Origins of Biodiversity Flashcards
The smaller somthing is the more you can fit into something else.
What kind of Organisms are the most diverse?
Smaller organisms (e.g., invertebrates) can take advantage of fewer resources. They have shorter generation cycles and reproduce at a higher rate creating more genetic variation.
You can fit more mice in a hole than you can deer.
What happens to abundance when the weight of organisms decreases?
You get higher abundance (e.g., There are more mice compared to deer)
There are so many plant species in this floor crack but that elephant ca
What is Fractual dimension?
As surface area gets smaller your habitat gets bigger (more detail)
E.g. an ant’s perspective of its terrain in comparison to us - i.e. A crack in the ground seems insignificant to us compared to an ant that sees the detail.
How do smaller organisms take advantage of their size?
They speciate more rapidly and occupy smaller niches (e.g., position on a feather - feather mites).
There are many ants in a colany and some can develope wings to find new
How do insects dominate terrestrial ecology?
They have high population sizes and divide and metamorphose (e.g. adapt wings) to occupy diff. niches and encourage dispersal.
There is no food on this island so I will fly to another.
How do wings increase resourceability?
Increases accessibility to inaccessible resources, establishes a wider distribution, and allows rapid dispersal.
There is no space on the tail so I will live on the head.
How does Co-evolution with other organisms encourage biodiversity?
Allows specialisation, especially on host species and parts of hosts (e.g. feather mites on condors).
If you live in a bog you can’t move but if you live outside you can move
How does the ability to disperse increase survival rates?
Less vulnerable to environmental changes (e.g., Monsoon season) and less prone to population fragmentation.
Being able to dig burrows is good but you can dig and fly can you?
How is being a generalist advantageous in a new environment? Give an example.
Higher rates of speciation which leads to specialization increased the rate of extinction. Any changes in their environment can lead to loss.
E.g. Melanesian ants - They only had high rates of extinction after they dispersed and speciated.
What is disharmony?
Disproportionate representation of some taxonomic groups
e.g. birds of Hawaii.
E.g. Honey creepers will often occupy niches filled by other spp.
Ant on a small island and a elephant in asia.
How does space affect the radiation of organisms?
Depending on the size of organisms they may require more or less land in order to radiate.
E.g. insects can radiate on small islands whereas Mammals require continents.
How many Million years ago did South America and Australia break apart from Gondwana?
South America joined North America 3 million years ago.
Australia became a large island continent 200 million years ago.
Eggs, pouch and placenta
What groups of spp. radiated during the three radiations in Australia?
1st -Monotremes - lay eggs
2nd- Marsupials - Carry young to early stage in the uterus and advanced stage in marsupium (pouch).
3rd- Placental mammals - across from Indonesia.
Pouch and mammary glands.
When did the two radiations occur in South America and what were their outcomes?
1st - 40-70 million years ago = Marsupial carnivores and placental herbivores.
2nd - Placental mammals - Island hopped from the world continent. (includes monkeys and rodents).
Panamanian land bridge..
What was the great American exchange?
The connection of South America and the world continent via the Panamanian land bridge around 3 million years which allowed the exchange of spp.
