Midterm 1 Flashcards
Endothermy
Ability to control body temp through internal metabolic processes and maintain homeostasis
Pokilothermy
organisms that have varible body temp and depend on outside factors to help regulate
Thermoregulation
ability to maintain a regular tissue temperature
4 means of heat transfer
Conduction - the direct transfer of heat between objects without the macroscopic motion of particles
convection - Heat transfer through fluid movements of substance
Evaporation - Heat dissipation
Thermal radiation - all animals emit infrared electromagnetic radiation that travels though the air and absorbs when it makes contact with something
Transient endothermy
maintain temp in certain part of their bodies that is generated by muscle contractions
- heat via constant movement
5 observations of natural selection
1: organisms have a great potential for fertility
2: natural population size doesn’t fluctuate
3: resources are limited
Infererence - struggle for existence
4: Variation occurs among individuals
5: variation is heriable
inference - find which possess traits favourable in competition in their environment will have differential survival
inference - over time population change with those possessing favourable characteristics
evolution
changes in genetic structure in populations over time
Genetic drift
change gene frequencies that happen randomly
Founder effect
loss of genetic variations when a new population is created - no selection
bottleneck
event that causes a decrease in population size
Gradualism
slow change over time
Allopatric population
two populations that become physically isolated that they become two separate populations
Sympatric
populations coexist together but are functionally seperate
morphology
understanding of the parts of an organism that:
shaped by internal/external factors
significance to these for functioning as a whole
limitations/possibilties these impose to evolution
Homologous structures
share a common ancestry but not necessarily the same function
- ex: 4 limb structures between humans and dolphins
Analogous structures
Share a similar function but not the same ancestral origin in the development
- ex; wings of bats and birds
Homoplastic structure
simply look alike but are not homologous or analogous
- ex: leaf bugs and actual leafs
Dispersal mechanisms
corridors
barrier
selective filter - some organisms can cross, some cant
sweepstakes - random event (bird in a hurricane)
Marsupials and evolution
are found in the areas that Eutheran (placental) mammals are not as present
- have many disadvantages that make them less likely to adapt to different climate
- but in Australia are abundant due to the amount of niches that were left unoccupied by mass extinction
4 eons
Hadean
Archean
Proterozoic
Phanerozoic - modern day
Mesozoic era
Age of the reptile
- largely cosisted of dinos, extinct reptile groups, and extant reptiles like turtles, alligators, snakes and lizards
Cenozoic
end of cretaceous, beginning of paleogene periods
- marked the loss of the dinos and other reptiles
- made room for mammals and birds to come in
Similarites between birds and reptiles
1: single occipital codyl (ball and socket joint)
2: single bone in the middle ear (stapes)
3: lower jaw made up of 5-6 bones
4: leg scales
5: Egg yolk polar development - yolk roates so embryo is always on top
6: hetergametic sex female - ZW (male ZZ)
7: nucleated red blood cells
8: Air sacs resemble chamelons and turtles
9: tetrachromatic vision (4 cones)
Archaeopteryx - ancient bird
both reptile and bird characteristics
