Lecture 19 Be able to explain the difference between natural selection and evolution Natural Selection causes evolution to happen variation in phenotype and heritable changes Examines the association between phenotype and fitness evolutionary success Evolution involves a change in DNA and genes over time is important because it produces new species REFER TO https www youtube com watch v GcjgWov7mTM Be able to explain the basic principles of natural selection Natural selection is a process in which individuals that have certain heritable traits survive and reproduce at a higher rate than other individuals with that trait Overtime natural selection can increase the match between organisms and the environment If an environment changes or if individuals move to a new environment natural selection may result in adaptation to these new conditions sometimes giving rise to new species Be able to distinguish between evolutionary change and other kinds of changes Evolutionary changes involve changes in genetic nature of populations Happens in populations can lead to changes in the mean phenotype of populations can lead to differentiation of populations can lead to formation of new species results in branching pattern of change over time Know that evolution produces allele frequency changes inherited phenotypic changes differences among populations new phenotypes and new species and phylogenetic relationships Lecture 20 Know that Darwin came up with his ideas after voyage on the Beagle Galapagos animals were influential Importance of evolution explanation for the diversity of life framework for understanding differences and similarities helps integrate different areas of biology explains otherwise inexplicable aspects of biology First idea new species originate from common ancestral forms through the accumulation of adaptations Refined idea published in Origin of Species stating evolution occurs through natural selection Know that Wallace independently came up with same idea Be able to explain the five ideas in Darwin s theory 1 evolution has happened 2 all life has a common ancestor 3 the diversity of life is a result of a series of splits in the lineage family tree of living things 4 Natural selection is the primary mechanism driving evolutionary change 5 Evolution occurs gradually over time at one point they were all same species but they start to become different species can be seen through phylogony Know that exposure to the diversity of life around the World was an important influence Predators prefer the green beetle so therefore the brown beetles will reproduce and there will be more brown in the population than green Understand the basic process of natural selection Process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits explains how adaptations arise Understand that evolution can be depicted as a branching tree Phylogeny branch points show formation of new species cross indicates the species have become extinct Terms Evolution descent with modification change in genetic composition of a population from generation to generation INDIVIDUALS DO NOT EVOLVE POPULATIONS EVOLVE natural selection Process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits fitness encompasses the ability to survive to reproductive age success at finding a mates and producing offspring More offspring higher fitness adaptation inherited characteristics of an organism that enhance their survivals and reproduction in specific environments ex Beaks of finches de to the specific foods on their home islands Lecture 21 Be able to describe the different types of evidence for evolution and explain their significance Life on Islands most island species are endemic only found there but most island species are very similar to species located on close islands or mainleands becayse islands are colonized by species from neighboring mainland then the species adapt to the new environment and give rise to new species Fossil Record shows over time descent with modification produced increasingly large differences among related groups of organisms ultimately resulting in the diversity we see today Fossils show the origin of the new group of mammals cetaceans originally land mammals Observation of Natural Selection through observation Darwin inferred that individuals that were well suited to their environment tended to create more offspring than those who weren t and over time favorable traits accumulate in the population Two famous examples 1 galapagos finch species time on x axis body size body shape beak shape size etc each undergoes drastic change during drought eating old large seeds so ones with big beaks were able to eat but little beaks unable to eat the seeds so died out 2 Trinidadian guppies Live in small rivers on top of mountain and small rivers in lower part Guppies are able to jump up waterfall so top river holds fish who eat young guppies but not large guppies Bottom river fish can eat guppies of anysize Natural selection guppies have to grow up and have babies if in bottom river in constant worry they need to breed as fast as possible on bottom so breed faster At the top river need to grow faster to save themselves so they waited to breed until grown Artificial Selection modifying species over many generations by selecting and breeding individual traits this results in crops livestock animals and pets bearing little resemblance to wild ancestors Comparative Anatomy Homology different species have same structures modified in different ways Forelimbs of all mammals have basic skeletal elements one large bone attached to two smaller bones attached to several small bones and attached to several metacarpals picture below Convergent Forms the independent evolution of similar features in different lineages because of natural selection Australian sugar glider is very similar to flying squirrel These are considered analogous not homologous because they share a similar function but different ancestry Ontogeny stages process of an organisms life from simple to more complex level Phylogeny evolutionary tree tree with multiple branchings from a common trunk out of twigs each fork of the tree represents the most recent common trunk out to the tips of the youngest twigs represents the diversity of the current population Molecular
View Full Document
Unlocking...