Studied by 0 people
Looks like no one added any tags here yet for you.
who is the father of taxonomy that was inspired by john ray
linnaeus
linnaeus proposed hierarchical classification of
organisms into levels
what are the classification of organism levels
class, order, genus, species
what are the three broad groups called
kingdoms
linnaeus also believed in
fixity of species
what is taxonomy?
science of defining and naming groups of organisms on the basis of SHARED CHARACTERISTICS
what is species?
group of organisms that can interbreed and produce fertile offspring
what is genus?
group of similar species
first four hierarchy of biological classification (IN ORDER)
species, genus, family, order
last three hierarchy of biological classification (IN ORDER)
class, phylum, kingdom
what is the basic unit of classification
species
what is speciation
making of a new species
speciation is a process by which
genetically distinct species arise
as adaptation and differences accumulate in speciation, organisms become so
different they can no longer interbreed
reproductive isolation may lead to
speciation
if gene pool is isolated, any mutation or selection that occurs is
no longer shared (no gene flow)
any significant evolutionary changes that occue in either population will result in
formation of a new. species (speciation)
what is gradualism?
slow accumulation of many heritable changes in a population due to small episode of natural selection
for gradualism, one species changes slowly over time until it looks so different
we call it a new species
anagenesis
unibranching
gradualism is rare compared to
branching speciation
what is branching?
type of speciation in which branching of new forms from an ancestral lineage occurs
cladogenesis
branching
for anagensis it is evolution within the lineage but for cladogenesis,
evolution due to splitting lineage
for anagensis there is no geographic barrier, but for cladogenesis
geographic barrier
example of anagenesis
horse
example of cladogenesis
darwin’s finches
what is punctuated equilibrium theory?
long periods of little to no evolutionary change punctuated by periods of rapid evolutionary change
for punctuated equilbrium theory, change mostly concentrated in
speciation events, cladogenesis
extinction and speciation are connected
true
mass extinction events often followed by
mass adaptive radiationswh
at is adaptive radiation?
diversification into different ecological niches
what is ancestral trait?
trait that evolved in a common acestor of both groups
what is derived trait?
trait that evolved in one group but not the other (a new trait)
what is a homologous structure?
shared evolutionary ancestor, similar structure but different function
what is analogous structure?
do not share a common ancestor, different structure but same function
wha tis parallel evolution?
when RELATED species evolve similar characteristics independently
what is the result of parallel evolution?
organisms that look alike and have a common acestry but live in different location
why does parallel evolution occur?
genetically related species adapt to similar environmental changes in similar ways
what is convergent evolution?
unrelated species from different locations begin to look alike because they inhabit similar environments
example of convergent evolution
tasmanian tiger and north american coyote
