ENVS 212 — Lecture 1

Evolution
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Terms in this set (18)
Evolution
•Evolution is about change in proportions through time
Biological Evolution
•Changes in the genetic properties of groups of organisms ("populations") over the course of generations
•Often referred to more simply as "descent with modification" or "genetic change over time"
Evolution Within Populations
•Change in gene frequencies between generations (e.g. shift in proportion of individuals with dark versus light wing coloration)
Evolution Between Populations (or Species)
•Change in proportion of genetically differentiated populations (e.g. shift in proportion of populations with dark versus light wing coloration)
Morphological Diversity
•Why do whales have lungs and snakes lack legs?
•Evolution is the only scientific explanation for many observed anatomical traits
Genetic Diversity
•Why do salamanders have 10x more DNA than humans?
•Human Genome
>>~3.2 billion base pairs
•Some Salamanders
>>~120 billion base pairs
Species Diversity
•Why are there so many species of insects?
Medicine
•How do bacteria, viruses, and parasites counter our immune system?
•How do bacteria, viruses, and parasites evolve resistance to our medicines?
Technology
•How do insects evolve resistance to pesticides?
Four Misconceptions
1. Evolution and natural selection are the same thing
2. Individual organisms undergo biological evolution
3. Evidence for evolution is limited, it is only an unsubstantiated theory
4. Evolution occurs within species, but it cannot explain the origin of new species
Misconception #1•*Evolution* and *natural selection* are the *same thing* >>Natural selection is *ONE mechanism* by which evolution occurs, but natural selection and evolution are *NOT one and the same* >>Evolution is simply *genetic change through time*, to deny evolution is to deny genetic change occurs >>But, *MUCH evolution* occurs due to *natural selection*Misconception #2•*Individual organisms* undergo biological evolution >>*Populations* or *groups of organisms* undergo evolution >>In biology, the change of individual organisms through their lifetime is termed "*development*"Misconception #3•*Evidence* for evolution is *limited*, it is only an *unsubstantiated theory* >>*Evidence* for evolution is *abundant*, stemming from numerous sources such as from the *fossil records*, *DNA* and *genomic data*, and *direct observations* in contemporary timeMisconception #4•Evolution occurs within species, but it *cannot explain* the *origin of new species* >>As for studies within species, there is *abundant evidence* that *NEW species form* via evolutionDevelopment•The *change* of *individual organisms* through their lifetimeThree Examples of Evidence for Evolution•*Antibiotic resistance* •*Pesticide resistance* •*Experimental evolution studies* in the laboratoryEvolution by Natural Selection in the LaboratoryEvidence for Evolution Through Fossil Records•*MISCONCEPTION*: There *aren't any intermediate forms* between major animal groups, and there are *few "missing links"* >>*MANY intermediate forms* and "*missing links*" have been found, with more found all the time