bio120
what is physioecology and why is it important
it is important as all organisms are adapted to thier evirontment and hence they have difference features and physiologies accorging to their environment. similar evnvi can cause similar species and this phenomen is called convergent evolution
what limits a species
species are mainly limited by their ranges of tolerance such as what we studied in the last lec about hutchinsons niche with environmental gradiensts on both axes. it is also limited by dispersal and abiootic facots like temperature and percipation and food resources and competition.
why do temperate animals have better tolerance in cold climates and why do they have a wider range of tolerance than tropical animals.
this has to do with temperature and seasonality, as we studied in the previous lecture the sun in directly shining on the trpoics near the equator and hecne its is always warm, beacuse of this the seasonality is meainly due to rainfall and this also happens all the time due to the hadley cells being right near eq and the ITCZ not movinf to much staying constant.
what are homeotherms and poikelotherms and how do they differ in their behavior
homeotherms are warm blooded animals like mammals and birds, ect while poikilotherms are cold blooded and they dont have systems like homeostasis in their body to regulate their temperature to deviate from the envoronment and hecne they have behavioral adaptations to keep up with the changing evo but mammals are able to maintain a constant internal environment and temoerature through homeostasis
what are the different forms of heat loss, heat gain
the different forms are
conduction which is when heat is transfered between solid subtrate objects through vibrational movmemt of molecules
convection is the heat ranser throgh moving molecues like water and air
radioation thorugh EM waves
redistribution
evaportation
SA/V ratio matters in heat loss ?
it does lerger SA?V ratio causes more heat loss and lower sa/v causes less heat loss
what is bergmans rule and give some examples and exceptions
bergmans rule is mainly dependant on size and that size matters due to sa/v ratio. if the size is bigger and it is more spherical than the sa/v ratio will be minimal and hence the organisms will have more tolerance to warmer climates and rimarily be founf there, such as polar bears and pikas. this only applies for homeotherms as they are the only ones capalble of mainting bidy temp. exceptions are elephants but they evolved from mammoths
bergmans rule also matters
it is to do with shape and that homeotherms have smaller apendages to deal with the cold weather eg pikas are not like reg rabbits they have less big ears bec they live in cold climates
other cooling mechanisms
insulation can be in form of fur for animals, feathiers for birds, blubber in whales and ect
evaporative cooling like dogs panting makes the sweat evaporte form their tongues and body.
redistribution/ vasodialation in which the blood is directed to blood vessels where there is alot of sa/v ratio and so the heat can be easily convected from there.
countercurrent where when arteries and veins are very close the heat is passed from the arteries which have warm blood to the veisn that have coldish blood after being exposed to cold conditions like a dogs paw
there are consraints and tradeoffs
like weasel needs to be small and thin to catch prey but it also makes then more vulnerable to their cold climate but they have behavior means to deal with that but this is an example of a trade off