Evolution Change Over Time Greek Philosophers Linnaeus Lamarck

Evolution –Change Over Time Greek Philosophers Linnaeus Lamarck

Descent with Modification- Natural Selection • Explains the adaptations of organisms and the unity and diversity of life • Charles Darwin- The Voyage of the Beagle • Focused on adaptations • Explained how they arise through natural selection • Wrote Origin of Species

Artificial Selection, Natural Selection and Adaptation • Artificial selection- humans modify species; choose desired traits • Natural selection – traits are chosen by environment • Why Darwin came to this conclusion 1. members of a population vary in inherited traits

• 2. All species can produce more offspring than their environment can support • Therefore: individuals with traits that allow them to have a higher probability of surviving will reproduce : this will allow favorable traits to accumulate in the population

Natural Selection • Is a process in which individuals have certain inheritable traits survive an reproduce at a higher rate than do other individuals who lack these traits • Process will eventually increase the frequency of adaptations that are favorable in a given environment

Evidence of Evolution 1. Natural Selection Peppered Moths

Drug Resident Bacteria • use of antibiotics • MRSA- methicillin resistant Staphylococcus aureus

Evidence of Evolution (cont) 2. Analysis of similarities among different organisms Homology- similarity from common ancestry homologous structures- similar in structure but have different function Examples-

• Vestigial structures – remnants of structures that served a function in the organism’s ancestors • Examples:

• Analogous structures – different structure similar function • Examples:

Evidence (cont) Convergent evolution – independent evolution of similar features in different lineages- resemblance is analogous Fossil Record- documents the pattern of evolution showing that past organisms differ from present day organisms Biogeography- scientific study of geographic distribution

Phylogeny- Evolutionary History of a Species or Group of Species Archaea Bacteria Domains Archaea Bacteria Kingdoms Protista Fungi Eukarya Plant Animal

Phylogenetic Tree- Cladistics

How to Read Phylogenetic Tree

• • 1 represents the most recent common ancestor of all members 2 represents where lineage diverges 3 represents common ancestor of taxa A, B, and C 4 represents that taxa B and C diverged after their shared lineage split from the lineage leading to taxon A

Derived Characteristics