Test 1 Flashcards
What are the 7 characteristics of life?
Growth
Energy Utilization
Cells
Homeostasis
Ordered Complexity
Evolutionary adaptation
Sensitivity to stimuli
OR G.E.C.H.O.E.S.
What are some problems with the 7 characteristics of life?
What if an organism doesn’t fit into all of the characteristics? (like viruses)
What are the levels of organization?
Cells
Organs and organ systems
Organisms
Populations
Communities
Ecosystems
(CELLS ARE THE SMALLEST UNIT OF LIFE)
What are emergent properties?
New properties emerge when units of biological material are put together. These properties cannot be deduced by looking at the parts themselves. (An example is life. You wouldn’t call the organs themselves alive but put together makes a complex human being.)
What is Inductive Reasoning?
Using related observation to arrive at a general conclusion (Bottom-up)
What is Deductive Reasoning?
Using a general principle or law to forecast specific results (Top-DOWN)
Does scientific inquiry use Inductive or Deductive Reasoning?
Inductive reasoning
What are the 6 steps in the scientific method?
Observation
Question
Hypothesis
Prediction
Experiment
Results
What are independent variables?
This is the condition that the researcher is changing.
What are dependent variables?
The variable being measured and reported. The dependent variable depends on the independent variable.
What is a control variable?
The variable that is not being changed between groups. (Not the same as the control group)
What is Qualitative data?
Observed data or descriptions that cannot be measured (e.g. color, smell, beauty)
What is Quantitative data?
Numbers that can be measured (e.g. Length, height, time)
What does theory mean in science?
a theory is the strongest explanation for a phenomenon; it is backed by an enormous amount of data and research.
What are the unifying themes in biology?
Cellular Structure and Function
Reproduction
Metabolism
Homeostasis
Heredity
Evolution
Interdependence
(CHHIMER)
Disprove the misconception: “If humans descended from monkeys, why are there still monkeys?”
Evolution teaches that humans and monkeys have a common ancestor.
Disprove the misconception: “Evolution is just a theory”
There is an insurmountable amount of evidence and data supporting the idea of evolution. Remember, to be considered a theory in science, you need years and years of data from across multiple disciplines backing an idea up.
Disprove the misconception: “Individuals evolve”
Populations evolve not individuals
Disprove the misconception: “Evolution explains the origin of life”
Evolution does not explain the source of life, it explains what happens once life was here, the first evidence we have is about 3.5 billion years ago with single celled organisms.
Disprove the misconception: “Organisms evolved on purpose”
evolution is not a being with a mind, there is no purpose. We just see that traits are selected for, or not, in individuals and as individuals change these groups, populations and species change.
What is evolution?
Change over time of a population of a species
What is macroevolution?
rise of new species (from old) and higher taxonomic groups with widely divergent characters (speciation)
What is microevolution?
Changes within a population in heritable characteristics/allele/gene frequency that can be observed over short periods of time (In microevolution, there’s a change within a population)
What is Charles Darwin known for?
-Said that life on earth could be descended from a common ancestor
-a naturalist, hypothesized that species change over the course of many generations by adapting to new environments
What is Alfred Russell Wallace known for?
A British naturalist, explorer, geographer, anthropologist, biologist, and illustrator. He is best known for independently conceiving the theory of evolution through natural selection.
What is Jean Baptiste-Lamarck known for?
Best known for his incorrect notion called “inheritance of acquired characteristics”
True/False: Evolution results in progress; organisms are always getting better through evolution.
False, Evolution doesn’t always make an organism better. (survivorship bias)
True/False: Evolution only occurs slowly and gradually.
False, Changes in an ecosystem/environment can happen very quickly. (Punctuated equilibrium)
What are the mechanisms of evolution?
Mutation
Natural selection
Gene flow (migration)
Genetic drift (random)
Recombination
Non-Random Mating
(MaNaGGeRR)
What is Mutation?
-a rare change in DNA
-the ultimate source of new alleles, or new genetic variation in any population
What is point mutation?
a point in DNA (A, T, C, or G) changes and binds to something it normally doesn’t bind to. (E.g. sickle cell anemia)
What is the raw material for selection?
genetic variation
What was Lamarck’s incorrect view of natural selection?
Behavior leads to changes that are passed on. (e.g. giraffes reach higher and higher for leaves so their neck grows)
Natural Selection acts on the ______.
Evolution acts on the _________.
individual, population
What is Gene Flow?
The flow of alleles in and out of a population due to the migration of individuals or gametes. (can occur when an individual travels from one geographic location to another)
What is Genetic Drift?
allele frequencies within a population change randomly which can reduce genetic variation in small populations
What are 2 types of Genetic Drift?
a population bottleneck and Founder effect
What is population bottleneck?
a chance event or catastrophe that can reduce the genetic variability within a population
What is the founder effect?
an event that initiates an allele frequency change in an isolated part of the population, which is not typical of the original population.
What is recombination?
combination of genetic material from two different gametes (Offspring differ from parents)
What is non-random mating?
The probability that two individuals in a population will mate is not the same for all possible pairs of individuals. (e.g. birds choosing mates with the most colors)
What are the 3 conditions for natural selection?
Variation, Inheritance, competition (VIC)
What is variation?
Individuals within a population have different characteristics/traits (or phenotypes).
what is inheritance?
Offspring inherit traits from their parents (transmission to the next generation)
What is competition?
Offspring with traits better matched to the environment survive and reproduce more effectively than others
What are the types of selection?
-Artificial
-Natural
-Stabilizing
-Directional
-Disruptive
-Sexual
A. Intrasexual
B. Intersexual
(SANDDS)
what is stabilizing selection?
Individuals with average phenotypes are favored. (E.g., Human birth weight)
What is directional selection?
