Populations and Selection Pressures
This post will go through some selection pressures in action for Prelim Biology.
The cane toad was an introduced species for agricultural purposes and despite starting with only 102 in the 1900s and releasing around 2400, the population has now grown to be well over 200 million. What is the cause of this growth?
The cane toad are a native species to South America where over millions and millions of years, their species have evolved in conjunction with all of the other species around it resulting in a complex network of predation and prey. In Australia, where there are no natural predators for the cane toad, they have gone unchecked. This has now lead to increased competition for native species who need to compete with this very hardy, highly toxic amphibian. The cane toad is highly adept for this environment as a result.
This is an invasive species, an introduced species that thrive due to a lack of negative selection pressures.
This video will go through cane toads in a little more depth.
This video contains some interesting facts about cane toads.
The prickly pear was another organism native to America, a drought-resistant succulent. It was another species introduced for agricultural purposes but unlike cane toads, are now in a controlled state. This video will go through prickly pears in Australia.
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