12 exam questions
where he comes from: low species biodiversity contrast to areas where he travelled
to high species diversity.
Northern brazil wher he first came. He was overwhelmed. Boy is this different than
in the uk.
Tropical forest had high species diversity. Many more biotic interactions. Animal-
animal, plant- animal etc.. abiotic factors are those involving physical fctors of
environment. Year round warmth results in rapid growth and insect/ microbial
populations. Pest and disease pressures on plants more intense. More bugs eating
Species diversity is high so distance from one indididual to another could be several
kilometers. Species similar not close together. How with this tree going to mate
when a partenor is so far away? How do the go about reproduction then? In
Ontario, wind is used to transport pollen. Wind in tropics isn’t important, instead its
animals that do pollination
Tropical forests are also largely evergreen ( non deciduous) unlike temperate
Dense canopy in tropical forest makes it harder for pollen to get transported by
Dan Janzen found that the euglossine bee as long distance pollinator of tropical
plants. Bees can travel 23 km between similar species of plants in a tropical forest.
He was interested in what mainatains diversity. Pest pressure. Best survival of seeds
occurs when the seeds are far away from mother as mother harbours disease which
can attack growing seeds. Thus strong selection for seed dispersal.
Any plant mutualism in acacia. Ants protect plant from herbivorous insect. The ants
get in return home, protein and sugars. He took a bunch of plant, de anted some
trees, and saw that the trees were defoliated by beatles. Selection for mutualism.
Experimental studies of ant lant mutualism
Amazonian forests has devils gardens which are areas where no plants grow near
trees of one specific species. The reason why no plants or trees live near duroia
hirsute is because ants who live on plant spray plants near the duroia with formic
acid and kill them
Giant amazon water lilly. In nature they are ratty because pests eat them. In botanicl
garden theyre pristine
Adaptations to pest pressures. Epiphytic life form boost species diversity. The use
trees as substrate to grow. Roots hang from trees, lichens are epiphytes,
Are particular trees favoures, how are the dispersed and what pollinates epiphytes
Slide 13: mimicry(dead leaf and live leaf), camouflages on leaves. Color indication of
plants to say ive been pollinated already go to someone else. Trees develop red.
Red leaves attract hummingbird. Bract is leaf with pigment in it.
Darwin finds fossils of giant armidillos. He saw living relatives of what living now
Beagles goes to Patagonia. Abiotic factors dominate landscapes and landscapes are
Abrupt treeline governed by abiotic factors. Trees can only get past certain point.
Slide 18: contrast between Patagonia and amazon forests. Lot less abiotic challenege
Familiar and unfamiliar groups in Patagonia: dark colored bee so that they can
absorb sun and warm up.black necked swan. Hey these are relatives to orgaisms I
am familiar with somewhere else. Cause is that similar environmental pressures
shape animals to look similar.
Biotic selection is operated.
Galapagos islands. 15 main islands of volcanic origins. 5-10 million years old. Flora
and fauna colonized by organisms capable of long distance dispersal from south
These species on islands provide evidence of early stages of speciation
Theory of evolution came from here
San cristobal wasn’t appealing to Darwin, its rocky, spiny and thick brush
Pricly pear cacti are first colonizers of isabela. They got there by long distance
dispersal. Birds eat there fruits, and seeds in fruits are in bird and defacated onto
lands far away.
Darwisn finches. Different finches have different bills for different purposes.
Adaptive raitation where selection has picked best purpose
Rosmarie and peter grant have studied Galapagos ficnhes for 35 years. Showed how
beeks change as a result of changes of resources on island ofdaphen major
Adaptive radiation is. Evolution of ecological and phenotypic diversity withina a
rapidly multiplying lineage as a result of specittion
1 ancestor which brings about many types of animals good at different jobs
tortoises under threat. One species where one male left
marine iguanas camouflage into black lava rock. Only marine iguana. They can expel
salt from nasal gland rulting on salt crystals formed on iguanas forhead.
Terrestrial iguana which has specialized jaw for eating pear
Flightless birds as a result of lack of need to get away from predator
Sexual selection. Sexually dimporphic birds
Beagle goes to Australia.
Slide 32: unique flra and fauna, continent which has been isolated for a along time.
Lot of endemic species. Shows many island characteristics. Radiation dn unique
Epiphetic ferns, wet forest
Dry forests aswel. Gum tree dominates. 700 species of eucalyptous
Koala eats gum leaves, which have chemical in them. Phenolics and terpenes.
Koalaos have evolved to detoxitfy these chemcials
Bush where flowers on ground. Pollinated by rodents
Came back and did work