bio test 2 studyguide

bio test 2 studyguide - Beak of the Finch...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Beak of the Finch essays-adaptation-natural variation-theme of studies-Natural selection-Darwinism and its ideas • Two major points o Evolution “ descent with modification ” explains both the unity and diversity of life All organisms are related by an ancestor Represented by a branching tree o Crucial mechanism of the evolutionary process, adaptation by natural selection 5 observations • 1. Populations have the capacity to grow in size (exponential growth) • 2. Populations tend to be stable in size (logistic growth and carrying capacity) • 3. Resources are limited • 4. Individuals in a population vary extensively in their traits (different colored ladybugs) • 5. Relatives resemble each other- some variation is heritable. 3 inferences • 1. More individuals are produced than the environment can support which leads to a “struggle for existence” and only few offspring survive. • 2. Survival and reproduction are NOT RANDOM, variation of traits effects fitness. • 3. Unequal ability of individuals to survive and reproduce leads to changes in a population with, favorable characteristics becoming more common over generations. 1 conclusion • population adapt to their environment because individuals vary, variation influences survival and reproduction, and the variation is heritable. • The best variants will be selected for, and their traits will become more common, shifting the average trait in the population toward a better form. -adaptations • Shifting the average traits in the population toward a better form-mechanism • Nature selects directly on individuals phenotype • Natural selection acts on individuals: (not evolution) o Some individuals have traits that are selected for o Others have traits that are selected against • Natural selection leads to evolution only when it chooses among heritable traits • Evolution occurs at the scale of the population-definition of fitness • fitness depends, in part, on inherited traits • variation of traits affects fitness-morphological convergence...
View Full Document

This note was uploaded on 02/07/2011 for the course BIOLOGY 301 taught by Professor Friedman during the Fall '10 term at South Carolina.

Page1 / 7

bio test 2 studyguide - Beak of the Finch...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online