evolution by natural selection Flashcards
what are the three condtions for evolution by natural selection
heritable characters
characters show differentiation between individuals
differential fitness
what is meant by heritable characters
heritable characteristics that are passed on from one generation to another
what is evolution
the genetic change overtime (ie change in allele frequency)
is all evolution caused by natural selection
no, some changes in gene frequency are not selected for
does natural selection act upon phenotypes or genotypes
phenotypes
natural selection is the only consistent force that leads to _______________
adaptations
how can we find evidence for evolution
fossils imperfection (bad design) bad geography molecular genetics natural selection in action
what can we see from trilobite fossils over 3 million years (short evolutionary time period)
the ribs increased in length and number
what are whales most closely related to
the hippopotamus
what did the whale originally begin as
a land mammal
what are two evolutionary changes of the whale
nostrils moved from the front to the back of the head to form a blowhole
back legs shrinking due to lack of use- no legs
what is the tiktaalik (370MYa) an example of
a missing link
the third eyelid is a reptilian vestige trait, why do we still have a remnant of it
we have no need of the third eyelid but it would be too complicated to get rid of so overtime it has decreased in size
what is the left recurrent laryngeal nerve an example of
bad design
does natural selection design
NO it tinkers
