macroevoltuion, adaptive radiation, extinction, coevolution Flashcards
what is the current 6th mass extinction event called ? tertiary cretaceous holocene pleistocene devonian
holocene eticntion due to human activity
what is co-speciation?
As the host speciates as does its related species, parasite or commensialist
As the host speciates as does its associated specialist, parasite or mutualist
the influence of closely associated species on each other in their evolution
relationship when one species cannot live without the other
OPTION B
a- not commensialists as they are neutral
c- this is coEVOLUTION
d- this is obligate mutualism
what is the earliest horse like form ? Miohippus Hyracotherium Equus Merychippus Pliohippus
hyracotherium
> have short flat teeth indccating HERBIVORY and browsing, not grazing
> 4 digits and 3 toes
what is allopatric speciation ?
barrier formation causes individuals to evolve in isolation, forming new distinct species
individuals enter a new niche, the population evolves in the isolated niche, forming new distinct species
individuals enter a new niche, adjacent to their current niche, the population evolve in the new niche forming a new species
individuals undergo genetic polymorphism, so the population evolves isolated within the larger population, forming a new distinct species
OPTION A - BARRIER
b- peripatric - isolated niche
c-parapatric - adjacent
d- sympatric as its within the same enviroment
changes in a gene pool as a result of a random event describes A cladogeneis B mutation C selection D genetic drift E bottleneck
OPTION D
GENETIC DRIFT can change allele frequencies due to chance/RANDOM
> right place right time
what is adaptive radiation?
lineage rapidly diversifies with newly formed species evolving different adaptations
during evolutionary history of horses, sometomes new species branhc off and live side by side. this is A anagenesis B monophyly C cladogeneis D polyphyly E commensilism
OPTION C
> branch is the key word here
when was the most severe mass exticntion event in the last 550 million years? late devonian ordovician- silurian cretaceous-tertiary permina-triassic triassic-jurassic
cretaceous-tertiary aka. K-T event
> knocked out the dinosaurs due to meteor impacts AND mantle plumes
what is a benifit to a mass extintion event
there are less predators, and less competiion so lots of adaptive radiation can occur/ diversification
When islands are colonised, evolution often takes an unusual trajectory. Which of the following features of islands/colonisation is MOST important in promoting new species to evolve? convergent evolution high mutation rate founder effect gene flow dispersal behavior
foudner effect!
> foundfer effect when population is established, bottleneck when population destroyed == reduction in genetic diveristy
which popualtion is more vunerable to gentic drift
large or smol?
small
> think about choosing candy, some options are eliminated
The formation of a new species from a surviving ancestral species while both continue to occur in the same geographic region is BEST termed: A allopatric speciation B peripatric speciation C parapatric speciation D sympatric speciation
SYMPATRIC
e.g. the galapogos finches - one island has many different species
The evolution of the horse is BEST characterised as which of the following: A convergent evolution B orthogeneis C porgessive evolution D branching phylogeny E all of the above
OPTION D
tapiers and rhinos are examples of animals that underwent different evolutionary pathways to horses. this is due to? migration genetic drift bottleneck continential drift extinction
continential drift
LAURASIA split into N.america -> horse and Europe ->odd toes mammals
what features does grass have that goes agaisnt herbivory?
high silica content making it verry tough
shoot apical meristem is near the ground making it hard to reach
BUT, horses stuck with herbivory and adapted instead!
how did the horses adapt to the expansion of grassslands?
highly crowned teeth to WEAR away the silica
larger brain cases to ACCOMODATE longer teeth
hiow many horse lineages radiated from merychippus? 3 4 5 6 7
AT LEAST 6
but only ONE lead to pliohippus -> eqqus -> modern horse
> modern horse survived so we think its linear evolution but no! its adaptive radiation
what are homeotic genes
genes which regulate the development of anatomical structures in various organisms such as echinoderms, insects, mammals, and plants.
what is phylogenetic congruence
when the tree topologies match
barnacles and whales are an example of obligate mutualsim parastie commensilism altruism non obligate mutualism
this is commensilim
- one benefits // can filter feed
- one has nuetral impact // whale lives life
beees and flowers are an example of obligate mutualsim parastie commensilism altruism non obligate mutualism
this is can be obligate or non-olbigate(fwcualtive) and depends on the perspective
> bees NEED floral resources. BUT bees can utilise many flower species so very few cases of cospeciation
flowers NEED pollinating. BUT some are hermaphroditic/self compatible
what is the very basis of mutualism
at least one benifits
postive - postive : mutulism
postive - neutral : commensilism
postive- negatvie : parasitic
why are there more co-evlution between moth and 3-toed sloth than 2-toed sloth
2 defecates in the air so less moths have acess to sloth fur
3 slides down tree where moth can access and repoduce in dung. in return, they live in fur fuelling algael growth to supplement nutrient poor sloth diet
when was the last major ice age// glacial maximum tertiary cretaceous holocene pleistocene devonian
pleistocene glaciation around 180,000 yrs ago
