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Biology

Modern-Day Examples

Evolutionary Change in Current Day

This post will go through some modern-day examples of evolutionary change for Prelim Biology.

Topic: Evolution – the Evidence

  • Explain modern-day examples that demonstrate evolutionary change, for example:
    • The cane toad
    • Antibiotic-resistant strains of bacteria

 

The Cane Toad

You may recall from an earlier post that cane toads are an invasive species that are threatening various native species due to its consumption of various resources, rapid reproduction, and lack of predators. What if I told you that they were spreading, and slightly changing while doing so?

What scientists have found is that cane toads heading the spread of the population tend to have longer limbs, which enhances jumping ability.

This is a short video about ‘super cane toads’.

 

This video goes through cane toads and natural selection.

 

This video is a great resource if you are interested in the cane toad and its microevolutionary changes.

 

Antibiotic Resistance

Another current issue related to rapid evolution in today’s society is the development of antibiotic resistance (when a bacteria dulls or nullifies the effect of antibiotics) in certain strains of bacteria. A great example is bacteria developing penicillin resistance.

As bacteria reproduce at a rapid rate, their rate of mutation is likewise high. Sometimes, bacteria may mutate and develop a gene that enables antibiotic resistance. These bacteria may pass on this gene to other bacteria or reproduce to make clones with the same gene. Due to the overuse of antibiotics as well as people not fully completing their cycle of antibiotics when prescribed, we have seen a rapid increase of antibiotic-resistant strains of bacteria.

This video goes through the causes of antibiotic resistance.

 

This video goes through penicillin.