Kingdom Phylum Class Order Family Genus Species Bottlenose Dolphin West Indian Manatee Galapagos Tortoise Kingdom Animalia Phylum Chordata Class Mammalia Sauropsida Order Cetacea Sirenia Testudines Family Delphinidae Trichechidae Testudinidae Genus Tursiops Trichechus Geochelone Species truncatus manatus nigra
Ursus americanus (American black bear) Ursus Ursidae Carnivora Species Genus Family Order Class Phylum Kingdom Domain Ursus americanus (American black bear) Ursus Ursidae Carnivora Mammalia Figure 1.14 Classifying life Chordata Animalia Eukarya
B-5.1 Summarize the process of natural selection You should be able to: Infer the fate of a particular species given a scenario of environmental change Compare microevolution and macroevolution Explain how changes in the environment may result in the appearance or disappearance of particular traits
Describes all changes that have transformed life on Earth From the earliest beginnings to the diversity of organisms in the world today
Branch of biological evolution Small scale Affects single population
Branch of biological evolution Large scale Affects changes in species across populations
Explanation of how evolution occurs Individual members of a population have different traits These traits allow them to interact with their environment more or less effectively than other members of population
Results from changes in inherited traits of a population over time Changes often increase a species’ fitness in its environment
Overproduction of offspring Variation Adaptation Descent with modification
The ability of a population to have many offspring raises the chance that some will survive It also increases competition for resources
Variation (we all look different!!) Exists within every population We all inherit different combinations of traits Exists in phenotypes of individuals The way they look (physical appearance): body structures & characteristics
Variation influences an organism’s ability to reproduce The way you look influences your ability to find, obtain, or utilize resources Ex. food, water, shelter, & oxygen Variation influences an organism’s ability to reproduce
It is controlled by both: genotype environment Individuals with phenotypes that do NOT interact well with environment are more likely to die/produce fewer offspring Compared to those who interact well with environment
Leads to the increase in frequency of: A particular structure Physiological process Behavior in a population of organisms that makes organism better able to survive & reproduce
In every generation: Organisms with specific beneficial inherited traits become more prevalent This is due to genetic variation
As a generation progresses (grows up): Organisms that carry genes that hinder their ability to meet day to day needs become less & less prevalent in population Organisms having a hard time finding, obtaining or utilizing food, water, shelter, or oxygen will be less healthy & more likely to die before reproducing Or produce less viable or fewer offspring
The gene pool of a population changes over time to favor the traits that are beneficial Fitness: measures how a particular trait contributes to reproductive success in a given environment Results from adaptations
Survival of the fittest Sometimes even known as: Survival of the fittest
Refers to changes that occur in species due to natural selection over successive generations As environment changes, entire process of natural selection can yield populations with new phenotypes adapted to new conditions
Results in population with: different structures live in different niches/habitats from ancestors Each successive living species will have descended with adaptations (or modifications) from previous generations
More individuals will have successful traits in successive generations As long as traits are beneficial to environmental conditions of organism
B-5.2 Explain how genetic processes result in the continuity of life-forms over time. You should be able to: Recall the similarities between organisms that live today with those that lived in the past Exemplify how genetic variability results in the continuity of life-forms Compare the results of sexual and asexual reproduction Summarize how sexual and asexual reproduction ensure that genetic material is passed to offspring allowing for the continuity of life-forms
All life that has ever existed on Earth share at least the same 2 structures: Nucleic acids – DNA or RNA – carry the code for the synthesis of organism’s proteins Proteins – composed of same 20 amino acids in all life forms on Earth
Process by which nucleic acids code for proteins is the same in all life-forms on Earth Transcription & translation
Result in offspring receiving same genetic information as parent(s) Reliable means of passing genetic information to offspring in all organisms Result in offspring receiving same genetic information as parent(s) Some genetic variability 2 types: Sexual Asexual