Individuals that vary in one direction from the mean are favored. (E.g., Resistance to tetrodotoxin (natural poison) in garter snakes)
-Directional selection can favor either extreme depending on the environment. (Peppered moth)
What is disruptive selection?
Individuals at both extremes are favored; resulting in a bimodal distribution. (E.g. Black-bellied seed crackers of Cameroon that have bills specialized to 2 different types of seeds)
What are the two different types of sexual selection?
Intrasexual (compete for mates) and Intersexual (attract the opposite sex)
what is sexual selection?
Type of NS; favors traits that enhance reproductive success.
What is Intrasexual Selection?
Traits that improves the ability to compete for mates (horns, antlers)
What is Intersexual Selection?
Traits that improve the ability to attract the opposite sex (bright colors, long tails, elaborate courtship displays)
What is the timeline for the discovery of evolution?
- Charles Darwin
-1831 – Received B.A. in Theology
-1831-1836 – Traveled around the world on HMS Beagle; collected thousands of plants & animals.
-1844 – Essay on origin of species, didn’t publish.
-1858 – Alfred Russel Wallace (ARW) sent his theory of evolution to Darwin.
-1859 – The Origin of Species by Means of Natural Selection published.
explain Sickle Cell Anemia
Sickle Cell Anemia warps the shape of red blood cells. This reduces their ability to deliver oxygen. These warped cells also cannot pass through capillaries leading to painful clots. The trait is useful because people who have one copy of the allele have a decreased risk of dying or getting sick from malaria. This is because malaria reproduces in red blood cells.
explain the evolution of the eye.
The history of eyes starts with light spots in single-cell organisms. The light-sensitive proteins are linked to its flagellum and activated when it finds light which its food is not far from. Eventually, this light spot became cupped rather than flat. Which allows for an organism to have a sense of direction as to where the light is coming from. This helped them find shade and hide from predators. Next, this cupped light spot became deeper and the opening to in the front became smaller. This increased the resolution of what an organism can see dramatically. Finally, transparent cells covered the hole to prevent infection. This allowed for fluid to fill the eye and eventually the addition of a lens.
Who is the founder of Biogeography?
Alfred Russell Wallace
What is Biogeography?
As species colonized new habitats, and old ranges were divided by barriers (e.g., mountains), they took on distributions they have today (Think Pangea)
What is convergent evolution?
Similar phenotypes evolve in distantly related species due to the same evolutionary pressures.
What is an Analogous Character?
similar characteristics occur because of environmental constraints and not due to a close evolutionary relationship
What are homologous structures?
similar characteristics occur due to a common ancestor
What is the biological species concept and what are some of its criticisms?
-Ernst Mayr, “… groups of actually or potentially interbreeding natural populations which are reproductively isolated from other such groups”, must produce viable offspring
-It’s difficult to apply to geographically separated populations, what about asexual organisms, what about categorizing fossils?
What is the ecological species concept?
a species is a set of organisms adapted to a particular set of resources in the environment.
What is the phylogenetic species concept?
an irreducible group whose members are descended from a common ancestor and who possess a combination of certain defining traits.
What is the evolutionary species concept?
a single lineage of ancestor-descendant populations of organisms which maintains its identity from other such lineages and which has its own evolutionary tendencies and historical fate.
What is a subspecies?
a biological classification that ranks below species which designates a population of a particular geographic region genetically distinguishable from other such populations of the same species that are capable of interbreeding where range overlaps
What is speciation?
the formation of two species from one original species
In what 2 ways does speciation occur?
Anagenesis and Cladogenesis
What is Anagenesis?
When a population of an entire species changes on the genetic level without a split
What is Cladogenesis?
Species splits into two genetically-distinct populations adapted to different ecosystems &/or survival strategies. (Both species may survive.)
What are the types of speciation?
Allopatric, Sympatric, parapatric, and peripatric speciation
What is Allopatric Speciation?
speciation that involves geographic isolation
What is Sympatric Speciation?
speciation that occurs in the same geographical area
What are the two paces of evolution?
Gradualism and Punctuated equilibrium
What is gradualism?
changes in species is slow and gradual, occurring in small periodic changes in gene pool
What is punctuated equilibrium?
occurs in spurts of relatively rapid change with long periods of non-change. (stabilizing and oscillating selection is responsible for stasis)
What is adaptive radiation?
a clade (group of related species) that has evolved into numerous, diverse forms
What are the 2 types of reproductive isolation?
prezygotic and postzygotic
What is prezygotic reproductive isolation?
isolation that prevents the fertilization of the egg via reproduction.
What are the different types of prezygotic reproductive isolation?
Temporal, habitat, behavioral, mechanical, and gametic
What is Temporal Isolation?
reproductive isolation due to species having different breeding schedules
what is Habitat Isolation?
reproductive isolation due to members of species moving or otherwise separated.
what is Behavioral Isolation?
reproductive isolation due to certain actions or behaviors (or the lack of them) impacts reproduction. (think mating calls)
what is Mechanical Isolation?
reproductive isolation due to their reproductive structures simply do not fit together
what is a gametic barrier?
reproductive isolation due to differences in their gamete cells (eggs and sperm) prevent fertilization
What are the types of Postzygotic reproductive isolation?
Hybrid inviability and hybrid sterility
What is postzygotic reproductive isolation?
A zygote is formed but this new hybrid cannot reproduce
what is hybrid inviability?
an embryo is produced, but cannot survive development
what is hybrid sterility?
different species can produce a viable offspring, but that offspring cannot reproduce
What is peripatric speciation?
a small group of individuals breaks off from the larger group to form a new species, due to physical barriers.
What is parapatric speciation?
a species is spread out over a very large geographical area, which results in individuals only mating with those in their immediate vicinity.
