Modern Biology Chapter 15

Similar features that originate from a shared common ancestor.

Structures with similar function and appearance but have different embryological and anatomical origins.

A feature that currently has no purpose but was useful in an ancestor

Genes for a trait remain unchanged - but are turne off in rare cases. They may be partially turned on and vestigial traits may occur

Started "onthageny recapituiates phylogeny" - embryology repeats evolutionary history. Only partially true - all vertebrates are developementally similar as embryos, but differ as they mature.

Organisms that arise from a common ancestor have similar DNA, RNA, and proteins.
The number of differences is proportional to the time period that has passed to a shared common ancestor.

Combining the theory of natural selection with the understanding of genetics. Explains the broadest range of observations and makes predictions. Models phylongy - the ancestral relationships between groups of organisms.

Created catastrophism - the belief that geological catastrophes in the past caused large groups of organisms to become extinct

Created uniformitarianism - the belief that geological processes are continuous through time

Proposed that similar species evolved from a single common ancestor. Hypothesized that acquired traits were passed on to the offspring

Arise due to the organisms experiences (not determined by genes)

Newer forms that appear are actually modified descendants of older species

Overproduction
Genetic Variation
Struggle to Survive
Differentiated Reproduction

An organisms genetic contribution to the next generation
High fitness allows more successful reproduction

The change of 2 or more species in close association with eachother.