Uses process of meiosis to create gametes Fertilization: embryo receives alleles from each parent for each trait New individual expresses a combination of traits Allows for variation within offspring
Genetic variability due to: Gene shuffling Crossing-over Recombination of DNA Mutations When gametes are produced, each parent’s alleles may be arranged in new ways in the offspring
Involves only 1 parent Offspring (for the most part) are genetically identical to the parent
Genetic variability only occurs through mutations in DNA Passed from parent to offspring Also a way organisms achieve variations as populations continue over time
Much faster than sexual reproduction Many offspring produced Advantages: Much faster than sexual reproduction Many offspring produced Well fit to continue life in current environment
Disadvantages: In changing conditions Genetically identical offspring respond to environment in the same way If population lacks traits that enable them to survive & reproduce, entire population could die off
Transfer of genetic material through reproduction is essential for survival of population Continuity of a species is contingent upon the genetic processes If organism can reproduce sexually AND asexually, they have an adaptive advantage for survival
B-5.3 Explain how diversity within a species increases the chances of survival You should be able to: Summarize the ways that diversity affects a species chances of survival Exemplify favorable traits that ensure reproductive success or species survival Infer the fate of a particular species in the face of a specific environmental change based on the degree of diversity of its members Compare the chances of 2 species to survive in the face of a specific environmental change
Shared between species that can interbreed All genes (includes different alleles) of all individuals in the population
Genetic change in 1 individual can spread through population How??: Individual mating with others in population Producing offspring with similar change Affected offspring reproducing
If the change increases fitness: Change will be beneficial (it’s good!) Eventually found in many individuals in population
Same gene pool different genotypes (letters) different phenotypes (looks) diversity, chances for species to survive during environmental changes
(than those with less favorable phenotypes) Well-suited individuals: Survive Reproduce At higher rates (than those with less favorable phenotypes)
Favorable phenotypes: Increase in frequency Become more common Increase the chances of survival of species
Enhance reproductive success Examples: Coloration Odors Competitive strength Courting behaviors
B-5.4 Explain how genetic variability & environmental factors lead to biological evolution. You should be able to: Summarize the factors influencing genetic variability in a population Summarize the Hardy-Weinberg principle Explain the process of speciation Summarize the patterns of macroevolution Compare gradual & mass extinction
Genetic drift Gene flow Non-random mating Mutations Natural selection
Random change in frequency of alleles of a population over time Rare alleles decrease in frequency Eventually become eliminated Due to chance Other alleles increase in frequency Become fixed Phenotypic changes more apparent in smaller populations
Populations gets significantly smaller in a short period of time Due to random environmental event Chance of survival is random No individual given preference over the other
Small group/population splits off from original population to form a new one When new colony is small, founders can strongly affect the population's genetic make-up far into the future
Movement of genes into or out of a population Occurs during movement of individuals between populations Migration increases variation of receiving population
Limits frequency of expression of certain alleles Selecting your mate; being “choosey” Limits frequency of expression of certain alleles RANDOM mating ensures that each individual has an equal chance of passing alleles to offspring
If genes mutate, new alleles may be introduced into the population Increase the frequencies & types of allele changes within the population If genes mutate, new alleles may be introduced into the population Allele frequencies change
Allows for the most favorable phenotypes to survive Survival of the fittest Traits passed on to future generations
When there is NO CHANGE in allele frequencies within a species Hardy-Weinberg principle
5 Conditions (required to maintain genetic equilibrium) Population must be VERY LARGE (No genetic drift occurs) NO movement into or out of population (no gene flow) Random mating MUST occur NO MUTATIONS within gene pool NO natural selection p. 401 & 402 in textbook
(The sum of the frequencies of both alleles is 100%.) Allele Frequencies p = the frequency of the dominant allele (represented here by A) q = the frequency of the recessive allele (represented here by a) For a population in genetic equilibrium: p + q = 1.0 (The sum of the frequencies of both alleles is 100%.)
