Transcript Introduction to Marine Biology

So you want to study marine biology?
Introduction to Marine Biology
Physical Oceanography – Waves, Tides, Ocean Circulation, Seawater, and Surfing?
Introduction to Marine Biology
Marine Biology - Species Diversity
Introduction to Marine Biology
Marine Biology – Habitats, Ecology, and Interaction with the environment
Introduction to Marine Biology
A few general concepts…
Evolution as the unifying theory of biology
Darwin’s theory of evolution by natural selection:
1. Genetic variation
2. Inheritance of variation by offspring
3. Natural selection – Selects for adaptations that enhance a) survival
b) reproduction
Sources of Variation?
1. Mutations – most destructive, but…
2. Sexual reproduction -
Introduction to Marine Biology
A few general concepts…
The scientific method- How do things work?
Steps:
1. Observation
2. Hypothesis
3. Experiment
4. Conclusion
Tested hypothesis
>>>>>>>>>>>>>>>>>>>>>>> Theory!!
Other things to consider:
1. Controls
2. Sample sizes
Atmospheric circulation
Different parts of the earth are heated by the sun at different rates.
Equatorial regions are exposed to more direct sun light and are therefore heated
more than the higher latitudes.
Atmospheric circulation
Note that the differential heating of the equatorial regions relative to the poles
results in the temperature difference with latitude, but does not explain “seasons”.
Seasons are a function of the tilted axis of the earth...
Atmospheric circulation
What happens to air as it heats up or cools down?
A convection current is formed.
Atmospheric circulation
Same thing happens to the earth!!
Atmospheric circulation
But things are not so simple on earth… the earth rotates… what is the effect of the rotation?
The Coriolis Effect -
The tendency of any object moving freely across the globe to
appear to curve to the right in the northern hemisphere, and
to the left in the southern hemisphere.
Reason? – has to do with differences in the cross-sectional
circumference of the earth as a function of
latitude…
Can you think of demonstrations to see how this
might work?
Atmospheric circulation
So what is the result of the coriolis effect on the atmospheric circulation of the earth?
What other factors can you think of that would influence atmospheric circulation?
Atmospheric circulation
What other factors can you think of that would influence atmospheric circulation?
There is a difference between the geographical equator and the meteorological equator.
Since the meteorological equator is not constant (because of the seasons), the position of
The intertropical convergence zone (ITCZ) changes…
And don’t forget about the potential effect of land masses, storm systems, and other
factors such as volcanoes, etc.
Atmospheric circulation
So although potentially variable, general patterns of atmospheric circulation are predictable.
Ocean circulation