2. Populations Co-Evolve Flashcards
Where are the largest land mammals on earth?
hotter areas of the world (Africa for example)
Why does North America have smaller land mammals?
co-evolution!
What is co-evolution?
reciprocal evolutionary effects between two species
What is an example of co-evolution?
the Madagascar star orchid (also known as Darwin’s orchid) has a very long nectar tube (unlike other orchids),
implies there is a pollinator with a really long tongue (there is, was found after the orchid)
Why do predators catch the old and weak?
not for the good of the prey species → it’s just easier to catch them
selection prefers predators that can catch prey and prey that avoid predators
called an evolutionary arms race (predator vs. prey)
What are advertent effects of human co-evolution with other beings?
domesticated animals and plants
animals domesticated us too in a way → we succumb to begging, etc.
plants have domesticated us to care for them so we can feed ourselves
- mutual taming
What are inadvertent effects of human co-evolution with other beings?
fisheries, pesticide & anti-biotic resistance
there is little reciprocity in these inadvertent effects
What is the co-evolutionary effect of fishing?
fisheries prefer to catch larger, fatter fish
evolution happening for skinnier or slower growing fish
(exactly the opposite of what is desired)
What are the effects of fish hatcheries?
hatchery fish are usually inferior to wild fish
- they don’t learn about their environment so they don’t do very well
- artificial selection in hatcheries (DIY evolution moment)
by releasing them we change the nature of wild fish populations (since the populations differ from each other even if they’re the same species)
Why are land mammals so much bigger in Africa than North America?
a relatively recent phenomenon
a lot of the bigger North American mammals are extinct
What happened to the larger land mammals in North America?
2 big hypotheses
- arrival of humans
- retreat of glaciers and global warming
people theorize that the arrival of Indigenous peoples on the Bering land-bridge and their capable hunting skills cause a co-evolution between them and the larger mammals with less evolutionary history
Why aren’t mass extinctions across the globe synchronized with each other?
synchronized with the arrival of humans
- none in Africa probably because that’s where we evolved (indicative of co-evolution)
places where there were extinctions indicate less co-evolutions
What should we do instead of exerting evolutionary effects on other species?
mutualism - develop co-evolutionary relationships with other species (not overpower or manipulate them into evolution)
What 2 evolutionary relationships can beings have with each other?
Species have evolutionary effects on other species & co-evolutionary relationships with other species
How long have humans exerted evolutionary effects on biodiversity?
10 000 years
