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MISCONCEPTIONS ABOUT EVOLUTION BY NATURAL SELECTION

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Presentation on theme: "MISCONCEPTIONS ABOUT EVOLUTION BY NATURAL SELECTION"— Presentation transcript:

1 MISCONCEPTIONS ABOUT EVOLUTION BY NATURAL SELECTION
"Misconception" = a popularly held belief about something that is nonetheless mistaken. e.g. Vikings never looked like this >

2 MISCONCEPTION #1 Natural selection involves organisms "trying" to adapt in order to survive. WRONG! Offspring have no way to "pick" the traits they inherit from their parents, nor any way to know what sort of environment they will be born into.    Born that way < This misconception may stem from a more common usage of the word “adapt” as in “I have adapted well to life in high school.” This does involve “trying”, but is a different sense of the word “adapt”.

3 MISCONCEPTION #2   Evolution is a "march of progress” in which organisms are always getting better.   WRONG! Evolution has no "direction." Many species have changed very little over millions of years. Others change drastically into many different species, depending on selection pressures. This isn't how it works -----> This is ----->

4 Evolution means that life changed
MISCONCEPTION #3 Evolution means that life changed "by chance." WRONG! While the mutations that are the source of genetic variation are random events, the process of evolution, natural selection, is not. Selection pressures act like filters, sorting those that happen to be fit from those that are not.

5 Q. What is the selection pressure making life “tough” for the bacteria, H. pylori?
The antibiotic is the selection pressure which leads to natural selection of antibiotic-resistant bacteria!

6 MISCONCEPTION #4 Natural selection is all about the big & strong dominating the small & weak. WRONG! Success in natural selection means getting more genes into the next generation. There are many ways to do this, including being better camouflaged, sneakier, shorter, quieter, more sharp-eyed, etc.

7 MISCONCEPTION #5 Evolution is about blending different organisms to produce new forms of life. WRONG! With very few exceptions, different types of organisms cannot produce fertile offspring. If only! ------>

8 Organisms can evolve over their lifetime.
MISCONCEPTION #6 Organisms can evolve over their lifetime. WRONG! Every living thing is born and dies with the same set of genes. Radical change during a lifetime is called metamorphosis, not evolution. Populations evolve, individuals don’t! Not a real organism >

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11 MISCONCEPTIONS Natural selection involves organisms "trying" to adapt in order to survive. Evolution is a "march of progress"; organisms are always getting better. Evolution means that life changed "by chance." Natural selection is all about the big & strong dominating the small & weak. Evolution is about blending different organisms to produce new forms Organisms can evolve over their lifetime.

12 SUMMARY of the MISCONCEPTIONS
Organisms "try" to adapt in order to survive. March of progress: Organisms get better as they evolve Species change "by chance." Only the strong survive and the weak die out. Evolution is when different species blend to produce new forms Organisms evolve over their lifetime.

13 True or False? 1. If an environment changes, the organisms will try to adapt in order to survive.


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