BIOL 2061 1st Edition Lecture 9Outline of Last Lecture I. BottleneckII. Founder EffectIII. Neutral Theory of EvolutionIV. Chapter 20- origin of SpeciesV. Various species conceptVI. Mechanisms of keeping species distinctOutline of Current Lecture I. Types of SpeciationII. Mechanisms of SpeciationIII. Evolutionary and developmental BiologyIV. Hox GenesV. Developmental genes that affect growth rateCurrent LectureI. Types of Speciation-a. Anagenesis- A single species transformed into a different species over the course of many generations.b. Cladogenesis- a species dividing into two or more speciesII. Mechanisms of speciation-a. Allopatric speciation- occurs when populations become separated geographicallyi. Most prevalent for cladogenesisThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.ii. Can also occur when a small population moves to a new location (foundereffect)iii. Genetic drift and natural selection may occuriv. Adaptive radiation- single species evolves into array of descendants that differ greatly in habitat, form or behavior.1. Ex. Darwin’s Finchesb. Sympatric speciation- occurs when populations are in the same geographic place.i. Occurs when members of a species that initially occupy the same habitat within the same range diverge into two or more different speciesii. Tends to involve abrupt genetic changes the lead to reproductive isolationiii. Happens more often in plantsIII. Evolutionary and Developmental Bio-a. Compares the development of different organisms in an attempt to understand ancestral relationships between organisms.b. Involves the discovery of genes that control development from embryo to adult.IV. Hox Genes-a. Found in all animalsb. Number and arrangement varies among different animalsc. Increases in the amount of hox genes may have led to more complex organismsd. Hox genes control body developmente. Comparison of hox gene evolution and animal evolution are very similarf. Simple animals=few hox genes and hox gene clustersV. Developmental genes that affect growth rate-a. Allometric growth- different parts of the body grow at different rates with respect to each otherb. Paedomorphosis- retention of juvenile traits in an adult organismc. Changes in growth rates can also affect the development stage at which one species reproduce compared to another