Anatomy Physiology I Unit 4 Evolution and Natural

Anatomy & Physiology I - Unit 4: Evolution and Natural Selection

Tree of Life ~2000

Tree pattern suggests evolution - the hierarchy of life is a family tree in which populations change with time. - in general, similarities between species are due to relatedness.

Evidence for evolution Fossils

Evidence for Evolution: Structural Similarities

Evidence for Evolution: Developmental Similarities Gill pouch Tail Chick Human Homology: similarities caused by common descent

But how do species evolve? Darwin figured out how. It’s a process similar to how humans breed animals Charles Darwin 1809 - 1882

Animal breeding aka “Artificial Selection”

How do you get this?

Evolution in action: Giraffe neck length

Happy Giraffes

Hungry Giraffes

Surviving Giraffes

With Evolution You Get: Taller giraffes over time

Evolution: A change in a population over time

Natural selection An environmental influence that gives some individuals in a population a reproductive or survival advantage over others. Principal cause of evolution.

Requirements for Evolution • Variability • Heritability • Differential survival or reproduction

Tall Giraffes Mutation: random genetic changes

Speciation: separation by natural events that causes new species to develop

Discussion Question: Are humans still evolving?

Common Misperception: Individuals evolve “And now there go the Wilsons!. . . Seems Like everyone’s evolving except us!”

Acquired characteristics are not inherited! as in…. .

Timmy & Gobbles

Evolution is slow Great Calendar 1 month 1 day 1 second Jan Earth forms Feb Mar 383 million years 143 years Apr First fossils May Jun Jul Aug Sep Oct First algae Nov Dec First land plants

December 1 Land animals 5 10 15 20 25 30 Dinosaurs extinct

December 31 11: 48 pm Modern humans leave Africa noon 1 2 3 4 5 6 7 8 9 10 11 12 11: 58: 23 pm Native Americans reach Americas

Classroom Assignment: Building the Perfect Beast - I want you to think about how the human body has evolved over time, and how it might have evolved better. - Today you are in charge of the world, and you have to think about ways to make the human species better adapted to the environment.

Building the Perfect Beast • Pick any ten attributes or parts of the human body • Note the defect of that part, or how it might be made better • Describe your changes, piece by piece, oh master of the universe… • Draw me a picture of your perfect beast