anatomy & evolution Flashcards
what can be used to construct phylogenies, was first constructed using
gene sequencing, RNA genes
vertebrates are part of a phylum -
chordata
chordates all have a long …. found in the mesoderm layer
notochord
modifications to the head of vertebrates allowed us to become …
predacious
the first vertebrates lacked -
jaws
can date fossils to tell us
the sequence of events
how are we tetrapods
vertebrates that live on land - needed many changes to anatomy (used to live in sea)
tetrapods - shift from respiration via gills to ….. respiratory system
lung based
evolution of tetrapod - gained a ….. - important to live on land
palate
extant tetrapods - (still living) involves (2)
amphibia and amniotes
are we amniotes or amphibia
amniotes
name amniote comes from
one of 3 membranes that surround embryo - closest membrane to embryo
allantois membrane around embryo
gas exchange and stores metabolic waste
-umbilical cord in mammals
chorion membrane around embryo
protective membrane around the egg (outer layer)
what layer around embryo contributes to umbilical cord
allantois
evolution of the mammal middle ear -
a new jaw joint evolved
mammals are split into 3 groups
monotremes, marsupials, eutherians
3 key events in evolution in our anatomy -
- we are vertebrates
- we have jaws
- tetrapods - moved to land from sea
phylogeny =
emergence of form through evolution
what can be used to construct phylogenies
comparisons between gene sequences from diff organisms
-related organisms share more closely related genes
phylogenies were first constructed using
ribosomal RNA genes
phylogenies are now constructed using
genome data
what phylum are we part of
chordata
in vertebrates, notochord is replaced by
vertebrae of backbone
the fossil record fills in the gaps between
jawless and jawed vertebrates
extant tetrapods
amphibia and amniotes
how many ear ossicles do mammals have
3
how are humans and chimps both primates
very similar genomes
very similar protein coding regions
come from one ancestor
3 key events in evolution underpin our anatomy
emergence of vertebrates
emergence of gnathostomes
tetrapods
