Studied by 3 peoplehomologous
similar structures in related species that have different functions, derived from a common ancestor or purpose
analogous
different structures that are formed in unrelated species that have similar purposes or functions
human arms, cat legs, whale fins, bat wings
examples of homologous structures
flying squirrels and flying lizards
examples of analogous structures
divergent evolution
when two or more species sharing a common ancestor become more different over time
convergent evolution
when two unrelated organisms develop similar adaptations because they live in similar environments
dogs breeds, bird beaks/species
examples of divergent evolution
birds, bats, insects forming wings
examples of convergent evolution
vestigial strucutres
a structure that was once useful, but is no longer and still remains anyway
too much energy would be wasted on deleting that DNA or structure of growth
why do vestigial structures stay in species despite being useless?
human appendix, whale hipbones, snake hipbones, blind fish eye sockets
examples of vestigial structures
atavism
a type of mutation that shows an ancestral trait expressed accidentally (ancestors used to have these traits)
turned off or on genes that previously expressed diff. characteristics
what do epigenetics have to do with vestigial structures and atavism?
contain DNA
what is one thing all species have in common
shared/similar DNA from common ancestors and evolution over time
what creates fundamental similarities across species on a biological level?
bacteria, archaea, eucarya
what are the three categories for types of ancestral groups?
clades
groups of organisms with a common ancestor
classify species based on fundamental traits or characteristics (ingroup vs outgroup)
what are the functions of clydograms?
different or unrelated species can have similar traits
why are clydograms usually not the most accurate method to map out species relatedness?
phylogeny
inferring relatedness based on derived characteristics or traits, used to make family trees and accurate guesses
provides map of which species are closely related based on DNA
what do phylogenetic trees do to determine species relatedness?
lemurs, taisers, new/old world monkeys, gibbons, orangutans, gorillas, chimpanzees
examples of primates related to humans
opposable thumbs, four limbs, omnivores/herbivores, large heads, family structures and 1 offspring per birth, 3D color vision
common characteristics of primates
bipedal, language, societal structures, advanced technology/tools, less body hair, curved spine, straight face, small jaws/teeth, short pelvis, long legs, short arms, large brain case
unique qualities humans have compared to other primates
large brains, skulls, teeth, jaw, they were shorter and lighter but had similar structures, diets, and behavioral patterns
what did human ancestors have in common?
can use hands for other things, running, walking efficiency, controlled breathing
advantages of being bipedal
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