Evolution Joke

Evolution Jean-Baptiste Lamarck was the first to propose evolution He believed that the mechanism for evolution was the inheritance of acquired traits E.g. A Body Builder would have children born with larger muscles

Darwin and Evolution

Darwin & Evolution 1. Different species of an organism are descendants from an ancestral species. In other words, species evolve over time. Known as descent with modification. 2. Evolution occurs by natural selection.

Lamarck Vs. Darwin

Point 1: Descent With Modification (a.k.a. Evolution) Occurs when a species of an organism accumulates modifications (i.e. mutations) which help it adapt to the environment Must affect an entire population’s gene pool in order to be considered evolution.

Point 2: Natural Selection Individuals with characteristics well suited to the environment leave more offspring on average than those less adapted to the same environment. Based on three observations: The Struggle for Existence Natural variations among members of a species Environmental influence on evolution

A. The Struggle For Existence Species tend to produce more offspring than can survive. Therefore individuals will compete with one another for limited resources E.g. Frog Eggs

Demonstration

B. Natural Variation Species are inherently different from one another. The organism best adapted to a particular environment has the best opportunity to survive and reproduce. This is referred to as fitness level.

Who has the selective reproductive advantage?

Which is More “Fit” Environment A: Hot climate Environment B: Cold climate

Test Your Knowledge: Which is More “Fit” Environment A: Consists of many predators adapted to poisonous prey. Environment B: A marsh Golden poisonous frog

Survival of the Fittest: Asian Carp Case Study

Survival of the Fittest: Asian Carp Case Study

Asian Carp Adaptations Feed on algae and plankton (food chain impact) Reproduce very quickly Can consume 1/5 of their weight per day Can grow over 100 pounds over their lifetime

C. Environment The environment determines which trait will be advantageous or harmful In this way the environment exerts a selective pressure on a population Case and point: Peppered Moth

Environment: Peppered Moth Case Study (Read Aloud) Before Industrial Evolution: Original peppered moth was light coloured They camouflaged with the light coloured trees and lichens. During Industrial Evolution: Black soot covered trees and lichens died. Moths that were dark coloured were harder to find (hid from predators) and thus better adapted to the environment.

Artificial Selection The process in which humans select the traits and breed organisms together to produce a desired result. E.g. Food Crops that produce better yield

Homework/In-class work Read page 310 and summarize the consequences of artificial selection Answer #1-5, 7, 13 (page 311)