans have lost our opposable toe o Upper body clavicle rotating forearm Sensory adaptations claws o Enhanced touch dermal ridges nerve endings nails not o Enhanced vision eyes rotated forward overlap in vision field color vision helps us decide when things are ripe Easier to see depth perception o Reduced smell Rhinarium lost Secondary sense to us short snout Dietary plasticity and dentition o Wide dietary range Different tooth types Reduced number of teeth o Specialization Tooth combs Canine premolar honing complex Cranial development o Sagittal crest mastication o All primates skulls reflect how we chew Parenteal investment primates have higher parental investment o Low birth rate o Adolescent developmental period o Brain development o Social complexity o Longevity Intelligence o Different parts of the brain have different functions Primate diversity beyond humans o New world monkeys central and south America o Old world monkeys asia and Africa Also include the apes o Prosimions south east asia and central Africa lemurs are only found in Madagascar Classification o Phenetics linnean clearly about taxonomy based on descriptions of what we can see o Cladistics evolutionary relationsihps between groups of Prosimians lemurs tarsiers slow loris old world o Retain rhinarium and snout good sense of smell and wet primates nose o Combination of nails and claws o Phalanges are less dextereous o Least evolved speices because they maintain many ancestral straights Anthropoids New World Primates platyrrhine o No rhinarium wet long snout o Rely less on their sense of smell o Prehensile tails likely o Forward facing nostrils o Arboreal habitats in latin America o Comes from south America or the carribean o Ex howler monkey Anthropoidea Old World Primates catarrhine o Terrestrial and arboreal habitats African and asia o No prehensile tail o Sideways facing nostrils o Ischial callositites Hominoidea The Apes o No tail o Highly intelligent o Menstrual cycle o Sing to eachother o ape locomotion brachiation knucle walking bipedialism o lesser apes lesser sexual dimorphism found in asia monogymous found in trees o greater apes chimps bonobos humans sexual dimorphism Week 7 Primate Societies 03 04 2014 Complex organization varies