Lab 13 Nat Sel PPS

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Transcript Lab 13 Nat Sel PPS

Natural Selection Lab

By Jane Horlings I ’ iwi, Hawaiian honeycreeper

Archaeopteryx

fossil Passenger pigeon, which became extinct in the early 1900s due to human hunting

History

• Ideas about evolution originated before Darwin • Aristotle • Fossils • Jean Baptiste de

Lamarck

Inheritance of acquired characteristics

Aristotle (UL), Ammonite fossil (UR), Lamarck (L)

History

• Lamarck – Characteristics which an organism developed during its lifetime were inherited – Now known to be invalid

History

• Charles Darwin • H.M.S. Beagle • South America & the Galapagos Islands H.M.S. Beagle (U), Galapagos turtle (LL), Darwin at early age (LR)

History

• Finches in the Galapagos

History

History

• Other scientists and research influenced Darwin’s theory • Charles

Lyell

: Principles of Geology Lyell

History

• Economist Thomas

Malthus

• Alfred Russel

Wallace

History

Wallace, early (R), and later in life (L)

History

• • Darwin proposed that evolution occurs by

natural selection

On the Origin of Species by Means of Natural Selection

published in 1859

History

• Darwin's theory had four parts: 1. Organisms produce more offspring than can survive to reproductive age 2. Members of a population vary and some of these variations are

heritable

3. Resources available to a population are limited 4. Organisms with the most favorable traits have

differential reproductive success

, and those traits are passed to the next generation

History

• The synthetic theory of evolution or Neo-Darwinism Darwin (R), Mendel (L)

History

Darwin in cartoon from 1800s Darwin died in 1882

Selection

Selection

= when some individuals leave behind more offspring than others, and the rate at which they do so is affected by their inherited characteristics • Selection can be

artificial

or

natural

Peppered moth

• Artificial selection

Selection

Selection

• Biotechnology / Genetic engineering

Selection

Natural selection

• Natural selection is the result of

differential reproduction

by members of a population • “ Reproduction of the fittest!

Selection

See? The offspring in the last generation now all have the gene allowing them to be resistant to the pesticide! This is a great example of selection!

End