Card Set Information
Reproductive isolating mechanism's
1) ecological RIM's
2) Temporal RIM's - breeding at diff times
3) Behavioral RIM's - potential mates, meet but do not mate. (visual, auditory, chemical (moth pheromone)
Hybridization and polyploidy
interbreed between 2 species
Hybrids are generally sterile
From species A and species B
genome of hybrid
: "AB" (1 set from 1 parent, 1 set from 2nd parent)
Chromosomes cant pair in meiosis:
: reproduce veg.
-become polyploid - more than 2 sets of chromosomes
(50% of plants are polyploid)
Where do polyploids come from?
: AB hybrid
-errors in mitosis or meiosis
AABB tetraploid - meiosis fine
(wheat, tobacco, crops)
How do we study macro evolution?
2) dating - radiometric
4) biochemical evidience/data
organs are homologous (similar in form because of common ancestory)
: anatomy of bones in arms (bats, humans)
: organs are analogous - similar in form because of similar functioon (insects and bird wings)
: a.a. sequences
: DNA nucl. seq.
-If 2 like species have closer seq. they are closer related.
Cheat grass 0
Sunflower 9 0
sage brush 8 1 0
How many diff. in a.a. in a part protein?
Time increases left to right
Pace of evolution:
What causes big change:
a) appearance of polyploid
b) developmental change early in dev.
c) change in regulatory genes
d) genetic drift
dissapearance of a taxonomic group
-physical factors (volacones, ice age)
-biotic factors (constantly occuring)
sometimes mass extinctions
65 million years ago- most recent (theory asteroid)