Genotype Frequencies (p + q)2 = 1 p2 + 2pq + q2 = 1 p2 = frequency of AA (homozygous dominant) 2pq = frequency of Aa (heterozygous) q2 = frequency of aa (homozygous recessive)
B-5.4 Part II: Explain how genetic variability & environmental factors lead to biological evolution. You should be able to: Summarize the factors influencing genetic variability in a population Summarize the Hardy-Weinberg principle Explain the process of speciation Summarize the patterns of macroevolution Compare gradual & mass extinction
Gradualism Punctuated equilibrium Adaptive radiation/divergent evolution Convergent evolution Coevolution Extinction
Gradual changes of a species Over long periods of time Example: Gradual trend toward larger or smaller body size
Periods of abrupt changes in a species After long periods of little change within species Example: Sudden change in species size or shape Due to environmental factors
Different species diverge (split-off) from a common ancestor Results in homologous structures Over many generations Organisms (whose ancestors were all of the same species) evolve variety of characteristics Allow them to survive in different niches
Different groups of organisms living in similar environments Produces species similar in appearance & behavior Analogous structures: Structures similar in appearance & function Different evolutionary origins
2 or more species Live near each other Species change in response to each other Evolution of 1 species may affect evolution of the other
Elimination of a species Often occurs when species as a whole cannot adapt to change in environment 2 types: Gradual Rapid
Speciation & gradual extinction occur at approximately the same rate Occurs at a slow rate May be due to: Other organisms Climate changes Natural disasters Speciation & gradual extinction occur at approximately the same rate
Occurs when catastrophic event changes the environment very suddenly Examples: Massive volcanic eruption Meteor hitting the Earth
B-5.5 Exemplify scientific evidence in the fields of anatomy, embryology, biochemistry, and paleontology that underlies the theory of biological evolution. You should be able to: Identify fields of science that provide evidence for biological evolution Illustrate evidence for biological evolution using pictures, diagrams or words Infer relationships among organisms based on evidence from each field of science listed Summarize the ways that each field of science listed provides evidence for evolutionary relationships
Anatomy-homologous structures & vestigial organs Embryology-study embryonic development Biochemistry-study genes & proteins Paleontology-study fossils (prehistoric life)
Study of structures of organisms Homologous structures: possible relationship between evolutionary paths of 2 species Explained by divergent evolution Same internal structure, shared common ancestor, different function Vestigial Organs: - structures with little or no function - remnants from common ancestors
Study of the embryonic development of organisms Comparing anatomies of embryos Early stages of development: pre-birth, pre-hatching, pre-germination
Study of chemical processes in organisms Studies genes & proteins to provide support for biological evolution
Study of prehistoric life Fossil record: Provides valid evidence of life forms & environments along a timeline Supports evolutionary relationships By showing similarities between current species & ancient species Shows pattern of gradual change from past to present
Reveals history that tells a story of types of organisms that lived on Earth Includes extinct organisms Provides relative ages of fossils
Fossil record – INCOMPLETE WHY?? Most organisms do not form fossils Have not found all fossils Under the ocean! Many gaps have been filled in as more fossils have been discovered Older fossils, less resemblance to modern species
B-5.6 Summarize ways that scientists use data from a variety of sources to investigate & critically analyze aspects of evolutionary theory. You should be able to: Compare the evidence within the fields that scientists use to critically analyze evolutionary ancestry Recall the evidence that analogous & homologous structures provide for evolutionary relationships Infer how the fossil record has challenged scientists in paleontology Explain how biochemists use DNA evidence to show evolutionary relationships
Study of data to trace history of species or group or related species Evolutionary history Study of data to trace history of species or group or related species Theory developed: All forms of life on Earth are related Ancestry of organisms can be traced back to common origin Evidence found in living & fossil organisms Physical features, structure of proteins, sequences in DNA/RNA
Tree showing evolutionary relationships among species sharing a common ancestor Each node with descendants most recent common ancestor Lengths correspond to time estimates
Classifies organisms into hierarchical groups Shows: Relatively recent common ancestors Shows sharing of homologous features
What structure do all organisms in this cladogram share? Vertebrae What do the four most recent organisms share? Amniotic egg Which shared a more recent common ancestor? Amphibians & Primates OR Primates & Rodents/Rabbits Primates & Rodents/Rabbits List the characteristics that amphibians and primates share. Vertebrae, Bony Skeleton, Four Limbs Vertebrae Amniotic egg Primates & Rodents/Rabbits Vertebrae, bony skeleton, four limbs,